Prometheus Biosciences (RXDX) 10-K2022 FY Annual report

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2022

OR

Commission File Number 001-40187

PROMETHEUS BIOSCIENCES, INC.

(Exact name of Registrant as specified in its charter)

Registrant’s telephone number, including area code: (858) 422-4300

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☒ No ☐

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Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

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Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒

As of June 30, 2022 (the last business day of the registrant’s most recently completed second fiscal quarter), the aggregate market value of the registrant’s common stock held by non-affiliates of the registrant was approximately $872.7 million, based on the closing price of the registrant’s common stock on the Nasdaq Global Select Market of $28.23 per share.

As of February 21, 2023, the registrant had 47,530,337 shares of common stock ($0.0001 par value) outstanding.

PROMETHEUS BIOSCIENCES, INC.

TABLE OF CONTENTS

FORM 10-K

For the Year Ended December 31, 2022

INDEX

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PART I

FORWARD-LOOKING STATEMENTS AND MARKET DATA

This Annual Report on Form 10-K (Annual Report) contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the Securities Act), Section 21E of the Securities Exchange Act of 1934, as amended (the Exchange Act). All statements other than statements of historical facts contained in this Annual Report, including statements regarding our future results of operations and financial position, business strategy, research and development plans, the anticipated timing, costs, design and conduct of our ongoing and planned preclinical studies and clinical trials for our product candidates, our plans to use our Prometheus360 product platform to expand our pipeline of product candidates and develop marketable products, the anticipated timing and costs of our development of diagnostics, the potential benefits from our collaboration arrangements with third parties and our plans to enter into additional arrangements, the timing and likelihood of regulatory filings and approvals for our product candidates and diagnostics, our ability to commercialize our product candidates, if approved, the impact of COVID-19 on our business, the pricing and reimbursement of our product candidates, if approved, and testing products, the potential to develop future product candidates, the timing and likelihood of success, plans and objectives of management for future operations, and future results of anticipated product development efforts, are forward-looking statements. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. This Annual Report also contains estimates and other statistical data made by independent parties and by us relating to market size and growth and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplates,” “believes,” “estimates,” “predicts,” “potential” or “continue” or the negative of these terms or other similar expressions. The forward-looking statements in this annual report are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking statements speak only as of the date of this Annual Report and are subject to a number of risks, uncertainties and assumptions, including, without limitation, the risk factors described in Part I, Item 1A, “Risk Factors.” The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

This Annual Report includes trademarks, tradenames and service marks that are the property of other organizations. Solely for convenience, trademarks and tradenames referred to in this Annual Report appear without the ® and ™ symbols, but those references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights, or that the applicable owner will not assert its rights, to these trademarks and tradenames.

We maintain a website at www.prometheusbiosciences.com, to which we regularly post copies of our press releases as well as additional information about us. Our filings with the Securities and Exchange Commission (SEC) are available free of charge through our website as soon as reasonably practicable after being electronically filed with or furnished to the SEC. Information contained in our website does not constitute a part of this report or our other filings with the SEC.

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Item 1. Business.

Overview

We are a clinical-stage biotechnology company pioneering a precision medicine approach to the discovery, development, and commercialization of novel therapeutic products for the treatment of immune-mediated diseases, starting first with inflammatory bowel disease (IBD). We leverage our proprietary precision medicine platform, Prometheus360™, which includes one of the world’s largest gastrointestinal (GI) bioinformatics databases and sample biobanks, to identify novel therapeutic targets, develop therapeutic candidates to engage those targets, and develop genetics-based diagnostic tests designed to identify patients more likely to respond to our therapeutic candidates. We have generated a robust pipeline of therapeutic development programs for the treatment of immune-mediated diseases.

Our lead product candidate, PRA023, is a humanized IgG1 monoclonal antibody (mAb) that has been shown to block the tumor necrosis factor (TNF)-like ligand 1A (TL1A), a target associated with both intestinal inflammation and fibrosis. We believe PRA023’s dual mechanism of action, targeting both inflammation and fibrosis, also provides a strong rationale for advancing PRA023 into clinical trials for indications beyond IBD.

In July 2021, we initiated ARTEMIS-UC, a global Phase 2 randomized placebo-controlled clinical trial of PRA023 in patients with moderate-to-severe ulcerative colitis (UC), and APOLLO-CD, a global Phase 2a open-label clinical trial in patients with moderate-to-severe Crohn’s disease (CD), each utilizing our genetics-based diagnostic candidate designed to identify patients who are predisposed to increased expression of TL1A and therefore potentially more likely to respond to PRA023.

In December 2022, we reported topline results from the initial cohort of ARTEMIS-UC (Cohort 1) and results from APOLLO-CD demonstrating strong efficacy and favorable safety results in both studies. We believe these results position PRA023 to be a potential first-in-class and best-in-class treatment for patients suffering from UC and CD.

In our ARTEMIS-UC Phase 2a study, the topline results for the key endpoints and safety were as follows:

In our APOLLO-CD Phase 2 study, the results for the key endpoints and safety were as follows:

We plan to advance PRA023 into Phase 3 studies for UC and CD in 2023 after we meet with the U.S. Food and Drug Administration (FDA) and other foreign regulatory authorities and finalize our Phase 3 clinical trial strategy. The expansion cohort of ARTEMIS-UC (Cohort 2) is designed to further assess the treatment effect of PRA023 in patients who test positive on our diagnostic candidate, and we expect topline results in the second quarter of 2023.

Beyond IBD, in March 2022 we initiated a Phase 2 clinical trial for PRA023 in Systemic Sclerosis-associated Interstitial Lung Disease (SSc-ILD). The FDA has granted fast track designation for PRA023 for the treatment of SSc-ILD. Topline results from our Phase 2 trial of PRA023 in Systemic Sclerosis-Associated Interstitial Lung Disease (ATHENA-SSc-ILD) are expected in the first half of 2024.

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We are evaluating potentially advancing PRA023 into clinical trials for other indications where there is a strong mechanistic rational and high unmet need, and plan to announce our fourth potential indication for PRA023 in 2023.

Inflammatory Bowel Disease

IBD is a complex disease with many contributing factors, including genetic, environmental and immunologic. UC and CD are two of the most common forms of IBD. Both UC and CD are chronic, relapsing, remitting, inflammatory conditions of the GI tract that begin most commonly during adolescence and young adulthood. UC involves the innermost lining of the large intestine, and symptoms include abdominal pain and diarrhea, frequently with blood and mucus. CD can affect the entire thickness of the bowel wall and all parts of the GI tract from mouth to anus. CD symptoms include abdominal pain, diarrhea, and other more systemic symptoms such as weight loss, nutritional deficiencies, and fever.

Current therapies used for the treatment of UC and CD apply a one-size-fits-all approach without regard to biologic variations amongst patients, and substantial unmet need remains. The current standard of care for the treatment of patients with moderate-to-severe IBD is typically anti-inflammatory agents; however, none of these therapies address fibrosis, or scarring, in IBD. The majority of IBD patients do not respond to first-line anti-TNF agents. Since the approval of the first anti-TNF agent for the treatment of CD in 1998, the availability of JAK inhibitors and newer biological agents, including anti-integrin and anti-IL12/23, has improved the care of moderate-to-severe IBD (JAK inhibitors in UC only). However, these subsequently approved therapies have generally failed to demonstrate a clinical remission effect size of more than 15% relative to placebo. Moreover, among those patients who do respond to therapy, up to 45% will lose response over time. Likewise, therapies under development have not demonstrated improved remission rates over previously approved therapies. In addition, in late 2021, the FDA issued a black box warning to the JAK drug class with indication for the treatment of arthritis and other inflammatory conditions, based on an increased risk of serious heart-related events such as heart attack or stroke, cancer, blood clots, and death.

IBD is estimated to affect over 2,000,000 people in the United States and over 5,000,000 people globally. The IBD market is approximately $18 billion globally and is estimated to grow to approximately $49 billion globally by 2030. The IBD market is highly concentrated, with four therapeutic products accounting for 75% of global revenues.

Our Precision Medicine Approach

Precision medicine involves the discovery and development of therapies that integrate clinical and molecular information based on the biological basis of disease to improve clinical decision-making and patient outcomes. We are pioneering the application of precision medicine in IBD and other immune-mediated diseases because we believe that by leveraging Prometheus360 we can identify novel therapeutic targets impacting the underlying pathways involved in IBD and the patient subgroups that may be more responsive to a particular therapy and then explore the utility of these therapies in other immune-mediated diseases where the same pathways are implicated.

We believe we have the potential to transform the entire IBD pharmaceutical value chain from discovery to commercialization with our precision medicine approach. Our Prometheus360 platform includes our extensive clinical database and associated biobank, which is one of the world’s largest collections of biospecimens from patients suffering from IBD and other GI disorders. This database and biobank, which we exclusively license from Cedars-Sinai Medical Center (Cedars-Sinai), includes more than 200,000 samples linked to extensive clinical data from over 20,000 patients collected over more than 20 years. This, in combination with our state-of-the-art machine-learning methodologies, make Prometheus360 a discovery engine for novel precision therapeutics and diagnostics.

We believe our precision medicine approach will result in a greater likelihood of identifying and developing the right drug for the right patient, help to maximize patient and trial outcomes, improve label claims, accelerate adoption of targeted therapeutics for addressable patients and provide attractive treatment options from a cost-benefit perspective for payors.

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Our Portfolio

We have a robust pipeline of clinical-stage product candidates and preclinical therapeutic development programs and plan to develop a diagnostic for each program to identify patients more likely to respond to drug. The following table summarizes our key current internal and partnered programs.

PRA023—anti-TL1A mAb

Our lead product candidate, PRA023, is a humanized IgG1 mAb that has been shown to bind and neutralize both the active trimeric form and inactive monomeric form of TL1A. We are developing PRA023 for the treatment of UC, CD and SSc-ILD. We believe PRA023’s dual mechanism of action, targeting both inflammation and fibrosis, also provides a strong rationale for advancing PRA023 into clinical trials for indications beyond IBD.

In December 2022, we reported topline results from Cohort 1 and results from APOLLO-CD demonstrating strong efficacy and favorable safety results in both studies. We plan to advance PRA023 into Phase 3 studies for UC and CD in 2023 after we meet with the FDA and foreign regulatory authorities and finalize our Phase 3 clinical trial strategy. Cohort 2 is designed to further assess the treatment effect of PRA023 in patients who test positive on our diagnostic candidate, and we expect results in the second quarter of 2023.

In March 2022, we initiated a Phase 2 clinical trial for PRA023 in SSc-ILD. The FDA has granted fast track designation for PRA023 for the treatment of SSc-ILD. Topline results from ATHENA-SSc-ILD are expected in the first half of 2024.

PRA052—anti-CD30L mAb

Our second product candidate, PRA052, is an anti-CD30L mAb. The CD30L-CD30 co-stimulatory pathway has been implicated in IBD by genetic, preclinical, and human translational data. In preclinical studies, CD30L antagonism was observed to improve multiple animal models of colitis. PRA052 is designed to have high affinity and specificity for CD30L and to block both transmembrane and soluble CD30L. We filed an investigational new drug application (IND) for PRA052 in the third quarter of 2022 and then initiated a Phase 1 single ascending dose/multiple ascending dose clinical trial in normal healthy volunteers in the fourth quarter of 2022. We expect topline results from the Phase 1 study in the fourth quarter of 2023. We are also developing a proprietary genetics-based diagnostic test for PRA052 to identify patients that are more likely to respond to CD30L inhibition.

In 2020, we entered into a co-development and manufacturing agreement with Dr. Falk Pharma GmbH (Falk) for PRA052, in order to leverage Falk’s experience in GI drug development and commercialization in Europe. Under this agreement, we granted to Falk exclusive commercialization rights in Europe, Australia and New Zealand for PRA052 and its corresponding diagnostic candidate, while we retained commercialization rights in the United States and the rest of the world. In 2021, we earned both preclinical milestone payments from Falk related to our selection of the PRA052 clinical candidate and our development of a diagnostic candidate for PRA052.

PR1100—Anti-cytokine receptor mAb

Our PR1100 program targets the receptor for a pro-inflammatory cytokine that has been linked to multiple immune-mediated diseases. In particular, the pathway modulated by our target has been associated, both functionally, and genetically with IBD, highlighting a

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possible role in the pathogenesis of this disease. We have identified SNPs in the gene locus of this target that are associated with IBD and potentially other immune-mediated diseases. We expect to submit an IND for our PR1100 therapeutic candidate in the fourth quarter of 2023.

PR2100—anti-Inflammatory Cytokine mAb

Our PR2100 program targets a cytokine implicated in a range of inflammatory and fibrotic diseases. In IBD specifically, this cytokine has been implicated to contribute to non-response to anti-TNF therapies. We have identified single nucleotide polymorphisms (SNPs) in the gene locus of this target that are associated with IBD and potentially other immune-mediated diseases. We expect to submit an IND for our PR2100 therapeutic candidate by the end of 2024.

PR300 Overview—GPCR Modulator Small Molecule

Our PR300 program targets an orphan G-protein coupled receptor (GPCR) expressed predominantly in the GI tract that we believe has important functions underlying intestinal epithelial integrity and innate immune cell function. We have identified a coding SNP in the gene of this target that represents a strong genetic association with IBD and potentially other immune-mediated diseases.

Other Development Programs

We continue to evaluate numerous other drug targets identified through Prometheus360 for therapeutic utility for potential drug discovery development.

Our Strategy

Our goal is to revolutionize the treatment of IBD and other immune-mediated diseases with a precision medicine approach for patients with significant unmet medical needs. The key elements of our strategy to achieve this goal are:

Limitations of Current IBD Drug Development

Despite the increasing global burden of IBD, the lack of evolution and innovation in drug development has left many patients with suboptimal responses to existing therapies. While there are many programs and mechanisms of action in development for IBD, nearly all are primarily focused on inflammation, and multiple programs are pursuing the same well-established targets and pathways. The quantitative efficacy of approved treatments and therapies in development has remained stagnant since the approval of the first anti-TNF antibody for use in IBD. There is a growing need to discover new targets and pathways that have the potential to deliver breakthrough efficacy and provide patients with more meaningful treatment options.

Attempts to identify new, targeted therapeutics for IBD through the use of publicly available clinical datasets have been hampered by the significant challenges associated with generating high-volume and high-quality data in a standardized manner from these datasets.

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Furthermore, while post-hoc analysis of clinical trial data can be helpful to retrospectively understand patient responses to particular therapeutics, the ability to use these data for understanding pathway pathogenesis in IBD or target discovery for IBD is limited.

Our Prometheus360TM Precision Medicine Platform

We believe that Prometheus360 can potentially revolutionize the drug development and treatment paradigm for patients by utilizing genetics-based precision medicine to increase our probability of success. Prometheus360 enables us to select drug targets genetically associated with diseases and develop genetic-based diagnostics designed to identify patients more likely to respond favorably to specific therapies we are developing. Prometheus360 has three main components: (1) our comprehensive clinical data; (2) our large collection of biospecimens; and (3) our advanced data analytics capabilities.

Prometheus360 includes our extensive clinical database and associated biobank, which is one of the world’s largest collections of biospecimens from patients suffering from IBD and other GI disorders. This database and biobank, which we exclusively license from Cedars-Sinai, includes more than 200,000 samples linked to extensive clinical data from over 20,000 patients collected and curated over more than 20 years. Clinical data sources included in Prometheus360 include electronic medical records, imaging data, clinical chemistry, pathology records and serologies. As such, clinical history, response to therapies and longitudinal data are available to us for analysis. In addition to clinical data, we have access to relevant, well-annotated patient samples for translational validation of therapeutic targets to help guide therapeutic development. Stored biorepository patient samples available to us include tissue biopsies (either from endoscopy or from surgery), serum/plasma, DNA, RNA, peripheral blood mononuclear cells (PBMC), lamina propria mononuclear cells (LPMC), immortalized patient-derived B cells, stool and mesenteric adipose tissue. For many patients, we have multiple types of samples collected over multiple years. Samples from Prometheus360 are routinely interrogated by deep molecular profiling including SNP genotyping, whole exome sequencing, RNA sequencing, immunohistochemistry, metabolomics and microbiomics. In addition to this large, well-annotated IBD cohort of data and biosamples, Prometheus360 also contains samples derived from independent cohorts and samples, such as samples collected from healthy relatives of patients, which we believe gives us a competitive advantage in the discovery and development of our novel drug targets, therapeutic candidates, and related diagnostic candidates.

Prometheus360 relies on advanced datamining and bio-analytical capabilities that we employ to uncover insights about immunological pathways that drive IBD and other immune-mediated diseases, while providing a holistic view of the biology surrounding potential targets. We apply machine-learning algorithms to our clinical data and molecular profiling data to reveal disease-related trends, patterns and associations that are more reflective of what happens at a molecular level in complex immune-mediated diseases. Unlike traditionally employed strategies such as relying on genome-wide association studies (GWAS) alone, our bioinformatics approach allows us to discover and examine the joint effects of multiple genetic variants working in concert in key inflammatory pathways that contribute to the development and progression of IBD and other immune-mediated diseases. As a consequence, our approach allows us to create complex algorithm-based diagnostic product candidates that we use to identify patients likely to benefit from our therapeutic product candidates.

IBD and Market Opportunity Overview

IBD is a chronic relapsing and remitting inflammatory disease of the GI tract. It is a complex disease with many contributing factors, including genetic, environmental and immunologic. IBD typically onsets during adolescence and young adulthood and is diagnosed based on clinical, laboratory, endoscopy and histopathology and/or imaging findings. The IBD market is approximately $18 billion globally and is estimated to grow to approximately $49 billion globally by 2030.

UC and CD are the two most common types of IBD. UC causes long-lasting inflammation and ulcers in the digestive tract and affects the innermost lining of the large intestine (colon) and rectum. UC is debilitating and can lead to life-threatening complications. There are no treatments that cure UC and patients often require life-long treatment. Symptoms include diarrhea, bloody stools, abdominal pain and cramping, urgency to defecate, inability to defecate despite urgency, weight loss, fatigue, and fever. Chronic inflammation associated with UC puts a patient at increased risk of developing colon cancer. UC affects an estimated 926,000 people in the United States and 2,750,000 people globally.

CD also causes long-lasting inflammation and ulcers in the digestive tract. It differs from UC in that it affects the entire thickness of the bowel wall and all parts of the digestive tract from mouth to anus. There are no treatments that cure the disease and patients often require life-long treatment. Symptoms include diarrhea, fever, fatigue, abdominal pain and cramping, bloody stools, mouth sores, reduced appetite and weight loss, and pain or drainage near or around the anus due to development of fistula from the inflammation. CD affects an estimated 1,157,000 people in the United States, and 2,446,000 people globally. The development of abnormal narrowing of the digestive tract, known as stricture, is common and is the leading indication requiring surgical intervention. Up to 70% of CD patients develop a stricturing or perforating complication, and the use of anti-inflammatory agents over the past decade has not materially changed the rate of need for surgical resection due to stricturing disease.

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IBD Current Treatments and Limitations

Medical treatment of IBD is typically divided into two types of therapy: induction and maintenance. Induction therapy is used to reduce inflammation quickly (in three months or less) and maintenance therapy is used to sustain that reduction after three months. Patients with IBD are classified as mild, moderate or severe, based on the level of symptoms experienced, inflammatory biomarkers, and severity of disease on endoscopy. The current standard of care for the treatment of patients with moderate-to-severe IBD is typically anti-inflammatory agents.

Aminosalicylates (5-ASAs) are used as a first-line therapy in mild-to-moderate UC. Corticosteroids are used primarily during induction therapy and are effective for reducing symptoms but not for mucosal healing. There are serious side effects with extended corticosteroid use, including lowered quality of life, bone loss, weight gain and cardiovascular complications. Because of these serious long-term safety concerns, corticosteroids are used primarily as a bridge to manage symptoms until immunomodulators or biologic agents become effective and enable mucosal healing. Oral immunosuppressants (e.g. azathioprine and 6-mercatopurine) have not been effective as induction agents and are generally used for steroid-sparing or as an adjunctive therapy for reducing immunogenicity against biologic agents. Oral immunosuppressants are also associated with known toxicities such as drops in white blood cell counts and increased risk for infection.

Since the approval of the first anti-TNF agent for the treatment of CD in 1998, the availability of JAK inhibitors (in UC) and newer biological agents, including anti-integrin and anti-IL12/23, as well as oral S1P modulators (in UC), has improved the care of moderate-to-severe IBD, but many of these are anti-inflammatory agents and have safety and tolerability concerns due to their systemic impact and resulting effects on the immune system outside of the GI tract. In late 2021, the FDA issued a black box warning to the JAK inhibitor drug class with indication for the treatment of arthritis and other inflammatory conditions, based on an increased risk of serious heart-related events such as heart attack or stroke, cancer, blood clots, and death.

More importantly, these subsequently approved therapies have generally failed to demonstrate a clinical remission effect size of more than 15% relative to placebo. Moreover, among those patients who do respond to therapy, up to 45% will lose response over time. As a consequence, despite the advances in approved therapies over the past two decades, more than 15% of UC and 50% of CD patients require surgery within 10 years of diagnosis. The most common cause of surgery in UC is progressive disease not responsive to medical therapy and in CD it is development of strictures and/or perforation, requiring surgical resection of the intestine.

While fibrosis and stricturing are common in CD, clinically observable colonic strictures have also been reported in up to 11% of patients with UC, and we believe microscopic submucosal fibrosis is actually much more prevalent in UC patients than reported. In a study that examined 89 consecutive UC colectomy specimens from Cleveland Clinic, submucosal fibrosis was detected in 100% of the specimens. Microscopic evidence of fibrosis in the colonic wall may have significant clinical implications such as motility abnormalities leading to symptoms such as diarrhea, abdominal pain, urgency and incontinence. It has long been speculated that intestinal fibrosis may be the underlying cause of persistent UC symptoms, after the resolution of inflammation, that is commonly misclassified as irritable bowel syndrome.

Current treatment of IBD applies a one-size-fits-all approach without regard to genetic or biological variations in patients. We believe there must be a paradigm shift towards developing specific therapies for patients whose disease is driven by a specific biology. To date, we believe there are no clinical stage programs focused on integrating precision therapeutics with diagnostics to overcome the limitations of a one-size-fits-all treatment approach for IBD. Additionally, despite the advances in anti-inflammatory therapeutics for the treatment of UC and CD over the past two decades, fibrosis in these patients has largely not been addressed by therapy, representing an area of high unmet need. There is currently no therapy approved or under development that directly targets the reversal of fibrosis in IBD.

Our Solutions for the Treatment of IBD

PRA023 (anti-TL1A mAb)

Our lead product candidate, PRA023, is a humanized IgG1 monoclonal antibody (mAb) that has been shown to block the tumor necrosis factor (TNF)-like ligand 1A (TL1A), a target associated with both intestinal inflammation and fibrosis. PRA023’s dual mechanism of action, targeting both inflammation and fibrosis, also provides a strong rationale for advancing PRA023 into clinical trials for indications beyond IBD. In December 2021, we announced topline results from our Phase 1 clinical trial for PRA023, a single center, double-blind, placebo-controlled study to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of PRA023 in normal healthy volunteers and observed that PRA023 was well-tolerated, with no safety signal identified during the study.

In December 2022, we reported topline results from Cohort 1 of our Phase 2 randomized placebo-controlled clinical trial of PRA023 in patients with moderate-to-severe UC (ARTEMIS-UC) and results from our open-label Phase 2a clinical trial of PRA023 in patients with moderate-to-severe CD (APOLLO-CD) and demonstrated strong efficacy and favorable safety results in both studies. Based on

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the totality of the data in these two studies, we intend to advance PRA023 into Phase 3 studies for UC and CD in 2023, after we meet with FDA and foreign regulatory authorities and finalize our P3 clinical trial strategy. In our Phase 3 trials, we plan to utilize our 200 mg/ml subcutaneous formulation in an autoinjector, which demonstrated greater than 80% bioavailability in our subcutaneous bridging study in Caucasian normal healthy volunteers.

ARTEMIS-UC: Phase 2 Clinical Trial of PRA023 in Ulcerative Colitis

Our Phase 2 ARTEMIS-UC clinical trial was a 12-week, double-blind, placebo-controlled, randomized study to evaluate the efficacy and safety of PRA023 in patients with moderately to severely active UC who have failed conventional or advanced therapy. PRA023 met the primary and all ranked secondary endpoints including clinical, endoscopic, histologic, and patient-reported outcome measures in Cohort 1 of the trial. All 68 of the 68 PRA023-treated patients completed the Cohort 1 study, compared to 60 of the 67 patients in the placebo group. The topline results for the key endpoints were as follows:

PRA023 was well tolerated in ARTEMIS-UC Cohort 1, with no treatment-emergent serious adverse events (SAEs), adverse events (AEs) leading to discontinuation, severe AEs, opportunistic infections or infusion reactions reported in the PRA023 treatment group. The only AE that occurred in more than two patients and at a higher frequency in the PRA023 group compared to placebo was COVID-19 (5 out of 68 [7.4%] and 3 out of 67 patients [4.5%], respectively).

We also conducted an interim analysis of ARTEMIS-UC, Cohort 1 to evaluate the effectiveness of our diagnostic candidate. Although from limited patient numbers, data from the subset of patients who tested positive on our diagnostic candidate (N=32) demonstrated a placebo-adjusted clinical remission rate of 37.5%, compared with the placebo-adjusted remission rate of 25.0% across all patients treated with PRA023 in Cohort 1. Cohort 2 is designed to further assess the treatment effect of PRA023 in patients who test positive on our diagnostic candidate, and we expect topline results in the second quarter of 2023.

The ARTEMIS-UC study also includes an open-label extension after the 12-week induction study. Clinical responders are stratified by their positive or negative diagnostic status and re-randomized into two different maintenance dose arms of 250 mg IV every 4 weeks or 100 mg IV every 4 weeks. Non-responders at the end of induction have the option for a course of open-label induction therapy. Responders at the end of this open-label induction therapy will be randomized to the two maintenance dose regimen and non-responders are discontinued from the study.

APOLLO-CD: Phase 2a Clinical Trial of PRA023 in Crohn’s Disease

Our Phase 2a APOLLO-CD clinical trial was a 12-week open-label study that enrolled 55 patients with moderate-to-severely active CD with endoscopically active disease who had failed conventional or biologic therapy. The study enrolled a highly refractory patient population with 70.9% of patients previously treated with at least one biologic therapy and 52.7% treated with two or more biologic therapies. The results on the key endpoints were as follows:

PRA023 was well tolerated in the APOLLO-CD study. There were no treatment-emergent SAEs, AEs leading to discontinuation, or severe AEs, in each case, assessed as related to PRA023 by the investigator. There were no opportunistic infections or infusion reactions reported. AEs that occurred in more than two patients included COVID-19, urinary tract infection, CD, anemia, nasopharyngitis and fatigue.

In the APOLLO-CD study, we utilized our prespecified genetic markers in an alternative CD-specific diagnostic algorithm which demonstrated 45.0% (9/20) endoscopic response relative to all-comers of 26% (13/50), and we plan to advance this alternative algorithm into registrational studies for CD. In addition, a compelling reduction in markers of inflammation and fibrosis was observed

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between pre-treatment and post-treatment with PRA023, as measured by circulating cytokine levels, immunohistochemistry and gene expression in disease tissue.

The APOLLO-CD study also includes an open-label extension at the end of the 12-week induction study, in which clinical responders are re-randomized to the two maintenance doses (250 mg IV every 4 weeks or 100 mg IV every 4 weeks) and non-responders will be discontinued from the study.

Phase 1 Clinical Trial of PRA023

In December 2021, reported results from our Phase 1 clinical trial of PRA023 in normal healthy volunteers. The Phase 1 clinical trial was a single-center, double-blind, placebo-controlled study in which normal healthy volunteers received IV administration of PRA023. The study enrolled 69 healthy volunteers with 6 cohorts of subjects in the single ascending dose (SAD) phase dosed up to 1000 mg and 3 cohorts of subjects in the multiple ascending dose (MAD) phase dosed up to 500 mg every other week for a total of three doses.

The primary outcome measure was safety and tolerability over 14 weeks in the SAD and 18 weeks in the MAD. PRA023 was well-tolerated, with 68 of the 69 patients completing all doses and the follow-up period. There were no apparent safety signals identified during the study. There were no infusion reactions nor drug-related extension in infusion time at doses of up to 1000 mg delivered intravenously over 30 minutes. There were no clinically significant changes reported in physical exam, lab values, ECG or vital signs. All adverse events assessed as related to the study drug, including somnolence, headache, diarrhea and dizziness, were mild in severity and equally distributed between PRA023 and placebo treatment arms. There were no related adverse events reported in the highest dose group of 500 mg every other week.

The Phase 1 study also evaluated the secondary outcome measures of pharmacokinetics (PK) and immunogenicity. Dose-proportional exposure was observed at doses of ≥ 100 mg. PRA023 demonstrated a half-life of approximately 19 days after administration of 500 mg every other week. We believe the PK profile observed in this study supports the dosing regimen selected for the currently ongoing Phase 2 UC and Phase 2a CD studies. Figures below show the geometric mean serum PRA023 concentration-to-time profile following single dose and multiple doses of PRA023 Q2W administration (on Days 1, 15, and 29) as IV infusion.

One of the secondary outcomes for the trial was the rate of immunogenicity associated with PRA023 after single and multiple doses, measured up to 14 and 18 weeks. The observed immunogenicity rate overall was 65% during the SAD and MAD phases of the study. Anti-drug antibodies (ADA) were observed to be associated with low doses and only when PRA023 drug concentration was low; specifically, there were no observations of ADA at PRA023 drug concentration greater than 29 µg/mL. ADAs did not have any apparent impact on safety outcomes, pharmacokinetics parameters, and pharmacodynamic (PD) parameters. Less than 20% of subjects who received clinically relevant doses of PRA023 (1,000 mg for SAD cohort and 200 mg to 500 mg for MAD cohort) developed ADAs through the prolonged follow up period and only in 1 out of 17 subjects (6%) across the clinically relevant dose groups developed neutralizing antibodies.

The Phase 1 study also evaluated target engagement by PRA023 by measuring the total TL1A level in the serum. PRA023 binds to both the active trimeric form of TLIA and the inactive monomeric form of TL1A. The Phase 1 data demonstrated that target engagement by PRA023 was more than 4-times higher than would otherwise be expected if PRA023 only bound to trimeric TL1A. We believe that neutralization of both forms of TL1A will lead to increased target engagement and thereby to potentially more effective reduction of active TL1A in the disease tissue. Figures below show the median serum TL1A concentration (semi-log scale) following single dose and multiple dose of PRA023 Q2W administration (on Days 1, 15, and 29) as IV infusion.

Preclinical Studies of PRA023

In in vitro studies, PRA023 blocked TL1A’s ability to bind and activate its receptor, DR3. In whole blood, PRA023 inhibited the TL1A-dependent IFN-g response following the ex vivo exposure to immune-complex and a combination of IL-12 and IL-18. Additionally, PRA023 was observed to be highly selective for TL1A with no detectable binding to related TNF super family members FAS, LIGHT, or TRAIL.

We assessed the potential toxicity of PRA023 in a series of nonclinical in vitro assays and in vivo studies in cynomolgus monkeys. The monkey was selected as a pharmacologically relevant nonclinical species because of similar TL1A protein sequence homology and nearly equivalent binding affinity of PRA023 to monkey TL1A, as compared to human. PRA023 is similarly active in monkey and human in vitro cell-based assays.

PRA023 has been engineered to remove the potential for the mAb to induce an immune response. In non-good laboratory practice (GLP) cell-based in vitro assays, PRA023 treatment did not lead to complement- or cell-mediated cytotoxicity or to cytokine release from peripheral blood cells thus indicating that it was not provoking an undesired immune response.

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In a non-GLP tolerability and pharmacokinetic (PK) study, cynomolgus monkeys (1/sex/group) were administered PRA023 IV at 30, 100 and 243 mg/kg/week on Days 1 and 8 and subsequently followed for approximately 11 weeks to assess systemic exposure of PRA023. There were no PRA023-related clinical observations or changes in body weight, clinical chemistry, or hematology parameters. PK measurements suggested that PRA023 has a half-life of 5 to 11 days in cynomolgus monkeys, which is consistent with human IgG1 in this species.

Six-week and 6-month Good Laboratory Practice (GLP) repeat-dose toxicity studies were conducted in cynomolgus monkeys with a 6-week recovery period. In the 6-month toxicity study, PRA023 was administered to monkeys once weekly via IV injection for up to 6 months. The no observed adverse effect level (NOAEL) in the 6-month study was 300 mg/kg/week (the highest dose tested). No PRA023-related mortality or clinical signs were observed, and no body weight, food consumption, clinal pathology (hematology, clinical chemistry, coagulation, urinalysis), ECG, ophthalmic, neurobehavioral, body temperature, respirator, organ weight, or macroscopic or microscopic changes were observed at the end of the dosing or recovery phases after six months of repeat dosing in monkeys. No PRA023-related effects were noted in lymphocyte subsets. All animals mounted a robust anti-KLH IgG and IgM response, suggesting an intact humoral immunity.

After IV administration of PRA023 to monkeys in the 6-week repeat-dose toxicity study, findings that were secondary to generation of ADA and immune complex deposition in response to administration of a foreign protein (humanized monoclonal antibody) to immunocompetent animals were observed (including the death of one low dose animal). Similar findings were not observed in the 6-month monkey toxicity study using the same dosing regimen and dose levels, confirming that the findings in the 6-week repeat-dose toxicity study were secondary to ADA formation and not directly related to the mechanism of action of PRA023.

PRA023 for the Treatment of Immune-Mediated Diseases – Beyond IBD

We believe PRA023 has the potential to be a differentiated therapy for patients suffering from various immune-mediated diseases, beyond IBD, due to PRA023’s unique dual mechanism including both anti-inflammatory and anti-fibrotic effects. The TL1A-DR3 pathway is known to broadly modulate multiple immune cell types and pathways, in addition to having a direct effect on fibroblasts proliferation and differentiation.

Systemic Sclerosis-associated Interstitial Lung Disease (SSc-ILD)

Systemic sclerosis, also called scleroderma, is an inflammatory autoimmune disease that causes fibrosis, or scarring/hardening, of skin and internal organs. It is not known what causes scleroderma, but this orphan disease affects more than 100,000 people in the United States and 80,000 people in Europe, with limited treatment options. More than half of scleroderma patients suffer from interstitial lung disease (ILD), a condition characterized by fibrosis and loss of function of the lungs. This syndrome is termed systemic sclerosis-associated interstitial lung disease (SSc-ILD), and it is the leading cause of morbidity and mortality in scleroderma, accounting for one third of deaths. SSc-ILD tends to present as nonspecific interstitial pneumonia, which implies a mixed pathogenesis of inflammation and fibrosis.

SSc-ILD is progressive in most patients and is thought to be largely irreversible. As a result, stabilization has historically been the goal of therapy. Immunosuppressive therapies are prescribed off-label and may provide some relief without specific approval for this indication. In the past two years, two biologics were approved for SSc-ILD, but these only modestly slow the rate of decline in lung function and neither of these therapies has led to meaningful benefits for disease modification as measured using skin thickness scoring, dyspnea, general quality of life or survival.

We believe SSc-ILD is a compelling third indication for PRA023. TL1A inhibition has a unique dual mechanism with both anti-inflammatory and anti-fibrotic effects and SSc-ILD is a disease of inflammation and fibrosis with a pathophysiology that implicates many pathways modulated by TL1A-DR3 interactions. Blocking TL1A has been linked to reductions in Th1, Th17 and Th2 immune responses, while also modulating key pro-fibrotic and pro-inflammatory cytokine such as IL-13 and TGF-β. In addition to their roles in driving inflammation, TL1A and DR3 have also been implicated in driving fibrosis by direct signaling in fibroblasts, even in the absence of a fully functional immune system, leading to collagen disposition and fibrosis.

A causal link between the TL1A-DR3 axis and fibrosis has been demonstrated in mouse models of lung fibrosis. Specifically, DR3 deficiency or TL1A blockade was sufficient to significantly ameliorate fibrotic lung remodeling in bleomycin and dust-mite antigen models. Additionally, direct instillation of recombinant TL1A into the lungs of mice initiated rapid onset of fibrosis and smooth muscle cell proliferation in a DR3-dependent manner. Primary human lung fibroblasts and bronchial epithelial cells express the TL1A receptor, DR3, and respond to recombinant TL1A in vitro by proliferating, expressing smooth muscle actin, and secreting extracellular matrix proteins, collagen, and periostin. Serum TL1A levels were higher in patients with systemic sclerosis than in healthy controls (p = 0.001) and TL1A mRNA expression in PBMCs was significantly higher in patients with systemic sclerosis compared with healthy controls (p < 0.001). Agents that disrupt the TL1A signaling through DR3 have the potential to prevent deregulated tissue cell activity in lung diseases that involve fibrosis and remodeling.

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PRA023 for SSc-ILD

In the first quarter of 2022, we initiated a Phase 2 clinical trial for PRA023 in SSc-ILD (ATHENA-SSc-ILD). The ATHENA-SSc-ILD is designed to enroll approximately 100 patients who will be randomized 1:1 to either the active or placebo arm. The primary endpoint of the trial will be the change in forced vital capacity (FVC) at 50 weeks. Secondary endpoints will include change in quantitative interstitial lung disease by centrally-read high-resolution computed tomography (HRCT) and improvement in the American College of Rheumatology Combined Response Index in Diffuse SSc (ACR-CRISS) score. We also plan to evaluate a variety of patient reported outcomes for dyspnea, disability, effects of skin thickening, and bowel function. This trial will also assess the performance of our diagnostic candidate for PRA023. Topline results from ATHENA-SSc-ILD are expected in the first half of 2024.

In January 2022, we announced that the FDA granted fast track designation for PRA023 for the treatment of SSc-ILD. Fast track designation aims to expedite the development and review process for new therapeutics that are intended to treat serious or life-threatening conditions and potentially address an unmet medical need. Drug candidates that are granted this designation are given the opportunity for more frequent interactions with the FDA, as well as potential pathways for expedited review and approval.

Intellectual Property

Our commercial success depends in part on our ability to obtain, maintain and protect intellectual property and other proprietary rights for our current and future product therapeutic and diagnostic candidates, novel discoveries, product development technologies, patient enrichment strategies and diagnostics, and know-how, to operate without infringing, misappropriating or otherwise violating the intellectual property and proprietary rights of others, and to prevent others from infringing, misappropriating or otherwise violating our intellectual property and proprietary rights. We seek to protect our proprietary position by, among other methods, filing or exclusively in-licensing U.S. and foreign patent applications related to our proprietary technology, inventions and improvements that are important to the development and implementation of our business. We also rely on trade secrets, know-how, continuing technological innovation and potential in-licensing of intellectual property to develop and maintain our proprietary position.

As for the therapeutic product candidates we are developing and seeking to commercialize, we intend to pursue composition and therapeutic method of use patents, dosage formulation patents, and therapeutic use patents on novel indications. For our therapeutic product candidates that are biologics, and more particularly monoclonal antibodies, we also intend to seek protection for epitopes, amino acid and nucleotide sequences, and other claims conventionally used to protect aspects of therapeutic biological agents. As for diagnostic and prognostic product candidates and therapeutic product candidates, we intend to pursue methods of use patents on novel patient selection methods for our therapeutic candidates and known compounds, and novel patient stratification criteria useful in the prognosis or diagnosis of disease. We may also pursue patents with respect to our proprietary screening and drug development processes and technology. We may also seek patent protection, either alone or jointly with our collaborators, as our collaboration agreements may dictate.

Our patent portfolio as of February 17, 2023 includes approximately 22 issued U.S. patents, 31 pending U.S. non-provisional patent applications and 26 pending U.S. provisional patent applications with claims relating to our diagnostic, prognostic, or therapeutic product candidates, all of which are owned or in-licensed by us. We own or co-own 5 of the issued U.S. patents and own or co-own approximately 9 of the pending U.S. non-provisional patent applications. We license approximately 21 of the issued U.S. patents, as well as 28 of the pending U.S. non-provisional patent applications. Our patent portfolio as of February 17, 2023 also includes approximately 11 pending Patent Cooperation Treaty (PCT) applications and certain foreign counterparts of the aforementioned U.S. patents and U.S. patent applications in at least one of the following foreign countries or regions: Argentina, Australia, Brazil, Canada, China, Hong Kong, India, Israel, Japan, Mexico, New Zealand, South Korea, and Taiwan and countries within the European Patent Convention and Eurasia with claims relating to our diagnostic, prognostic, or therapeutic product candidates.

With respect to our lead therapeutic product candidate, PRA023, we own and/or license four issued U.S. patents, four pending U.S. non-provisional patent applications, seven pending U.S. provisional patent applications, and four pending PCT applications in fourteen different patent families relating to the composition of PRA023 and/or its therapeutic use, as well as one issued U.S. patent, two pending U.S. non-provisional patent applications, three pending U.S. provisional patent applications, and one pending PCT applications in three different patent families related to the diagnostic for PRA023. In addition, our patent portfolio directed to the composition of PRA023 and its diagnostic includes foreign counterparts in foreign countries or regions, including Argentina, Australia, Brazil, Israel, India, Mexico, South Africa, Chile, United Kingdom, Colombia, Egypt, United Arab Emirates, Saudi Arabia, Iran, Kuwait, Taiwan, Japan, Laos, Malaysia, Philippines, Singapore, Thailand, Brunei, Canada, Cambodia, Hong Kong, Korea, China, Indonesia, New Zealand, Venezuela, as well as countries within the European Patent Convention and Eurasian Patent Organization. As of February 17, 2023, we expect the expiry dates for the issued U.S. patents for the composition of PRA023 to be 2037 for the first patent family, 2039 for the second patent family, 2040 for the third family, and 2042 for the fourth family, without taking into account any possible patent term adjustment or extensions and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees.

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As of February 17, 2023, we own and/or license one pending U.S. non-provisional patent application and two pending U.S. provisional patent applications related to the composition of PRA052 and its therapeutic use, and we co-own and license one pending U.S. non-provisional patent application and four U.S. provisional patent applications related to patient selection for our PRA052 program. In addition, our non-U.S. patent portfolio directed to the composition of PRA052 or patient selection for PRA052 includes one pending PCT application and foreign counterparts of the aforementioned U.S. patent application in foreign countries or regions, including Australia, Canada, China, Hong Kong, Japan, New Zealand, South Korea, and Taiwan, as well as countries within the European Patent Convention. As of February 17, 2023, we expect the U.S. non-provisional patent application related to the composition of PRA052 and its therapeutic use, if issued, to expire no earlier than 2042, without taking into account any possible patent term adjustment or extensions and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees.

Provisional patent applications are not eligible to become issued patents until, among other things, we file a non-provisional patent application within 12 months of filing of one or more of our related provisional patent applications. Moreover, PCT patent applications are not eligible to become an issued patent until, among other things, we file one or more national stage patent applications within, depending on the country, 30 to 32 months of the PCT application’s priority date in the countries in which we seek patent protection. If we do not timely file any non-provisional patent applications or national stage patent applications, we may lose our priority date with respect to our provisional patent applications or PCT patent applications and any patent protection on the inventions disclosed in our provisional patent applications. While we intend to timely file non-provisional patent applications relating to our provisional patent applications and national stage patent applications relating to our PCT patent applications, we cannot predict whether any such patent applications will result in the issuance of patents that provide us with any competitive advantage.

Individual issued patents extend for varying periods depending on the date of filing of the patent application or the date of patent issuance and the legal term of patents in the countries in which they are obtained. Generally, utility patents issued for applications filed in the United States are granted a term of 20 years from the earliest effective filing date of a non-provisional patent application. The term of a patent, and the protection it affords, is therefore limited and once the patent term of our issued patents have expired, we may face competition, including from other competing technologies. Because of the extensive time required for clinical development and regulatory review of a drug we may develop, it is possible that, before any of our product candidates can be commercialized, any related patent may expire or remain in force for only a short period following commercialization, thereby reducing any advantage of any such patent.

In addition, in certain instances, a U.S. patent term can be extended to recapture a portion of the term effectively lost as a result of the FDA regulatory review period or delay by the USPTO in issuing the patent. However, with respect to patent term extensions granted as a result of the FDA regulatory review period, the restoration period cannot be longer than five years, the total patent term including the restoration period must not exceed 14 years following FDA approval, only one patent applicable to each regulatory review period may be extended and only those claims covering the approved drug or a method for using it may be extended. We may not receive an extension if we fail to exercise due diligence during the testing phase or regulatory review process, fail to apply within applicable deadlines, fail to apply prior to expiration of relevant patents or otherwise fail to satisfy applicable requirements. Moreover, the length of the extension could be less than we request. There can be no assurance that we will benefit from any patent term extension or favorable adjustment to the term of any of our patents.

The duration of foreign patents varies in accordance with provisions of applicable local law, but typically is also 20 years from the earliest effective filing date. However, the actual protection afforded by a patent varies on a product by product basis, from country to country, and depends upon many factors, including the type of patent, the scope of its coverage, the availability of regulatory related extensions, the availability of legal remedies in a particular country and the validity and enforceability of the patent. As a result, our owned and licensed patent portfolio may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours.

If we do not adequately protect our intellectual property, third parties, including our competitors, may be able to use our technologies to produce and market drugs or diagnostic and/or prognostic products in direct competition with us and erode our competitive advantage. The patent positions of biotechnology and pharmaceutical products and processes like those we may develop and commercialize are generally uncertain and involve complex legal and factual questions that may diminish our ability to protect our intellectual property. For more information regarding risks related to our intellectual property, see “Risk Factors—Risks Related to Our Intellectual Property.”

Rapidly evolving patent laws in the United States and elsewhere make it difficult to predict the breadth of claims that may be allowed or enforced in our patents. Moreover, patent offices in general can require that patent applications concerning pharmaceutical and/or biotechnology-related inventions be limited or narrowed substantially to cover only the specific innovations exemplified in the patent application, thereby limiting the scope of protection against competitive challenges. Thus, even if we are able to obtain patents, the patents may be substantially narrower than anticipated.

Our ability to maintain and defend our intellectual property and proprietary position for our products, product candidates and other technologies will depend on our success in obtaining effective claims and enforcing those claims once granted. We do not know

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whether any of the patent applications that we may file or license from third parties will result in the issuance of any patents. The issued patents that we own, may receive in the future, or license from third parties may be challenged, invalidated, held unenforceable, narrowed or circumvented, and the rights granted under any issued patents may not provide us with proprietary protection or competitive advantages against third parties, including our competitors, with similar technology. Furthermore, third parties, including our competitors, may be able to independently develop and commercialize similar drugs or products, or duplicate our technology, business model or strategy without infringing our patents.

Trade Secrets

We also rely upon unpatented trade secrets and know-how and continuing technological innovation to develop, protect and maintain our competitive position and aspects of our business that are not amenable to, or that we do not presently consider appropriate for, patent protection and prevent competitors from reverse engineering or copying our technologies. However, the foregoing rights are difficult to protect. We seek to protect our proprietary information, in part, using confidentiality agreements with our commercial partners, collaborators, employees and consultants and invention assignment agreements with our employees. We also have confidentiality agreements or invention assignment agreements with our commercial partners and selected consultants. These agreements are designed to protect our proprietary information and, in the case of the invention assignment agreements, to grant us ownership of technologies that are developed through a relationship with a third party. These agreements may be breached, and we may not have adequate remedies for any breach. There can be no assurance that these agreements will be self-executing or otherwise provide meaningful protection for our trade secrets or other intellectual property or proprietary information. In addition, our trade secrets may otherwise become known or be independently discovered by third parties, including our competitors. To the extent that our commercial partners, collaborators, employees and consultants use intellectual property owned by others in their work for us, disputes may arise as to the rights in related or resulting know-how and inventions. For more information regarding risks related to our trade secrets, see “Risk Factors—Risks Related to Our Intellectual Property.”

Collaboration and License Agreement Overview

Our Collaboration with Cedars-Sinai Medical Center

In September 2017, we entered into an exclusive license agreement with Cedars-Sinai, as amended and restated (the Cedars-Sinai Agreement) that grants us an exclusive, worldwide license from Cedars-Sinai with respect to certain patent rights, information and materials related to therapeutic targets and diagnostic product candidates for the diagnosis and treatment of IBD and other immune-mediated diseases, in each case to conduct research and development, as well as to commercialize diagnostic or therapeutic products (Cedars-Sinai Products) that are covered by the patents or that are developed through use of the licensed rights. As upfront consideration for the original license agreement, we issued to Cedars-Sinai 257,500 shares of fully vested common stock and 335,000 shares of restricted common stock, which shares fully vested in September 2020. We are obligated to pay Cedars-Sinai low- to mid-single digit percentage royalties on net sales of therapeutic and diagnostic Cedars-Sinai Products. In August 2021, we amended and restated the Cedars-Sinai Agreement to, among other things, add a joint steering committee and cover new intellectual property.

The technology subject to the foregoing license includes information and materials arising out of the Cedars-Sinai database and biobank, as well as exclusive access to this database and biobank to develop diagnostic and therapeutic products for human use, which biobank is an integral part of our Prometheus360 platform. All of our current pipeline programs and any related diagnostic candidates are all covered as Cedars-Sinai Products under the agreement, to the extent covered by the licensed patents or developed through the licensed rights. We were also granted an exclusive first right to negotiate with Cedars-Sinai to obtain exclusive licenses to future patent rights claiming inventions invented by certain Cedars-Sinai employees after the effective date of the agreement through any use of the patent rights and technology licensed to us by Cedars-Sinai. We have the right to sublicense our rights under the license agreement, subject to certain conditions. We are required to use commercially reasonable efforts to develop and commercialize Cedars-Sinai Products and to achieve certain development and regulatory milestones.

The term of, and our royalty obligations under, the license agreement expires on a licensed Cedars-Sinai Product-by-Cedars-Sinai Product and country-by-country basis on the later of ten years from the date of first commercial sale or when there is no longer a valid patent covering such licensed Cedars-Sinai Product in such country. As of February 17, 2023, the estimated expiry date for the latest to expire valid patent will be July 2043, if issued. We may terminate the agreement in the event that we determine that it would not be commercially reasonable to continue to develop and/or commercialize Cedars-Sinai Products. Cedars-Sinai may terminate the agreement if the performance by either party would jeopardize Cedars-Sinai’s legal status or is illegal or unethical. In addition, either party may terminate the agreement in the event of an uncured material breach by the other party. The agreement will terminate automatically in the event of our bankruptcy. Upon termination of the agreement for any reason all rights and licenses granted to us under the agreement will terminate.

Our Collaboration with Dr. Falk Pharma GmbH

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In July 2020, we entered into a co-development and manufacturing agreement (the Falk Agreement) with Dr. Falk Pharma GmbH (Falk), pursuant to which we will co-develop and commercialize, exclusively in our respective territories, our PR052 therapeutic product candidate and related diagnostic candidate. Under the Falk Agreement, we are obligated to use commercially reasonable efforts to conduct such development activities under an agreed development plan and we are responsible for regulatory approvals and commercialization of any products in the United States and the rest of the world, other than the Falk territory. Falk is responsible for regulatory approvals and commercialization of any products in the European Union, United Kingdom, Switzerland, the countries of the European Economic Area (excluding Malta and the Republic of Cyprus), Australia and New Zealand (Falk territory). Under the agreement, Falk agreed to fund 25% of our third-party development costs set forth in the development plan.

Under the agreement, Falk paid us an upfront payment following our mutual agreement on the development plan and milestone payments upon the selection of a clinical candidate for our PRA052 program and upon our development of a diagnostic candidate for the PRA052 program. Falk is also obligated to pay us a mid-single to low-double digit royalty on net sales of all products incorporating antibodies covered by the agreement in the Falk territory. We agreed to pay Falk a low-single digit royalty on net sales for such products in our territory. Any intellectual property, including know-how, owned by us, Falk, or our respective affiliates that existed prior to the effective date of the agreement or is generated during the term of the agreement, that is also necessary or useful to develop, manufacture, or commercialize the compounds and/or products that result from the collaboration, are jointly owned by us and Falk at a share of 75% for us and a 25% for Falk.

The term of, and our respective royalty obligations under, the agreement expires on a product-by-product and country-by-country basis on the later of (i) ten years from the date of first commercial sale, (ii) when there is no longer a valid patent covering a product in such country, or (iii) expiration of any applicable regulatory exclusivity for such product. As of February 17, 2023, the estimated expiry date for the latest to expire valid patent will be July 2043, if issued. Falk may terminate the agreement without cause, and either party may terminate the agreement for regulatory or scientific reasons. In the event of such termination, all licenses granted to the terminating party will cease and be transferred to the non-terminating party, and such non-terminating party will have access to the know-how and any other intellectual property controlled by the terminating party, if in existence as of the effective date of the agreement or during the term of the agreement, provided the know-how and other intellectual property is necessary or useful to develop, manufacture, or commercialize the therapeutic candidates under the PRA052 program, subject to the obligation to pay the applicable royalties to the terminating party. In addition, either party may terminate the agreement in the event of an uncured material breach by, or bankruptcy of, the other party. In the event of such termination, the terminating party has the option to purchase the non-terminating party’s ownership share of any jointly owned intellectual property at a fair market price. Additionally, in the event of such termination for uncured material breach or bankruptcy: all rights of the terminating party granted under the agreement will be maintained and extended as required to develop, manufacture and commercialize the compounds and/or products that result from the collaboration for the remainder of the term, while any licenses granted to the non-terminating party shall terminate upon the effective date of termination and the obligation of each party to co-fund development will remain unaffected.

Manufacturing

We do not own or operate, and currently have no plans to establish, any manufacturing facilities. We rely, and expect to continue to rely on third parties for the manufacture of our product candidates and related raw materials, including our autoinjector, for preclinical and clinical development, as well as for commercial manufacture of any of our product candidates that receive marketing approval. We believe there are multiple sources for all of the materials required for the manufacture of our product candidates and development programs. As our product candidates advance through development, we expect to enter into longer-term commercial supply agreements with key suppliers and manufacturers to fulfill and secure our production needs.

Sales and Marketing

We believe that we can maximize the value of our products by retaining substantial commercialization rights to our therapeutic and diagnostic product candidates. As we progress PRA023 and other development programs through clinical development, we will leverage the knowledge and experience of our commercial team and company brand awareness to prepare for and implement a potential product launch. We may also explore and evaluate entering into strategic collaborations for specific therapeutic indications or geographic territories in order to maximize the value of PRA023 and our product candidates.

We have global commercial rights to PRA023 and our diagnostic candidate. Our current commercial strategy is to market PRA023 and the diagnostic candidate using a dedicated sales force focused on selected gastroenterologists, rheumatologists, and other physicians in the United States. These target prescribers are typically affiliated with leading hospitals and medical centers and tend to have well-established referral networks. We expect to benefit from preexisting relationships with many of these prescribers and believe that we can appropriately manage outreach and effectively commercialize PRA023 through a specialty care sales model. We retain rights similar to those for PRA023 for each of our unpartnered programs. For PRA052, which is subject to the Falk collaboration, we have exclusively outlicensed commercialization rights to Falk in Europe, Australia and New Zealand. However, we

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retain commercial rights to our PRA052 program in the United States and the rest of the world and plan to take a similar commercialization approach as with PRA023, if approved.

Competition

The biotechnology and pharmaceutical industries are characterized by rapidly advancing technologies, intense competition and a strong emphasis on proprietary products. While we believe that our scientific knowledge, technology and development experience, our Prometheus360 platform and our pioneering culture provide us with competitive advantages, we face potential competition from many different sources, including major pharmaceutical, specialty pharmaceutical and biotechnology companies, academic institutions, governmental agencies and public and private research institutions. Any therapeutic candidates and diagnostics that we successfully develop and commercialize will compete with existing products and new products that may become available in the future.

Many of the companies against which we are competing or against which we may compete in the future have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals and marketing approved products than we do. Mergers and acquisitions in the pharmaceutical and biotechnology industry may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs.

Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize therapeutic products that are safer, more effective, have fewer or less severe side effects, or diagnostics that are more effective, are more convenient or are less expensive than any products that we may develop. Our competitors also may obtain FDA or other regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market. In addition, our ability to compete may be affected in many cases by insurers or other third-party payors seeking to encourage the use of generic products, including biosimilars.

The key competitive factors affecting the success of all of our therapeutic product candidates if approved, are likely to be efficacy, safety, convenience, price, the level competition, intellectual property protection and the availability of reimbursement from government and other third-party payors.

If approved for the treatment of patients with moderate-to-severe IBD, PRA023 and our other development programs would compete with Entyvio, which is an a4b7 integrin antibody marketed by Takeda, Humira, which is a TNF antibody marketed by AbbVie Inc., Remicade, which is a TNF antibody marketed by Johnson & Johnson, Stelara, which is an IL-12/IL-23 antibody marketed by Johnson & Johnson, Xeljanz, which is a JAK1 inhibitor marketed by Pfizer Inc., Simponi, which is a TNF antibody marketed by Johnson & Johnson, and Zeposia, which is a S1P inhibitor marketed by Bristol-Myers Squibb Company.

We are aware of several companies with product candidates in development for the treatment of patients with UC and/or CD, including but not limited to Roivant Sciences RVT-3101 (formerly Pfizer Inc.’s PF-06480605), which is an anti-TL1A antibody being developed in Phase 2 clinical trials, Rinvoq, which is a JAK1 inhibitor being developed in Phase 3 clinical trials by AbbVie Inc., and mirikizumab, which is an anti-IL-23 antibody being developed in Phase 3 clinical trials by Eli Lilly and Company. We are also aware of additional product candidates in clinical trials by AbbVie Inc., Abivax S.A., Amgen Inc., Applied Molecular Transport Inc., Arena Pharmaceuticals, Inc., AstraZeneca Pharmaceuticals LP, Bausch Health Companies, Inc., Bristol-Myers Squibb Company, C.H. Boehringer Sohn AG & Ko. KG, EA Pharma Co., Ltd., Gilead Sciences, Inc., Gossamer Bio, Inc., Johnson & Johnson, Landos Biopharma, Inc., Morphic Holding, Inc., Merck & Co. Inc., Novartis International AG, Protagonist Therapeutics, Inc., RedHill Biopharma Ltd., Seres Therapeutics, Inc., and Ventyx Biosciences, Inc. In addition, biosimilars of Humira, Stelara and Entyvio are expected in coming years and will provide cost-effective alternatives within the biologic class.

If approved for the treatment of patients with SSc-ILD, PRA023 would compete with Ofev, which is a tyrosine kinase inhibitor marketed by Boehringer Ingelheim AG and Actemra, which is an IL-6 antibody marketed by F. Hoffmann-La Roche AG. We are aware of several companies with product candidates in development for the treatment of patients for SSc-ILD, including but not limited to Castle Creek Biosciences, Inc., Certa Therapeutics Pty Ltd., Chemomab Therapeutics Ltd., Cumberland Pharmaceuticals Inc., Emerald Health Pharmaceuticals Inc., Forbius PTY Limited, GlaxoSmithKline plc., Horizon Therapeutics plc, Incyte Corporation, Johnson & Johnson, Kyowa Kirin plc, Merck & Co., Inc., Mitsubishi Tanabe Pharma Corporation, Sanofi S.A., and Seagen, Inc.

Government Regulation

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Government authorities in the United States, at the federal, state and local level, and other countries extensively regulate, among other things, the research, development, testing, manufacture, quality control, approval, labeling, packaging, storage, record-keeping, promotion, advertising, distribution, marketing, post-approval monitoring and reporting, pricing, and export and import of diagnostic tests and pharmaceutical products such as those we are currently marketing and developing. The process of obtaining and maintaining regulatory approvals and the subsequent compliance with appropriate federal, state, local, and foreign statutes and regulations require the expenditure of substantial time and financial resources.

U.S. Regulation of Diagnostic Tests and other Medical Devices

In the United States, the laws and regulations governing the marketing of diagnostic products are evolving, extremely complex, and in many instances, there are no significant regulatory or judicial interpretations of these laws and regulations. The Federal Food, Drug and Cosmetic Act (FDCA) defines a medical device to include any instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar or related article, including a component part, or accessory, intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease, in man or other animals. Among other things, pursuant to the FDCA and its implementing regulations, the FDA regulates the research, testing, manufacturing, safety, labeling, storage, recordkeeping, premarket clearance or approval, marketing and promotion and sales and distribution of medical devices in the United States to ensure that medical products distributed domestically are safe and effective for their intended uses.

PMA Pathway

We are developing diagnostic candidates designed to be used in connection with our therapeutic product candidates, if approved. Diagnostic products are regulated by the FDA as medical devices. The FDA categorizes medical devices into one of three classes—Class I, II, or III—based on the risks presented by the device and the regulatory controls necessary to provide a reasonable assurance of the device’s safety and effectiveness. Class I includes devices with the lowest risk to the patient and are those for which safety and effectiveness can be assured by adherence to the FDA’s General Controls for medical devices, which include compliance with the applicable portions of the Quality System Regulation (QSR) facility registration and product listing, reporting of adverse medical events, and truthful and non-misleading labeling, advertising, and promotional materials. Class II devices are subject to the FDA’s General Controls, and special controls as deemed necessary by the FDA to ensure the safety and effectiveness of the device. Special controls are established by the FDA for a specific device type and often include specific labeling provisions, performance metrics, and other types of controls that mitigate risks of the device (usually incorrect results for an in-vitro diagnostic device (IVD)). Devices deemed by the FDA to pose the greatest risks, such as life sustaining, life supporting or some implantable devices, or devices that have a new intended use, or use advanced technology that is not substantially equivalent to that of a legally marketed device, are placed in Class III, requiring approval of an application for premarket approval (PMA). Some pre-amendment devices are unclassified, but are subject to the FDA’s premarket notification and clearance process in order to be commercially distributed.

Class III devices generally require PMA approval before they can be marketed. Obtaining PMA approval requires the submission of “valid scientific evidence” to the FDA to support a finding of a reasonable assurance of the safety and effectiveness of the device. A PMA must provide complete analytical and clinical performance data and also information about the device and its components regarding, among other things, device design, manufacturing and labeling. Following receipt of a PMA, the FDA determines whether the application is sufficiently complete to permit a substantive review. If the FDA accepts the application for review, it has 180 days under the FDCA to complete its review of a PMA, although in practice, FDA’s review often takes significantly longer, and can take up to several years. An advisory panel of experts from outside the FDA may be convened to review and evaluate the application and provide recommendations to the FDA as to the approvability of the device. The FDA may or may not accept the panel’s recommendation. As part of the FDA’s review of a PMA, the FDA will typically inspect the manufacturer’s facilities for compliance with QSR requirements, which impose requirements related to design controls, manufacturing controls, documentation and other quality assurance procedures. The user fee costs and the length of FDA review time for obtaining PMA approval are significantly higher than for a 510(k) notification or a de novo classification.

The FDA will approve the new device for commercial distribution if it determines that the data and information in the PMA constitute valid scientific evidence and that there is reasonable assurance that the device is safe and effective for its intended use(s). The FDA may approve a PMA with post-approval conditions intended to ensure the safety and effectiveness of the device, including, among other things, restrictions on labeling, promotion, sale and distribution, and collection of long-term follow-up data from patients in the clinical study that supported PMA approval or requirements to conduct additional clinical studies post-approval. The FDA may condition PMA approval on some form of post-market surveillance when deemed necessary to protect the public health or to provide additional safety and efficacy data for the device in a larger population or for a longer period of use. In such cases, the manufacturer might be required to follow certain patient groups for a number of years and to make periodic reports to the FDA on the clinical status of those patients. Failure to comply with the conditions of approval can result in material adverse enforcement action, including withdrawal of the approval.

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Certain changes to an approved device, such as changes in manufacturing facilities, methods, or quality control procedures, or changes in the design performance specifications, which affect the safety or effectiveness of the device, require submission of a PMA supplement. PMA supplements often require submission of the same type of information as a PMA, except that the supplement is limited to information needed to support any changes from the device covered by the original PMA and may not require as extensive clinical data or the convening of an advisory panel. Certain other changes to an approved device require the submission of a new PMA, such as when the design change causes a different intended use, mode of operation, and technical basis of operation, or when the design change is so significant that a new generation of the device will be developed, and the data that were submitted with the original PMA are not applicable for the change in demonstrating a reasonable assurance of safety and effectiveness.

We expect that any companion diagnostic candidates we develop, either alone or in collaboration with third parties, will require approval of a PMA before they can be marketed for use with a therapeutic product.

510(k) Notification Pathway

To obtain 510(k) clearance, a manufacturer must submit a premarket notification demonstrating to the FDA’s satisfaction that the proposed device is “substantially equivalent” to another legally marketed device that itself does not require PMA approval (a predicate device). A predicate device is a legally marketed device that is not subject to premarket approval, i.e., a device that was legally marketed prior to May 28, 1976 (pre-amendments device) and for which a PMA is not required, a device that has been reclassified from Class III to Class II or I, or a device that was found substantially equivalent through the 510(k) process. The FDA’s 510(k) clearance process usually takes from three to twelve months, but often takes longer. FDA may require additional information, including clinical data, to make a determination regarding substantial equivalence. In addition, the FDA collects user fees for certain medical device submissions and annual fees and for medical device establishments. If the FDA agrees that the device is substantially equivalent to a lawfully marketed predicate device, it will grant 510(k) clearance to authorize the device for commercialization. If the FDA determines that the device is “not substantially equivalent” to a previously cleared device, the device is automatically designated as a Class III device. The device sponsor must then fulfill more rigorous PMA requirements, or can request a risk-based classification determination for the device in accordance with the de novo process, which is a route to market for novel medical devices that are low to moderate risk and are not substantially equivalent to a predicate device, discussed below.

After a device receives 510(k) clearance, any modification that could significantly affect its safety or effectiveness, or that would constitute a major change or modification in its intended use, will require a new 510(k) clearance or, depending on the modification, PMA approval. The FDA requires each manufacturer to determine whether the proposed change requires submission of a 510(k) or a PMA in the first instance, but the FDA can review any such decision and disagree with a manufacturer’s determination. Many minor modifications are accomplished by a “letter to file” in which the manufacturer documents the rationale for the change and why a new 510(k) is not required. However, if the FDA disagrees with a manufacturer’s determination, the FDA can require the manufacturer to cease marketing and/or request the recall of the modified device until 510(k) marketing clearance or PMA approval is obtained. Also, in these circumstances, the manufacturer may be subject to significant regulatory fines or penalties.

Over the last several years, the FDA has proposed reforms to its 510(k) clearance process, and such proposals could include increased requirements for clinical data and a longer review period, or could make it more difficult for manufacturers to utilize the 510(k) clearance process for their products. For example, in November 2018, FDA officials announced steps that the FDA intended to take to modernize the premarket notification pathway under Section 510(k) of the FDCA. Among other things, the FDA announced that it planned to develop proposals to drive manufacturers utilizing the 510(k) pathway toward the use of newer predicates. These proposals included plans to potentially sunset certain older devices that were used as predicates under the 510(k) clearance pathway, and to potentially publish a list of devices that have been cleared on the basis of demonstrated substantial equivalence to predicate devices that are more than 10 years old.

These proposals have not yet been finalized or adopted, and the FDA may work with Congress to implement such proposals through legislation. More recently, in September 2019, the FDA published revised final guidance outlining an optional “safety and performance based” premarket review pathway for manufacturers of “well-understood device types” to demonstrate substantial equivalence under the 510(k) clearance pathway, by demonstrating that such device meets objective safety and performance criteria established by the FDA, obviating the need for manufacturers to compare the safety and performance of their medical devices to specific predicate devices in the clearance process. The FDA maintains a list of device types appropriate for the “safety and performance based pathway” and has continued to develop product-specific guidance documents that identify the performance criteria for each such device type, as well as recommended the testing methods for such devices where feasible.

If no legally marketed predicate can be identified for a new device to enable use of the 510(k) pathway, the device is automatically classified under the FDCA into Class III, which generally requires PMA approval. However, the FDA can reclassify or seek de novo classification for a device that meets the FDCA standards for a Class I or Class II device, permitting the device to be marketed without PMA approval. To grant such a reclassification, the FDA must determine that the FDCA’s general controls alone, or general controls

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and special controls together, are sufficient to provide a reasonable assurance of the device’s safety and effectiveness. The de novo classification route is generally less burdensome than the PMA approval process.

De Novo Classification

Medical device types that the FDA has not previously classified as Class I, II or III are automatically classified under the FDCA into Class III regardless of the level of risk they pose. The Food and Drug Administration Modernization Act of 1997 established a route to market for low to moderate risk medical devices that are automatically placed into Class III due to the absence of a predicate device, called the “Request for Evaluation of Automatic Class III Designation,” or the de novo classification procedure. This procedure allows a manufacturer whose novel device is automatically classified into Class III to request down-classification of its medical device into Class I or Class II on the basis that the device presents low or moderate risk, rather than requiring the submission and approval of a PMA application. Prior to the enactment of the Food and Drug Administration Safety and Innovation Act of 2012 (FDASIA) a medical device could be eligible for de novo classification only if the manufacturer first submitted a 510(k) premarket notification and received a determination from the FDA that the device was not substantially equivalent to a legally marketed predicate device. FDASIA streamlined the de novo classification pathway by permitting manufacturers to request de novo classification directly without first submitting a 510(k) premarket notification to the FDA and receiving a not substantially equivalent determination. If the manufacturer seeks reclassification into Class II, the manufacturer must include a draft proposal for special controls that are necessary to provide a reasonable assurance of the safety and effectiveness of the medical device. In addition, the FDA may reject the request if it identifies a legally marketed predicate device that would be appropriate for a 510(k) notification, determines that the device is not low to moderate risk, or that general controls would be inadequate to control the risks and special controls cannot be developed. After a device receives de novo classification, any modification that could significantly affect its safety or efficacy, or that would constitute a major change or modification in its intended use, will require a new 510(k) clearance or, depending on the modification, another de novo request or even PMA approval.

Investigational Device Exemption Process.

Clinical trials are almost always required to support a PMA and are sometimes required to support a 510(k) submission. All clinical investigations of investigational devices to determine safety and effectiveness must be conducted in accordance with the FDA’s IDE regulations which govern investigational device labeling, prohibit promotion of the investigational device, and specify an array of recordkeeping, reporting and monitoring responsibilities of study sponsors and study investigators. If the device presents a “significant risk” to human health, the FDA requires the device sponsor to submit an IDE application to the FDA, which must become effective prior to commencing human clinical trials. A significant risk device is one that presents a potential for serious risk to the health, safety or welfare of a patient and either is implanted, used in supporting or sustaining human life, substantially important in diagnosing, curing, mitigating or treating disease or otherwise preventing impairment of human health, or otherwise presents a potential for serious risk to a subject. An IDE application must be supported by appropriate data, such as animal and laboratory test results, showing that it is safe to test the device in humans and that the testing protocol is scientifically sound. The IDE will automatically become effective 30 days after receipt by the FDA, unless the FDA notifies the company that the investigation may not begin. If the FDA determines that there are deficiencies or other concerns with an IDE for which it requires modification, the FDA may permit a clinical trial to proceed under a conditional approval.

In addition, the study must be approved by, and conducted under the oversight of, an Institutional Review Board (IRB) for each clinical site. The IRB is responsible for the initial and continuing review of the IDE, and may pose additional requirements for the conduct of the study. If an IDE application is approved by the FDA and one or more IRBs, human clinical trials may begin at a specific number of investigational sites with a specific number of patients, as approved by the FDA. If the device presents a non-significant risk to the patient, a sponsor may begin the clinical trial after obtaining approval for the trial by one or more IRBs without separate approval from the FDA, but must still follow abbreviated IDE requirements, such as monitoring the investigation, ensuring that the investigators obtain informed consent, and labeling and record-keeping requirements. Acceptance of an IDE application for review does not guarantee that the FDA will allow the IDE to become effective and, if it does become effective, the FDA may or may not determine that the data derived from the trials support the safety and effectiveness of the device or warrant the continuation of clinical trials. An IDE supplement must be submitted to, and approved by, the FDA before a sponsor or investigator may make a change to the investigational plan that may affect its scientific soundness, study plan or the rights, safety or welfare of human subjects.

During a study, the sponsor is required to comply with the applicable FDA requirements, including, for example, trial monitoring, selecting clinical investigators and providing them with the investigational plan, ensuring IRB review, adverse event reporting, record keeping, and prohibitions on the promotion of investigational devices or on making safety or effectiveness claims for them. The clinical investigators in the clinical study are also subject to FDA regulations and must obtain patient informed consent, rigorously follow the investigational plan and study protocol, control the disposition of the investigational device, and comply with all reporting and recordkeeping requirements. Additionally, after a trial begins, we, the FDA or the IRB could suspend or terminate a clinical trial at any time for various reasons, including a belief that the risks to study subjects outweigh the anticipated benefits.

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Expedited Development and Review Programs for Medical Devices

Through recent federal legislation, the FDA has implemented a Breakthrough Devices Program, which is a voluntary program offering manufacturers of certain devices an opportunity to interact with the FDA more frequently and efficiently as they develop their products with the goal of expediting commercialization of such products to help patients have more timely access. The program is available to medical devices that meet certain eligibility criteria, including that the device provides more effective treatment or diagnosis of life-threatening or irreversibly debilitating diseases or conditions, and constitutes a device (i) that represents a breakthrough technology, (ii) for which no approved or cleared alternatives exist, (iii) that offer significant advantages over existing approved or cleared alternatives, or (iv) the availability of which is in the best interest of patients. Devices granted Breakthrough Device designation are eligible to rely on certain features of the Breakthrough Device Program, including interactive and timely communications with FDA staff, use of post-market data collection, when scientifically appropriate, to facilitate expedited and efficient development and review of the device, opportunities for efficient and flexible clinical study design and priority review of premarket submissions.

Postmarket Regulation of Medical Devices

After a device is cleared or approved by the FDA for marketing, numerous and pervasive regulatory requirements continue to apply. These include:

Device manufacturing processes subject to FDA oversight are required to comply with the applicable portions of the QSR, which cover the methods and the facilities and controls for the design, manufacture, testing, production, processes, controls, quality assurance, labeling, packaging, distribution, installation and servicing of finished devices intended for human use. The QSR also requires, among other things, maintenance of a device master file, device history file, and complaint files. Manufacturers are subject to periodic scheduled or unscheduled inspections by the FDA. A failure to maintain compliance with the QSR requirements could result in the shut-down of, or restrictions on, manufacturing operations and the recall or seizure of products. The discovery of previously unknown problems with products, including unanticipated adverse events or adverse events of increasing severity or frequency, whether resulting from the use of the device within the scope of its clearance or off-label by a physician in the practice of medicine, could result in restrictions on the device, including the removal of the product from the market or voluntary or mandatory device recalls.

The FDA has broad regulatory compliance and enforcement powers. If the FDA determines that a manufacturer has failed to comply with applicable regulatory requirements, it can take a variety of compliance or enforcement actions, including the following:

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Regulation of Companion Diagnostics

If safe and effective use of a therapeutic depends on an IVD, then the FDA generally will require approval or clearance of that diagnostic, known as a companion diagnostic, at the same time that the FDA approves the therapeutic product. In August 2014, the FDA issued final guidance clarifying the requirements that will apply to approval of therapeutic products and in vitro companion diagnostics. According to the guidance, if the FDA determines that a companion diagnostic device is essential to the safe and effective use of a novel therapeutic product or indication, FDA generally will not approve the therapeutic product or new therapeutic product indication if the companion diagnostic device is not approved or cleared for that indication. Approval or clearance of the companion diagnostic device will ensure that the device has been adequately evaluated and has adequate performance characteristics in the intended population. The review of in vitro companion diagnostics in conjunction with the review of our therapeutic product candidates will, therefore, likely involve coordination of review by the FDA’s Center for Drug Evaluation and Research or the FDA’s Center for Biologics Evaluations and Research and the FDA’s Center for Devices and Radiological Health Office of In Vitro Diagnostics and Radiological Health.

U.S. Regulation of Drugs and Biologics

In the United States, the FDA regulates drugs under the FDCA, and its implementing regulations, and biologics under the FDCA and the Public Health Service Act and its implementing regulations. FDA approval is required before any new unapproved drug or dosage form, including a new use of a previously approved drug, can be marketed in the United States. Drugs and biologics are also subject to other federal, state, and local statutes and regulations. The process required by the FDA before product candidates may be marketed in the United States generally involves the following:

An IND is a request for authorization from the FDA to administer an investigational new drug product to humans. The central focus of an IND submission is on the general investigational plan and the protocol or protocols for preclinical studies and clinical trials. The IND also includes results of animal and in vitro studies assessing the toxicology, PK, pharmacology and PD characteristics of the product, chemistry, manufacturing and controls (CMC) information, and any available human data or literature to support the use of the investigational product. An IND must become effective before human clinical trials may begin. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day period, raises safety concerns or questions about the proposed clinical trial. In such a case, the IND may be placed on clinical hold and the IND sponsor and the FDA must resolve any outstanding concerns or questions before the clinical trial can begin. Submission of an IND therefore may or may not result in FDA authorization to begin a clinical trial.

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Clinical trials involve the administration of the investigational product to human subjects under the supervision of qualified investigators in accordance with GCP, which includes the requirement that all research subjects provide their informed consent for their participation in any clinical study. Clinical trials are conducted under protocols detailing, among other things, the objectives of the study, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. A separate submission to the existing IND must be made for each successive clinical trial conducted during product development and for any subsequent protocol amendments. While the IND is active, progress reports summarizing the results of the clinical trials and nonclinical studies performed since the last progress report, among other information, must be submitted at least annually to the FDA, and written IND safety reports must be submitted to the FDA and investigators for serious and unexpected suspected adverse events, findings from other studies suggesting a significant risk to humans exposed to the drug, findings from animal or in vitro testing suggesting a significant risk to humans exposed to the drug, and any clinically important increased rate of a serious suspected adverse reaction compared to that listed in the protocol or investigator brochure.

Furthermore, an independent IRB for each site proposing to conduct the clinical trial must review and approve the plan for any clinical trial and its informed consent form before the clinical trial begins at that site, and must monitor the study until completed. Regulatory authorities, the IRB or the sponsor may suspend a clinical trial at any time on various grounds, including a finding that the subjects are being exposed to an unacceptable health risk or that the trial is unlikely to meet its stated objectives. Some studies also include oversight by an independent group of qualified experts organized by the clinical study sponsor, known as a data safety monitoring board, which provides authorization for whether or not a study may move forward at designated check points based on access to certain data from the study and may halt the clinical trial if it determines that there is an unacceptable safety risk for subjects or other grounds, such as no demonstration of efficacy. There are also requirements governing the reporting of ongoing preclinical studies and clinical trials and clinical study results to public registries.

The clinical investigation of a drug is generally divided into three phases. Although the phases are usually conducted sequentially, they may overlap or be combined.

In some cases, the FDA may condition approval of an NDA or BLA for a product candidate on the sponsor’s agreement to conduct additional clinical studies after approval. In other cases, a sponsor may voluntarily conduct additional clinical studies after approval to gain more information about the drug. Such post-approval studies are typically referred to as Phase 4 clinical studies. Concurrent with clinical trials, companies may complete additional animal studies and develop additional information about the biological characteristics of the product candidate, and must finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, must develop methods for testing the identity, strength, quality and purity of the final product, or for biologics, the safety, purity and potency.

NDA and BLA Review Process

Assuming successful completion of all required testing in accordance with all applicable regulatory requirements, the results of product development, nonclinical studies and clinical trials are submitted to the FDA as part of an NDA or BLA requesting approval to market the product for one or more indications. The NDA or BLA must include all relevant data available from pertinent preclinical studies and clinical trials, including negative or ambiguous results as well as positive findings, together with detailed information relating to the product’s CMC and proposed labeling, among other things. Data can come from company-sponsored clinical studies intended to test the safety and effectiveness of the product, or from a number of alternative sources, including studies initiated and sponsored by investigators. The submission of an NDA or BLA requires payment of a substantial application user fee to the FDA, unless a waiver or exemption applies.

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In addition, under the Pediatric Research Equity Act (PREA), an NDA or BLA or supplement to an NDA or BLA must contain data to assess the safety and effectiveness of the biological product candidate for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The FDASIA requires that a sponsor who is planning to submit a marketing application for a drug or biological product that includes a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration submit an initial pediatric study plan within sixty days after an end-of-Phase 2 meeting or as may be agreed between the sponsor and FDA. Unless otherwise required by regulation, PREA does not apply to any biological product for an indication for which orphan designation has been granted.

Within 60 days following submission of the application, the FDA reviews the submitted BLA or NDA to determine if the application is substantially complete before the agency accepts it for filing. The FDA may refuse to file any NDA or BLA that it deems incomplete or not properly reviewable at the time of submission and may request additional information. In this event, the NDA or BLA must be resubmitted with the additional information. Once an NDA or BLA has been accepted for filing, the FDA’s goal is to review standard applications within ten months after the filing date, or, if the application qualifies for priority review, six months after the FDA accepts the application for filing. In both standard and priority reviews, the review process may also be extended by FDA requests for additional information or clarification. The FDA reviews an NDA to determine, among other things, whether a product is safe and effective for its intended use and whether its manufacturing is sufficient to assure and preserve the product’s identity, strength, quality and purity. The FDA reviews a BLA to determine, among other things, whether a product is safe, pure and potent and the facility in which it is manufactured, processed, packed or held meets standards designed to assure the product’s continued safety, purity and potency. When reviewing an NDA or BLA, the FDA may convene an advisory committee to provide clinical insight on application review questions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

Before approving an NDA or BLA, the FDA will typically inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving an NDA or BLA, the FDA will typically inspect one or more clinical sites to assure compliance with GCP.

After the FDA evaluates the NDA or BLA and conducts inspections of manufacturing facilities where the investigational product and/or its drug substance will be produced, the FDA may issue an approval letter or a Complete Response letter. An approval letter authorizes commercial marketing of the product with specific prescribing information for specific indications. A Complete Response letter will describe all of the deficiencies that the FDA has identified in the NDA or BLA, except that where the FDA determines that the data supporting the application are inadequate to support approval, the FDA may issue the Complete Response letter without first conducting required inspections, testing submitted product lots and/or reviewing proposed labeling. In issuing the Complete Response letter, the FDA may recommend actions that the applicant might take to place the NDA or BLA in condition for approval, including requests for additional information or clarification. The FDA may delay or refuse approval of an NDA or BLA if applicable regulatory criteria are not satisfied, require additional testing or information and/or require post-marketing testing and surveillance to monitor safety or efficacy of a product.

If regulatory approval of a product is granted, such approval will be granted for particular indications and may entail limitations on the indicated uses for which such product may be marketed. For example, the FDA may approve the NDA or BLA with a Risk Evaluation and Mitigation Strategy (REMS) to ensure the benefits of the product outweigh its risks. A REMS is a safety strategy to manage a known or potential serious risk associated with a product and to enable patients to have continued access to such medicines by managing their safe use, and could include medication guides, physician communication plans, or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. The FDA also may condition approval on, among other things, changes to proposed labeling or the development of adequate controls and specifications. Once approved, the FDA may withdraw the product approval if compliance with pre- and post-marketing requirements is not maintained or if problems occur after the product reaches the marketplace. The FDA may require one or more Phase 4 post-market studies and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization, and may limit further marketing of the product based on the results of these post-marketing studies.

Regulation of Combination Products

Certain therapeutic products are comprised of multiple components, such as drug components and device components, that would normally be subject to different regulatory frameworks by the FDA and frequently regulated by different centers at the FDA. These products are known as combination products. Under the FDCA, the FDA is charged with assigning a center with primary jurisdiction, or a lead center, for review of a combination product. The determination of which center will be the lead center is based on the “primary mode of action” of the combination product. Thus, if the primary mode of action of a drug-device combination product is attributable to the drug product, the FDA center responsible for premarket review of the drug product would have primary jurisdiction

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for the combination product. The FDA has also established the Office of Combination Products to address issues surrounding combination products and provide more certainty to the regulatory review process. That office serves as a focal point for combination product issues for agency reviewers and industry. It is also responsible for developing guidance and regulations to clarify the regulation of combination products, and for assignment of the FDA center that has primary jurisdiction for review of combination products where the jurisdiction is unclear or in dispute. A combination product with a primary mode of action attributable to the drug or biologic component generally would be reviewed and approved pursuant to the drug approval processes set forth in the FDCA. In reviewing the NDA for such a product, however, FDA reviewers would consult with their counterparts in the FDA’s Center for Devices and Radiological Health to ensure that the device component of the combination product met applicable requirements regarding safety, effectiveness, durability and performance. In addition, under FDA regulations, combination products are subject to cGMP requirements applicable to both drugs and devices, including the QSR applicable to medical devices.

Expedited Development and Review Programs for Drugs and Biologics

The FDA offers a number of expedited development and review programs for qualifying product candidates. The fast track program is intended to expedite or facilitate the process for reviewing product candidates that meet certain criteria. Specifically, product candidates are eligible for fast track designation if they are intended to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. Fast track designation applies to the combination of the product candidate and the specific indication for which it is being studied. The sponsor of a fast track product candidate has opportunities for more frequent interactions with the review team during product development and, once an NDA or BLA is submitted, the application may be eligible for priority review. A fast track product candidate may also be eligible for rolling review, where the FDA may consider for review sections of the NDA or BLA on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the sections of the NDA or BLA, the FDA agrees to accept sections of the NDA or BLA and determines that the schedule is acceptable, and the sponsor pays any required user fees upon submission of the first section of the NDA or BLA.

A product candidate intended to treat a serious or life-threatening disease or condition may also be eligible for breakthrough therapy designation to expedite its development and review. A product candidate can receive breakthrough therapy designation if preliminary clinical evidence indicates that the product candidate, alone or in combination with one or more other drugs or biologics, may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The designation includes all of the fast track program features, as well as more intensive FDA interaction and guidance beginning as early as Phase 1 and an organizational commitment to expedite the development and review of the product candidate, including involvement of senior managers.

Any marketing application for a drug or biologic submitted to the FDA for approval, including a product candidate with a fast track designation and/or breakthrough therapy designation, may be eligible for other types of FDA programs intended to expedite the FDA review and approval process, such as priority review and accelerated approval. An NDA or BLA is eligible for priority review if the product candidate has the potential to provide a significant improvement in the treatment, diagnosis or prevention of a serious disease or condition. For new-molecular-entity NDAs and original BLAs, priority review designation means the FDA’s goal is to take action on the marketing application within six months of the 60-day filing date (as compared to ten months under standard review).

Additionally, product candidates studied for their safety and effectiveness in treating serious or life-threatening diseases or conditions may receive accelerated approval upon a determination that the product candidate has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. As a condition of accelerated approval, the FDA will generally require the sponsor to perform adequate and well-controlled confirmatory clinical studies to verify and describe the anticipated effect on irreversible morbidity or mortality or other clinical benefit. Products receiving accelerated approval may be subject to expedited withdrawal procedures if the sponsor fails to conduct the required confirmatory studies in a timely manner or if such studies fail to verify the predicted clinical benefit. In addition, the FDA currently requires as a condition for accelerated approval pre-approval of promotional materials, which could adversely impact the timing of the commercial launch of the product.

Fast track designation, breakthrough therapy designation, priority review, and accelerated approval do not change the standards for approval but may expedite the development or approval process. Even if a product qualifies for one or more of these programs, the FDA may later decide that the product no longer meets the conditions for qualification or decide that the time period for FDA review or approval will not be shortened. We may explore some of these opportunities for our product candidates as appropriate.

Orphan Drug Designation

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Under the Orphan Drug Act, the FDA may grant orphan designation to a drug or biologic intended to treat a rare disease or condition, which is a disease or condition that affects fewer than 200,000 individuals in the United States, or more than 200,000 individuals in the United States for which there is no reasonable expectation that the cost of developing and making available in the United States a drug or biologic for this type of disease or condition will be recovered from sales in the United States for that drug or biologic. Orphan drug designation must be requested before submitting an NDA or BLA. After the FDA grants orphan drug designation, the generic identity of the therapeutic agent and its potential orphan use are disclosed publicly by the FDA. The orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review or approval process.

If a product that has orphan drug designation subsequently receives the first FDA approval for the disease or condition for which it has such designation, the product is entitled to orphan drug exclusive approval (or exclusivity), which means that the FDA may not approve any other applications, including a full NDA or BLA, to market the same drug or biologic for the same disease or condition for seven years, except in limited circumstances, such as a showing of clinical superiority to the product with orphan drug exclusivity or if the FDA finds that the holder of the orphan drug exclusivity has not shown that it can assure the availability of sufficient quantities of the orphan drug to meet the needs of patients with the disease or condition for which the drug or biologic was designated. Orphan drug exclusivity does not prevent the FDA from approving a different drug or biologic for the same disease or condition, or the same drug or biologic for a different disease or condition. Among the other benefits of orphan drug designation are tax credits for certain research and a waiver of the NDA or BLA application user fee.

A designated orphan drug may not receive orphan drug exclusivity if it is approved for a use that is broader than the disease or condition for which it received orphan designation. In addition, exclusive marketing rights in the United States may be lost if the FDA later determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantities of the product to meet the needs of patients with the rare disease or condition.

Post-Approval Requirements for Drugs and Biologics

Any products manufactured or distributed pursuant to FDA approvals are subject to pervasive and continuing regulation by the FDA, including, among other things, requirements relating to record-keeping, reporting of adverse experiences, periodic reporting, product sampling and distribution, and advertising and promotion of the product. After approval, most changes to the approved product, such as adding new indications or other labeling claims, are subject to prior FDA review and approval. There also are continuing user fee requirements, under which the FDA assesses an annual program fee for each product identified in an approved NDA or BLA. Drug and biologic manufacturers and their subcontractors are required to register their establishments with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMPs, which impose certain procedural and documentation requirements upon us and our third-party manufacturers. Changes to the manufacturing process are strictly regulated, and, depending on the significance of the change, may require prior FDA approval before being implemented. FDA regulations also require investigation and correction of any deviations from cGMPs and impose reporting requirements upon us and any third-party manufacturers that we may decide to use. Accordingly, manufacturers must continue to expend time, money and effort in the area of production and quality control to maintain compliance with cGMPs and other aspects of regulatory compliance.

The FDA may withdraw approval if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or with manufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information; imposition of post-market studies or clinical studies to assess new safety risks; or imposition of distribution restrictions or other restrictions under a REMS program. Other potential consequences include, among other things:

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The FDA closely regulates the marketing, labeling, advertising and promotion of biologics. A company can make only those claims relating to safety and efficacy, purity and potency that are approved by the FDA and in accordance with the provisions of the approved label. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses. Failure to comply with these requirements can result in, among other things, adverse publicity, warning letters, corrective advertising and potential civil and criminal penalties. Physicians may prescribe legally available products for uses that are not described in the product’s labeling and that differ from those tested by us and approved by the FDA. Such off-label uses are common across medical specialties. Physicians may believe that such off-label uses are the best treatment for many patients in varied circumstances. The FDA does not regulate the behavior of physicians in their choice of treatments. The FDA does, however, restrict manufacturer’s communications on the subject of off-label use of their products.

Drug Product Marketing Exclusivity

Market exclusivity provisions authorized under the FDCA can delay the submission or the approval of certain marketing applications. For example, the FDCA provides a five-year period of non-patent data exclusivity within the United States to the first applicant to obtain approval of an NDA for a new chemical entity. A drug is a new chemical entity if the FDA has not previously approved any other new drug containing the same active moiety, which is the molecule or ion responsible for the action of the drug substance. During the exclusivity period, the FDA may not approve or even accept for review an abbreviated new drug application (ANDA) or an NDA submitted under Section 505(b)(2), or 505(b)(2) NDA, submitted by another company for another drug based on the same active moiety, regardless of whether the drug is intended for the same indication as the original innovative drug or for another indication, where the applicant does not own or have a legal right of reference to all the data required for approval. However, an application may be submitted after four years if it contains a certification of patent invalidity or non-infringement to one of the patents listed with the FDA by the innovator NDA holder.

The FDCA alternatively provides three years of marketing exclusivity for an NDA, or supplement to an existing NDA if new clinical investigations, other than bioavailability studies, that were conducted or sponsored by the applicant are deemed by the FDA to be essential to the approval of the application, for example new indications, dosages or strengths of an existing drug. This three-year exclusivity covers only the modification for which the drug received approval on the basis of the new clinical investigations and does not prohibit the FDA from approving ANDAs or 505(b)(2) NDAs for drugs containing the active agent for the original indication or condition of use. Five-year and three-year exclusivity will not delay the submission or approval of a full NDA. However, an applicant submitting a full NDA would be required to conduct or obtain a right of reference to any preclinical studies and adequate and well-controlled clinical trials necessary to demonstrate safety and effectiveness.

Pediatric exclusivity is another type of marketing exclusivity available in the United States. Pediatric exclusivity provides for an additional six months of marketing exclusivity attached to another period of exclusivity if a sponsor conducts clinical trials in children in response to a written request from the FDA. The issuance of a written request does not require the sponsor to undertake the described clinical trials. In addition, orphan drug exclusivity, as described above, may offer a seven-year period of marketing exclusivity, except in certain circumstances.

Biosimilars and Reference Product Exclusivity

The Biologics Price Competition and Innovation Act of 2009 (BPCIA) created an abbreviated approval pathway for biological products that are highly similar, or “biosimilar,” to or interchangeable with an FDA-approved reference biological product. The FDA has issued several guidance documents outlining an approach to review and approval of biosimilars. Biosimilarity, which requires that there be no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency, is generally shown through analytical studies, animal studies, and a clinical study or studies. Interchangeability requires that a product is biosimilar to the reference product and the product must demonstrate that it can be expected to produce the same clinical results as the reference product in any given patient and, for products that are administered multiple times to an individual, the biologic and the reference biologic may be alternated or switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic. A product shown to be biosimilar or interchangeable with an FDA-approved reference biological product may rely in part on the FDA’s previous determination of safety and effectiveness for the reference product for approval, which can potentially reduce the cost and time required to obtain approval to market the product.

Under the BPCIA, an application for a biosimilar product may not be submitted to the FDA until four years following the date that the reference product was first licensed by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first licensed. During this 12-year period of exclusivity, another company may still market a competing version of the reference product if the FDA approves a full BLA for the competing product containing that applicant’s own preclinical data and data from adequate and well-controlled clinical trials to demonstrate the safety,

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purity and potency of its product. The BPCIA also created certain exclusivity periods for biosimilars approved as interchangeable products. At this juncture, it is unclear whether products deemed “interchangeable” by the FDA will, in fact, be readily substituted by pharmacies, which are governed by state pharmacy law.

A biological product can also obtain pediatric market exclusivity in the United States. Pediatric exclusivity, if granted, adds six months to existing exclusivity periods and patent terms. This six-month exclusivity, which runs from the end of other exclusivity protection or patent term, may be granted based on the voluntary completion of a pediatric study in accordance with an FDA-issued “Written Request” for such a study.

U.S. Healthcare Fraud and Abuse Laws and Compliance Requirements

In addition to FDA regulation of pharmaceutical products, U.S. federal and state healthcare laws and regulations restrict business practices in the pharmaceutical industries. These laws may impact, among other things, our current and future business operations, including our clinical research activities, and constrain the business or financial arrangements and relationships with healthcare providers and other parties. These laws include anti-kickback, self-referral and false claims laws, civil monetary penalties laws, and transparency laws with respect to drug pricing and payments or other transfers of value made to physicians and other licensed healthcare professionals. In addition to the federal laws summarized below, we may also be subject to similar state and local laws and regulations that may apply to business practices, including but not limited to, research, distribution, sales and marketing arrangements and claims involving healthcare items or services reimbursed by non-governmental third-party payors, including private insurers, or by patients themselves.

The federal Anti-Kickback Statute prohibits, among other things, individuals or entities from knowingly and willfully offering, paying, soliciting or receiving remuneration, directly or indirectly, overtly or covertly, in cash or in kind to induce or in return for purchasing, leasing, ordering or arranging for or recommending the purchase, lease or order of any item or service reimbursable under Medicare, Medicaid or other federal healthcare programs. A person or entity does not need to have actual knowledge of this statute or specific intent to violate it in order to have committed a violation.

The federal civil and criminal false claims laws, including the civil False Claims Act, and civil monetary penalties laws prohibit, among other things, any individual or entity from knowingly presenting, or causing to be presented, a false claim for payment to the federal government, knowingly making, using or causing to be made or used a false record or statement material to a false or fraudulent claim to the federal government, or from knowingly making a false statement to avoid, decrease or conceal an obligation to pay money to the federal government. In addition, the government may assert that a claim including items or services resulting from a violation of the federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of the civil False Claims Act.

The federal Health Insurance Portability and Accountability Act of 1996 (HIPAA) created additional federal criminal statutes that prohibit, among other things, knowingly and willfully executing a scheme to defraud any healthcare benefit program, including private third-party payors and knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statement in connection with the delivery of or payment for healthcare benefits, items or services. Similar to the U.S. federal Anti-Kickback Statute, a person or entity does not need to have actual knowledge of the healthcare fraud statute implemented under HIPAA or specific intent to violate it in order to have committed a violation.

The federal Physician Payments Sunshine Act requires certain manufacturers of drugs, devices, biologics and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program, with specific exceptions, to report annually to the Centers for Medicare & Medicaid Services (CMS) information related to payments or other transfers of value made to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors), certain non-physician practitioners (physician assistants, nurse practitioners, clinical nurse specialists, certified nurse anesthetists, anesthesiology assistants and certified nurse-midwives) and teaching hospitals, and applicable manufacturers and applicable group purchasing organizations to report annually to CMS ownership and investment interests held by physicians (as defined under the statute) and their immediate family members.

Similar state and local laws and regulations may also restrict business practices in the pharmaceutical industry, such as state anti-kickback and false claims laws, which may apply to business practices, including but not limited to, research, distribution, sales and marketing arrangements and claims involving healthcare items or services reimbursed by non-governmental third-party payors, including private insurers, or by patients themselves; state laws that require pharmaceutical companies to comply with the industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government, or otherwise restrict payments that may be made to healthcare providers and other potential laws and regulations that require drug manufacturers to file reports relating to pricing and marketing information or which require tracking gifts and other remuneration and items of value provided to physicians, other healthcare providers and entities; and state and local laws that require the registration of pharmaceutical sales representatives.

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Violation of any of such laws or any other governmental regulations that apply may result in significant criminal, civil and administrative penalties including damages, fines, imprisonment, disgorgement, additional reporting requirements and oversight if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance with these laws, contractual damages, reputational harm, diminished profits and future earnings, disgorgement, exclusion from participation in government healthcare programs and the curtailment or restructuring of our operations.

U.S. Coverage and Reimbursement of Drugs

Significant uncertainty exists as to the coverage and reimbursement status of any product candidate for which we may seek regulatory approval. Sales in the United States will depend, in part, on the availability of sufficient coverage and adequate reimbursement from third-party payors, which include government health programs such as Medicare, Medicaid, TRICARE and the Veterans Administration, as well as managed care organizations and private health insurers. Prices at which we or our customers seek reimbursement for our product candidates can be subject to challenge, reduction or denial by third-party payors.

The process for determining whether a third-party payor will provide coverage for a product is typically separate from the process for setting the reimbursement rate that the payor will pay for the product. In the United States, there is no uniform policy among payors for coverage or reimbursement. Decisions regarding whether to cover any of a product, the extent of coverage and amount of reimbursement to be provided are made on a plan-by-plan basis. Third-party payors often rely upon Medicare coverage policy and payment limitations in setting their own coverage and reimbursement policies, but also have their own methods and approval processes. Therefore, coverage and reimbursement for products can differ significantly from payor to payor. As a result, the coverage determination process is often a time-consuming and costly process that can require manufacturers to provide scientific and clinical support for the use of a product to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance.

Third-party payors are increasingly challenging the price and examining the medical necessity and cost-effectiveness of medical products and services, in addition to their safety and efficacy. Adoption of price controls and cost-containment measures, and adoption of more restrictive policies in jurisdictions with existing controls and measures, could further limit sales of any product that receives approval. Third-party payors may not consider our product candidates to be medically necessary or cost-effective compared to other available therapies, or the rebate percentages required to secure favorable coverage may not yield an adequate margin over cost or may not enable us to maintain price levels sufficient to realize an appropriate return on our investment in drug development. Additionally, decreases in third-party reimbursement for any product or a decision by a third-party payor not to cover a product could reduce physician usage and patient demand for the product.

U.S. Healthcare Reform

In the United States, there have been, and continues to be, legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay marketing approval of product candidates, restrict or regulate post-approval activities, and affect the profitable sale of product candidates. Among policy makers and payors in the United States, there is significant interest in promoting changes in healthcare systems with the stated goals of containing healthcare costs, improving quality and/or expanding access. In the United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by major legislative initiatives.

By way of example, in March 2010, the Patient Protection and Affordable Care Act (ACA), was passed, which substantially changed the way healthcare is financed by both governmental and private insurers, and significantly affected the pharmaceutical and medical device industries. The ACA, among other things, increased the minimum level of Medicaid rebates payable by manufacturers of brand name drugs from 15.1% to 23.1%; extended the Medicaid rebate obligation to utilization of prescriptions of individuals enrolled in Medicaid managed care organizations; implemented a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled, infused, instilled, implanted, or injected; required manufacturers to participate in a coverage gap discount program, in which manufacturers must agree to offer point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D; imposed a non-deductible annual fee on pharmaceutical manufacturers or importers who sell certain “branded prescription drugs” to specified federal government programs; expanded eligibility criteria for Medicaid programs; creates a new Patient-Centered Outcomes Research Institute to oversee, identify priorities in, and conduct comparative clinical effectiveness research, along with funding for such research; and established a Center for Medicare and Medicaid Innovation at the CMS to test innovative payment and service delivery models to lower Medicare and Medicaid spending, potentially including prescription drug spending.

Since its enactment, there have been judicial, executive and political challenges to certain aspects of the ACA. On June 17, 2021, the U.S. Supreme Court dismissed the most recent judicial challenge to the ACA brought by several states without specifically ruling on the constitutionality of the ACA. In addition, other legislative changes have been proposed and adopted since the ACA was enacted.

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For example, on March 11, 2021, President Biden signed the American Rescue Plan Act of 2021 into law, which eliminates the statutory Medicaid drug rebate cap, currently set at 100% of a drug’s average manufacturer price, beginning January 1, 2024.

Moreover, heightened governmental scrutiny is likely to continue over the manner in which manufacturers set prices for their marketed products, which has already resulted in several Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for pharmaceutical products. On August 16, 2022, President Biden signed the Inflation Reduction Act of 2022 (IRA) into law. This statute marks the most significant action by Congress with respect to the pharmaceutical industry since adoption of the ACA in 2010. Among other things, the IRA requires manufacturers of certain drugs to engage in price negotiations with Medicare (beginning in 2026), imposes rebates under Medicare Part B and Medicare Part D to penalize price increases that outpace inflation (first due in 2023), and replaces the Part D coverage gap discount program with a new discounting program (beginning in 2025). The IRA permits the Secretary of the Department of Health and Human Services (HHS) to implement many of these provisions through guidance, as opposed to regulation, for the initial years. For that and other reasons, it is currently unclear how the IRA will be effectuated, and while the impact of the IRA on the pharmaceutical industry cannot yet be fully determined, it is likely to be significant.

Individual states in the United States have also become increasingly active in implementing regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine which drugs and suppliers will be included in their healthcare programs. Furthermore, there has been increased interest by third-party payors and governmental authorities in reference pricing systems and publication of discounts and list prices.

Foreign Regulation

In order to market any product outside of the United States, we would need to comply with numerous and varying regulatory requirements of other countries and jurisdictions regarding quality, safety and efficacy and governing, among other things, clinical trials, marketing authorization, commercial sales and distribution of our products. Whether or not we obtain FDA approval for a product, we would need to obtain the necessary approvals by the comparable foreign regulatory authorities before we can commence clinical trials or marketing of the product in foreign countries and jurisdictions. Although many of the issues discussed above with respect to the United States apply similarly in the context of the European Union (EU), the approval process varies between countries and jurisdictions and can involve additional product testing and additional administrative review periods. The time required to obtain approval in other countries and jurisdictions might differ from and be longer than that required to obtain FDA approval. Regulatory approval in one country or jurisdiction does not ensure regulatory approval in another, but a failure or delay in obtaining regulatory approval in one country or jurisdiction may negatively impact the regulatory process in others.

To market a medicinal product in the European Economic Area (EEA) (which is comprised of the 27 EU member states plus Norway, Iceland and Liechtenstein), we must obtain a Marketing Authorization (MA). There are two types of marketing authorizations:

Under the above described procedures, before granting the MA, the EMA or the competent authorities of the member states of the EEA make an assessment of the risk-benefit balance of the product on the basis of scientific criteria concerning its quality, safety and efficacy.

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Data and marketing exclusivity

In the EEA, new products authorized for marketing, or reference products, qualify for eight years of data exclusivity and an additional two years of market exclusivity upon marketing authorization. The data exclusivity period prevents generic or biosimilar applicants from relying on the preclinical and clinical trial data contained in the dossier of the reference product when applying for a generic or biosimilar marketing authorization in the EU during a period of eight years from the date on which the reference product was first authorized in the EU. The market exclusivity period prevents a successful generic or biosimilar applicant from commercializing its product in the EU until 10 years have elapsed from the initial authorization of the reference product in the EU. The 10-year market exclusivity period can be extended to a maximum of 11 years if, during the first eight years of those 10 years, the marketing authorization holder obtains an authorization for one or more new therapeutic indications which, during the scientific evaluation prior to their authorization, are held to bring a significant clinical benefit in comparison with existing therapies.

Pediatric investigation plan

In the EEA, marketing authorization applications for new medicinal products not authorized have to include the results of studies conducted in the pediatric population, in compliance with a pediatric investigation plan (PIP) agreed with the EMA’s Pediatric Committee (PDCO). The PIP sets out the timing and measures proposed to generate data to support a pediatric indication of the drug for which marketing authorization is being sought. The PDCO can grant a deferral of the obligation to implement some or all of the measures of the PIP until there are sufficient data to demonstrate the efficacy and safety of the product in adults. Further, the obligation to provide pediatric clinical trial data can be waived by the PDCO when these data is not needed or appropriate because the product is likely to be ineffective or unsafe in children, the disease or condition for which the product is intended occurs only in adult populations, or when the product does not represent a significant therapeutic benefit over existing treatments for pediatric patients. Once the marketing authorization is obtained in all EU member states and study results are included in the product information, even when negative, the product is eligible for six months’ supplementary protection certificate extension.

Clinical trials

Clinical trials of medicinal products in the EU must be conducted in accordance with EU and national regulations and the International Conference on Harmonization guidelines on GCPs as well as the applicable regulatory requirements and the ethical principles that have their origin in the Declaration of Helsinki. Additional GCP guidelines from the European Commission, focusing in particular on traceability, apply to clinical trials of ATMPs. If the sponsor of the clinical trial is not established within the EU, it must appoint an entity within the EU to act as its legal representative. The sponsor must take out a clinical trial insurance policy, and in most EU member states, the sponsor is liable to provide ‘no fault’ compensation to any study subject injured in the clinical trial.

The regulatory landscape related to clinical trials in the EU has been subject to recent changes. The EU Clinical Trials Regulation (CTR) which was adopted in April 2014 and repeals the EU Clinical Trials Directive, became applicable on January 31, 2022. Unlike directives, the CTR is directly applicable in all EU member states without the need for member states to further implement it into national law. The CTR notably harmonizes the assessment and supervision processes for clinical trials throughout the EU via a Clinical Trials Information System, which contains a centralized EU portal and database.

While the Clinical Trials Directive required a separate clinical trial application (CTA) to be submitted in each member state, to both the competent national health authority and an independent ethics committee, much like the FDA and IRB respectively, the CTR introduces a centralized process and only requires the submission of a single application to all member states concerned. The CTR allows sponsors to make a single submission to both the competent authority and an ethics committee in each member state, leading to a single decision per member state. The CTA must include, among other things, a copy of the trial protocol and an investigational medicinal product dossier containing information about the manufacture and quality of the medicinal product under investigation. The assessment procedure of the CTA has been harmonized as well, including a joint assessment by all member states concerned, and a separate assessment by each member state with respect to specific requirements related to its own territory, including ethics rules. Each member state’s decision is communicated to the sponsor via the centralized EU portal. Once the CTA is approved, clinical study development may proceed.

The CTR foresees a three-year transition period. The extent to which ongoing and new clinical trials will be governed by the CTR varies. For clinical trials whose CTA was made under the Clinical Trials Directive before January 31, 2022, the Clinical Trials Directive will continue to apply on a transitional basis for three years. Additionally, sponsors may still choose to submit a CTA under either the Clinical Trials Directive or the CTR until January 31, 2023 and, if authorized, those will be governed by the Clinical Trials Directive until January 31, 2025. By that date, all ongoing trials will become subject to the provisions of the CTR.

Medicines used in clinical trials must be manufactured in accordance with good manufacturing practice. Other national and EU-wide regulatory requirements may also apply and compliance with these requirements is subject to inspections by competent authorities of the EU member states.

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Privacy and data protection laws

Numerous state, federal and foreign laws, regulations, and standards govern the collection, use, access to, confidentiality and security of health-related and other personal information, including clinical trial data, and could apply now or in the future to our operations or the operations of our partners. In the United States, numerous federal and state laws and regulations, including data breach notification laws, health information privacy and security laws and consumer protection laws and regulations govern the collection, use, disclosure, and protection of health-related and other personal information. In addition, certain foreign laws govern the privacy and security of personal data, including health-related data. Privacy and security laws, regulations, and other obligations are constantly evolving, may conflict with each other to complicate compliance efforts, and can result in investigations, proceedings, or actions that lead to significant civil and/or criminal penalties and restrictions on data processing.

Employees

As of February 21, 2023, we had 97 full-time employees and no part-time employees. Of these employees, 71 are engaged in research and development. We consider our relationship with our employees to be good.

Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, and incentivizing our management team and our clinical, scientific and other employees and consultants. The principal purposes of our equity and cash incentive plans are to attract, retain and motivate personnel through the granting of stock-based and cash-based compensation awards, in order to align our interests and the interests of our stockholders with those of our employees and consultants.

Available Information

Our internet address is www.prometheusbiosciences.com. Our investor relations website is located at https://ir.prometheusbiosciences.com. We make available free of charge on our investor relations website under “SEC Filings” our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, our directors’ and officers’ Section 16 reports and any amendments to those reports as soon as reasonably practicable after filing or furnishing such materials to the SEC. They are also available for free on the SEC’s website at www.sec.gov.

We use our investor relations website as a means of disclosing material non-public information and for complying with our disclosure obligations under Regulation FD. Investors should monitor such website, in addition to following our press releases, SEC filings and public conference calls and webcasts. Information relating to our corporate governance is also included on our investor relations website The information in or accessible through the SEC and our website are not incorporated into, and are not considered part of, this filing.

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Item 1A. Risk Factors.

You should carefully consider the following risk factors, together with the other information contained in this Annual Report, including our financial statements and the related notes and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” before making a decision to purchase or sell shares of our common stock. We cannot assure you that any of the events discussed in the risk factors below will not occur. These risks could have a material and adverse impact on our business, results of operations, financial condition and growth prospects. If that were to happen, the trading price of our common stock could decline. Additional risks and uncertainties not presently known to us or that we currently deem immaterial also may impair our business operations or financial condition. In this section, we first provide a summary of the principal risks and uncertainties we face and then provide a full set of risk factors and discuss them in greater detail.

Summary of Risks Related to Our Business

The principal risks and uncertainties affecting our business include the following:

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Risks Related to Our Limited Operating History, Financial Position and Capital Requirements

We have a limited operating history, have incurred significant operating losses since our inception and expect to incur significant losses for the foreseeable future. We may not be able to generate sufficient revenue to achieve and maintain profitability.

The development of product candidates, including therapeutic product candidates and diagnostic tests, is a highly speculative undertaking and involves a substantial degree of risk. We are in the early stages of our development efforts and have only two product candidates, PRA023 and PRA052, in clinical development. We commenced operations in 2016, and to date, we have focused primarily on organizing and staffing our company, business planning, raising capital, developing Prometheus360, discovering and identifying product candidates, establishing our intellectual property portfolio and conducting research and preclinical studies. Our approach to the discovery and development of product candidates based on Prometheus360 is unproven, and we do not know whether we will be able to develop any product candidates that succeed in clinical development or products of commercial value. As an organization, we have not yet successfully developed and validated a diagnostic test, obtained regulatory approvals, manufactured a commercial-scale product, or arranged for a third party to do so on our behalf, or conducted sales and marketing activities necessary for successful product commercialization. Consequently, any predictions made about our future success or viability may not be as accurate as they could be if we had a history of successfully developing and commercializing therapeutic products or diagnostics.

To date, we have only generated revenue from our diagnostic services business, Prometheus Laboratories, Inc. (PLI), which we acquired from Nestlé on June 30, 2019 and spun-off in December 2020, a co-development and manufacturing agreement (the Falk Agreement) with Dr. Falk Pharma GmbH (Falk) and a collaboration agreement with Millennium Pharmaceuticals, Inc., a subsidiary of Takeda Pharmaceutical Company Limited (the Takeda Agreement). We have incurred significant operating losses since our inception. We do not have any product candidates approved for sale, and we may never generate any significant revenue from product sales. Our net losses, including those generated from PLI, were $141.8 million, $90.2 million, and $37.1 million for the years ended December 31, 2022, 2021, and 2020, respectively. As of December 31, 2022, we had an accumulated deficit of $331.1 million. Substantially all of our losses have resulted from expenses incurred in connection with our research and development programs and from general and administrative costs associated with our operations. All of our development programs will require substantial additional development time and resources before we would be able to apply for or receive regulatory approvals and begin generating revenue from product sales. We expect to continue to incur losses for the foreseeable future, and we anticipate these losses will increase substantially as we continue our development of, seek regulatory approval for, and potentially commercialize any of our therapeutic product candidates and diagnostic candidates.

To become and remain profitable, we must succeed in developing and eventually commercializing products that generate significant revenue. This will require us to be successful in a range of challenging activities, including completing preclinical studies and clinical trials of our product candidates, identifying lead product candidates, discovering additional product candidates, obtaining regulatory approval for these product candidates and manufacturing, marketing and selling any products for which we may obtain regulatory approval. We are only in the preliminary stages of most of these activities. We may never succeed in these activities and, even if we do, may never generate revenues that are significant enough to achieve profitability. In addition, we have not yet demonstrated an ability to successfully overcome many of the risks and uncertainties frequently encountered by companies in new and rapidly evolving fields, particularly in the biotechnology industry. Because of the numerous risks and uncertainties associated with biopharmaceutical and diagnostic product development, we are unable to accurately predict the timing or amount of increased expenses or when, or if, we will be able to achieve profitability. Even if we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable may have an adverse effect on the value of our company and could impair our ability to raise capital, expand our business, maintain our research and development efforts, diversify our product candidates or even continue our operations. A decline in the value of our company could also cause you to lose all or part of your investment.

We will require substantial additional financing to achieve our goals, and a failure to obtain this necessary capital when needed on acceptable terms, or at all, could force us to delay, limit, reduce or terminate our development programs, commercialization efforts or other operations.

The development of therapeutic product candidates and diagnostic candidates is capital-intensive. We expect our expenses to increase in connection with our ongoing activities, particularly as we conduct our ongoing and planned clinical trials for PRA023, ongoing and planned preclinical and clinical trials for PRA052, and ongoing and planned preclinical trials for our other therapeutic product candidates and diagnostic candidates, and seek regulatory approval for our current therapeutic product candidates and diagnostic candidates and any future therapeutic product candidates and diagnostic candidates we may develop. If we obtain regulatory approval for any of our therapeutic product candidates or diagnostic candidates, we also expect to incur significant commercialization expenses related to product manufacturing, marketing, sales and distribution. Because the outcome of any preclinical study or clinical trial is highly uncertain, we cannot reasonably estimate the actual amounts necessary to successfully complete the development and

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commercialization of our therapeutic product candidates or diagnostic candidates. Furthermore, we expect to continue to incur additional costs associated with operating as a public company. Accordingly, we will need to obtain substantial additional funding in connection with our continuing operations. If we are unable to raise capital when needed or on attractive terms, we could be forced to delay, reduce or eliminate our research and development programs or any future commercialization efforts.

We believe our existing cash and cash equivalents, will enable us to fund our operations for at least the next 12 months. We have based these estimates on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect. Our operating plans and other demands on our cash resources may change as a result of many factors currently unknown to us, and we may need to seek additional funds sooner than planned, through public or private equity (including through our Open Market Sale Agreement) or debt financings or other capital sources, including potentially additional collaborations, licenses and other similar arrangements. In addition, we may seek additional capital due to favorable market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. Attempting to secure additional financing may divert our management from our day-to-day activities, which may adversely affect our ability to develop our product candidates.

Our future capital requirements will depend on many factors, including, but not limited to:

Identifying potential product candidates and conducting preclinical studies and clinical trials is a time consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to obtain regulatory approval and commercialize our therapeutic product candidates and diagnostic candidates. In addition, our product candidates, if approved, may not achieve commercial success. Our therapeutic commercial revenues, if any, will be derived from sales of products that we do not expect to be commercially available for many years, if at all.

Accordingly, we will need to continue to rely on additional financing to achieve our business objectives. Adequate additional financing may not be available to us on acceptable terms, or at all.

Raising additional capital may cause dilution to our stockholders, restrict our operations or require us to relinquish rights to our technologies, product candidates or testing products.

Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs through equity offerings, debt financings, or other capital sources, including potential additional collaborations, licenses and other similar arrangements. To the extent that we raise additional capital through the sale of equity or convertible debt securities, your ownership interest will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect your rights as a common stockholder. Any future debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, selling or licensing our assets,

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making capital expenditures, declaring dividends or encumbering our assets to secure future indebtedness. Such restrictions could adversely impact our ability to conduct our operations and execute our business plan.

If we raise additional funds through future collaborations, licenses and other similar arrangements, we may have to relinquish valuable rights to our future revenue streams, research programs, product candidates, Prometheus360 or diagnostic candidates, or grant licenses on terms that may not be favorable to us and/or that may reduce the value of our common stock. If we are unable to raise additional funds through equity or debt financings or other arrangements when needed or on terms acceptable to us, we would be required to delay, limit, reduce, or terminate our product development or future commercialization efforts or grant rights to develop and market product candidates or testing products that we would otherwise prefer to develop and market ourselves.

Risks Related to the Discovery, Development and Regulatory Approval of Our Product Candidates, including our Therapeutic Product Candidates and Diagnostic Candidates

Our approach to the discovery and development of precision medicines based on Prometheus360 is unproven, and we do not know whether we will be able to develop any therapeutics or diagnostic products of commercial value, or if competing technological approaches will limit the commercial value of our therapeutic product candidates and diagnostic candidates or render Prometheus360 obsolete.

We have concentrated our therapeutic product research and development efforts on the application of precision medicine to the treatment and diagnosis of IBD and other immune-mediated diseases, and our future success depends on the successful development of products based on Prometheus360 and the continued development of this platform. However, neither we nor any other company has received regulatory approval to market therapeutics targeting specific subpopulations of IBD patients. The success of our business depends primarily upon our ability to identify, develop and commercialize precision medicine products based on Prometheus360, which leverages a novel and unproven approach of applying data analytics and machine learning to the thousands of samples available to us through the biobank we license from Cedars-Sinai. We have not yet succeeded and may not succeed in demonstrating safety and efficacy for any product candidates in clinical trials or in obtaining marketing approval thereafter. Our research methodology and novel approach to precision medicine for IBD and other immune-mediated diseases may be unsuccessful in identifying additional therapeutic product candidates, and any therapeutic product candidates discovered using Prometheus360 may be shown to have harmful side effects or may have other characteristics that may necessitate additional clinical testing, or make the therapeutic product candidates unmarketable or unlikely to receive marketing approval. Further, because all of our therapeutic product candidates and development programs utilize Prometheus360, adverse developments with respect to one of our programs may have a significant adverse impact on the actual or perceived likelihood of success and value of our other programs.

In addition, the biotechnology and biopharmaceutical industries are characterized by rapidly advancing technologies. Our future success will depend in part on our ability to maintain a competitive position with Prometheus360, which relies on our ability to access the biobank owned and controlled by Cedars-Sinai as well as to maintain our exclusive license with Cedars-Sinai. If access to the biobank is lost or limited, it may materially and adversely affect our ability to create and develop therapeutic product candidates and diagnostic candidates and to compete effectively. Our competitors may render our approach obsolete, or limit the commercial value of our therapeutic product candidates and diagnostic candidates, by advances in existing technological approaches or the development of new or different approaches, potentially eliminating the advantages in our drug discovery process that we believe we derive from our research approach and proprietary technologies. By contrast, adverse developments with respect to other companies that attempt to use a similar approach to our approach may adversely impact the actual or perceived value of Prometheus360 and potential of our product candidates. If any of these events occur, we may be forced to abandon our development efforts for a program or programs, which would have a material adverse effect on our business and could potentially cause us to cease operations.

We are early in our development efforts and have only two product candidates in clinical development. All of our other development programs are in the preclinical or discovery stage. If we are unable to successfully develop, obtain regulatory approval for and ultimately commercialize therapeutic product candidates and related diagnostic candidates, or experience significant delays in doing so, our business will be materially harmed.

We are in the early stages of our development efforts and have only two product candidates, PRA023 and PRA052, in clinical development. All of our other development programs are in the preclinical or drug discovery stage. We have invested substantially all of our efforts in developing Prometheus360, identifying potential therapeutic product candidates and conducting clinical trials and preclinical studies. Although PRA023 and PRA052 have entered clinical trials, we will need to progress our other development programs through IND-enabling studies and receive authorization from the Food and Drug Administration (FDA) to proceed under an IND prior to initiating their clinical development. Our ability to generate therapeutic product revenues, which we do not expect will occur for many years, if ever, will depend heavily on the successful development and eventual commercialization of our product candidates.

In addition, our therapeutic development programs contemplate the development of diagnostics that are designed to provide additional insight into our target patient populations. Diagnostics are subject to regulation as medical devices and must themselves be authorized for marketing by the FDA or certain other foreign regulatory agencies before we may commercialize our diagnostic candidates.

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The success of our therapeutic product candidates will depend on several factors, including the following:

If we are unable to develop, obtain regulatory approval for, or, if approved, successfully commercialize our therapeutic product candidates or diagnostic candidates, we may not be able to generate sufficient revenue to continue our business.

Preclinical and clinical development involves a lengthy and expensive process with an uncertain outcome, and the results of preclinical studies and early clinical trials are not necessarily predictive of future results. Our product candidates may not achieve favorable results in preclinical studies or clinical trials or receive regulatory approval on a timely basis, if at all.

Preclinical and clinical development is expensive and can take many years to complete, and its outcome is inherently uncertain. We cannot guarantee that any preclinical studies or clinical trials will be conducted as planned or completed on schedule, if at all, and failure can occur at any time during the preclinical study or clinical trial process. Despite promising preclinical or clinical results, any product candidate can unexpectedly fail at any stage of preclinical or clinical development. The historical failure rate for product candidates in our industry is high.

The results from preclinical studies or clinical trials of a product candidate may not predict the results of later clinical trials of the product candidate, and interim, topline, or preliminary results of a clinical trial are not necessarily indicative of final results. Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy characteristics despite having progressed through preclinical studies and initial clinical trials. In particular, while we have conducted certain preclinical and clinical studies of PRA023 and preclinical studies of PRA052 and other potential product candidates targeting IBD, we do not know whether PRA023, PRA052 or the other potential product candidates will perform in future clinical trials as they have performed in these prior studies. The positive results we have observed for PRA023 in our Phase 2 and earlier clinical trials and preclinical animal models may not be predictive of our ongoing and future clinical trials in UC, CD or SSc-ILD or future trials of PRA023 in these or other indications.

It is not uncommon to observe results in clinical trials that are unexpected based on preclinical studies and early clinical trials, and many product candidates fail in clinical trials despite very promising early results. Moreover, preclinical and clinical data may be susceptible to varying interpretations and analyses. A number of companies in the biopharmaceutical and biotechnology industries have suffered significant setbacks in clinical development even after achieving promising results in earlier studies. Such setbacks have occurred and may occur for many reasons, including, but not limited to: clinical sites and investigators may deviate from clinical trial

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protocols, whether due to lack of training or otherwise, and we may fail to detect any such deviations in a timely manner; patients may fail to adhere to any required clinical trial procedures, including any requirements for post-treatment follow-up; our product candidates may fail to demonstrate effectiveness or safety in certain patient subpopulations, which has not been observed in earlier trials due to limited sample size, lack of analysis or otherwise; or our clinical trials may not adequately represent the patient populations we intend to treat, whether due to limitations in our trial designs or otherwise, such as where one patient subgroup is overrepresented in the clinical trial. There can be no assurance that we will not suffer similar setbacks despite the data we observed in earlier or ongoing studies. Based upon negative or inconclusive results, we or any future collaborator may decide, or regulators may require us, to conduct additional preclinical studies or clinical trials, which would cause us to incur additional operating expenses and delays and may not be sufficient to support regulatory approval on a timely basis or at all.

For the foregoing reasons, we cannot be certain that any of our ongoing and planned clinical trials will be successful.

Any difficulties or delays in the commencement or completion, or termination or suspension, of our ongoing or planned clinical trials could result in increased costs to us, delay or limit our ability to generate revenue and adversely affect our commercial prospects.

Before obtaining marketing approval from regulatory authorities for the sale of PRA023, PRA052 or any future product candidates, we must conduct extensive clinical trials to demonstrate the safety and efficacy of the product candidates in humans. Before we can initiate clinical trials for any future product candidates, we must submit the results of preclinical studies to the FDA or comparable foreign regulatory authorities along with other information, including information about product candidate chemistry, manufacturing and controls and our proposed clinical trial protocol, as part of an IND or, in the case of a diagnostic candidate, an investigational device exemption (IDE) application or similar regulatory filing required for authorization to proceed with clinical development. The FDA or comparable foreign regulatory authorities may require us to conduct additional preclinical studies for any product candidate before it allows us to initiate clinical trials under any IND, IDE, or similar regulatory filing, which may lead to delays and increase the costs of our preclinical development programs. Moreover, even if we commence clinical trials, issues may arise that could cause regulatory authorities to suspend or terminate such clinical trials. Any such delays in the commencement or completion of our ongoing or planned clinical trials for PRA023, PRA052 or any other product candidate could significantly affect our product development timelines and product development costs.

We do not know whether our planned and ongoing trials will begin on time or be completed on schedule, if at all. The commencement, data readouts and completion of clinical trials can be delayed for a number of reasons, including delays related to:

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We could encounter delays if a clinical trial is suspended or terminated by us, by the IRBs of the institutions in which such trials are being conducted, by a Data Safety Monitoring Board for such trial or by the FDA or comparable foreign regulatory authorities. Such authorities may impose such a suspension or termination due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA or comparable foreign regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a drug or diagnostic, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial. In addition, changes in regulatory requirements and policies may occur, and we may need to amend clinical trial protocols to comply with these changes. Amendments may require us to resubmit our clinical trial protocols to IRBs for reexamination, which may impact the costs, timing or successful completion of a clinical trial.

Further, conducting clinical trials in foreign countries presents additional risks that may delay completion of our clinical trials. These risks include the failure of enrolled patients in foreign countries to adhere to clinical protocol as a result of differences in healthcare services or cultural customs, managing additional administrative burdens associated with foreign regulatory schemes, as well as political and economic risks, including war, relevant to such foreign countries. This could hinder the completion of our clinical trials and/or analyses of clinical results, which could materially harm our business.

Moreover, principal investigators for our clinical trials may serve as scientific advisors or consultants to us from time to time and receive compensation in connection with such services. Under certain circumstances, we may be required to report some of these relationships to the FDA or comparable foreign regulatory authorities. The FDA or comparable foreign regulatory authority may conclude that a financial relationship between us and a principal investigator has created a conflict of interest or otherwise affected interpretation of the study. The FDA or comparable foreign regulatory authority may therefore question the integrity of the data generated at the applicable clinical trial site and the utility of the clinical trial itself may be jeopardized. This could result in a delay in approval, or rejection, of our marketing applications by the FDA or comparable foreign regulatory authority, as the case may be, and may ultimately lead to the denial of marketing approval of one or more of our product candidates.

If we experience delays in the completion of, or termination of, any clinical trial of our product candidates, the commercial prospects of our product candidates will be harmed, and our ability to generate product revenues from any of these product candidates will be delayed. Any delays in completing our clinical trials will increase our costs, slow down our product candidate development and approval process and jeopardize our ability to commence product sales and generate revenues. Such delays could also shorten any period during which we may have the exclusive right to commercialize our product candidates and our competitors may be able to bring products to market before we do, and the commercial viability of our product candidates could be significantly reduced. In addition, many of the factors that cause, or lead to, the termination or suspension of, or a delay in the commencement or completion of, clinical trials may also ultimately lead to the denial of regulatory approval of a product candidate. Any of these occurrences may harm our business, financial condition and prospects significantly.

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We may find it difficult to enroll patients in our clinical trials. If we encounter difficulties enrolling subjects in our clinical trials, our clinical development activities could be delayed or otherwise adversely affected.

Patient enrollment is a significant factor in the timing of clinical trials, and the timing of our clinical trials depends, in part, on the speed at which we can recruit patients to participate in our trials, as well as completion of required follow-up periods. We may not be able to initiate or continue clinical trials for our product candidates if we are unable to identify and enroll a sufficient number of eligible patients to participate in these trials as required by the FDA or similar regulatory authorities outside the United States. Subject enrollment is affected by many factors including the size and nature of the patient population, the severity of the disease under investigation, the availability and efficacy of approved drugs and diagnostics for the disease under investigation, the proximity of patients to clinical sites, the eligibility and exclusion criteria for the trial, the design of the clinical trial, the risk that enrolled patients will not complete a clinical trial, our ability to recruit clinical trial investigators with the appropriate competencies and experience, patient referral practices of physicians, the ability to monitor patients adequately during and after treatment, competing clinical trials and clinicians’ and patients’ perceptions as to the potential advantages and risks of the product candidate being studied in relation to other available therapies, including any new products that may be approved for the indications we are investigating as well as any product candidates under development.

We will be required to identify and enroll a sufficient number of subjects for each of our clinical trials. Utilizing our precision medicine approach, we may focus our development activities on genetically or biomarker defined patients that we believe will be most likely to respond to our therapeutic product candidates. As a result, the potential patient populations for our clinical trials may be narrowed, and we may experience difficulties in identifying and enrolling a sufficient number of patients in our clinical trials. We may not be able to initiate or continue clinical trials if we are unable to locate a sufficient number of eligible subjects to participate in the clinical trials required by the FDA or comparable foreign regulatory authorities.

Other pharmaceutical or biotechnology companies targeting the same diseases as our therapeutic product candidates are recruiting clinical trial patients from these patient populations, which may make it more difficult to fully enroll our clinical trials. Our inability to enroll a sufficient number of subjects for any of our future clinical trials would result in significant delays or may require us to abandon one or more clinical trials altogether. In addition, the process of finding and diagnosing subjects may prove costly.

Moreover, we rely on CROs and clinical trial sites to ensure proper and timely conduct of our clinical trials and, while we intend to enter into agreements governing their services, we will have limited influence over their actual performance. We cannot assure you that our assumptions used in determining expected clinical trial timelines are correct or that we will not experience delays in enrollment, which would result in the delay of completion of such trials beyond our expected timelines.

Use of our therapeutic product candidates could be associated with side effects, adverse events or other properties or safety risks, which could delay or preclude approval, cause us to suspend or discontinue clinical trials, abandon a therapeutic product candidate, limit the commercial profile of an approved label or result in other significant negative consequences that could severely harm our business, prospects, operating results and financial condition.

As is the case with biopharmaceuticals generally, it is likely that there may be side effects and adverse events associated with our therapeutic product candidates’ use. Results of our clinical trials could reveal a high and unacceptable severity and prevalence of side effects or unexpected characteristics. Undesirable side effects caused by our therapeutic product candidates could cause us or regulatory authorities to interrupt, delay or halt clinical trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or comparable foreign regulatory authorities. The drug-related side effects could affect patient recruitment or the ability of enrolled patients to complete the trial or result in potential product liability claims. Any of these occurrences may harm our business, financial condition and prospects significantly.

Moreover, if our therapeutic product candidates are associated with undesirable side effects in clinical trials or have characteristics that are unexpected, we may elect to abandon their development or limit their development to more narrow uses or subpopulations in which the undesirable side effects or other characteristics are less prevalent, less severe or more acceptable from a risk-benefit perspective, which may limit the commercial expectations for the therapeutic product candidate, if approved. We may also be required to modify our study plans based on findings after we commence our clinical trials. Many compounds that initially showed promise in early-stage testing have later been found to cause side effects that prevented further development of the compound. In addition, regulatory authorities may draw different conclusions or require additional testing to confirm these determinations.

It is possible that as we test our therapeutic product candidates in larger, longer and more extensive clinical trials, or as the use of these therapeutic product candidates becomes more widespread if they receive regulatory approval, illnesses, injuries, discomforts and other adverse events that were observed in earlier trials, as well as conditions that did not occur or went undetected in previous trials, may be reported by subjects. If such side effects become known later in development or upon approval, if any, such findings may harm our business, financial condition and prospects significantly.

Patients treated with our products, if approved, may experience previously unreported adverse reactions, and it is possible that the FDA or other regulatory authorities may ask for additional safety data as a condition of, or in connection with, our efforts to obtain

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approval of our therapeutic product candidates. In addition, a number of potentially significant negative consequences could result, including:

Any of these events could prevent us from achieving or maintaining market acceptance of a particular therapeutic product candidate, if approved, and could significantly harm our business, results of operations and prospects.

As an organization, we have never completed any late-stage clinical trials or submitted an application for regulatory approval, and may be unable to do so for any of our product candidates.

We are early in our development efforts and will need to successfully complete later-stage and pivotal clinical trials in order to obtain FDA or comparable foreign regulatory approval to market PRA023, PRA052 or any other therapeutic product candidates. Carrying out clinical trials and the submission of a successful BLA or NDA is a complicated process. As an organization, we have not completed a Phase 3 registrational program, have limited experience as a company in preparing, submitting and prosecuting regulatory filings, and have not submitted a BLA or NDA or other comparable foreign regulatory submission for any therapeutic product candidate. In addition, we have had limited interactions with the FDA and cannot be certain how many clinical trials of PRA023 or any other product candidates will be required or how such trials should be designed. For instance, in 2023, we plan to meet with the FDA and foreign regulatory authorities regarding the design of our pivotal Phase 3 programs for PRA023 in UC and CD, and these regulatory authorities may recommend changes to our proposed study designs, including the number and size of registrational clinical trials required to be conducted in our Phase 3 programs. Consequently, we may be unable to successfully and efficiently execute and complete necessary clinical trials in a way that leads to regulatory submission and approval of PRA023 or any of our other therapeutic product candidates. We may require more time and incur greater costs than our competitors and may not succeed in obtaining regulatory approvals of therapeutic product candidates that we develop. Failure to commence or complete, or delays in, our ongoing or planned clinical trials, could prevent us from or delay us in submitting BLAs or NDAs for and commercializing our therapeutic product candidates.

Changes in methods of product candidate manufacturing or formulation may result in additional costs or delay.

As product candidates progress through clinical trials to marketing approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods and formulation, are altered along the way in an effort to optimize safety, efficacy, stability, purity, yield and manufacturing batch size, minimize costs and achieve consistent quality and results. Such changes carry the risk that they will not achieve these intended objectives and/or may lead to delays and additional costs. Additionally, any changes we may make to our product candidates may cause such candidates to perform differently than in prior clinical trials, or could negatively affect our ability to utilize or interpret our existing data. Such changes could delay initiation or completion of clinical trials, lead to negative trial results, require the conduct of bridging studies or clinical trials or the repetition of one or more studies or clinical trials, increase development costs, delay potential regulatory approval and jeopardize our ability to commercialize our product candidates or generate revenue. We may also make formulation or manufacturing changes to our product candidates, in which case we may need to conduct additional preclinical or clinical studies to bridge our modified product candidates to earlier versions. For example, we completed a bridging study of a 200 mg/ml subcutaneous formulation of PRA023 in Caucasian normal healthy volunteers to facilitate the implementation of an auto-injector in potential future registrational studies of PRA023. While we do not expect that further bridging studies will be required before we can commence such registrational studies, any additional required studies could delay the development of PRA023 and increase our development costs.

Our product candidates are subject to extensive regulation and compliance, which is costly and time consuming, and such regulation may cause unanticipated delays or prevent the receipt of the required approvals to commercialize our product candidates.

The clinical development, manufacturing, labeling, packaging, storage, record-keeping, advertising, promotion, import, export, marketing, distribution and adverse event reporting, including the submission of safety and other information, of our product candidates are subject to extensive regulation by the FDA in the United States and by comparable foreign regulatory authorities in

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foreign markets. In the United States, we are not permitted to market our product candidates until we receive regulatory approval from the FDA. The process of obtaining regulatory approval is expensive, often takes many years following the commencement of clinical trials and can vary substantially based upon the type, complexity and novelty of the product candidates involved, as well as the target indications and patient population. Approval policies or regulations may change, and the FDA has substantial discretion in the drug approval process, including the ability to delay, limit or deny approval of a product candidate for many reasons. Despite the time and expense invested in clinical development of product candidates, regulatory approval is never guaranteed. Neither we nor any current or future collaborator is permitted to market any of our product candidates in the United States until we receive approval from the FDA.

Prior to obtaining approval to commercialize a product candidate in the United States or abroad, we or our collaborators must demonstrate with substantial evidence from adequate and well-controlled clinical trials, and to the satisfaction of the FDA or comparable foreign regulatory authorities, that such product candidates are safe and effective, or with respect to a biological product candidate, safe, pure and potent, for their intended uses. Results from preclinical studies and clinical trials can be interpreted in different ways. Even if we believe the preclinical or clinical data for our product candidates are promising, such data may not be sufficient to support approval by the FDA and comparable foreign regulatory authorities. The FDA or comparable foreign regulatory authorities, as the case may be, may also require us to conduct additional preclinical studies or clinical trials for our product candidates either prior to or post-approval, or may object to elements of our clinical development program.

The FDA or comparable foreign regulatory authorities can delay, limit or deny approval of a product candidate for many reasons, including:

This lengthy approval process, as well as the unpredictability of the results of clinical trials, may result in our failing to obtain regulatory approval to market any of our product candidates, which would significantly harm our business, results of operations and prospects. In addition, even if we obtain approval of our product candidates, regulatory authorities may approve any of our product candidates for fewer or more limited indications than we request, may impose significant limitations in the form of narrow indications, warnings, or a Risk Evaluation and Mitigation Strategy (REMS).

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In addition, with respect to foreign markets, approval procedures vary among countries and, in addition to the foregoing risks, may involve additional product testing, administrative review periods and agreements with pricing authorities. In addition, events raising questions about the safety of certain marketed biopharmaceuticals may result in increased cautiousness by the FDA and comparable foreign regulatory authorities in reviewing new drugs or biologics based on safety, efficacy or other regulatory considerations and may result in significant delays in obtaining regulatory approvals. Any delay in obtaining, or inability to obtain, applicable regulatory approvals would prevent us or any of our potential future collaborators from commercializing our product candidates.

Additional time may be required to obtain marketing authorizations for any of our product candidates that we develop as combination products.

We are developing an auto-injector device designed to be used in combination with PRA023. We anticipate that, if this auto-injector is successfully developed and implemented in our clinical studies, PRA023 would be regulated as a combination product by the FDA and other regulatory authorities. Combination products require coordination within the FDA and within comparable regulatory agencies for review of their drug and device components. For example, the FDA’s review of a marketing application for PRA023 may include the participation of both the FDA’s Center for Drug Evaluation and Research and the FDA’s Center for Devices and Radiological Health. Although the FDA and comparable foreign agencies have or may have systems in place for the review and approval of combination products, we may experience additional delays in the development and commercialization of such product candidates due to regulatory timing constraints and uncertainties in the product development and approval process. Moreover, although we anticipate that the device component of any combination product candidates we develop will be reviewed within the usual time frames expected for the underlying drug component application, and that no separate marketing application for the device components of such product candidates will be required in the United States, the FDA or comparable regulatory authorities may delay approval or require us to conduct additional studies with the auto-injector which may delay the approval of the combination product.

If we are unable to successfully develop companion or complementary diagnostics for our therapeutic product candidates, or experience significant delays in doing so, our therapeutic development strategy may be harmed and we may not realize the full commercial potential of our therapeutic product candidates.

Because we are focused on precision medicine, in which genetic alterations or predictive biomarkers will be used to identify the right patients for our product candidates, we believe that our success will depend, in part, on our ability to develop diagnostics for use with our therapeutic product candidates. Although we currently plan to focus our PRA023 diagnostic development program on so-called complementary diagnostics, which are generally not required for the safe and effective use of a therapeutic product candidate, but may aid in treatment decisions, it is possible that our development program for PRA023 or other product candidates will require us to develop and commercialize a companion diagnostic. Companion diagnostics are developed in conjunction with clinical programs for the associated product and are subject to regulation as medical devices by the FDA and comparable regulatory authorities. In general, if the FDA determines that a companion diagnostic is essential to the safe and effective use of a novel therapeutic product or indication, the FDA will generally not approve the therapeutic product if the companion diagnostic is not also approved or cleared for that indication. Accordingly, the FDA expects to review and approve simultaneously the NDA or BLA and PMA submissions for a therapeutic and its companion diagnostic, respectively, so any delay in diagnostic approval could delay or prevent approval of the therapeutic product. The approval of a companion diagnostic as part of the product label will also limit the use of the therapeutic product candidate to only those patients who express the specific genetic alteration or biomarker it was developed to detect. Also, to the extent other approved diagnostics are able to broaden their labeling claims to include our approved therapeutic products, if any, we may be forced to abandon our companion diagnostic development plans or we may not be able to compete effectively upon approval, which could adversely impact our ability to generate revenue from the sale of our approved products and our business operations.

In addition, it may be necessary to resolve issues such as selectivity/specificity, analytical validation, reproducibility, or clinical validation of companion diagnostics during the development and regulatory approval processes. Moreover, even if data from preclinical studies and early clinical trials appear to support development of a companion diagnostic for a therapeutic product candidate, data generated in later clinical trials may fail to support the analytical and clinical validation of the companion diagnostic. If we are required to develop companion diagnostics for use with our therapeutic product candidates, we may encounter difficulties in developing, obtaining regulatory approval for, manufacturing and commercializing companion diagnostics similar to those we face with respect to our therapeutic product candidates themselves, including issues with achieving regulatory clearance or approval, production of sufficient quantities at commercial scale and with appropriate quality standards, and in gaining market acceptance.

If we or any third parties we may engage are unable to successfully develop companion diagnostics for our therapeutic product candidates, or experience delays in doing so:

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As a result of any of these events, our business, financial condition, results of operations and prospects could be materially and adversely affected.

We have limited experience in developing and commercializing diagnostics and have never applied for or obtained regulatory clearance or approval for any diagnostic tests.

To be successful in developing and commercializing therapeutic product candidates in combination with diagnostic candidates, we will need to address a number of scientific, technical, regulatory and logistical challenges. We currently anticipate that we or a collaborator will need to obtain marketing authorization from the FDA in order to legally market such diagnostics in the United States. As a company, we have little experience in the development of diagnostic tests and may not be successful in developing appropriate diagnostics to pair with any of our therapeutic product candidates that receive marketing approval, and have never applied for or obtained regulatory clearance or approval of any such diagnostic tests. Given our limited experience in developing diagnostic tests, we may rely in part or in whole on third parties for their design, development and manufacture of such tests.

Before a new medical device, or a new intended use of, claim for, or significant modification to an existing device, can be marketed in the United States, a company must first submit an application for and receive 510(k) clearance pursuant to a premarket notification submitted under Section 510(k) of the Federal Food, Drug, and Cosmetic Act (FDCA), de-novo classification, or PMA approval from FDA, unless an exemption applies. The PMA approval pathway, which we expect to pursue for our companion diagnostic product candidates, requires an applicant to demonstrate the safety and effectiveness of the product based, in part, on valid scientific evidence, including, but not limited to, technical, preclinical, and clinical data. The 510(k) pathway requires a FDA finding that the test is substantially equivalent to a legally marketed predicate device. If no legally marketed predicate can be identified to enable use of the 510(k) pathway, the device is automatically classified under the FDCA into Class III, which generally requires PMA approval. However, for low- to moderate-risk novel devices, FDA allows for the possibility of marketing authorization through the “de novo classification” process rather than requiring the device to be subject to PMA approval. Products that are approved through a PMA application generally need prior FDA approval before modifications can be made that affect safety or effectiveness, and certain modifications to a 510(k)-cleared device may also require FDA premarket review before the modified product can be marketed. If we are unable to successfully develop, obtain regulatory clearance for and commercialize diagnostics to pair with our therapeutic product candidates, it could adversely impact our ability to develop and generate revenue from our product candidates.

We may expend our limited resources to pursue a particular product candidate and fail to capitalize on product candidates or indications that may be more profitable or for which there is a greater likelihood of success.

Because we have limited financial and managerial resources, we focus on specific product candidates and specific indications. As a result, we may forgo or delay pursuit of opportunities with other product candidates that could have had greater commercial potential. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs and product candidates for specific indications may not yield any commercially viable product candidates. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through collaborations, licenses and other similar arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate.

We intend to conduct certain of our clinical trials globally. However, the FDA and other foreign equivalents may not accept data from such trials, in which case our development plans will be delayed, which could materially harm our business.

We intend to conduct certain of our future clinical trials globally. The acceptance of study data from clinical trials conducted outside the United States or another jurisdiction by the FDA or comparable foreign regulatory authority may be subject to certain conditions or may not be accepted at all. In cases where data from foreign clinical trials are intended to serve as the sole basis for marketing approval in the United States, the FDA will generally not approve the application on the basis of foreign data alone unless (i) the data are applicable to the U.S. population and U.S. medical practice; (ii) the trials were performed by clinical investigators of recognized competence and pursuant to GCP regulations; and (iii) the data may be considered valid without the need for an on-site inspection by the FDA, or if the FDA considers such inspection to be necessary, the FDA is able to validate the data through an on-site inspection or other appropriate means. In addition, even where the foreign study data are not intended to serve as the sole basis for approval, the FDA will not accept the data as support for an application for marketing approval unless the study is well-designed and well-conducted in accordance with GCP requirements and the FDA is able to validate the data from the study through an onsite inspection if deemed necessary. Many foreign regulatory authorities have similar approval requirements. In addition, such foreign trials would be subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. There can be no assurance that the FDA or any comparable foreign regulatory authority will accept data from trials conducted outside of the United States or the applicable jurisdiction. If the FDA or any comparable foreign regulatory authority does not accept such data, it would result in the need for additional trials, which could be costly and time-consuming, and which may result in current or future product candidates that we may develop not receiving approval for commercialization in the applicable jurisdiction.

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Conducting clinical trials outside the United States also exposes us to additional risks, including risks associated with:

For instance, as a result of Russia’s invasion of Ukraine in February 2022, the United States and its European allies have imposed significant sanctions against Russia, including regional embargoes, full blocking sanctions, and other restrictions targeting major Russian financial institutions. Our ability to conduct future clinical trials in Russia, parts of Ukraine and elsewhere in the region is restricted under applicable sanctions laws, which may require us to identify alternative trial sites, which may increase our development costs and delay the clinical development of our product candidates. All of the foregoing could impede the execution of our clinical development plans, which could materially harm our business.

Interim, topline and preliminary data from our preclinical studies and clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data.

From time to time, we may publicly disclose interim, preliminary or topline data from our preclinical studies and clinical trials, which is based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the particular trial. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. As a result, the interim, preliminary or topline results that we report may differ from future results of the same trials, or different conclusions or considerations may qualify such results, once additional data have been received and fully evaluated. Topline and preliminary data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously published. As a result, topline and preliminary data should be viewed with caution until the final data are available.

From time to time, we may also disclose interim data from our clinical studies. Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available or as patients from our clinical trials continue other treatments for their disease. Adverse differences between preliminary, topline or interim data and final data could significantly harm our business prospects. In addition, disclosure of interim data by us or by our competitors could result in volatility in the price of our common stock.

Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and the value of our company in general. In addition, the information we choose to publicly disclose regarding a particular study or clinical trial is based on what is typically extensive information, and you or others may not agree with what we determine is the material or otherwise appropriate information to include in our disclosure, and any information we determine not to disclose may ultimately be deemed significant with respect to future decisions, conclusions, views, activities or otherwise regarding a particular product, product candidate or our business. If the topline data that we report differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize, our product candidates may be harmed, which could harm our business, operating results, prospects or financial condition.

Fast Track designation by the FDA for PRA023 or our other product candidates may not actually lead to a faster development or regulatory review or approval process.

We have been granted a fast track designation for PRA023 by the FDA for the treatment of SSc-ILD and may seek fast track designations for our other product candidates. The fast track program is intended to expedite or facilitate the process for reviewing new product candidates that meet certain criteria. Specifically, new drugs and biologics are eligible for fast track designation if they are intended, alone or in combination with one or more drugs or biologics, to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. Fast track designation applies to the combination of the product candidate and the specific indication for which it is being studied. With regard to a fast track product candidate, the FDA may consider for review sections of the NDA or BLA on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the sections of the NDA or BLA, the FDA agrees to accept sections of the NDA or BLA and determines that the schedule is acceptable, and the sponsor pays any required user fees upon submission of the first section of the NDA or BLA.

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Obtaining a fast track designation does not change the standards for product approval, but may expedite the development or approval process. For example, even though the FDA has granted such designation for PRA023 for the treatment of SSc-ILD, it may not actually result in faster clinical development or regulatory review or approval. Furthermore, such a designation does not increase the likelihood that PRA023 or any other product candidate that may be granted fast track designation will receive marketing approval in the United States.

Disruptions at the FDA and other government agencies caused by funding shortages or global health concerns could hinder their ability to hire, retain or deploy key leadership and other personnel, or otherwise prevent new or modified products from being developed, approved or commercialized in a timely manner or at all, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, statutory, regulatory and policy changes, the FDA’s ability to hire and retain key personnel and accept the payment of user fees, and other events that may otherwise affect the FDA’s ability to perform routine functions. Average review times at the FDA have fluctuated in recent years as a result. In addition, government funding of other government agencies that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable. Disruptions at the FDA and other agencies may also slow the time necessary for new drugs, biologics, and medical devices, or modifications to approved drugs, biologics, and medical devices to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, over the last several years, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical FDA employees and stop critical activities.

Separately, in response to the COVID-19 pandemic, the FDA postponed most inspections of domestic and foreign manufacturing facilities at various points. Even though the FDA has since resumed standard inspection operations of domestic facilities where feasible, the FDA has continued to monitor and implement changes to its inspectional activities to ensure the safety of its employees and those of the firms it regulates as it adapts to the evolving COVID-19 pandemic, and any resurgence of the virus or emergence of new variants may lead to further inspectional delays. Regulatory authorities outside the United States may adopt similar restrictions or other policy measures in response to the COVID-19 pandemic. If a prolonged government shutdown occurs, or if global health concerns continue to prevent the FDA or other regulatory authorities from conducting their regular inspections, reviews or other regulatory activities, it could significantly impact the ability of the FDA or other regulatory authorities to timely review and process our regulatory submissions, which could have a material adverse effect on our business.

Risks Related to Our Reliance on Third Parties

We are substantially dependent upon the Cedars-Sinai license agreement for access to the Cedars-Sinai database and biobank, which supports Prometheus360.

We rely on access to the Cedars-Sinai database and biobank and its over 200,000 samples linked to extensive clinical data from patients in order to stratify patients and carry out our precision medicine approach. We exclusively license the rights to the database and biobank from Cedars-Sinai under our license agreement. Cedars-Sinai may terminate the license agreement under certain circumstances, including as a result of our uncured breach of the agreement. Cedars-Sinai stores its biobank samples in a single location in Southern California, and we therefore are exposed to the risk that such samples could be destroyed pursuant to a natural or man-made disaster or that they may otherwise become unavailable. Without access to this data and samples, our business would be materially and adversely affected because we may not be able to identify additional therapeutic targets and/or develop therapeutic and diagnostic product candidates for development. Additionally, any dispute with Cedars-Sinai may result in costly litigation that diverts our management’s attention and resources away from our day-to-day activities and which may adversely affect our business, financial condition, results of operation and prospects.

We have entered, and may in the future seek to enter into, collaborations, licenses and other similar arrangements and may not be successful in doing so, and even if we are, we may relinquish valuable rights and may not realize the benefits of such relationships.

We have entered into a co-development and manufacturing agreement with Falk pursuant to which we will co-develop and commercialize PRA052 and its potential companion diagnostic candidate for the treatment of IBD, exclusively in our respective territories. With respect to Falk, and what we expect will be the case with any future license or collaboration agreements, we have and would expect to have limited control over the amount and timing of resources that our collaborators dedicate to the development or commercialization of our product candidates. Our ability to generate revenues from these arrangements will depend on our collaborators’ willingness to successfully develop and commercialize the applicable development programs. Falk may terminate our collaboration agreement for convenience and under certain other circumstances, including as a result of our uncured material breach of the agreement. Any such termination may adversely affect our business, financial condition, results of operation and prospects.

We may seek to enter into additional collaborations, joint ventures, licenses and other similar arrangements for the development or commercialization of other product candidates due to capital costs required to develop or commercialize the product candidate. We may not be successful in our efforts to establish such collaborations for our product candidates because our research and development pipeline may be insufficient, our product candidates may be deemed to be at too early of a stage of development for collaborative effort or third parties may not view our product candidates as having the requisite potential to demonstrate safety and efficacy or

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significant commercial opportunity. In addition, we face significant competition in seeking appropriate strategic partners, and the negotiation process can be time-consuming and complex. We may have to relinquish valuable rights to our future revenue streams, research programs, product candidates or Prometheus360, or grant licenses on terms that may not be favorable to us, as part of any such arrangement, and such arrangements may restrict us from entering into additional agreements with other potential collaborators. We cannot be certain that, following a collaboration, license or strategic transaction, we will achieve an economic benefit that justifies such transaction.

The success of our collaboration arrangements will depend heavily on the efforts and activities of our collaborators and partners. Collaborations are subject to numerous risks, which may include the following risks to us:

We rely on third parties to conduct our preclinical and clinical studies and will rely on third parties to conduct our future clinical trials. If these third parties do not successfully carry out their contractual duties, comply with applicable regulatory requirements or meet expected deadlines, our development programs and our ability to seek or obtain regulatory approval for or commercialize our product candidates may be delayed.

We are dependent on third parties to conduct our preclinical studies and expect to rely on such third parties for our current and future clinical trials, including our ongoing and planned clinical trials of PRA023 and PRA052. Specifically, we have used and relied on, and intend to use and rely on, medical institutions, clinical investigators, CROs and consultants to conduct our preclinical studies and planned clinical trials in accordance with our clinical protocols and regulatory requirements. These CROs, investigators and other third parties play a significant role in the conduct and timing of these trials and subsequent collection and analysis of data. While we have and will have agreements governing the activities of our third-party contractors, we have limited influence over their actual performance. Nevertheless, we are responsible for ensuring that each of our clinical trials is conducted in accordance with the applicable protocol and legal, regulatory and scientific standards, and our reliance on our CROs and other third parties does not relieve us of our regulatory responsibilities. We and our CROs are required to comply with GCP requirements, which are regulations and guidelines enforced by the FDA and comparable foreign regulatory authorities for all of our product candidates in clinical

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development. Regulatory authorities enforce these GCPs through periodic inspections of trial sponsors, principal investigators and trial sites. If we or any of our CROs or trial sites fail to comply with applicable GCPs, the clinical data generated in our clinical trials may be deemed unreliable, and the FDA or comparable foreign regulatory authorities may require us to perform additional clinical trials before approving our marketing applications. In addition, our clinical trials must be conducted with products produced under cGMP regulations. Our failure to comply with these regulations may require us to repeat clinical trials, which would delay the regulatory approval process.

There is no guarantee that any of our CROs, investigators or other third parties will devote adequate time and resources to such trials or perform as contractually required. If any of these third parties fail to meet expected deadlines, adhere to our clinical protocols or meet regulatory requirements, or otherwise performs in a substandard manner, our clinical trials may be extended, delayed or terminated. In addition, many of the third parties with whom we contract may also have relationships with other commercial entities, including our competitors, for whom they may also be conducting clinical trials or other development activities that could harm our competitive position. In addition, principal investigators for our clinical trials are expected to serve as scientific advisors or consultants to us from time to time and may receive cash or equity compensation in connection with such services. If these relationships and any related compensation result in perceived or actual conflicts of interest, or the FDA concludes that the financial relationship may have affected the interpretation of the study, the integrity of the data generated at the applicable clinical trial site may be questioned and the utility of the clinical trial itself may be jeopardized, which could result in the delay or rejection by the FDA of any BLA, NDA or PMA we submit. Any such delay or rejection could prevent us from commercializing our product candidates.

If any of our relationships with these third parties terminate, we may not be able to enter into arrangements with alternative third parties on commercially reasonable terms or at all. Switching or adding additional CROs, investigators and other third parties involves additional cost and requires our management’s time and focus. In addition, there is a natural transition period when a new CRO commences work. As a result, delays occur, which can materially impact our ability to meet our desired clinical development timelines. Though we carefully manage our relationships with our CROs, investigators and other third parties, there can be no assurance that we will not encounter challenges or delays in the future or that these delays or challenges will not have a material adverse impact on our business, financial condition and prospects.

We rely on third parties for the manufacture of our product candidates for preclinical and clinical development. This reliance on third parties increases the risk that we will not have sufficient quantities of our product candidates or products or such quantities at an acceptable cost, which could delay, prevent or impair our development or commercialization efforts.

We do not own or operate manufacturing facilities and have no plans to develop our own clinical or commercial-scale manufacturing capabilities. We rely and expect to continue to rely on third parties for the manufacture of our product candidates and related raw materials, including our autoinjector, for preclinical and clinical development, as well as for commercial manufacture if any of our product candidates receive marketing approval. The facilities used by third-party manufacturers to manufacture our product candidates must be approved by the FDA and any comparable foreign regulatory authority pursuant to inspections that will be conducted after we submit a BLA, NDA or PMA to the FDA or any comparable filing to a foreign regulatory authority. We do not control the manufacturing process of, and are completely dependent on, third-party manufacturers for compliance with cGMP requirements for manufacture of products. If these third-party manufacturers cannot successfully manufacture material that conforms to our specifications and the strict regulatory requirements of the FDA or any comparable foreign regulatory authority, they will not be able to secure and/or maintain regulatory approval for their manufacturing facilities. In addition, we have no control over the ability of third-party manufacturers to maintain adequate quality control, quality assurance and qualified personnel. If the FDA or any comparable foreign regulatory authority does not approve these facilities for the manufacture of our product candidates or if it withdraws any such approval in the future, we may need to find alternative manufacturing facilities, which would significantly impact our ability to develop, obtain regulatory approval for or market our product candidates, if approved. Our failure, or the failure of our third-party manufacturers, to comply with applicable regulations could result in sanctions being imposed on us, including clinical holds, fines, injunctions, civil penalties, delays, suspension or withdrawal of approvals, seizures or recalls of product candidates or products, operating restrictions and criminal prosecutions, any of which could significantly and adversely affect supplies of our products.

Our or a third party’s failure to execute on our manufacturing requirements on commercially reasonable terms and in compliance with cGMP could adversely affect our business in a number of ways, including:

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In addition, we may be unable to establish any agreements with third-party manufacturers or to do so on acceptable terms. Even if we are able to establish agreements with third-party manufacturers, reliance on third-party manufacturers entails additional risks, including:

Our product candidates and any products that we may develop may compete with other product candidates and products for access to manufacturing facilities. There are a limited number of manufacturers that operate under cGMP regulations and that might be capable of manufacturing for us.

Any performance failure on the part of our existing or future manufacturers could delay clinical development or marketing approval, and any related remedial measures may be costly or time consuming to implement. We do not currently have arrangements in place for redundant supply or a second source for all required raw materials used in the manufacture of our product candidates. If our existing or future third-party manufacturers cannot perform as agreed, we may be required to replace such manufacturers and we may be unable to replace them on a timely basis or at all.

Our current and anticipated future dependence upon others for the manufacture of our product candidates or products may adversely affect our future profit margins and our ability to commercialize any products that receive marketing approval on a timely and competitive basis.

Our reliance on third parties requires us to share our trade secrets, which increases the possibility that a competitor will discover them or that our trade secrets will be misappropriated or disclosed.

Because we currently rely on third parties to manufacture our product candidates and to perform quality testing, we must, at times, share our proprietary technology and confidential information, including trade secrets, with them. We seek to protect our proprietary technology, in part, by entering into confidentiality agreements, and, if applicable, material transfer agreements, collaborative research agreements, consulting agreements or other similar agreements with our collaborators, advisors, employees and consultants prior to beginning research or disclosing proprietary information. These agreements typically limit the rights of the third parties to use or disclose our confidential information. Despite the contractual provisions employed when working with third parties, the need to share trade secrets and other confidential information increases the risk that such trade secrets become known by our competitors, are intentionally or inadvertently incorporated into the technology of others or are disclosed or used in violation of these agreements. Given that our proprietary position is based, in part, on our know-how and trade secrets and despite our efforts to protect our trade secrets, a competitor’s discovery of our proprietary technology and confidential information or other unauthorized use or disclosure would impair our competitive position and may have a material adverse effect on our business, financial condition, results of operations and prospects.

Risks Related to Commercialization of Our Product Candidates and Testing Products

Even if we receive marketing authorization for any therapeutic product candidate or diagnostic candidate, we will be subject to ongoing regulatory obligations and continued regulatory review, which may result in significant additional expense. Additionally, our therapeutic product candidates and diagnostic candidates, if authorized for sale, could be subject to labeling and other restrictions on marketing or withdrawal from the market, and we may be subject to penalties if we fail to comply with regulatory requirements or if we experience unanticipated problems with our therapeutic product candidates and diagnostic candidates, when and if any of them are approved.

Any marketing authorizations that we may receive for our product candidates, including any therapeutic product candidates or diagnostic candidates, will require the submission of reports to regulatory authorities and surveillance to monitor the safety and efficacy of the product candidate, may contain significant limitations related to use restrictions for specified age groups, warnings, precautions or contraindications, and may include burdensome post-approval study or risk management requirements. For example, the FDA may require a REMS in order to approve our therapeutic product candidates, which could entail requirements for a medication guide, physician training and communication plans or additional elements to ensure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. In addition, if one of our product candidates is approved, it will be subject to ongoing regulatory requirements for manufacturing, labeling, packaging, storage, advertising, promotion, sampling, record-keeping, conduct of post-marketing studies and submission of safety, efficacy, and other post-market information, including both federal and state requirements in the United States and requirements of comparable foreign regulatory authorities.

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Manufacturers and manufacturers’ facilities are required to comply with extensive FDA and comparable foreign regulatory authority requirements, including ensuring that quality control and manufacturing procedures conform to cGMP regulations. As such, we and our contract manufacturers will be subject to continual review and inspections to assess compliance with cGMP and adherence to commitments made in any approved marketing application. Accordingly, we and others with whom we work must continue to expend time, money and effort in all areas of regulatory compliance, including manufacturing, production and quality control.

If the FDA or another regulatory authority discovers previously unknown problems with a product, such as adverse events of unanticipated severity or frequency, or problems with the facility where the product is manufactured, or disagrees with the promotion, marketing or labeling of a product, such regulatory authorities may impose restrictions on that product or us, including requiring withdrawal of the product from the market. If we fail to comply with applicable regulatory requirements, a regulatory authority or enforcement authority may, among other things:

Any government investigation of alleged violations of law could require us to expend significant time and resources in response and could generate negative publicity. Any failure to comply with ongoing regulatory requirements may adversely affect our ability to commercialize and generate revenue from our products. If regulatory sanctions are applied or if regulatory approval is withdrawn, our business will be seriously harmed.

Moreover, the policies of the FDA and of other regulatory authorities may change, and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates. For example, on February 23, 2022, the FDA issued a proposed rule to amend the Quality System Regulation, which establishes cGMP requirements for medical device manufacturers, to align more closely with the International Organization for Standardization standards. This proposal has not yet been finalized or adopted. Accordingly, it is unclear the extent to which this or any other proposals, if adopted, could impose additional or different regulatory requirements on us that could increase the costs of compliance or otherwise create competition that may negatively affect our business. We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative or executive action, either in the United States or abroad. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may be subject to enforcement action and we may not achieve or sustain profitability.

The commercial success of our product candidates will depend upon the degree of market acceptance of such product candidates by physicians, patients, healthcare payors and others in the medical community.

Our product candidates may not be commercially successful. Even if any of our product candidates receive regulatory approval, they may not gain market acceptance among physicians, patients, healthcare payors or the medical community. The commercial success of any of our current or future product candidates will depend significantly on the broad adoption and use of the resulting product by physicians and patients for approved indications. The degree of market acceptance of our products will depend on a number of factors, including:

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If any product candidate is approved but does not achieve an adequate level of acceptance by physicians, hospitals, healthcare payors or patients, we may not generate sufficient revenue from that product and may not become or remain profitable. Our efforts to educate the medical community and third-party payors regarding the benefits of our products may require significant resources and may never be successful.

The FDA and other regulatory agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses. If we are found or alleged to have improperly promoted off-label uses, we may become subject to significant liability.

The FDA and other regulatory agencies strictly regulate the promotional claims that may be made about prescription products, as our product candidates would be, if approved. In particular, a product may not be promoted for uses that are not approved by the FDA or such other regulatory agencies as reflected in the product’s approved labeling. If we receive marketing approval for a product candidate, physicians may nevertheless prescribe it to their patients in a manner that is inconsistent with the approved label. If we are found to have promoted such off-label uses, we may become subject to significant liability. The federal government has levied large civil and criminal fines against companies for alleged improper promotion and has enjoined several companies from engaging in off-label promotion. The FDA has also required companies to enter into consent decrees or permanent injunctions under which specified promotional conduct is changed or curtailed. If we cannot successfully manage the promotion of our product candidates, if approved, we could become subject to significant liability, which would materially adversely affect our business and financial condition.

Our therapeutic product candidates for which we intend to seek approval as biologics may face competition sooner than anticipated.

The ACA includes a subtitle called the Biologics Price Competition and Innovation Act of 2009 (BPCIA), which created an abbreviated approval pathway for biological products that are biosimilar to or interchangeable with an FDA-licensed reference biological product. Under the BPCIA, an application for a highly similar or “biosimilar” product may not be submitted to the FDA until four years following the date that the reference product was first approved by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first approved. During this 12-year period of exclusivity, another company may still market a competing version of the reference product if the FDA approves a full BLA for the competing product containing the sponsor’s own preclinical data and data from adequate and well-controlled clinical trials to demonstrate the safety, purity and potency of their product.

We believe that any of our therapeutic product candidates approved as biologics under a BLA should qualify for the 12-year period of exclusivity. However, there is a risk that this exclusivity could be shortened due to congressional action or otherwise, or that the FDA will not consider our therapeutic product candidates to be reference products for competing products, potentially creating the opportunity for competition sooner than anticipated. Other aspects of the BPCIA, some of which may impact the BPCIA exclusivity provisions, have also been the subject of recent litigation. Moreover, the extent to which a biosimilar, once approved, will be substituted for any reference products in a way that is similar to traditional generic substitution for non-biological products is not yet clear, and will depend on a number of marketplace and regulatory factors that are still developing.

The successful commercialization of our product candidates, if approved, will depend in part on the extent to which governmental authorities and health insurers establish coverage, adequate reimbursement levels and favorable pricing policies. Failure to obtain or maintain coverage and adequate reimbursement for our product candidates could limit our ability to market those products and decrease our ability to generate revenue.

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The availability of coverage and the adequacy of reimbursement by governmental healthcare programs such as Medicare and Medicaid, private health insurers and other third-party payors are essential for most patients to be able to afford prescription medications such as our product candidates, if approved. Our ability to achieve coverage and acceptable levels of reimbursement for our products by third-party payors will have an effect on our ability to successfully commercialize those products. Even if we obtain coverage for a given product by a third-party payor, the resulting reimbursement payment rates may not be adequate or may require co-payments that patients find unacceptably high. We cannot be sure that coverage and reimbursement in the United States, the European Union or elsewhere will be available for any product that we may develop, and any reimbursement that may become available may be decreased or eliminated in the future.

Third-party payors increasingly are challenging prices charged for biopharmaceutical products and services, and many third-party payors may refuse to provide coverage and reimbursement for particular drugs when an equivalent generic drug or a less expensive therapy is available. It is possible that a third-party payor may consider our product candidates as substitutable and only offer to reimburse patients for the less expensive product. These payors may deny or revoke the reimbursement status of a given product or establish prices for new or existing marketed products at levels that are too low to enable us to realize an appropriate return on our investment in product development. If reimbursement is not available or is available only at limited levels, we may not be able to successfully commercialize our products, if approved, and may not be able to obtain a satisfactory financial return on products that we may develop.

There is significant uncertainty related to third-party payor coverage and reimbursement of newly approved products. In the United States, third-party payors, including private and governmental payors, such as the Medicare and Medicaid programs, play an important role in determining the extent to which new drugs will be covered. Some third-party payors may require pre-approval of coverage for new or innovative devices or drug therapies before they will reimburse healthcare providers who use such therapies. It is difficult to predict at this time what third-party payors will decide with respect to the coverage and reimbursement for our products.

Obtaining and maintaining reimbursement status is time consuming, costly and uncertain. The Medicare and Medicaid programs increasingly are used as models for how private payors and other governmental payors develop their coverage and reimbursement policies for drugs. However, no uniform policy for coverage and reimbursement for products exists among third-party payors in the United States. Therefore, coverage and reimbursement for products can differ significantly from payor to payor. As a result, the coverage determination process is often a time consuming and costly process that will require us to provide scientific and clinical support for the use of our products to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance. Furthermore, rules and regulations regarding reimbursement change frequently, in some cases at short notice, and we believe that changes in these rules and regulations are likely.

In addition, companion diagnostic tests require coverage and reimbursement separate and apart from the coverage and reimbursement for their companion pharmaceutical or biological products. Similar challenges to obtaining coverage and reimbursement, applicable to pharmaceutical or biological products, will apply to diagnostic tests. Additionally, if any companion diagnostic provider is unable to obtain reimbursement or is inadequately reimbursed, that may limit the availability of such companion diagnostic, which would negatively impact prescriptions for our product candidates, if approved.

Outside the United States, international operations are generally subject to extensive governmental price controls and other market regulations, and we believe the increasing emphasis on cost-containment initiatives in Europe and other countries has and will continue to put pressure on the pricing and usage of our products. In many countries, the prices of medical products are subject to varying price control mechanisms as part of national health systems. Other countries allow companies to fix their own prices for medical products but monitor and control company profits. Additional foreign price controls or other changes in pricing regulation could restrict the amount that we are able to charge for our product candidates, if approved. Accordingly, in markets outside the United States, the reimbursement for our product candidates may be reduced compared with the United States and may be insufficient to generate commercially reasonable revenue and profits.

Moreover, increasing efforts by governmental and third-party payors in the United States and abroad to cap or reduce healthcare costs may cause such organizations to limit both coverage and the level of reimbursement for newly approved products and, as a result, they may not cover or provide adequate payment for our products. We expect to experience pricing pressures in connection with the sale of any of our product candidates due to the trend toward managed healthcare, the increasing influence of health maintenance organizations and additional legislative changes. The downward pressure on healthcare costs in general, particularly prescription drugs and surgical procedures and other treatments, has become very intense. As a result, increasingly high barriers are being erected to the entry of new products.

We face significant competition, and if our competitors develop technologies or product candidates more rapidly than we do or their technologies are more effective, our business and our ability to develop and successfully commercialize products may be adversely affected.

The biotechnology and biopharmaceutical industries are characterized by rapidly advancing technologies, intense competition and a strong emphasis on proprietary and novel products and product candidates. Our competitors have developed, are developing or may develop products, product candidates and processes competitive with our product candidates. Any product candidates that we

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successfully develop and commercialize will compete with existing therapies and new therapies that may become available in the future. We believe that a significant number of products are currently under development, and may become commercially available in the future, for the treatment of IBD and other immune-mediated diseases. Our competitors include larger and better funded pharmaceutical, specialty pharmaceutical and biotechnology companies. Moreover, we may also compete with universities, governmental agencies and other research institutions who may be active in the indications we are targeting and could be in direct competition with us. We also compete with these organizations in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. Smaller or early stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies.

We expect to face competition from existing products and products in development for each of our therapeutic product candidates. If approved for the treatment of patients with moderate-to-severe IBD, PRA023, PRA052 and our other development programs would compete with Entyvio, which is an a4b7 integrin antibody marketed by Takeda, Humira, which is a TNF antibody marketed by AbbVie Inc., Remicade, which is a TNF antibody marketed by Johnson & Johnson, Stelara, which is an IL-12/IL-23 antibody marketed by Johnson & Johnson, Xeljanz, which is a JAK1 inhibitor marketed by Pfizer Inc., Simponi, which is a TNF antibody marketed by Johnson & Johnson, and Zeposia, which is a S1P inhibitor marketed by Bristol-Myers Squibb Company.

We are aware of several companies with product candidates in development for the treatment of patients with UC and/or CD, including but not limited to Roivant Sciences RVT-3101 (formerly Pfizer Inc.’s PF-06480605), which is an anti-TL1A antibody being developed in Phase 2 clinical trials, Rinvoq, which is a JAK1 inhibitor being developed in Phase 3 clinical trials by AbbVie Inc., and mirikizumab, which is an anti-IL-23 antibody being developed in Phase 3 clinical trials by Eli Lilly and Company. We are also aware of additional product candidates in clinical trials by AbbVie Inc., Abivax S.A., Amgen Inc., Applied Molecular Transport Inc., Arena Pharmaceuticals, Inc., AstraZeneca Pharmaceuticals LP, Bausch Health Companies, Inc., Bristol-Myers Squibb Company, C.H. Boehringer Sohn AG & Ko. KG, EA Pharma Co., Ltd., Gilead Sciences, Inc., Gossamer Bio, Inc., Johnson & Johnson, Landos Biopharma, Inc., Morphic Holding, Inc., Merck & Co. Inc., Novartis International AG, Protagonist Therapeutics, Inc., RedHill Biopharma Ltd., Seres Therapeutics, Inc., and Ventyx Biosciences, Inc. In addition, biosimilars of Humira, Stelara and Entyvio are expected in coming years and will provide cost-effective alternatives within the biologic class.

If approved for the treatment of patients with SSc-ILD, PRA023 would compete with Ofev, which is a tyrosine kinase inhibitor marketed by Boehringer Ingelheim AG and Actemra, which is an IL-6 antibody marketed by F. Hoffmann-La Roche AG. We are aware of several companies with product candidates in development for the treatment of patients for SSc-ILD, including but not limited to Castle Creek Biosciences, Inc., Certa Therapeutics Pty Ltd., Chemomab Therapeutics Ltd., Cumberland Pharmaceuticals Inc., Emerald Health Pharmaceuticals Inc., Forbius PTY Limited, GlaxoSmithKline plc., Horizon Therapeutics plc, Incyte Corporation, Johnson & Johnson, Kyowa Kirin plc, Merck & Co., Inc., Mitsubishi Tanabe Pharma Corporation, Sanofi S.A., and Seagen, Inc.

Many of our competitors have significantly greater financial, technical, manufacturing, marketing, sales and supply resources or experience than we do. If we successfully obtain approval for any product candidate, we will face competition based on many different factors, including the safety and effectiveness of our products, the ease with which our products can be administered, the effectiveness of any related companion diagnostic tests, the timing and scope of regulatory approvals for these products, the availability and cost of manufacturing, marketing and sales capabilities, price, reimbursement coverage and patent position. Competing products could present superior treatment alternatives, including by being more effective, safer, more convenient, less expensive or marketed and sold more effectively than any products we may develop. Competitive products or technological approaches may make any products we develop, or Prometheus360, obsolete or noncompetitive before we recover the expense of developing and commercializing our product candidates. If we are unable to compete effectively, our opportunity to generate revenue from the sale of our products we may develop, if approved, could be adversely affected.

If the market opportunities for our products are smaller than we believe they are, our revenue may be adversely affected, and our business may suffer.

The precise incidence and prevalence for all the conditions we aim to address with our product candidates are unknown. Our projections of both the number of people who have these diseases, as well as the subset of people with these diseases who have the potential to benefit from treatment with our therapeutic product candidates, are based on our beliefs and estimates. These estimates have been derived from a variety of sources, including the scientific literature, surveys of clinics, patient foundations or market research, and may prove to be incorrect. Further, new trials may change the estimated incidence or prevalence of these diseases. The total addressable market across all of our product candidates will ultimately depend upon, among other things, the diagnosis criteria included in the final label for each of our product candidates approved for sale for these indications, the availability of alternative treatments and the safety, convenience, cost and efficacy of our therapeutic product candidates relative to such alternative treatments, acceptance by the medical community and patient access, drug pricing and reimbursement. The number of patients in the United States and other major markets and elsewhere may turn out to be lower than expected, patients may not be otherwise amenable to treatment with our products or new patients may become increasingly difficult to identify or gain access to, all of which would adversely affect our results of operations and our business. Further, even if we obtain significant market share for our product

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candidates, because some of our potential target populations are very small, we may never achieve profitability despite obtaining such significant market share.

Our future growth may depend, in part, on our ability to operate in foreign markets, where we would be subject to additional regulatory burdens and other risks and uncertainties.

Our future growth may depend, in part, on our ability to develop and commercialize our product candidates in foreign markets. We are not permitted to market or promote any of our product candidates before we receive regulatory approval from applicable regulatory authorities in foreign markets, and we may never receive such regulatory approvals for any of our product candidates. To obtain separate regulatory approval in many other countries we must comply with numerous and varying regulatory requirements regarding safety and efficacy and governing, among other things, clinical trials, commercial sales, pricing and distribution of our product candidates. If we obtain regulatory approval of our product candidates and ultimately commercialize our products in foreign markets, we would be subject to additional risks and uncertainties, including:

Risks Related to Our Business Operations and Industry

Our operating results may fluctuate significantly, which makes our future operating results difficult to predict and could cause our operating results to fall below expectations or any guidance we may provide.

Our quarterly and annual operating results may fluctuate significantly, which makes it difficult for us to predict our future operating results. These fluctuations may occur due to a variety of factors, many of which are outside of our control, including, but not limited to:

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The cumulative effects of these factors could result in large fluctuations and unpredictability in our quarterly and annual operating results. As a result, comparing our operating results on a period-to-period basis may not be meaningful. Investors should not rely on our past results as an indication of our future performance.

This variability and unpredictability could also result in our failing to meet the expectations of industry or financial analysts or investors for any period. If our revenue or operating results fall below the expectations of analysts or investors or below any forecasts we may provide to the market, or if the forecasts we provide to the market are below the expectations of analysts or investors, the price of our common stock could decline substantially. Such a stock price decline could occur even when we have met any previously publicly stated revenue or earnings guidance we may provide.

We are dependent on the services of our management and other clinical and scientific personnel, and if we are not able to retain these individuals or recruit additional management or clinical and scientific personnel, our business will suffer.

Our success depends in part on our continued ability to attract, retain and motivate highly qualified management, clinical and scientific personnel. We are highly dependent upon our senior management, as well as our senior scientists and other members of our management team. The loss of services of any of these individuals could delay or prevent the successful development of our product pipeline, initiation or completion of our preclinical studies and clinical trials or the commercialization of our product candidates. Although we have executed employment agreements or offer letters with each member of our senior management team, these agreements are terminable at will with or without notice and, therefore, we may not be able to retain their services as expected. We do not currently maintain “key person” life insurance on the lives of our executives or any of our employees. This lack of insurance means that we may not have adequate compensation for the loss of the services of these individuals.

We will need to expand and effectively manage our managerial, operational, financial and other resources in order to successfully pursue our clinical development and commercialization efforts. We may not be successful in maintaining our unique company culture and continuing to attract or retain qualified management and scientific and clinical personnel in the future due to the intense competition for qualified personnel among biopharmaceutical, biotechnology and other businesses, particularly in the San Diego area. Our industry has experienced a high rate of turnover of management personnel in recent years. If we are not able to attract, integrate, retain and motivate necessary personnel to accomplish our business objectives, we may experience constraints that will significantly impede the achievement of our development objectives, our ability to raise additional capital and our ability to implement our business strategy.

We may encounter difficulties in managing our growth and expanding our operations successfully.

We had 97 full-time employees and no part-time employees as of February 21, 2023. As we continue development and pursue the potential commercialization of our product candidates, as well as function as a public company, we will need to expand our financial, development, regulatory, manufacturing, marketing and sales capabilities or contract with third parties to provide these capabilities for us. As our operations expand, we expect that we will need to manage additional relationships with various strategic partners, suppliers and other third parties. Our future financial performance and our ability to develop and commercialize our product candidates and to compete effectively will depend, in part, on our ability to manage any future growth effectively.

We are subject to various federal, state and foreign healthcare fraud and abuse laws and regulations, which could increase compliance costs, and our failure to comply with these laws and regulations could harm our results of operations and financial condition.

Our business operations and current and future arrangements with investigators, healthcare professionals, consultants, third-party payors and customers expose us to broadly applicable foreign, federal and state fraud and abuse and other healthcare laws and regulations. These laws may constrain the business or financial arrangements and relationships through which we conduct our operations and how we research, market, sell and distribute any products for which we obtain marketing approval. Such laws include:

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Efforts to ensure that our current and future business arrangements with third parties will comply with applicable healthcare laws and regulations will involve ongoing substantial costs. It is possible that governmental authorities will conclude that our business practices, including certain consulting agreements with physicians, some of whom are in a position to prescribe our product candidates, if approved, and are compensated in the form of stock or stock options for services provided to us, may not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations are found to be in violation of any of these laws or any other governmental regulations that may apply to us, we may be subject to significant penalties, including civil, criminal and administrative penalties, damages, fines, disgorgement, imprisonment, exclusion from participation in government funded healthcare programs, such as Medicare and Medicaid, integrity oversight and reporting obligations, contractual damages, reputational harm, diminished profits and future earnings and the curtailment or restructuring of our operations. Defending against any such actions can be costly, time-consuming and may require significant financial and personnel resources. Therefore, even if we are successful in defending against any such actions that may be brought against us, our business may be impaired. Further, if any of the physicians or other healthcare providers or entities with whom we expect to do business is found to be not in compliance with applicable laws, they may be subject to significant criminal, civil or administrative sanctions, including exclusions from government funded healthcare program.

Recently enacted legislation, future legislation and healthcare reform measures may increase the difficulty and cost for us to obtain marketing approval for and commercialize our product candidates and may affect the prices we may set.

In the United States and some foreign jurisdictions, there have been, and we expect there will continue to be, a number of legislative and regulatory changes to the healthcare system, including cost-containment measures that may reduce or limit coverage and reimbursement for newly approved drugs and affect our ability to profitably sell any product candidates for which we obtain marketing approval. In particular, there have been and continue to be a number of initiatives at the U.S. federal and state levels that seek to reduce healthcare costs and improve the quality of healthcare.

For example, in March 2010, the ACA was enacted in the United States. Among the provisions of the ACA of importance to our potential product candidates, the ACA: established an annual, nondeductible fee on any entity that manufactures or imports specified branded prescription drugs and biologic agents; extended manufacturers’ Medicaid rebate liability to covered drugs dispensed to individuals who are enrolled in Medicaid managed care organizations; expands eligibility criteria for Medicaid programs; expands the entities eligible for discounts under the Public Health program; increases the statutory minimum rebates a manufacturer must pay under the Medicaid Drug Rebate Program; creates a new Medicare Part D coverage gap discount program; establishes a new Patient-Centered Outcomes Research Institute to oversee, identify priorities in and conduct comparative clinical effectiveness research, along with funding for such research; and establishes a Center for Medicare Innovation at CMS to test innovative payment and service delivery models to lower Medicare and Medicaid spending.

Since its enactment, there have been judicial, executive and Congressional challenges to certain aspects of the ACA. On June 17, 2021, the U.S. Supreme Court dismissed the most recent judicial challenge to the ACA brought by several states without specifically ruling on the constitutionality of the ACA. Prior to the Supreme Court’s decision, President Biden issued an executive order initiating a special enrollment period from February 15, 2021 through August 15, 2021 for purposes of obtaining health insurance coverage

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through the ACA marketplace. The executive order also instructed certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare, including among others, reexamining Medicaid demonstration projects and waiver programs that include work requirements, and policies that create unnecessary barriers to obtaining access to health insurance coverage through Medicaid or the ACA. It is unclear how the healthcare reform measures will impact our business..

In addition, other legislative changes have been proposed and adopted since the ACA was enacted. The American Rescue Plan Act of 2021 was signed into law, which eliminates the statutory cap on the Medicaid drug rebate, currently set at 100% of a drug’s AMP, beginning January 1, 2024. Further, there has been heightened governmental scrutiny in the United States of pharmaceutical pricing practices in light of the rising cost of prescription drugs. Such scrutiny has resulted in several recent congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient assistance programs, and reform government program reimbursement methodologies for products. Most recently, the Inflation Reduction Act of 2022, or IRA, included a number of significant drug pricing reforms, which include the establishment of a drug price negotiation program within the U.S. Department of Health and Human Services, or HHS (beginning in 2026) that requires manufacturers to charge a negotiated “maximum fair price” for certain selected drugs or pay an excise tax for noncompliance, the establishment of rebate payment requirements on manufacturers under Medicare Parts B and D to penalize price increases that outpace inflation (first due in 2023), and a redesign of the Part D benefit, as part of which manufacturers are required to provide discounts on Part D drugs (beginning in 2025). The IRA permits the HHS Secretary to implement many of these provisions through guidance, as opposed to regulation, for the initial years. Additional drug pricing proposals could appear in future legislation. Further, it is possible that additional governmental action is taken in response to the COVID-19 pandemic.

At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. Legally mandated price controls on payment amounts by third-party payors or other restrictions could harm our business, results of operations, financial condition and prospects. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other healthcare programs. This could reduce the ultimate demand for our therapeutic product candidates, if approved, or put pressure on our product pricing, which could negatively affect our business, results of operations, financial condition and prospects.

We expect that these new laws and other healthcare reform measures that may be adopted in the future may result in additional reductions in Medicare and other healthcare funding, more rigorous coverage criteria, new payment methodologies and additional downward pressure on the price that we receive for any approved product. Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private payors. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability or commercialize our product candidates, if approved.

If product liability lawsuits are brought against us, we may incur substantial liabilities and may be required to limit commercialization of our products.

We face an inherent risk of product liability as a result of the clinical trials of our product candidates and will face an even greater risk if we commercialize our product candidates. For example, we may be sued if our product candidates allegedly cause injury or are found to be otherwise unsuitable during product testing, manufacturing, marketing or sale. Any such product liability claims may include allegations of defects in manufacturing, defects in design, a failure to warn of dangers inherent in the product candidate, negligence, strict liability and a breach of warranties. Claims may be brought against us by clinical trial participants, patients or others using, administering or selling products that may be approved in the future. Claims could also be asserted under state consumer protection acts.

If we cannot successfully defend ourselves against product liability claims, we may incur substantial liabilities or be required to limit or cease the commercialization of our products. Even a successful defense would require significant financial and management resources. Regardless of the merits or eventual outcome, liability claims may result in:

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We currently hold approximately $10 million in product liability insurance coverage in the aggregate. We may need to increase our insurance coverage as we expand our clinical trials or if we commence commercialization of our product candidates. Insurance coverage is increasingly expensive. Our inability to obtain and retain sufficient product liability insurance at an acceptable cost to protect against potential product liability claims could prevent or inhibit the commercialization of our product candidates. Although we will maintain such insurance, any claim that may be brought against us could result in a court judgment or settlement in an amount that is not covered, in whole or in part, by our insurance or that is in excess of the limits of our insurance coverage. Our insurance policies will also have various exclusions, and we may be subject to a product liability claim for which we have no coverage. We may have to pay any amounts awarded by a court or negotiated in a settlement that exceed our coverage limitations or that are not covered by our insurance, and we may not have, or be able to obtain, sufficient capital to pay such amounts.

Our insurance policies are expensive and only protect us from some business risks, which will leave us exposed to significant uninsured liabilities.

We do not carry insurance for all categories of risk that our business may encounter. Some of the policies we currently maintain include property, general liability, employment benefits liability, business automobile, workers’ compensation, products liability, malicious invasion of our electronic systems, directors’ and officers’, employment practices and fiduciary liability insurance. We do not know, however, if we will be able to maintain insurance with adequate levels of coverage. Any significant uninsured liability may require us to pay substantial amounts, which would adversely affect our financial position and results of operations.

We and any of our current and potential future collaborators will be required to report to regulatory authorities if any of our approved products cause or contribute to adverse medical events, and any failure to do so would result in sanctions that would materially harm our business.

If we or any of our current and potential future collaborators are successful in commercializing our products, the FDA and foreign regulatory authorities would require that we and such collaborators report certain information about adverse medical events if those products may have caused or contributed to those adverse events. The timing of our obligation to report would be triggered by the date we become aware of the adverse event as well as the nature of the event. We and any of our current or potential future collaborators or CROs may fail to report adverse events within the prescribed timeframe. If we or any of our current or potential future collaborators or CROs fail to comply with such reporting obligations, the FDA or a foreign regulatory authority could take action, including criminal prosecution, the imposition of civil monetary penalties, seizure of our products or delay in approval or clearance of future products.

Our business could be affected by litigation, government investigations and enforcement actions.

We currently operate in a number of jurisdictions in a highly regulated industry and we could be subject to litigation, government investigation and enforcement actions on a variety of matters in the United States or foreign jurisdictions, including, without limitation, intellectual property, regulatory, product liability, environmental, whistleblower, false claims, privacy, anti-kickback, anti-bribery, securities, commercial, employment and other claims and legal proceedings which may arise from conducting our business. Any determination that our operations or activities are not in compliance with existing laws or regulations could result in the imposition of fines, civil and criminal penalties, equitable remedies, including disgorgement, injunctive relief and/or other sanctions against us, and remediation of any such findings could have an adverse effect on our business operations.

Legal proceedings, government investigations and enforcement actions can be expensive and time consuming. An adverse outcome resulting from any such proceeding, investigations or enforcement actions could result in significant damages awards, fines, penalties, exclusion from the federal healthcare programs, healthcare debarment, injunctive relief, product recalls, reputational damage and modifications of our business practices, which could have a material adverse effect on our business and results of operations.

Our employees and independent contractors, including principal investigators, CROs, consultants and vendors, may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements.

We are exposed to the risk that our employees and independent contractors, including principal investigators, CROs, consultants and vendors may engage in misconduct or other illegal activity. Misconduct by these parties could include intentional, reckless and/or negligent conduct or disclosure of unauthorized activities to us that violate: (i) the laws and regulations of the FDA and other similar regulatory requirements, including those laws that require the reporting of true, complete and accurate information to such authorities, (ii) manufacturing standards, including cGMP requirements, (iii) federal and state data privacy, security, fraud and abuse and other healthcare laws and regulations in the United States and abroad or (iv) laws that require the true, complete and accurate reporting of financial information or data. Activities subject to these laws also involve the improper use or misrepresentation of information obtained in the course of clinical trials, the creation of fraudulent data in our preclinical studies or clinical trials or illegal

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misappropriation of drug product, which could result in regulatory sanctions and cause serious harm to our reputation. It is not always possible to identify and deter misconduct by employees and other third parties, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. In addition, we are subject to the risk that a person or government could allege such fraud or other misconduct, even if none occurred. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business and financial results, including, without limitation, the imposition of significant civil, criminal and administrative penalties, damages, monetary fines, disgorgements, possible exclusion from participation in Medicare, Medicaid and other federal healthcare programs, imprisonment, contractual damages, reputational harm, diminished profits and future earnings, additional reporting requirements and oversight if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance with these laws and curtailment of our operations, any of which could adversely affect our ability to operate our business and our results of operations.

We may engage in strategic transactions that could impact our liquidity, increase our expenses and present significant distractions to our management.

From time to time, we may consider strategic transactions, including acquisitions of companies, asset purchases and out-licensing or in-licensing of intellectual property, products or technologies. Additional potential transactions that we may consider in the future include a variety of business arrangements, including spinoffs, strategic partnerships, joint ventures, restructurings, divestitures, business combinations and investments. Any future transactions could increase our near and long-term expenditures, result in potentially dilutive issuances of our equity securities, including our common stock, or the incurrence of debt, contingent liabilities, amortization expenses or acquired in-process research and development expenses, any of which could affect our financial condition, liquidity and results of operations. Future acquisitions may also require us to obtain additional financing, which may not be available on favorable terms or at all. These transactions may never be successful and may require significant time and attention of our management. In addition, the integration of any business that we may acquire in the future may disrupt our existing business and may be a complex, risky and costly endeavor for which we may never realize the full benefits of the acquisition. Accordingly, although there can be no assurance that we will undertake or successfully complete any additional transactions of the nature described above, any additional transactions that we do complete could have a material adverse effect on our business, results of operations, financial condition and prospects.

Our business, operations and clinical development timelines and plans are subject to risks arising from the COVID-19 pandemic and other epidemic diseases.

The COVID-19 worldwide pandemic has presented substantial public health and economic challenges and has affected our employees, patients, physicians and other healthcare providers, communities and business operations, as well as the U.S. and global economies and financial markets. International and U.S. governmental authorities in impacted regions have taken, and may continue to take, actions in an effort to slow the spread of COVID-19 and variants of the virus. The continued spread of COVID-19 and the measures taken by governmental authorities, and any future epidemic or pandemic disease outbreaks, may cause disruptions that could severely impact our business, preclinical studies, clinical trials and financial condition, including by:

The extent to which the COVID-19 pandemic impacts our results will depend on future developments that are highly uncertain and cannot be predicted, including new information that may emerge concerning the severity of the virus, the identification of new variants, the rate of vaccine administration, and the actions taken to contain its impact. The COVID-19 pandemic and mitigation measures have had and may continue to have an adverse impact on global economic conditions, which could have an adverse effect on our business and financial condition, including impairing our ability to raise capital when needed. To the extent the COVID-19 pandemic adversely affects our business and financial results, it may also have the effect of heightening many of the other risks described in this section. In addition, if in the future there is an outbreak of another highly infectious or contagious disease or other health concern, we may be subject to similar risks as posed by COVID-19.

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Our ability to use net operating loss carryforwards and other tax attributes may be limited.

We have incurred substantial losses during our history, do not expect to become profitable in the near future and may never achieve profitability. To the extent that we continue to generate taxable losses, unused losses will carry forward to offset future taxable income, if any, until such unused losses expire, if at all. At December 31, 2022, we had federal and state net operating loss (NOL) carryforwards of approximately $164.1 million and $222.5 million, respectively.

Under the Tax Act, federal NOL carryforwards arising in tax years beginning after December 31, 2017, may be carried forward indefinitely. Under the Coronavirus Aid, Relief and Economic Security Act (the CARES Act), federal NOL carryforwards arising in tax years beginning after December 31, 2017 and before January 1, 2021 may be carried back to each of the five tax years preceding the tax year of such loss. The deductibility of federal NOL carryforwards, particularly for tax years beginning after December 31, 2020, may be limited, along with NOLs generated in states that conform to the Tax Act or the CARES Act. In addition, our NOL carryforwards are subject to review and possible adjustment by the IRS and state tax authorities. Under Section 382 of the Internal Revenue Code of 1986, (as amended, the Code), our federal and state NOL carryforwards, as well as research credit carryovers, may become subject to an annual limitation in the event of certain cumulative changes in the ownership of our company. An “ownership change” pursuant to Section 382 of the Code generally occurs if one or more stockholders or groups of stockholders who own at least 5% of a company’s stock increase their ownership by more than 50 percentage points over their lowest ownership percentage within a rolling three-year period. Similar rules may apply under state tax laws. We had an ownership change analysis completed through December 31, 2022 and determined that the Company experienced ownership changes on May 31, 2017, September 1, 2017, September 26, 2017, May 29, 2019 March 27, 2020 and January 29, 2021. Based on the annual limitations associated with the change dates, the Company determined that, with the exception of $968,000 of federal research credits and $562,000 of California NOLs, the Company’s federal and state NOLs and credits generated prior to these change dates will be fully available within the carryover period, subject to an annual limitation on NOLs generated prior to January 29, 2021. The Company’s use of federal and state NOLs and credit carryforwards could be further limited by the provisions of Section 382 depending on the timing and amount of additional equity securities that have or will be issued subsequently to December 31, 2022. If an ownership change(s) occur subsequent to December 31, 2022, the Company’s NOLs and credits may be restricted or eliminated. If eliminated, the related asset would be removed from deferred tax assets with a corresponding reduction in the valuation allowance. Due to the existence of the valuation allowance, limitations created by future ownership changes, if any, will not impact the Company’s effective tax rate.

Risks Related to Our Intellectual Property

If we are unable to obtain and maintain patent protection for our therapeutic and diagnostic programs and other proprietary technologies we may develop, or if the scope of the patent protection obtained is not sufficiently broad, our competitors could develop and commercialize products and technology similar or identical to ours, and our ability to successfully commercialize our therapeutic and diagnostic programs and other proprietary technologies we may develop may be adversely affected.

Our success depends in large part on our ability and the ability of our licensors and collaborators to obtain and maintain patent protection in the United States and other countries with respect to our therapeutic and diagnostic programs and other proprietary technologies we may develop. We seek to protect our proprietary position, in part, by filing patent applications in the United States and abroad relating to our therapeutic and diagnostic programs and other proprietary technologies we may develop. If we or our licensors are unable to obtain or maintain patent protection with respect to our therapeutic programs and other proprietary technologies we may develop, our business, financial condition, results of operations and prospects could be materially harmed.

Our current patent portfolio contains a limited number of patents and patent applications, some of which are in-licensed from third parties, related to various aspects of our therapeutic and diagnostic programs. While we co-own with Dr. Falk Pharma GmbH one U.S. pending PCT application related to the composition of PRA052, we do not currently own or license any issued composition of matter patents covering PRA052, and we cannot be certain that any non-provisional patent applications we or our licensors may file will result in issued patent claims covering the composition of matter of PRA052. Provisional patent applications are not eligible to become issued patents until, among other things, a non-provisional patent application is filed claiming priority to one or more of our related provisional applications within 12 months of filing the first-filed provisional patent application. Composition-of-matter patents on the active pharmaceutical ingredient, or API, in prescription drug products are generally considered to be the strongest form of intellectual property protection for drug products because those types of patents provide protection without regard to any particular method of use or manufacture or formulation of the API used. Method-of-use patents protect the use of a product for the specified method and formulation patents cover formulations of the API. These types of patents do not prevent a competitor or other third party from developing or marketing an identical product for an indication that is outside the scope of the patented method or from developing a different formulation that is outside the scope of the patented formulation. Moreover, with respect to method-of-use patents, even if competitors or other third parties do not actively promote their product for our targeted indications or uses for which we may obtain patents, physicians may recommend that patients use these products off-label, or patients may do so themselves. Although off-label use may infringe or contribute to the infringement of method-of-use patents, the practice is common, and this type of infringement is difficult to prevent or prosecute. Accordingly, there can be no assurance that our patent portfolio will provide us with any competitive advantage.

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Changes in either the patent laws or their interpretation in the United States and other countries may diminish our ability to protect our inventions, obtain, maintain and enforce our intellectual property rights and, more generally, could affect the value of our intellectual property or narrow the scope of our protection. We cannot predict whether the patent applications we or our licensors are currently pursuing will issue as patents in any particular jurisdiction or whether the claims of any issued patents will provide sufficient protection against competitors or other third parties.

The patent prosecution process is expensive, time-consuming, and complex, and we may not be able to file, prosecute, maintain, defend, enforce, or license all necessary or desirable patent applications at a reasonable cost or in a timely manner. It is also possible that we will fail to identify patentable aspects of our research and development output in time to obtain patent protection. Moreover, in some circumstances, we do not have the right to control the preparation, filing and prosecution of patent applications, or to maintain and defend the patents, directed to technology that we license from third parties. We may also require the cooperation of our licensor in order to enforce the licensed patent rights, and such cooperation may not be provided. Therefore, these patents and patent applications may not be prosecuted and enforced in a manner consistent with the best interests of our business. We cannot be certain that patent prosecution and maintenance activities by our licensors have been or will be conducted in compliance with applicable laws and regulations, which may affect the validity and enforceability of such patents or any patents that may issue from such patent applications. If our licensors fail to do so, this could cause us to lose rights in any applicable intellectual property that we in-license, and as a result, our ability to develop and commercialize products or product candidates may be adversely affected and we may be unable to prevent competitors from making, using and selling competing products.

In addition, although we enter into non-disclosure and confidentiality agreements with parties who have access to confidential or patentable aspects of our research and development output, such as our employees, corporate collaborators, outside scientific collaborators, CROs, contract manufacturers, consultants, advisors and other third parties, any of these parties may breach the agreements and disclose such output before a patent application is filed, thereby jeopardizing our ability to obtain or maintain valid and enforceable patent protection. Furthermore, publications of discoveries in the scientific literature often lag behind the actual discoveries, and patent applications in the United States and other jurisdictions are typically not published until 18 months after filing or until issuance, or in some cases not at all. Therefore, we cannot be certain that we or our licensors were the first to make the inventions claimed in any of our owned or licensed patents or pending patent applications, or that we or our licensors were the first to file for patent protection of such inventions.

The patent position of biotechnology and pharmaceutical companies is highly uncertain in general, involves complex legal and factual questions, and has been the subject of much litigation in recent years. As a result, the issuance, scope, validity, enforceability and commercial value of our patent rights are highly uncertain. Our owned or in-licensed patent applications may not result in patents being issued which protect our therapeutic and diagnostic programs and other proprietary technologies we may develop or which effectively prevent others from commercializing competitive technologies and products.

Moreover, the claim coverage in a patent application can be significantly reduced before a corresponding patent issues. Even if our owned or in-licensed patent applications issue as patents, they may not issue in a form that will provide us with meaningful protection, prevent competitors or other third parties from competing with us, or otherwise provide us with any competitive advantage. Any patents issuing from our owned or in-licensed patent applications may be challenged, narrowed, circumvented or invalidated by third parties. Consequently, we do not know whether our therapeutic and diagnostic programs and other proprietary technology will be protectable or remain protected by valid and enforceable patents. Even if a patent issues, our competitors or other third parties may be able to circumvent the patent by developing similar or alternative technologies or products in a non-infringing manner which could materially adversely affect our business, financial condition, results of operations and prospects. In addition, given the amount of time required for the development, testing and regulatory review of our therapeutic and diagnostic programs and eventual product candidates, patents protecting our product candidates might expire before or shortly after such product candidates are commercialized. As a result, our intellectual property may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours.

The issuance of a patent is not conclusive as to its inventorship, scope, validity, or enforceability and our patent rights may be challenged in the courts or patent offices in the United States and abroad. We or any of our licensors may be subject to a third-party pre-issuance submission of prior art to the United States Patent and Trademark Office (USPTO) or become involved in opposition, derivation, revocation, reexamination, post-grant and inter partes review, or other similar proceedings challenging our patent rights. An adverse determination in any such submission, proceeding or litigation could reduce the scope of, or invalidate or render unenforceable, our patent rights, allow third parties to commercialize our therapeutic and diagnostic programs and other proprietary technologies we may develop and compete directly with us, without payment to us, or result in our inability to manufacture or commercialize products without infringing third-party patent rights. Such proceedings also may result in substantial cost and require significant time from our scientists and management, even if the eventual outcome is favorable to us.

Moreover, some of our owned and in-licensed patent rights are, and may in the future be, co-owned with third parties. If we are unable to obtain an exclusive license to any such third-party co-owners’ interest in such patent rights, such co-owners may be able to license their rights to other third parties, including our competitors, and our competitors could market competing products and technology. In addition, we may need the cooperation of any such co-owners of such patent rights in order to enforce such patent rights against third

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parties, and such cooperation may not be provided to us. Any of the foregoing could have a material adverse effect on our competitive position, business, financial conditions, results of operations, and prospects.

Furthermore, our owned and in-licensed patent rights may be subject to a reservation of rights by one or more third parties. For example, the research resulting in certain of our patent rights and technology was funded in part by the U.S. government. As a result, the government may have certain rights, or march-in rights, to such patent rights and technology. When new technologies are developed with government funding, the government generally obtains certain rights in any resulting patents, including a non-exclusive license authorizing the government to use the invention for non-commercial purposes. These rights may permit the government to disclose our confidential information to third parties and to exercise march-in rights to use or allow third parties to use our licensed technology. The government can exercise its march-in rights if it determines that action is necessary because we fail to achieve practical application of the government-funded technology, because action is necessary to alleviate health or safety needs, to meet requirements of federal regulations, or to give preference to U.S. industry. In addition, our rights in such inventions may be subject to certain requirements to manufacture products embodying such inventions in the U.S. Any exercise by the government of such rights could harm our competitive position, business, financial condition, results of operations and prospects.

We may not be able to protect our intellectual property and proprietary rights throughout the world.

Filing, prosecuting, maintaining and defending patents on our therapeutic and diagnostic programs and other proprietary technologies we may develop in all countries throughout the world would be prohibitively expensive, and the laws of foreign countries may not protect our rights to the same extent as the laws of the United States. Consequently, we may not be able to prevent third parties from practicing our inventions in all countries outside the United States, or from selling or importing products made using our inventions in and into the United States or other jurisdictions. Competitors may use our technologies in jurisdictions where we have not obtained patent protection to develop their own products and, further, may export otherwise infringing products to territories where we have patent protection but enforcement is not as strong as that in the United States. These products may compete with our products, and our patent rights or other intellectual property rights may not be effective or sufficient to prevent them from competing.

Many companies have encountered significant problems in protecting and defending intellectual property rights in foreign jurisdictions. The legal systems of certain countries, such as certain developing countries, do not favor the enforcement of patents, trade secrets and other intellectual property protection, particularly those relating to biotechnology products, which could make it difficult for us to stop the infringement of our patent rights or marketing of competing products in violation of our intellectual property and proprietary rights generally. In addition, some jurisdictions, such as Europe, Japan and China, may have a higher standard for patentability than in the United States, including, for example, the requirement of claims having literal support in the original patent filing and the limitation on using supporting data that is not in the original patent filing. Under those heightened patentability requirements, we may not be able to obtain sufficient patent protection in certain jurisdictions even though the same or similar patent protection can be secured in the U.S. and other jurisdictions.

Proceedings to enforce our intellectual property and proprietary rights in foreign jurisdictions could result in substantial costs and divert our efforts and attention from other aspects of our business, could put our patent rights at risk of being invalidated or interpreted narrowly, could put our owned or in-licensed patent applications at risk of not issuing and could provoke third parties to assert claims against us. We may not prevail in any lawsuits that we initiate, and the damages or other remedies awarded, if any, may not be commercially meaningful. Accordingly, our efforts to enforce our intellectual property and proprietary rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we develop or license.

Many countries have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third parties. In addition, many countries limit the enforceability of patents against government agencies or government contractors. In these countries, the patent owner may have limited remedies, which could materially diminish the value of such patent. If we or any of our licensors are forced to grant a license to third parties with respect to any patents relevant to our business, our competitive position may be impaired, and our business, financial condition, results of operations and prospects may be adversely affected.

In 2012, the European Patent Package, or EU Patent Package, regulations were passed with the goal of providing a single pan-European Unitary Patent and a new European Unified Patent Court, or UPC, for litigation involving European patents. Implementation of the EU Patent Package will likely occur in the first half of 2023. Under the UPC, all European patents, including those issued prior to ratification of the European Patent Package, will by default automatically fall under the jurisdiction of the UPC. The UPC will provide our competitors with a new forum to centrally revoke our European patents, and allow for the possibility of a competitor to obtain pan-European injunctions. It will be several years before we will understand the scope of patent rights that will be recognized and the strength of patent remedies that will be provided by the UPC. Under the EU Patent Package as currently proposed, we will have the right to opt our patents out of the UPC over the first seven years of the court’s existence, but doing so may preclude us from realizing the benefits of the new unified court.

Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment, and other requirements imposed by government patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.

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Periodic maintenance fees, renewal fees, annuity fees, and various other government fees on patents and patent applications will be due to be paid to the USPTO and various government patent agencies outside of the United States over the lifetime of our owned or licensed patents and patent applications. In certain circumstances, we rely on our licensing partners to pay these fees due to U.S. and non-U.S. patent agencies. The USPTO and various non-U.S. government agencies require compliance with several procedural, documentary, fee payment and other similar provisions during the patent application process. We are also dependent on our licensors to take the necessary action to comply with these requirements with respect to our licensed intellectual property. In some cases, an inadvertent lapse can be cured by payment of a late fee or by other means in accordance with the applicable rules. There are situations, however, in which non-compliance can result in abandonment or lapse of the patent or patent application, resulting in a partial or complete loss of patent rights in the relevant jurisdiction. In such an event, potential competitors might be able to enter the market with similar or identical products or technology, which could have a material adverse effect on our business, financial condition, results of operations, and prospects.

The COVID-19 pandemic or any future public health issue may impair our and our licensors’ ability to comply with these procedural, document submission, fee payment, and other requirements imposed by government patent agencies, which may materially and adversely affect our ability to obtain or maintain patent protection for our products and product candidates. There may be situations in which a delay in, or failure to, file a patent application pertaining to certain subject matter will result in a lack of patent protection of that subject matter. Similarly, there may be situations in which a delay in, or failure to, respond to a patent office communication, pay a requisite fee, or otherwise maintain a patent application will result in loss of patent rights to that subject matter. In such an event, potential competitors might be able to enter the market with similar or identical products or technology, which could have a material adverse effect on our business, financial condition, results of operations, and prospects.

Changes in U.S. patent law could diminish the value of patents in general, thereby impairing our ability to protect our products.

Changes in either the patent laws or interpretation of the patent laws in the United States could increase the uncertainties and costs surrounding the prosecution of patent applications and the enforcement or defense of issued patents. Assuming that other requirements for patentability are met, prior to March 2013, in the United States, the first to invent the claimed invention was entitled to the patent, while outside the United States, the first to file a patent application was entitled to the patent. After March 2013, under the Leahy-Smith America Invents Act (the America Invents Act) enacted in September 2011, the United States transitioned to a first inventor to file system in which, assuming that other requirements for patentability are met, the first inventor to file a patent application will be entitled to the patent on an invention regardless of whether a third party was the first to invent the claimed invention. A third party that files a patent application in the USPTO after March 2013, but before us could therefore be awarded a patent covering an invention of ours even if we had made the invention before it was made by such third party. This will require us to be cognizant going forward of the time from invention to filing of a patent application. Since patent applications in the United States and most other countries are typically not published until 18 months after filing or until issuance, or in some cases not at all, we cannot be certain that we were the first to either (i) file any patent application related to our therapeutic and diagnostic programs and other proprietary technologies we may develop or (ii) invent any of the inventions claimed in our owned or in-licensed patent applications.

The America Invents Act also includes a number of significant changes that affect the way patent applications will be prosecuted and also may affect patent litigation. These include allowing third party submission of prior art to the USPTO during patent prosecution and additional procedures to attack the validity of a patent by USPTO administered post-grant proceedings, including post-grant review, inter partes review and derivation proceedings. Because of a lower evidentiary standard in USPTO proceedings compared to the evidentiary standard in United States federal courts necessary to invalidate a patent claim, a third party could potentially provide evidence in a USPTO proceeding sufficient for the USPTO to hold a claim invalid even though the same evidence would be insufficient to invalidate the claim if first presented in a district court action. Accordingly, a third party may attempt to use the USPTO procedures to invalidate our patent claims that would not have been invalidated if first challenged by the third party as a defendant in a district court action. Therefore, the America Invents Act and its implementation could increase the uncertainties and costs surrounding the prosecution of our owned or in-licensed patent applications and the enforcement or defense of patents issuing from those patent applications, all of which could have a material adverse effect on our business, financial condition, results of operations and prospects.

In addition, the patent positions of companies in the development and commercialization of biologics and pharmaceuticals, as well as diagnostic methods, are particularly uncertain. Recent U.S. Supreme Court rulings have narrowed the scope of patent protection available in certain circumstances and weakened the rights of patent owners in certain situations. For example, U.S. Supreme Court rulings, such as Mayo Collaborative Servs. v. Prometheus Labs., Inc., 566 U.S. 66 (2012) and Alice Corp. Pty. Ltd. v. CLS Bank Int’l, 573 U.S. 208 (2014), have created judicial exceptions to patentability of diagnostic methods in the U.S. that are directed to laws of nature or natural phenomena. As such, we cannot guarantee that we will be able to obtain patents covering our diagnostic candidates, including any companion diagnostics. These cases and others like them have created uncertainty with respect to the validity and enforceability of patents, once obtained. Depending on future actions by the U.S. Congress, the federal courts and the USPTO, the laws and regulations governing patents could change in unpredictable ways. In addition, the complexity and uncertainty of European patent laws have also increased in recent years. Any of the foregoing could have a material adverse effect on our owned and in-licensed patent portfolio and our ability to protect and enforce our intellectual property in the future.

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Issued patents covering our therapeutic or diagnostic programs or other proprietary technologies we may develop could be found invalid or unenforceable if challenged in court or before administrative bodies in the United States or abroad.

Our patent rights may be subject to priority, validity, inventorship and enforceability disputes. Legal proceedings relating to intellectual property claims, with or without merit, are unpredictable and generally expensive and time-consuming and likely to divert significant resources from our core business, including distracting our management and scientific personnel from their normal responsibilities and generally harm our business. If we or our licensors are unsuccessful in any of these proceedings, such patents and patent applications may be narrowed, invalidated or held unenforceable, we may be required to obtain licenses from third parties, which may not be available on commercially reasonable terms or at all, or we may be required to cease the development, manufacture or commercialization of our product candidates. Any of the foregoing could have a material adverse effect on our business, financial condition, results of operations and prospects.

If we or one of our licensors initiated legal proceedings against a third party to enforce a patent covering our therapeutic or diagnostic programs or other proprietary technologies we may develop, the defendant could counterclaim that such patent is invalid or unenforceable. In patent litigation in the United States, defendant counterclaims alleging invalidity or unenforceability are commonplace. Grounds for a validity challenge could be an alleged failure to meet any of several statutory requirements, including lack of novelty, obviousness or non-enablement. Grounds for an unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheld relevant information from the USPTO, or made a misleading statement, during prosecution. Third parties may raise claims challenging the validity or enforceability of a patent before administrative bodies in the United States or abroad, even outside the context of litigation. Such mechanisms include re-examination, post-grant review, inter partes review, derivation proceedings, and equivalent proceedings in foreign jurisdictions (e.g., opposition proceedings). Such proceedings could result in the revocation of, cancellation of or amendment to our patent rights in such a way that they no longer cover our therapeutic and diagnostic programs and other proprietary technologies we may develop. The outcome following legal assertions of invalidity and unenforceability is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art, of which we or our licensing partners and the patent examiner were unaware during prosecution. If a third party were to prevail on a legal assertion of invalidity or unenforceability, we would lose at least part, and perhaps all, of the patent protection on our therapeutic and diagnostic programs and other proprietary technologies we may develop. Such a loss of patent protection would have a material adverse impact on our business, financial condition, results of operations and prospects.

Patent terms may be inadequate to protect our competitive position on products and product candidates for an adequate amount of time.

Patents have a limited lifespan. In the United States, if all maintenance fees are timely paid, the natural expiration of a patent is generally 20 years from its earliest U.S. non-provisional or international patent application filing date. Various extensions may be available, but the life of a patent, and the protection it affords, is limited. Even if patents covering our product candidates are obtained, once the patent has expired, we may be vulnerable to competition from competitive products, including generics or biosimilars. Given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such product candidates might expire before or shortly after such product candidates are commercialized. As a result, our owned and licensed patent portfolio may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours.

If we do not obtain patent term extension for our product candidate, our business may be materially harmed.

Depending upon the timing, duration and specifics of any FDA marketing approval of any of our product candidates, one or more of our issued U.S. patents may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Action of 1984 (Hatch-Waxman Amendments). The Hatch-Waxman Amendments permit a patent extension term (PTE) of up to five years as compensation for patent term lost during the FDA regulatory review process. A patent term extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval, only one patent may be extended and only those claims covering the approved drug, a method for using it or a method for manufacturing it may be extended. Similar patent term restoration provisions to compensate for commercialization delay caused by regulatory review are also available in certain foreign jurisdictions, such as in Europe under Supplemental Protection Certificate (SPC). However, we may not be granted an extension because of, for example, failing to exercise due diligence during the testing phase or regulatory review process, failing to apply within applicable deadlines, failing to apply prior to expiration of relevant patents, or otherwise failing to satisfy applicable requirements. Moreover, the applicable time period or the scope of patent protection afforded could be less than we request. If we are unable to obtain patent term extension or term of any such extension is less than we request, our competitors may obtain approval of competing products following our patent expiration, and our business, financial condition, results of operations and prospects could be materially harmed.

We may be subject to claims challenging the inventorship of our owned or in-licensed patent rights and other intellectual property.

We may be subject to claims that former employees, collaborators or other third parties have an interest in our patent rights, trade secrets, or other intellectual property as an inventor or co-inventor. For example, we may have inventorship disputes arise from conflicting obligations of consultants or others who are involved in developing our therapeutic and diagnostic programs and other

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proprietary technologies we may develop. Litigation may be necessary to defend against these and other claims challenging inventorship or our patent rights, trade secrets or other intellectual property. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights, such as exclusive ownership of, or right to use, intellectual property that is important to our therapeutic and diagnostic programs and other proprietary technologies we may develop. Even if we are successful in defending against such claims, litigation could result in substantial costs and be a distraction to our management and other employees. Any of the foregoing could have a material adverse effect on our business, financial condition, results of operations and prospects.

If we are unable to protect the confidentiality of our trade secrets, our business and competitive position would be harmed.

In addition to seeking patent protection for our therapeutic and diagnostic programs and other proprietary technologies we may develop, we also rely on trade secrets and confidentiality agreements to protect our unpatented know-how, technology, and other proprietary information and to maintain our competitive position. With respect to Prometheus360 and our development programs, we consider trade secrets and know-how to be one of our important sources of intellectual property. Trade secrets and know-how can be difficult to protect. In particular, the trade secrets and know-how in connection with Prometheus360, development programs and other proprietary technology we may develop may over time be disseminated within the industry through independent development, the publication of journal articles describing the methodology and the movement of personnel with scientific positions in academia and industry.

We seek to protect these trade secrets and other proprietary technology, in part, by entering into non-disclosure and confidentiality agreements with parties who have access to them, such as our employees, corporate collaborators, outside scientific collaborators, CROs, contract manufacturers, consultants, advisors and other third parties. We also enter into confidentiality and invention or patent assignment agreements with our employees and consultants. We cannot guarantee that we have entered into such agreements with each party that may have or have had access to our trade secrets or proprietary technology and processes. Despite these efforts, any of these parties may breach the agreements and disclose our proprietary information, including our trade secrets, and we may not be able to obtain adequate remedies for such breaches. Enforcing a claim that a party illegally disclosed or misappropriated a trade secret is difficult, expensive and time-consuming, and the outcome is unpredictable. In addition, some courts inside and outside the United States are less willing or unwilling to protect trade secrets. If any of our trade secrets were to be lawfully obtained or independently developed by a competitor or other third party, we would have no right to prevent them from using that technology or information to compete with us. If any of our trade secrets were to be disclosed to or independently developed by a competitor or other third party, our competitive position would be materially and adversely harmed.

We may be subject to claims that third parties have an ownership interest in our trade secrets. For example, we may have disputes arise from conflicting obligations of our employees, consultants or others who are involved in developing our product candidate. Litigation may be necessary to defend against these and other claims challenging ownership of our trade secrets. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable trade secret rights, such as exclusive ownership of, or right to use, trade secrets that are important to our therapeutic and diagnostic programs and other proprietary technologies we may develop. Such an outcome could have a material adverse effect on our business. Even if we are successful in defending against such claims, litigation could result in substantial costs and be a distraction to our management and other employees. Any of the foregoing could have a material adverse effect on our business, financial condition, results of operations and prospects.

We may not identify relevant third-party patents or may incorrectly interpret the relevance, scope or expiration of a third-party patent, which might adversely affect our ability to develop and market our products and product candidates.

We cannot guarantee that any of our patent searches or analyses, including the identification of relevant patents, the scope of patent claims or the expiration of relevant patents, are complete or thorough, nor can we be certain that we have identified each and every third-party patent and pending patent application in the United States and abroad that is relevant to or necessary for the commercialization of our current and future products and product candidates in any jurisdiction. The scope of a patent claim is determined by an interpretation of the law, the written disclosure in a patent and the patent’s prosecution history. Our interpretation of the relevance or the scope of a patent or a pending patent application may be incorrect, which may negatively impact our ability to market our products. We may incorrectly determine that our products or product candidates are not covered by a third-party patent or may incorrectly predict whether a third party’s pending patent application will issue with claims of relevant scope. Our determination of the expiration date of any patent in the United States or abroad that we consider relevant may be incorrect, and we may incorrectly conclude that a third-party patent is invalid and unenforceable. Our failure to identify and correctly interpret relevant patents may negatively impact our ability to develop and market our products and product candidates.

Any of the foregoing could have a material adverse effect on our business, financial condition, results of operations and prospects.

We may be subject to claims that our employees, consultants or advisors have wrongfully used or disclosed alleged trade secrets of their current or former employers or claims asserting ownership of what we regard as our own intellectual property.

Some of our employees, consultants and advisors are currently or were previously employed at universities or other biotechnology or pharmaceutical companies, including our competitors or potential competitors. Although we try to ensure that our employees,

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consultants and advisors do not use the proprietary information or know-how of others in their work for us, we may be subject to claims that we or these individuals have used or disclosed intellectual property, including trade secrets or other proprietary information, of any such individual’s current or former employer. Litigation may be necessary to defend against these claims. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel. Even if we are successful in defending against such claims, litigation could result in substantial costs and be a distraction to our management.

In addition, while it is our policy to require our employees and contractors who may be involved in the conception or development of intellectual property to execute agreements assigning such intellectual property to us, we may be unsuccessful in executing such an agreement with each party who, in fact, conceives or develops intellectual property that we regard as our own. The assignment of intellectual property rights may not be self-executing, or the assignment agreements may be breached, and we may be forced to bring claims against third parties, or defend claims that they may bring against us, to determine the ownership of what we regard as our intellectual property. Such claims could have a material adverse effect on our business, financial condition, results of operations and prospects.

Third-party claims of intellectual property infringement, misappropriation or other violations against us or our collaborators may prevent or delay the development and commercialization of our therapeutic and diagnostic programs and other proprietary technologies we may develop.

Our commercial success depends in part on our ability, and the ability of our collaborators, to avoid infringing, misappropriating and otherwise violating the patents and other intellectual property rights of third parties. There is a substantial amount of complex litigation involving patents and other intellectual property rights in the biotechnology and pharmaceutical industries, as well as administrative proceedings for challenging patents, including interference, derivation and reexamination proceedings before the USPTO or oppositions and other comparable proceedings in foreign jurisdictions. As discussed above, recently, due to changes in U.S. law, new procedures including inter partes review and post-grant review have also been implemented. As stated above, these changes add uncertainty to the possibility of challenges to our patent rights in the future.

Numerous U.S. and foreign issued patents and pending patent applications owned by third parties exist in the fields in which we are commercializing or plan to commercialize our therapeutic and diagnostic programs and in which we are developing other proprietary technologies. As the biotechnology and pharmaceutical industries expand and more patents are issued, and as we gain greater visibility and market exposure as a public company, the risk that our therapeutic and diagnostic programs and commercializing activities may give rise to claims of infringement of the patent rights of others increases. We cannot assure you that our therapeutic and diagnostic programs and other proprietary technologies we may develop will not infringe existing or future patents owned by third parties. We may not be aware of patents that have already been issued and that a third party, including a competitor in the fields in which we are developing our therapeutic and diagnostic programs, might assert as infringed by us. It is also possible that patents owned by third parties of which we are aware, but which we do not believe we infringe or that we believe we have valid defenses to any claims of patent infringement, could be found to be infringed by us. It is not unusual that corresponding patents issued in different countries have different scopes of coverage, such that in one country a third-party patent does not pose a material risk, but in another country, the corresponding third-party patent may pose a material risk to our products or product candidates. As such, we monitor third-party patents in the relevant pharmaceutical markets. In addition, because patent applications can take many years to issue, there may be currently pending patent applications that may later result in issued patents that we may infringe.

In the event that any third-party claims that we infringe their patents or that we are otherwise employing their proprietary technology without authorization and initiates litigation against us, even if we believe such claims are without merit, a court of competent jurisdiction could hold that such patents are valid, enforceable and infringed by us. Defense of infringement claims, regardless of their merit, would involve substantial litigation expense and would be a substantial diversion of management and other employee resources from our business, and may impact our reputation. In the event of a successful claim of infringement against us, we may be enjoined from further developing or commercializing the infringing products or technologies. In addition, we may have to pay substantial damages, including treble damages and attorneys’ fees for willful infringement, obtain one or more licenses from third parties, pay royalties and/or redesign our infringing products or technologies, which may be impossible or require substantial time and monetary expenditure. Such licenses may not be available on commercially reasonable terms or at all. Even if we are able to obtain a license, the license would likely obligate us to pay license fees or royalties or both, and the rights granted to us might be nonexclusive, which could result in our competitors gaining access to the same intellectual property. If we are unable to obtain a necessary license to a third-party patent on commercially reasonable terms, we may be unable to commercialize the infringing products or technologies or such commercialization efforts may be significantly delayed, which could in turn significantly harm our business. In addition, we may in the future pursue patent challenges with respect to third-party patents, including as a defense against the foregoing infringement claims. The outcome of such challenges is unpredictable.

Even if resolved in our favor, the foregoing proceedings could be very expensive, particularly for a company of our size, and time-consuming. Such proceedings could substantially increase our operating losses and reduce the resources available for development activities or any future sales, marketing or distribution activities. We may not have sufficient financial or other resources to conduct such proceedings adequately. Some of our competitors may be able to sustain the costs of litigation or administrative proceedings

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more effectively than we can because of greater financial resources. Such legal proceedings may also absorb significant time of our technical and management personnel and distract them from their normal responsibilities. Uncertainties resulting from such proceedings could impair our ability to compete in the marketplace. In addition, there could be public announcements of the results of hearings, motions or other interim proceedings or developments and if securities analysts or investors perceive these results to be negative, it could have a substantial adverse effect on the price of our common stock. The occurrence of any of the foregoing could have a material adverse effect on our business, financial condition or results of operations.

We may become involved in lawsuits to protect or enforce our patent rights and other intellectual property rights, which could be expensive, time consuming and unsuccessful.

Third parties, such as a competitor, may infringe our patent rights. In an infringement proceeding, a court may decide that a patent owned by or licensed to us is invalid or unenforceable or may refuse to stop the other party from using the technology at issue on the grounds that the patent does not cover such technology. In addition, our patent rights may become involved in inventorship, priority or validity disputes. To counter or defend against such claims can be expensive and time consuming. An adverse result in any litigation proceeding could put our patent rights at risk of being invalidated, held unenforceable or interpreted narrowly. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation and proceedings, there is a risk that some of our confidential information could be compromised by disclosure during such litigation and proceedings.

Even if resolved in our favor, litigation or other legal proceedings relating to intellectual property claims may cause us to incur significant expenses and could distract our personnel from their normal responsibilities. In addition, there could be public announcements of the results of hearings, motions or other interim proceedings or developments, and if securities analysts or investors perceive these results to be negative, it could have a substantial adverse effect on the price of our common stock. Such litigation or proceedings could substantially increase our operating losses and reduce the resources available for development activities or any future sales, marketing or distribution activities. We may not have sufficient financial or other resources to conduct such litigation or proceedings adequately. Some of our competitors may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their greater financial resources and more mature and developed intellectual property portfolios. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could have a material adverse effect on our ability to compete in the marketplace. The occurrence of any of the foregoing could have a material adverse effect on our business, financial condition or results of operations.

If our trademarks and trade names are not adequately protected, then we may not be able to build name recognition in our markets of interest and our business may be adversely affected.

Our registered or unregistered trademarks or trade names may be challenged, infringed, circumvented or declared generic or determined to be infringing on other marks. During trademark registration proceedings, we may receive rejections of our applications by the USPTO or in other foreign jurisdictions. Although we are given an opportunity to respond to such rejections, we may be unable to overcome them. In addition, in the USPTO and in comparable agencies in many foreign jurisdictions, third parties are given an opportunity to oppose pending trademark applications and to seek to cancel registered trademarks. Opposition or cancellation proceedings may be filed against our trademarks, which may not survive such proceedings. Moreover, any name we have proposed to use with our product candidate in the United States must be approved by the FDA, regardless of whether we have registered it, or applied to register it, as a trademark. Similar requirements exist in Europe. The FDA typically conducts a review of proposed product names, including an evaluation of potential for confusion with other product names. If the FDA or an equivalent administrative body in a foreign jurisdiction objects to any of our proposed proprietary product names, we may be required to expend significant additional resources in an effort to identify a suitable substitute name that would qualify under applicable trademark laws, not infringe the existing rights of third parties and be acceptable to the FDA. Furthermore, in many countries, owning and maintaining a trademark registration may not provide an adequate defense against a subsequent infringement claim asserted by the owner of a senior trademark.

We may not be able to protect our rights to these trademarks and trade names, which we need to build name recognition among potential partners or customers in our markets of interest. At times, competitors or other third parties may adopt trade names or trademarks similar to ours, thereby impeding our ability to build brand identity and possibly leading to market confusion. In addition, there could be potential trade name or trademark infringement claims brought by owners of other registered trademarks or trademarks that incorporate variations of our registered or unregistered trademarks or trade names. Over the long term, if we are unable to establish name recognition based on our trademarks and trade names, then we may not be able to compete effectively and our business may be adversely affected. Our efforts to enforce or protect our proprietary rights related to trademarks, trade names, domain name or other intellectual property may be ineffective and could result in substantial costs and diversion of resources and could adversely affect our business, financial condition, results of operations and prospects.

Intellectual property rights do not necessarily address all potential threats.

The degree of future protection afforded by our intellectual property rights is uncertain because intellectual property rights have limitations and may not adequately protect our business or permit us to maintain our competitive advantage. For example:

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Should any of the foregoing occur, it could adversely affect our business, financial condition, results of operations and prospects.

We depend on intellectual property licensed from third parties, and our licensors may not always act in our best interest. If we fail to comply with our obligations under our intellectual property licenses, if the licenses are terminated or if disputes regarding these licenses arise, we could lose significant rights that are important to our business.

We are dependent, in part, on patents, know-how and other intellectual property and proprietary technology licensed from others. We are a party to a number of license agreements under which we are granted rights to intellectual property that are important to our business and we may enter into additional license agreements in the future. For example, in September 2017, we entered into an exclusive license agreement with Cedars-Sinai, as amended and restated in 2021, that grants us an exclusive license from Cedars-Sinai under certain patent rights, information and materials related to novel therapeutic targets and diagnostic products for our therapeutic programs that are important to our business. This agreement and our other existing license agreements impose, and we expect that any future license agreements where we in-license intellectual property, will impose on us, various development, regulatory and/or commercial diligence obligations, payment of milestones and/or royalties and other obligations. If we fail to comply with our obligations under these agreements, or we are subject to bankruptcy-related proceedings, the licensor may have the right to terminate the license, in which event we would not be able to develop or market products covered by the license.

If we or our licensors fail to adequately protect our licensed intellectual property, our ability to commercialize product candidates could suffer. We do not have complete control over the maintenance, prosecution and litigation of our in-licensed patents, patent applications and other intellectual property and may have limited control over future intellectual property that may be in-licensed. For example, we cannot be certain that activities such as the maintenance and prosecution by our licensors have been or will be conducted in compliance with applicable laws and regulations or will result in valid and enforceable patents and other intellectual property rights. It is possible that our licensors’ conduct of intellectual property enforcement or defense proceedings may be less vigorous than had we conducted them ourselves, or may not be conducted in accordance with our best interests.

In addition, the agreements under which we license intellectual property or technology from third parties are complex, and certain provisions in such agreements may be susceptible to multiple interpretations. The resolution of any contract interpretation disagreement that may arise could narrow what we believe to be the scope of our rights to the relevant patents, know-how and other intellectual property and proprietary technology, or increase what we believe to be our financial or other obligations under the relevant agreement. Disputes that may arise between us and our licensors regarding intellectual property subject to a license agreement could include disputes regarding:

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If disputes over intellectual property that we have licensed prevent or impair our ability to maintain our current licensing arrangements on acceptable terms, we may be unable to successfully develop and commercialize the affected technology, products or product candidates. As a result, any termination of or disputes over our intellectual property license agreements could result in the loss of our ability to develop and commercialize Prometheus360, or our therapeutic and diagnostic products or product candidates, or we could lose other significant rights, any of which could have a material adverse effect on our business, financial condition, results of operations and prospects.

For example, our agreements with certain of our third-party research partners provide that improvements developed in the course of our relationship may be owned solely by either us or our third-party research partner, or jointly between us and the third party. If we determine that rights to such improvements owned solely by a research partner or other third party with whom we collaborate are necessary to commercialize our product candidates or maintain our competitive advantage, we may need to obtain a license from such third party in order to use the improvements and continue developing, manufacturing or marketing our products or product candidates. We may not be able to obtain such a license on an exclusive basis, on commercially reasonable terms, or at all, which could prevent us from commercializing our products or product candidates or allow our competitors or others the chance to access technology that is important to our business. We also may need the cooperation of any co-owners of our intellectual property in order to prosecute, maintain, defend and enforce such intellectual property against third parties, and such cooperation may not be provided to us.

We may not be successful in obtaining or maintaining necessary rights to product components and processes for our development pipeline through acquisitions and in-licenses.

The growth of our business may depend in part on our ability to acquire, in-license or use third-party intellectual property and proprietary rights. Other pharmaceutical companies and academic institutions may own patents or may have filed, or be planning to file, patent applications potentially relevant to our business. In order to avoid infringing such patent rights, we may find it necessary or prudent to obtain licenses to such patent rights from such third-parties. For example, our product candidates may require specific formulations to work effectively and efficiently, we may develop product candidates containing our compounds and pre-existing pharmaceutical compounds, or we may be required by the FDA or comparable foreign regulatory authorities to provide a companion diagnostic test or tests with our product candidates, any of which could require us to obtain rights to use intellectual property held by third parties. In addition, with respect to any patent or other intellectual property rights we may co-own with third parties, we may require licenses to such co-owners’ interest to such patent or other intellectual property rights. We may be unable to acquire or in-license any compositions, methods of use, processes or other third-party intellectual property rights from third parties that we identify as necessary or important to our business operations. In addition, we may fail to obtain any of these licenses at a reasonable cost or on reasonable terms, if at all. Were that to happen, we may need to cease use of the compositions or methods covered by those third-party intellectual property rights, and may need to seek to develop alternative approaches that do not infringe, misappropriate or otherwise violate those intellectual property rights, which may entail additional costs and development delays, even if we were able to develop such alternatives, which may not be feasible. Even if we are able to obtain a license, it may be non-exclusive, which means that our competitors may also receive access to the same technologies licensed to us. In that event, we may be required to expend significant time and resources to develop or license replacement technology.

Additionally, we sometimes collaborate with academic institutions to accelerate our preclinical research or development under written agreements with these institutions. In certain cases, these institutions provide us with an option to negotiate a license to any of the institution’s rights in technology resulting from the collaboration. Even if we hold such an option, we may be unable to negotiate a license from the institution within the specified timeframe or under terms that are acceptable to us. If we are unable to do so, the institution may offer the intellectual property rights to others, potentially blocking our ability to pursue our program.

The licensing and acquisition of third-party intellectual property rights is a competitive area, and companies that may be more established or have greater resources than we do may also be pursuing strategies to license or acquire third-party intellectual property rights that we may consider necessary or attractive in order to commercialize our product candidates. More established companies may have a competitive advantage over us due to their size, resources and greater clinical development and commercialization capabilities. In addition, companies that perceive us to be a competitor may be unwilling to assign or license rights to us. There can be no assurance that we will be able to successfully complete these types of negotiations and ultimately acquire the rights to the intellectual property related to the products or product candidates that we may seek to develop or market. If we are unable to

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successfully obtain rights to required third-party intellectual property or to maintain the existing intellectual property rights we have, we may have to abandon development of certain programs and our business, financial condition, results of operations and prospects could suffer.

We, our collaborators and our service providers may be subject to a variety of data privacy and security laws, regulations, contractual obligations and industry standards, which could increase compliance costs and our failure to comply with them could subject us to potentially significant liability, fines or penalties and otherwise harm our business.

We, our collaborators and our service providers maintain a large quantity of sensitive information, including confidential business information, health-related and other personal information, and are subject to laws and regulations governing the privacy and security of such information. The global data protection landscape is rapidly evolving, and we and our collaborators and service providers may be affected by or subject to new, amended or existing laws and regulations in the future, including as our operations continue to expand or if we operate in foreign jurisdictions. These laws and regulations may be subject to differing interpretations, which adds to the complexity of processing personal data. Guidance on implementation and compliance practices are often updated or otherwise revised. This may create uncertainty in our business, affect our ability to operate in certain jurisdictions or to collect, store, transfer, use, share and otherwise process personal information, necessitate the acceptance of more onerous obligations in our contracts, result in liability or impose additional costs on us. The cost of compliance with these laws, regulations and standards is high and is likely to increase in the future. Any failure or perceived failure by us to comply with federal, state or foreign laws or regulation, our internal policies and procedures or our contracts governing our processing of personal information could result in negative publicity, government investigations and enforcement actions, claims by third parties and damage to our reputation, any of which could have a material adverse effect on our business, financial condition, results of operations and prospects.

As our operations and business grow, we may become subject to or affected by new or additional data protection laws and regulations and face increased scrutiny or attention from regulatory authorities. In the United States, there are numerous federal and state data privacy and security laws and regulations governing the collection, use, disclosure and protection of personal information, including health information privacy laws, security breach notification laws and consumer protection laws(e.g., Section 5 of the Federal Trade Commission Act), that govern the collection, use, storage, transfer, disclosure, protection and other processing of health-related and other personal information could apply to our operations or the operations of our collaborators and third-party providers. In addition, we may obtain health information from third parties (including research institutions from which we obtain clinical trial data) that are subject to privacy and security requirements under HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act, and the regulations promulgated thereunder. Depending on the facts and circumstances, we could be subject to significant penalties if we violate HIPAA.

In addition, certain state laws govern the privacy and security of health-related and other personal information in certain circumstances, some of which are more stringent than HIPAA, broader in scope or offer greater individual rights with respect to protected health information than HIPAA. These laws are evolving rapidly and may differ from each other in significant ways and may not have the same effect, thus complicating compliance efforts. Such laws and regulations will be subject to interpretation by various courts and other governmental authorities, thus creating potentially complex compliance issues for us and our future customers and strategic partners. Failure to comply with these laws, where applicable, can result in the imposition of significant civil and/or criminal penalties and private litigation. For example, the California Consumer Privacy Act (CCPA), which went into effect on January 1, 2020, gives California residents individual privacy rights to access and delete their personal information, opt out of certain personal information sharing, and receive detailed information about how their personal information is used. The CCPA provides for civil penalties for violations, as well as a private right of action for data breaches that have increased the likelihood of, and risks associated with data breach litigation. The CCPA may increase our compliance costs and potential liability and many similar laws have been proposed at the federal level and in other states. Further, the California Privacy Rights Act (CPRA) generally went into effect on January 1, 2023, and significantly amends the CCPA. The CPRA imposes additional data protection obligations on covered businesses, including additional consumer rights processes, limitations on data uses, new audit requirements for higher risk data, and opt outs for certain uses of sensitive data. It has also created a new California data protection agency authorized to issue substantive regulations and could result in increased privacy and information security enforcement. Additional compliance investment and potential business process changes may be required. Similar laws have passed in Virginia, Colorado, Connecticut and Utah, and have been proposed in other states and at the federal level, reflecting a trend toward more stringent privacy legislation in the United States. The enactment of such laws could have potentially conflicting requirements that would make compliance challenging. In the event that we are subject to or affected by HIPAA, the CCPA, the CPRA or other domestic privacy and data protection laws, any liability from failure to comply with the requirements of these laws could adversely affect our financial condition.

There also are a wide variety of privacy laws in other countries that may impact our operations, now or in the future. For example, in Europe, the GDPR imposes stringent requirements regarding the collection, use, disclosure, storage, transfer or other processing of personal data of individuals within the EEA, including providing information to individuals regarding data processing activities, implementing safeguards to protect the security and confidentiality of personal data, providing notification of data breaches and taking certain measures when engaging third-party processors. Companies that must comply with the GDPR face increased compliance obligations and risk, including more robust regulatory enforcement of data protection requirements and potential fines for

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noncompliance of up to €20 million or 4% of the annual global revenue of the noncompliant company, whichever is greater. The GDPR also confers a private right of action in some circumstances on data subjects and consumer associations to lodge complaints with supervisory authorities, seek judicial remedies and obtain compensation for damages resulting from violations of the GDPR.

Among other things, the GDPR requires the establishment of a lawful basis for the processing of data, imposes requirements relating to the consent of the individuals to whom the personal data relates, including detailed notices for clinical trial subjects and investigators, as well as requirements regarding the security of personal data and notification of data processing obligations to the competent national data processing authorities. In addition, the GDPR increases the scrutiny of transfers of personal data from clinical trial sites located in the EEA to the United States and other jurisdictions that the European Commission does not recognize as having “adequate” data protection laws. Recent legal developments in Europe have created complexity and uncertainty regarding transfers of personal data from the EEA to the United States. For example, on July 16, 2020, the Court of Justice of the European Union (CJEU) limited how organizations could lawfully transfer personal data from the EU/EEA to the United States by invalidating the EU-US Privacy Shield Framework (Privacy Shield) for purposes of international transfers and imposing further restrictions on the use of standard contractual clauses (SCCs). In March 2022, the US and EU announced a new regulatory regime intended to replace the invalidated regulations; however, this new EU-US Data Privacy Framework has not been implemented beyond an executive order signed by President Biden on October 7, 2022 on Enhancing Safeguards for United States Signals Intelligence Activities. European court and regulatory decisions subsequent to the CJEU decision of July 16, 2020 have taken a restrictive approach to international data transfers. As supervisory authorities issue further guidance on personal data export mechanisms, including circumstances where the SCCs cannot be used, and/or start taking enforcement action, we could suffer additional costs, complaints and/or regulatory investigations or fines, and/or if we are otherwise unable to transfer personal data between and among countries and regions in which we operate, it could affect the manner in which we provide our services, the geographical location or segregation of our relevant systems and operations, and could adversely affect our financial results.

Further, since January 1, 2021, following the withdrawal of the UK from the European Union and the EEA and the end of the transition period, we have had to comply with the GDPR and separately the GDPR as implemented in the UK, each regime having the ability to fine up to the greater of €20 million/£17 million or 4% of global turnover.

In many jurisdictions, enforcement actions and consequences for noncompliance are rising. In the United States, these include enforcement actions in response to rules and regulations promulgated under the authority of federal agencies and state attorneys general and legislatures and consumer protection agencies. In addition, privacy advocates and industry groups have regularly proposed, and may propose in the future, self-regulatory standards that may legally or contractually apply to us. If we fail to follow these security standards, even if no personal information is compromised, we may incur significant fines or experience a significant increase in costs.

Many state legislatures have adopted legislation that regulates how businesses operate online, including measures relating to privacy, data security and data breaches. Laws in all U.S. states require businesses to provide notice to customers whose personally identifiable information has been disclosed as a result of a data breach. The laws are not consistent, and compliance in the event of a widespread data breach is costly.

Compliance with U.S. and international data protection laws and regulations could require us to take on more onerous obligations in our contracts, restrict our ability to collect, use and disclose data, update our data privacy and security policies and procedures, or in some cases, impact our ability to operate in certain jurisdictions. Failure by us or our collaborators and service providers to comply with U.S. and international data protection laws and regulations could result in government enforcement actions (which could include civil or criminal penalties), private litigation and/or adverse publicity and could negatively affect our operating results and business. Moreover, clinical trial subjects about whom we or our potential collaborators obtain information, as well as the providers who share this information with us, may contractually limit our ability to use and disclose the information. Claims that we have violated individuals’ privacy rights, failed to comply with data protection laws, or breached our contractual obligations, even if we are not found liable, could be expensive and time consuming to defend, could result in adverse publicity and could have a material adverse effect on our business, financial condition, results of operations and prospects.

Risks Related to Our Common Stock

The trading price of the shares of our common stock could be highly volatile, and purchasers of our common stock could incur substantial losses.

Our stock price has been, and is likely to continue to be, volatile. The stock market in general and the market for stock of biopharmaceutical companies in particular have experienced extreme volatility that has often been unrelated to the operating performance of particular companies. As a result of this volatility, investors may not be able to sell their common stock at or above the price at which they paid. The market price for our common stock may be influenced by those factors discussed in this “Risk Factors” section and many others, including:

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In addition, in the past, stockholders have initiated class action lawsuits against biopharmaceutical companies following periods of volatility in the market prices of these companies’ stock. Such litigation, if instituted against us, could cause us to incur substantial costs and divert our management’s attention and resources, which could have a material adverse effect on our business, financial condition and results of operations.

An active, liquid and orderly market for our common stock may not be maintained.

We can provide no assurance that we will be able to maintain an active trading market for our common stock. The lack of an active market may impair your ability to sell your shares at the time you wish to sell them or at a price that you consider reasonable. An inactive market may also impair our ability to raise capital by selling shares and may impair our ability to acquire other businesses or technologies using our shares as consideration, which, in turn, could materially adversely affect our business.

Our executive officers, directors and principal stockholders, if they choose to act together, have the ability to control or significantly influence all matters submitted to stockholders for approval.

As of February 21, 2023, our executive officers, directors and greater than 5% stockholders, in the aggregate, own approximately 37.7% of our outstanding common stock. As a result, such persons, acting together, have the ability to control or significantly influence all matters submitted to our board of directors or stockholders for approval, including the appointment of our management, the election and removal of directors and approval of any significant transaction, as well as our management and business affairs. This concentration of ownership may have the effect of delaying, deferring or preventing a change in control, impeding a merger, consolidation, takeover or other business combination involving us, or discouraging a potential acquiror from making a tender offer or otherwise attempting to obtain control of our business, even if such a transaction would benefit other stockholders.

We do not currently intend to pay dividends on our common stock, and, consequently, your ability to achieve a return on your investment will depend on appreciation, if any, in the price of our common stock.

We have never declared or paid any cash dividend on our common stock. We currently anticipate that we will retain future earnings for the development, operation and expansion of our business and do not anticipate declaring or paying any cash dividends for the foreseeable future. In addition, under the terms of our Loan Agreement, we are prohibited from paying any cash dividends without the consent of the lenders and any future debt agreements may preclude us from paying dividends. Any return to stockholders will therefore be limited to the appreciation of their stock. There is no guarantee that shares of our common stock will appreciate in value or even maintain the price at which stockholders have purchased their shares.

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If we fail to maintain proper and effective internal control over financial reporting, our ability to produce accurate and timely financial statements could be impaired, investors may lose confidence in our financial reporting and the trading price of our common stock may decline.

Pursuant to Section 404 of Sarbanes-Oxley, our management is required to report upon the effectiveness of our internal control over financial reporting, and our independent registered public accounting firm will be required to attest to the effectiveness of our internal control over financial reporting. The rules governing the standards that must be met for management to assess our internal control over financial reporting are complex and require significant documentation, testing and possible remediation. To comply with the requirements of being a reporting company under the Exchange Act, we are in process of implementing additional financial and management controls and reporting systems and procedures. If we or our auditors are unable to conclude that our internal control over financial reporting is effective, investors may lose confidence in our financial reporting and the trading price of our common stock may decline.

Although we have determined that our internal control over financial reporting was effective as of December 31, 2022, we cannot assure you that there will not be material weaknesses or significant deficiencies in our internal control over financial reporting in the future. For example, in connection with the audits of our 2019 and 2020 annual consolidated financial statements, we and our independent registered public accounting firm identified a material weakness in our internal controls due to a lack of controls in the financial closing and reporting process, including a lack of segregation of duties and the documentation and design of formalized processes and procedures in the revenue cycle. Any failure to maintain internal control over financial reporting could severely inhibit our ability to accurately report our financial condition, results of operations or cash flows. If we are unable to conclude that our internal control over financial reporting is effective, or if our independent registered public accounting firm determines we have a material weakness or significant deficiency in our internal control over financial reporting once that firm begin its Section 404 reviews, investors may lose confidence in the accuracy and completeness of our financial reports, the market price of our common stock could decline, and we could be subject to sanctions or investigations by Nasdaq, the SEC or other regulatory authorities. Failure to remedy any material weakness in our internal control over financial reporting, or to implement or maintain other effective control systems required of public companies, could also restrict our future access to the capital markets.

Provisions in our governing documents and under Delaware law could discourage a takeover that stockholders may consider favorable and may lead to entrenchment of management.

Our amended and restated certificate of incorporation and amended and restated bylaws contain provisions that could significantly reduce the value of our shares to a potential acquiror or delay or prevent changes in control or changes in our management without the consent of our board of directors. The provisions in our charter documents include the following:

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We are also subject to the anti-takeover provisions contained in Section 203 of the Delaware General Corporation Law. Under Section 203, a corporation may not, in general, engage in a business combination with any holder of 15% or more of its capital stock unless the holder has held the stock for three years or, among other exceptions, the board of directors has approved the transaction.

Our amended and restated certificate of incorporation provides that the Court of Chancery of the State of Delaware will be the exclusive forum for substantially all disputes between us and our stockholders, which could limit our stockholders’ ability to obtain a favorable judicial forum for disputes with us or our directors, officers or employees.

Our amended and restated certificate of incorporation provides that the Court of Chancery of the State of Delaware will be the exclusive forum for any derivative action or proceeding brought on our behalf, any action asserting a breach of fiduciary duty, any action asserting a claim against us arising pursuant to the Delaware General Corporation Law, our amended and restated certificate of incorporation or our amended and restated bylaws, or any action asserting a claim against us that is governed by the internal affairs doctrine; provided, that, this provision would not apply to suits brought to enforce a duty or liability created by the Exchange Act. Furthermore, our amended and restated certificate of incorporation also provides that unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States will be the exclusive forum for the resolution of any complaint asserting a cause of action arising under the Securities Act. These choice of forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers or other employees, which may discourage such lawsuits against us and our directors, officers and other employees. By agreeing to this provision, however, stockholders will not be deemed to have waived our compliance with the federal securities laws and the rules and regulations thereunder. Furthermore, the enforceability of similar choice of forum provisions in other companies’ certificates of incorporation has been challenged in legal proceedings, and it is possible that a court could find these types of provisions to be inapplicable or unenforceable. If a court were to find the choice of forum provisions in our amended and restated certificate of incorporation to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions, which could adversely affect our business and financial condition.

General Risk Factors

We incur significant increased costs as a result of operating as a public company, and our management is required to devote substantial time to new compliance initiatives.

As a public company, we incur significant legal, accounting and other expenses that we did not incur as a private company. We are subject to the reporting requirements of the Exchange Act, which requires, among other things, that we file with the SEC annual, quarterly and current reports with respect to our business and financial condition. In addition, Sarbanes-Oxley, as well as rules subsequently adopted by the SEC and Nasdaq to implement provisions of Sarbanes-Oxley, impose significant requirements on public companies, including requiring establishment and maintenance of effective disclosure and financial controls and changes in corporate governance practices. Further, pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, the SEC has adopted additional rules and regulations in these areas, such as mandatory “say on pay” voting requirements and “pay versus performance” disclosure requirements. Stockholder activism, the current political environment and the current high level of government intervention and regulatory reform may lead to substantial new regulations and disclosure obligations, which may lead to additional compliance costs and impact the manner in which we operate our business in ways we cannot currently anticipate.

The rules and regulations applicable to public companies have substantially increased and may continue to increase our legal and financial compliance costs and have made some activities more time consuming and costly. If these requirements divert the attention of our management and personnel from other business concerns, they could have a material adverse effect on our business, financial condition and results of operations. The increased costs will decrease our net income or increase our net loss, and may require us to reduce costs in other areas of our business or increase the prices of our products or services. We cannot predict or estimate the amount or timing of additional costs we may incur to respond to these requirements. The impact of these requirements could also make it more difficult for us to attract and retain qualified persons to serve on our board of directors, our board committees or as executive officers.

We are subject to U.S. and certain foreign export and import controls, sanctions, embargoes, anti-corruption laws and anti-money laundering laws and regulations. Compliance with these legal standards could impair our ability to compete in domestic and international markets. We could face criminal liability and other serious consequences for violations, which could harm our business.

We are subject to export control and import laws and regulations, including the U.S. Export Administration Regulations, U.S. Customs regulations, and various economic and trade sanctions regulations administered by the U.S. Treasury Department’s Office of Foreign Assets Controls and anti-corruption and anti-money laundering laws and regulations, including the U.S. Foreign Corrupt Practices Act of 1977, as amended, the U.S. domestic bribery statute contained in 18 U.S.C. § 201, the U.S. Travel Act, the USA

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PATRIOT Act and other state and national anti-bribery and anti-money laundering laws in the countries in which we conduct activities. Anti-corruption laws are interpreted broadly and prohibit companies and their employees, agents, CROs, contractors and other collaborators and partners from authorizing, promising, offering, providing, soliciting or receiving, directly or indirectly, improper payments or anything else of value to recipients in the public or private sector. We may engage third parties for clinical trials outside of the United States, to sell our products abroad once we enter a commercialization phase, and/or to obtain necessary permits, licenses, patent registrations and other regulatory approvals. For example, we have engaged CROs to conduct our Phase 2 trials outside the United States, including in Russia and Ukraine. Additionally, we exclusively outlicensed commercialization rights for our PRA052 program to Falk in Europe, Australia and New Zealand. We have direct or indirect interactions with officials and employees of government agencies or government-affiliated hospitals, universities and other organizations. We can be held liable for the corrupt or other illegal activities of our employees, agents, CROs, contractors and other collaborators and partners, even if we do not explicitly authorize or have actual knowledge of such activities. Any violations of the laws and regulations described above may result in substantial civil and criminal fines and penalties, imprisonment, the loss of export or import privileges, debarment, tax reassessments, breach of contract and fraud litigation, reputational harm and other consequences.

Furthermore, U.S. export control laws and economic sanctions prohibit the provision of certain products and services to countries, governments, and persons targeted by U.S. sanctions. U.S. sanctions that have been or may be imposed as a result of military conflicts in other countries may impact our ability to continue activities at clinical trial sites within regions covered by such sanctions. For example, as a result of the military conflict between Russia and Ukraine, the United States and its European allies have recently announced the imposition of sanctions on certain industry sectors and parties in Russia and the regions of Donetsk and Luhansk in Ukraine, as well as enhanced export controls on certain products and industries. These and any additional sanctions and export controls, as well as any economic countermeasures by the governments of Russia or other jurisdictions, could adversely impact our ability to continue activities at clinical trial sites within regions covered by such sanctions or directly or indirectly disrupt our supply chain. If we fail to comply with export and import regulations and such economic sanctions, penalties could be imposed, including fines and/or denial of certain export privileges.

We and any of our third-party manufacturers or suppliers may use potent chemical agents and hazardous materials, and any claims relating to improper handling, storage or disposal of these materials could be time consuming or costly.

We and any of our third-party manufacturers or suppliers and current or potential future collaborators will use biological materials, potent chemical agents and may use hazardous materials, including chemicals and biological agents and compounds that could be dangerous to human health and safety of the environment. Our operations and the operations of our third-party manufacturers and suppliers also produce hazardous waste products. Federal, state and local laws and regulations govern the use, generation, manufacture, storage, handling and disposal of these materials and wastes. Compliance with applicable environmental laws and regulations may be expensive, and current or future environmental laws and regulations may impair our product development efforts. In addition, we cannot eliminate the risk of accidental injury or contamination from these materials or wastes. We do not carry specific biological or hazardous waste insurance coverage, and our property, casualty and general liability insurance policies specifically exclude coverage for damages and fines arising from biological or hazardous waste exposure or contamination. In the event of contamination or injury, we could be held liable for damages or be penalized with fines in an amount exceeding our resources, and our clinical trials or regulatory approvals could be suspended. Although we maintain workers’ compensation insurance for certain costs and expenses we may incur due to injuries to our employees resulting from the use of hazardous materials or other work-related injuries, this insurance may not provide adequate coverage against potential liabilities. We do not maintain insurance for toxic tort claims that may be asserted against us in connection with our storage or disposal of biologic, hazardous or radioactive materials.

In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations, which have tended to become more stringent over time. These current or future laws and regulations may impair our research, development or production efforts. Failure to comply with these laws and regulations also may result in substantial fines, penalties or other sanctions or liabilities, which could materially adversely affect our business, financial condition, results of operations and prospects.

Our information technology systems, or those of any of our CROs, manufacturers, other contractors or consultants or current or potential future collaborators, may fail or experience security breaches or other unauthorized or improper access, which could result in a material disruption of our product development programs.

In the ordinary course of business, we collect, store, transmit and otherwise process large amounts of data including, without limitation, proprietary business information and personal information. Despite the implementation of security measures, our information technology systems (including infrastructure) and those of our current and any future CROs and other contractors, consultants and collaborators are vulnerable to privacy and information security incidents, such as data breaches, damage from computer viruses, cybersecurity threats (such as denial-of-service attacks, cyberattacks or cyber-intrusions over the Internet, hacking, phishing and other social engineering attacks), unauthorized access or use, natural disasters, terrorism, war and telecommunication and electrical failures. As we become more dependent on information technologies to conduct our operations, such incidents, including deliberate attacks and attempts to gain unauthorized access to computer systems and networks, may increase in frequency and sophistication. If such an event were to occur and cause interruptions in our operations or result in the unauthorized disclosure of or

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access to health-related or other personal information, it could result in a material disruption of our development programs and our business operations, whether due to a loss of our trade secrets or other similar disruptions. Some of the federal, state and foreign government requirements include obligations of companies to notify individuals of security breaches involving particular personally identifiable information, which could result from breaches experienced by us or by our vendors, contractors, or organizations with which we have formed strategic relationships.

Because the techniques used to obtain unauthorized access, disable or degrade service or sabotage systems change frequently and often are not recognized until launched against a target, we and our partners may be unable to anticipate these techniques or to implement adequate preventative measures. Further, we do not have any control over the operations of the facilities or technology of our cloud and service providers, including any third-party vendors that collect, process and store personal information on our behalf. Our systems, servers and platforms and those of our service providers may be vulnerable to computer viruses or physical or electronic break-ins that our or their security measures may not detect. Individuals able to circumvent such security measures may misappropriate our confidential or proprietary information, disrupt our operations, damage our computers or otherwise impair our reputation and business. We may need to expend significant resources and make significant capital investment to protect against security breaches or to mitigate the impact of any such breaches. There can be no assurance that we or our third-party providers will be successful in preventing security breaches or successfully mitigating their effects.

We and certain of our service providers are from time to time subject to cyberattacks and security incidents. Any security breach or other incident, whether real or perceived, that results in a loss of or accidental, unlawful or unauthorized access to, use of, release of, or other processing of personal, proprietary or other sensitive information could impact our reputation, cause us to incur significant liability and costs, including legal expenses, fines and penalties for any noncompliance with any privacy and security laws, harm customer confidence, hurt our expansion into new markets, cause us to incur remediation costs, or cause us to lose existing customers. For example, the loss of clinical trial data from clinical trials could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data. We also rely on third parties to manufacture our product candidates, and similar events relating to their computer systems could also have a material adverse effect on our business. Any insurance we maintain against the risk of this type of loss may not be sufficient to cover actual losses, or may not apply to the circumstances relating to any particular loss. For further discussion on the potential liability related to the violation of these laws, see “Risk Factors – We, our collaborators and our service providers may be subject to a variety of privacy and data security laws and contractual obligations, which could increase compliance costs and our failure to comply with them could subject us to potentially significant fines or penalties and otherwise harm our business.”

Business disruptions could seriously harm our future revenue and financial condition and increase our costs and expenses.

Our operations could be subject to earthquakes, power shortages, telecommunications failures, water shortages, floods, hurricanes, typhoons, fires, extreme weather conditions, medical epidemics and other natural or manmade disasters or business interruptions, for which we are predominantly self-insured. We rely on third-party manufacturers to produce our product candidates. Our ability to obtain clinical supplies of our product candidates could be disrupted if the operations of these suppliers were affected by a man-made or natural disaster or other business interruption. In addition, our corporate headquarters is located in San Diego, California near major earthquake faults and fire zones, and the ultimate impact on us of being located near major earthquake faults and fire zones and being consolidated in a certain geographical area is unknown. The occurrence of any of these business disruptions could seriously harm our operations and financial condition and increase our costs and expenses.

Unstable market and economic conditions may have serious adverse consequences on our business, financial condition and stock price.

The global credit and financial markets have recently experienced extreme volatility and disruptions, including severely diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, increases in unemployment rates and uncertainty about economic stability. The financial markets and the global economy may also be adversely affected by the current or anticipated impact of military conflict, including the conflict between Russia and Ukraine, terrorism or other geopolitical events. Sanctions imposed by the United States and other countries in response to such conflicts, including the one in Ukraine, may also adversely impact the financial markets and the global economy, and any economic countermeasures by the affected countries or others could exacerbate market and economic instability. There can be no assurance that further deterioration in credit and financial markets and confidence in economic conditions will not occur. Our general business strategy may be adversely affected by any such economic downturn, volatile business environment or continued unpredictable and unstable market conditions. If the current equity and credit markets deteriorate, it may make any necessary debt or equity financing more difficult, more costly and more dilutive. Failure to secure any necessary financing in a timely manner and on favorable terms could have a material adverse effect on our growth strategy, financial performance and stock price and could require us to delay or abandon clinical development plans. In addition, there is a risk that one or more of our current service providers, manufacturers and other partners may not survive an economic downturn, which could directly affect our ability to attain our operating goals on schedule and on budget.

Changes in U.S. tax law may materially adversely affect our financial condition, results of operations and cash flows.

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Changes in laws and policy relating to taxes may have an adverse effect on our financial condition, results of operations and cash flows. For example, the Tax Act significantly changed the U.S. federal income taxation of U.S. corporations. The Tax Act remains unclear in various respects and has been, and may continue to be, the subject of amendments and technical corrections, as well as interpretations and implementing regulations by the Treasury and Internal Revenue Service (IRS), which have lessened or increased certain adverse impacts of the Tax Act and may continue to do so in the future. In addition, it is unclear how these U.S. federal income tax changes will affect state and local taxation, which often uses federal taxable income as a starting point for computing state and local tax liabilities. On March 27, 2020, the CARES Act was signed into law to address the COVID-19 crisis. The CARES Act is an approximately $2 trillion emergency economic stimulus package that includes numerous U.S. federal income tax provisions, including the modification of: (i) NOL rules (as discussed above), (ii) the alternative minimum tax refund and (iii) business interest deduction limitations under Section 163(j) of the Code). We continue to work with our tax advisors and auditors to determine the full impact the Tax Act and the CARES Act will have on us. We urge our investors to consult with their legal and tax advisors with respect to any changes in tax law and the potential tax consequences of investing in our common stock.

The 2017 tax reform act amended the Code, effective for amounts paid or incurred in tax years beginning after December 31, 2021, to eliminate the immediate expensing of research and experimental expenditures (R&E) and require taxpayers to charge their R&E expenditures and software development costs (collectively, R&E expenditures) to a capital account. Capitalized costs are required to be amortized over five years (15 years for expenditures attributable to foreign research). Additionally, we may claim the R&E credit only for costs that are eligible to be treated as R&E expenditures under the Code, it is expected that any amounts treated as qualified research expenditures for purposes of the R&E credit also will be capitalized under Code. Generally, we would expect both the amount of our net operating losses and R&E credits generated to decrease compared to tax years 2021 and prior over the next 5 years. Due to our full federal valuation allowance, we anticipate these changes to be immaterial.

If securities or industry analysts do not publish research or reports or publish unfavorable research or reports about our business, our stock price and trading volume could decline.

The trading market for our common stock will depend in part on the research and reports that securities or industry analysts publish about us, our business, our market or our competitors. If one or more of the analysts who covers us downgrades our stock, our stock price would likely decline. If one or more of these analysts ceases to cover us or fails to regularly publish reports on us, interest in our stock could decrease, which could cause our stock price or trading volume to decline.

We could be subject to securities class action litigation.

In the past, securities class action litigation has often been brought against a company following a decline in the market price of its securities. This risk is especially relevant for us, because biotechnology and biopharmaceutical companies have experienced significant stock price volatility in recent years. If we face such litigation, even if ultimately decided in our favor, it could result in substantial costs and a diversion of our management’s attention and resources, which could harm our business.

Item 1B. Unresolved Staff Comments.

None.

Item 2. Properties.

Our corporate headquarters is currently located at 3050 Science Park Road, San Diego, California where we lease approximately 55,000 square feet of office and laboratory space. Our lease will expire in mid-2033 with an option to extend the term of the lease for an additional five years and may be terminated early in certain circumstances. We believe that are existing facilities are adequate to meet our needs for the foreseeable future.

For additional information, see Note 10, Commitments and Contingencies included in Item 15 of this Annual Report.

Item 3. Legal Proceedings.

We are not currently subject to any material legal proceedings. From time to time, we may be involved in legal proceedings or subject to claims incident to the ordinary course of business. Regardless of the outcome, such proceedings or claims can have an adverse impact on us because of defense and settlement costs, diversion of resources and other factors, and there can be no assurances that favorable outcomes will be obtained.

Item 4. Mine Safety Disclosures.

Not applicable.

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PART II

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

Market Information

Our common stock is listed on the Nasdaq Global Select Market under the symbol “RXDX.”

Holders of Common Stock

As of February 21, 2023, there were 47,530,337 shares of our common stock outstanding held by approximately 17 holders of record of our common stock. This number was derived from our shareholder records and does not include beneficial owners of our common stock whose shares are held in the name of various dealers, clearing agencies, banks, brokers and other fiduciaries.

Dividend Policy

We have never declared or paid any cash dividends on our capital stock. We intend to retain future earnings, if any, to finance the operation of our business and do not anticipate paying any cash dividends in the foreseeable future. Any future determination related to dividend policy will be made at the discretion of our board of directors after considering our financial condition, results of operations, capital requirements, business prospects and other factors the board of directors deems relevant, and subject to the restrictions contained in any future financing instruments.

Securities Authorized for Issuance Under Equity Compensation Plans

See Item 12 of Part III of this Annual Report for information about our equity compensation plans which is incorporated by reference herein.

Performance Graph

The following stock performance graph illustrates a comparison from March 12, 2021 (the date our common stock commenced trading on the Nasdaq Global Select Market) through December 31, 2022, of the total cumulative stockholder return on our common stock, the Nasdaq Composite Index and the Nasdaq Biotechnology Index. The graph assumes an initial investment of $100 on March 12, 2021 at the opening trading price of $19.00 per share, and that all dividends were reinvested, although dividends have not been declared on our common stock. The comparisons in the graph are required by the SEC and are not intended to forecast or be indicative of possible future performance of our common stock.

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Unregistered Sales of Equity Securities

None.

Use of Proceeds

On March 11, 2021, our registration statement on Form S-1 (File No. 333-253323) was declared effective by the SEC for our IPO. At the closing of the offering on March 16, 2021, we sold 11,500,000 shares of common stock, which included the exercise in full by the underwriters of their option to purchase 1,500,000 additional shares, at an initial public offering price of $19.00 per share and received gross proceeds of $218.5 million, which resulted in net proceeds to us of approximately $199.8 million, after deducting underwriting discounts and commissions of approximately $15.3 million and offering-related transaction costs of approximately $3.4 million. None of the expenses associated with the initial public offering were paid to directors, officers, persons owning ten percent or more of any class of equity securities, or to their associates, or to our affiliates. SVB Leerink LLC and Credit Suisse Securities (USA) LLC acted as joint book-running managers for the offering.

As of December 31, 2022, we estimate that we have used approximately $67.0 million of the proceeds from our IPO for general corporate purposes, including the advancement of our development programs. There has been no material change in the planned use of proceeds from our initial public offering from that described in the Prospectus.

Issuer Repurchases of Equity Securities

None.

Item 6. [Reserved]

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Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following discussion and analysis of our financial condition and operating results together with our financial statements and related notes included elsewhere in this Annual Report. This discussion and analysis contains forward-looking statements based upon current beliefs, plans and expectations that involve risks, uncertainties and assumptions. Our actual results may differ materially from those anticipated in these forward-looking statements as a result of various factors, including those set forth under “Risk Factors” or in other parts of this Annual Report. For the comparison of the financial results for the fiscal years ended December 31, 2021 and 2020, see Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations, in our Annual Report on Form 10-K for the fiscal year ended December 31, 2021, filed with the SEC on March 9, 2022 and incorporated herein by reference.

Overview

We are a clinical-stage biotechnology company pioneering a precision medicine approach to the discovery, development, and commercialization of novel therapeutic products for the treatment of immune-mediated diseases, starting first with inflammatory bowel disease (IBD). We leverage our proprietary precision medicine platform, Prometheus360™, which includes one of the world’s largest gastrointestinal (GI) bioinformatics databases and sample biobanks, to identify novel therapeutic targets, develop therapeutic candidates to engage those targets, and develop genetics-based diagnostic tests designed to identify patients more likely to respond to our therapeutic candidates. We have generated a robust pipeline of therapeutic development programs for the treatment of immune-mediated diseases.

Our lead product candidate, PRA023, is a humanized IgG1 monoclonal antibody (mAb) that has been shown to block the tumor necrosis factor (TNF)-like ligand 1A (TL1A), a target associated with both intestinal inflammation and fibrosis. PRA023’s dual mechanism of action, targeting both inflammation and fibrosis, also provides a strong rationale for advancing PRA023 into clinical trials for indications beyond IBD.

In July 2021, we initiated ARTEMIS-UC, a global Phase 2 randomized placebo-controlled clinical trial of PRA023 in patients with moderate-to-severe ulcerative colitis (UC) and APOLLO-CD, a global Phase 2a open-label clinical trial in patients with moderate-to-severe Crohn’s disease (CD), each utilizing our genetics-based diagnostic candidate designed to identify patients who are predisposed to increased expression of TL1A and therefore potentially more likely to respond to PRA023.

In December 2022, we reported topline results from the initial cohort of ARTEMIS-UC (Cohort 1) and results from APOLLO-CD demonstrating strong efficacy and favorable safety results in both studies. We believe these results position PRA023 to be a potential first-in-class and best-in-class treatment for patients suffering from UC and CD.

We plan to advance PRA023 into pivotal Phase 3 clinical trials for UC and CD in 2023 after we meet with the U.S. Food and Drug Administration (FDA) and foreign regulatory authorities and finalize our Phase 3 clinical trial strategy. The expansion cohort of ARTEMIS-UC (Cohort 2) is designed to further assess the treatment effect of PRA023 in patients who test positive on our diagnostic candidate, and we expect results in the second quarter of 2023.

In March 2022, we initiated a Phase 2 clinical trial for PRA023 in Systemic Sclerosis-associated Interstitial Lung Disease (SSc-ILD). The FDA has granted fast track designation for PRA023 for the treatment of SSc-ILD. Topline results from our Phase 2 trial of PRA023 in Systemic Sclerosis-Associated Interstitial Lung Disease (ATHENA-SSc-ILD) are expected in the first half of 2024. We are evaluating potentially advancing PRA023 into clinical trials for other indications where there is a strong mechanistic rational and high unmet need, and plan to announce our fourth indication for PRA023 in 2023.

Our second product candidate, PRA052, is an anti-CD30L mAb. The CD30L-CD30 co-stimulatory pathway has been implicated in IBD by genetic, preclinical, and human translational data. We filed an investigational new drug application (IND) for PRA052 in the third quarter of 2022 and then initiated a Phase 1 single ascending dose/multiple ascending dose clinical trial in normal healthy volunteers in the fourth quarter of 2022. We expect topline results from the Phase 1 study in the fourth quarter of 2023. We are also developing a proprietary genetics-based diagnostic test for PRA052 to identify patients that are more likely to respond to CD30L inhibition.

We continue to explore additional potential indications for our development programs and evaluate numerous other drug targets, identified through Prometheus360, for therapeutic utility for potential drug discovery development. We may also explore and evaluate entering into strategic collaborations for specific therapeutic indications or geographic territories in order to maximize the value of PRA023 and our other product candidates. The research and development of therapeutic product candidates and diagnostics comprises our therapeutics business segment.

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On June 30, 2019, we acquired from Nestlé Prometheus Laboratories, Inc. (PLI), which marketed and conducted several laboratory developed tests useful to gastroenterologists in monitoring their IBD patients’ disease state. Prior to our acquisition of PLI in June 2019, we had devoted substantially all of our resources to organizing and staffing our company, business planning, raising capital, developing our Prometheus360 platform, discovering and identifying potential product candidates, establishing our intellectual property portfolio and conducting research and preclinical studies, and providing other general and administrative support for these operations.

On December 31, 2020, we completed the spinoff of PLI by making an in-kind distribution of 100% of our interest in PLI to our stockholders of record on December 30, 2020. Except as specifically indicated, the discussion of our operations excludes the operations of PLI, which are reported as a discontinued operation in the accompanying consolidated financial statements included elsewhere in this Annual Report and in the following discussion.

We do not expect to generate any revenue from therapeutic product sales until we successfully complete development and obtain regulatory approval for one or more of our therapeutic product candidates and diagnostics, which we expect will take a number of years and may never occur.

We have incurred operating losses in each year since inception. Our net losses, including those generated from PLI, were $141.8 million, $90.2 million and $37.1 million for the years ended December 31, 2022, 2021, and 2020, respectively. As of December 31, 2022, we had an accumulated deficit of $331.1 million. We expect our expenses and operating losses will increase substantially as we conduct our ongoing planned preclinical studies and clinical trials, continue our research and development activities, develop and validate diagnostics, utilize third parties to manufacture our product candidates and related raw materials, hire additional personnel, protect our intellectual property and incur additional costs associated with being a public company, including audit, legal, regulatory, and tax-related services associated with maintaining compliance with exchange listing and SEC requirements, director and officer insurance premiums, and investor relations costs. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending on the timing of our preclinical studies and clinical trials and our expenditures on other research and development activities, as well as the generation of any services and collaboration revenue.

From inception and to the date of our initial public offering (IPO) in March 2021, we had raised a total of $175.6 million to fund our operations from gross proceeds from the sale and issuance of convertible preferred stock and $7.5 million from proceeds under our loan and security agreement (Loan Agreement) with Oxford Finance LLC and its affiliates (Oxford)(Oxford Loan). In March 2021, we completed our IPO with the sale of 11,500,000 shares of common stock, which included the exercise in full by the underwriters of their option to purchase 1,500,000 additional shares, at an initial public offering price of $19.00 per share and received net of approximately $199.8 million. In July 2021, we voluntarily prepaid the aggregate outstanding principal balance of the Oxford Loan of $7.5 million plus an additional $0.5 million consisting of the prepayment penalty, accrued interest, and final payment due under the terms of the Loan Agreement and Oxford released all liens against our assets and terminated our other applicable obligations. In December 2022, we completed the sale of an aggregate of 4,545,455 shares of our common stock in an underwritten public offering, at a price of $110.00 per share for net proceeds of $470.5 million. As of December 31, 2022, we have sold 2,540,348 shares of common stock under our Open Market Sale Agreement (Sale Agreement) at a weighted-average price of $35.19 per share resulting in net proceeds of $85.9 million. As of December 31, 2022, we had cash, cash equivalents and short-term investments of $695.8 million.

Based on our current operating plan, we believe that our existing cash and cash equivalents will be sufficient to fund our operations for at least the next 12 months from the date of issuance of these financial statements. If we obtain regulatory approval for any of our therapeutic product candidates and diagnostics, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution, including royalty payments under our license and collaboration agreements. As we continue to advance our pipeline of diagnostic products, we expect to incur additional costs associated with conducting clinical studies to demonstrate the utility of our products and support reimbursement efforts. Accordingly, until such time as we can generate significant revenue from sales of our product candidates, if ever, we expect to finance our cash needs through equity offerings, debt financings or other capital sources, including potential additional collaborations, licenses and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. Our failure to raise capital or enter into such other arrangements when needed would have a negative impact on our financial condition and could force us to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.

License and Collaboration Agreements

Our Collaboration with Cedars-Sinai Medical Center

In September 2017, we entered into an exclusive license agreement with Cedars-Sinai Medical Center (Cedars-Sinai), as amended and restated (the Cedars-Sinai Agreement), pursuant to which Cedars-Sinai granted us an exclusive, worldwide license with

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respect to certain patents, information and materials related to therapeutic targets and diagnostic products, to conduct research, develop, and commercialize therapeutic and diagnostic products for human use. The licensed technology includes information and materials arising out of Cedars-Sinai’s database and biobank, as well as exclusive access to this database and biobank, which is an integral part of our Prometheus360 platform. As upfront consideration for the license agreement, we issued to Cedars-Sinai 257,500 shares of fully vested common stock and 335,000 shares of restricted common stock, which shares fully vested in September 2020. We are obligated to pay Cedars-Sinai low- to mid-single digit percentage royalties on net sales of therapeutic and diagnostic products covered under the agreement, including any related diagnostic products, subject to the terms and conditions set forth in the Cedars-Sinai Agreement. In August 2021, we amended and restated the Cedars-Sinai Agreement to, among other things, add a joint steering committee and cover new intellectual property.

Our Collaboration with Dr. Falk Pharma

In July 2020, we entered into a co-development and manufacturing agreement (the Falk Agreement) with Dr. Falk Pharma GmbH (Falk), pursuant to which we will co-develop and commercialize, exclusively in our respective territories, our PRA052 therapeutic product candidate and diagnostic test. Under the Falk Agreement, we are obligated to use commercially reasonable efforts to conduct such development activities under an agreed development plan and we are responsible for regulatory approvals and commercialization of any products in the United States and the rest of the world, other than the Falk territory. Falk is responsible for regulatory approvals and commercialization of any products in the European Union, United Kingdom, Switzerland, the countries of the European Economic Area (excluding Malta and the Republic of Cyprus), Australia and New Zealand (Falk territory). Falk has agreed to fund 25% of our third-party development costs set forth in the development plan. Under the agreement, Falk paid us an upfront payment of $2.5 million and made a second payment of $2.5 million following the parties’ mutual agreement on the development plan. In addition, in June 2021, Falk made a milestone payment of $10 million to us upon the selection of a clinical candidate for our PRA052 program and, in December 2021, Falk made the final milestone payment of $5 million to us, based on our development of a companion diagnostic candidate for the PRA052 program. Falk is also obligated to pay us a mid-single to low-double digit royalty on net sales of all products incorporating antibodies covered by the agreement in the Falk territory and we agreed to pay Falk a low-single digit royalty on net sales for such products in our territory, subject to the terms and conditions set forth in the Falk Agreement.

Components of Results of Operations

Revenue

Collaboration revenue

We currently derive all of our revenue from our collaboration agreement. For the foreseeable future, we expect to generate revenue from services performed under the Falk Agreement. We may receive a combination of upfront payments and milestone payments under our current and/or future collaboration agreements.

We do not expect to generate any revenue from the sale of therapeutic products unless and until such time that our therapeutic product candidates and diagnostics have advanced through clinical development and regulatory approval, if ever. We expect that any revenue we generate, if at all, will fluctuate from quarter-to-quarter as a result of the timing and amount of payments relating to such services and milestones and the extent to which any of our therapeutic product candidates are approved and successfully commercialized. If we fail to complete preclinical and clinical development of therapeutic product candidates or obtain regulatory approval for them, our ability to generate future revenues, and our results of operations and financial position would be adversely affected.

Operating Expenses

Research and Development

Research and development expenses consist of external and internal costs associated with our research and development activities, including our discovery and research efforts, the preclinical and clinical development of our product candidates and the development and validation of our diagnostics. Our research and development expenses include:

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The following table summarizes our research and development expenses by program for the periods indicated (in thousands):

We expect our research and development expenses to increase for the foreseeable future as we continue to progress our Phase 2 and Phase 3 clinical trials of PRA023 globally, advance PRA052 through a Phase 1 clinical trial, develop diagnostic candidates, and continue to advance several preclinical research and development programs. The process of conducting preclinical studies and clinical trials necessary to obtain regulatory approval is costly and time consuming. We may never succeed in achieving marketing approval for any of our product candidates.

The timelines and costs with research and development activities are uncertain and can vary significantly for each product candidate and development program and are difficult to predict. We anticipate we will make determinations as to which programs to pursue and how much funding to direct to each program on an ongoing basis in response to preclinical and clinical results, regulatory developments, ongoing assessments as to each program’s commercial potential, and our ability to maintain or enter into new collaborations, to the extent we determine the resources or expertise of a collaborator would be beneficial for a given program. We will need to raise substantial additional capital in the future. In addition, we cannot forecast which development programs may be subject to future collaborations, when such arrangements will be secured, if at all, and to what degree such arrangements would affect our development plans and capital requirements.

Our development costs may vary significantly based on factors such as:

General and Administrative

General and administrative expenses consist primarily of employee-related expenses, including salaries, benefits and stock-based compensation, for employees in our finance, accounting, legal, human resources, business development and support functions. Other general and administrative expenses include allocated facility, information technology and depreciation related costs not otherwise included in research and development expenses and professional fees for auditing, tax, intellectual property and legal

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services. Costs related to filing and pursuing patent applications are recognized as general and administrative expenses as incurred since recoverability of such expenditures is uncertain.

We expect our general and administrative expenses will increase for the foreseeable future to support our increased research and development activities.

Interest and Other Income (Expense)

Interest income

Interest income consists primarily of interest earned on our cash, cash equivalents, and short-term investments.

Interest expense

Interest expense consists of interest expense incurred in connection with our borrowings under the Loan Agreement and non-cash interest expense associated with the deferred purchase payments for PLI.

Loss on early extinguishment of debt

Loss on early extinguishment of debt consists of the unamortized debt issuance costs, prepayment penalty and final payment due under the terms of the Loan Agreement.

Change in fair value of preferred stock purchase liability

In connection with the issuance of our Series D convertible preferred stock in 2020, the investors agreed to buy, and we agreed to sell, additional shares of such preferred convertible stock at the original issue price upon the achievement of pre-defined milestones. These contractual obligations were required to be accounted for as liabilities and remeasured to fair value at each reporting date, with any change in the fair value reported as a component of other income (expense). In January 2021, with the issuance of the Series D-2 convertible preferred stock, this contractual obligation was settled and the preferred stock purchase right liability was remeasured to fair value on the purchase date and recorded to convertible preferred stock, which was then subsequently reclassified to permanent equity in connection with the IPO.

Change in fair value of preferred stock warrant liability

Changes in the fair value of preferred stock warrant liabilities relates to warrants for the purchase of convertible preferred stock issued in connection with our Loan Agreement. These warrants were converted into warrants for the purchase of common stock in connection with our IPO and were reclassified into stockholders’ equity.

Results of Operations

Comparison of the Years Ended December 31, 2022 and 2021

This section provides an analysis of our financial results for the fiscal year ended December 31, 2022 compared to the fiscal year ended December 31, 2021.

The following table summarizes our results of operations for the years ended December 31, 2022 and 2021 (in thousands):

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Revenue

Revenue was $6.8 million for the year ended December 31, 2022 compared to $3.1 million for the year ended December 31, 2021. The increase of $3.7 million is mainly due to increase in revenue generated under the Falk Agreement.

Research and Development Expenses

Research and development expenses were $112.8 million for the year ended December 31, 2022 compared to $62.4 million for the year ended December 31, 2021. The increase of $50.4 million for the year ended December 31, 2022 compared to the year ended December 31, 2021 was primarily driven by a $15.6 million increase in clinical trial expenses related to our global Phase 2 clinical trials of PRA023, a $11.8 million increase in expense related to our contract manufacturing activities to support our clinical trials, a $7.9 million increase in expenses related to personnel costs due to additional headcount to support increased development and clinical trial activities, and a $5.3 million increase in stock-based compensation expense, with the remainder due to increases in expenses related to research and development expenses for our other pre-clinical development programs and for ongoing development activities associated with our two most advanced programs, PRA023 and PRA052.

General and Administrative Expenses

General and administrative expenses were $39.7 million for the year ended December 31, 2022 compared to $28.5 million for the year ended December 31, 2021. The increase of $11.2 million for the year ended December 31, 2022 compared to the year ended December 31, 2021 was primarily driven by a $4.8 million increase in stock-based compensation expense, a $2.5 million increase in personnel costs, a $1.5 million increase in consulting expenses, and a $1.0 million increase in facility expenses to support our expanded operations.

Other Income (Expense), Net

Interest income

Interest income was $4.0 million for the year ended December 31, 2022 and $0.1 million for the year ended December 31, 2021. The increase of $3.9 million was primarily due to higher interest rates and investment in marketable securities.

Interest expense

Interest expense was zero for the year ended December 31, 2022 compared to interest expense of $0.9 million for the year ended December 31, 2021. The decrease of $0.9 million for the year ended December 31, 2022 compared to the year ended December 31, 2021 was primarily related to the payoff of debt under the Loan Agreement in the third quarter of 2021.

Loss on early extinguishment of debt

Loss on early extinguishment of debt of $0.6 million for the year ended December 31, 2021 consists of the unamortized debt issuance costs, prepayment penalty and final payment due under the terms of the Loan Agreement.

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Change in Fair Value of Convertible Preferred Stock Purchase Right Liability

The change in fair value of convertible preferred stock purchase right liability decreased $1.0 million. In January 2021, with the issuance of the Series D-2 convertible preferred stock, this contractual obligation was settled and the preferred stock purchase right liability was remeasured to fair value on the purchase date and reclassified to permanent equity.

Liquidity and Capital Resources

Sources of Liquidity

From our inception to the date of our IPO, we received aggregate gross proceeds of $175.6 million from the sale of convertible preferred stock, $7.5 million from borrowings under our Loan Agreement with Oxford and $8.2 million from amounts received under the Falk and Takeda Agreements. In March 2021, we completed our IPO with the sale of 11,500,000 shares of common stock, which included the exercise in full by the underwriters of their option to purchase 1,500,000 additional shares, at an initial public offering price of $19.00 per share and received gross proceeds of $218.5 million, which resulted in net proceeds to us of approximately $199.8 million, after deducting underwriting discounts and commissions of approximately $15.3 million and offering-related transaction costs of approximately $3.4 million. As of December 31, 2022, we had cash, cash equivalents, and short-term investments of $695.8 million.

Oxford Loan and Security Agreement

In January 2020, we entered into the Loan Agreement with Oxford, which provided for total borrowings of up to $25.0 million, of which $7.5 million was drawn upon execution of the agreement. In July 2021, we voluntarily prepaid the aggregate outstanding principal balance of $7.5 million plus an additional $0.5 million consisting of the prepayment penalty, final payment, and accrued interest due under the terms of the Loan Agreement, and the Loan Agreement was terminated in accordance with its terms. All liens and security interests securing the Oxford Loan were released upon termination. No additional amounts remain available for borrowing.

Under the Loan Agreement, interest accrued at an annual rate equal to the sum of (I) the greater of (a) the 30-day U.S. LIBOR rate reported the last business day of the month that immediately preceded the month in which the interest will accrue, and (b) 2.01%, plus (II) 5.98%. Notwithstanding the foregoing, the annual rate was at no time to be less than 7.99%. From March 1, 2020 through February 28, 2023, we were required to make interest only payments.

In connection with execution of the Loan Agreement, we issued Oxford a warrant to purchase 112,500 shares of our Series C convertible preferred stock at an exercise price of $1.00 per share, exercisable at any time following issuance. The preferred stock warrant has a term of ten years. The warrant became exercisable for an aggregate of 14,884 shares of our common stock at an exercise price of $7.558 per share upon the completion of our IPO. In December 2022, Oxford cashless exercised the warrant for 13,849 shares.

Open Market Sale Agreement

On April 1, 2022, we entered into the Sale Agreement with Jefferies LLC (the Agent), pursuant to which we may, from time to time, offer and sell shares of our common stock having an aggregate offering price of up to $150.0 million in “at the market” offerings through the Agent. Sales of the shares of common stock, if any, will be made at prevailing market prices at the time of sale, or as otherwise agreed with the Agent. The Agent will receive a commission from us of 3.0% of the gross proceeds of any shares of common stock sold under the Sale Agreement.

We are not obligated to sell, and the Agent is not obligated to buy or sell, any shares of common stock under the Sale Agreement. No assurance can be given that we will sell any shares of common stock under the Sale Agreement, or, if we do, as to the price or amount of shares of common stock that we sell or the dates when such sales will take place. During the year ended December 31, 2022, we sold 2,540,348 shares of common stock under the Sale Agreement at a weighted-average price of $35.19 resulting in net proceeds of approximately $85.9 million. As of December 31, 2022, we may sell up to an additional $60.6 million of shares of our common stock under the Sale Agreement.

Public Offering of Common Stock

On December 8, 2022, we entered into an underwriting agreement (Underwriting Agreement) with Goldman Sachs & Co. LLC, SVB Securities LLC and Jefferies LLC, as representatives of the several underwriters named therein (collectively, Underwriters),

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relating to the issuance and sale of 4,545,455 shares of our common stock. In addition, under the terms of the Underwriting Agreement, we granted the Underwriters a 30-day option to purchase up to 681,818 additional shares of common stock at $110.00 per share. On December 13, 2022, we completed the sale of an aggregate of 4,545,455 shares of our common stock at a price of $110.00 per share. The net proceeds to us from the offering were approximately $470.5 million after deducting underwriting discounts, commissions, and public offering expenses. In January 2023, the Underwriters exercised the option to purchase an additional 483,256 shares resulting in net proceeds of approximately $50.1 million after deducting offering costs.

Future Capital Requirements

As of December 31, 2022, we had cash, cash equivalents, and short-term investments in the amount of $695.8 million. Based upon our current operating plans, we believe that our existing cash, cash equivalents, and short-term investments will be sufficient to fund our operations for at least the next 12 months from the date of issuance of these financial statements. However, our forecast of the period of time through which our financial resources will be adequate to support our operations is a forward looking statement that involves risks and uncertainties, and actual results could vary materially. We have based this estimate on assumptions that may prove to be wrong, and we could deplete our capital resources sooner than we expect. Additionally, the process of conducting preclinical studies and testing product candidates in clinical trials is costly, and the timing of progress and expenses in these studies and trials is uncertain.

Our future capital requirements are difficult to forecast and will depend on many factors, including but not limited to:

Other than our collaboration agreements, we have no other committed sources of capital. Until we can generate a sufficient amount of product revenue to finance our cash requirements, if ever, we expect to finance our future cash needs primarily through equity offerings, debt financings or other capital sources, including potential collaborations, licenses and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interest of our stockholders will be or could be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our common stockholders. Any future debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise additional funds through other collaborations or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds through equity or debt

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financings when needed, we may be required to delay, limit, reduce or terminate our product development or commercialization efforts or grant rights to develop and market product candidates to third parties that we would otherwise prefer to develop and market ourselves.

Cash Flows

The following table shows a summary of our cash flows for the periods presented (in thousands):

Operating Activities

Cash used in operating activities was $123.3 million during the year ended December 31, 2022, compared to cash used in operating activities of $63.5 million during the year ended December 31, 2021. The increase of $59.7 million was primarily the result of the increase in net loss of $51.6 million and changes in operating assets and liabilities of $14.0 million, partially offset by increases in noncash charges of $5.8 million. The increase in net cash used in changes in our operating assets and liabilities for the year ended December 31, 2022 compared to the year ended December 31, 2021 was primarily driven by a $16.3 million decrease in deferred revenue as a result of milestone payments received under the Falk Agreement during the year ended December 31, 2021. The $5.8 million increase in noncash charges was primarily driven by an increase in stock-based compensation expense.

Investing Activities

Net cash used in investing activities was $403.8 million and $1.1 million for the years ended December 31, 2022 and 2021, respectively, primarily due to purchases of marketable securities, partially offset by proceeds from maturities of marketable securities.

Financing Activities

Net cash provided by financing activities was $562.2 million during the year ended December 31, 2022 as compared to $267.7 million during the year ended December 31, 2021. During the year ended December 31, 2022, we received proceeds of $589.4 million from the sale of our common stock in public offerings, offset by payments of $32.9 million in public offering costs, $5.0 million from stock option exercises, and $0.7 million from issuance of common stock under the ESPP. During the year ended December 31, 2021, we received proceeds of $218.5 million from the sale of our common stock in our IPO, proceeds of $73.7 million from the sale of shares of our Series D-2 convertible preferred stock, net of issuance costs, and proceeds of $0.4 million from the issuance of common stock under the employee stock purchase plan offset by $8.0 million used in repayment of debt and $17.3 million in financing costs.

Critical Accounting Polices and Estimates

This management discussion and analysis of financial condition and results of operations is based on our financial statements, which have been prepared in accordance with GAAP. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities revenue and expenses.

On an ongoing basis, we evaluate these estimates and judgments. We base our estimates on historical experience and on various assumptions that we believe to be reasonable under the circumstances. These estimates and assumptions form the basis for making judgments about the carrying values of assets and liabilities and the recording of revenue and expenses that are not readily apparent from other sources. Actual results may differ materially from these estimates.

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While our significant accounting policies are described in more detail in Note 2 to our consolidated financial statements included elsewhere in this Annual Report, we believe the following accounting policies and estimates to be most critical to the preparation of our consolidated financial statements.

Revenue Recognition

To date, all of our revenue has been derived from our collaboration agreements with Falk and Takeda. The terms of these arrangements include payments to us for the following: non-refundable, upfront license fees; development, regulatory and commercial milestone payments; payments for research, and royalties on net sales of licensed products.

We recognize revenue in accordance with Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (ASC 606). In accordance with ASC 606, we perform the following steps in determining the appropriate amount of revenue to be recognized as we fulfill our obligations under each of these agreements: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when, or as satisfy each performance obligation. At contract inception, once the contract is determined to be within the scope of ASC 606, we assess the goods or services promised within each contract and determine those that are performance obligations and assesses whether each promised good or service is distinct. We then recognize as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied.

With respect to our assessment of the Falk and Takeda Agreements, we identified one performance obligation for each deliverable under the agreement since the delivered elements are not distinct within the context of the contract. Accordingly, we will recognize revenue for the transaction price in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses over the period over which it expects to deliver its performance obligations. We included certain milestones in the transaction price as they were deemed not probable of significant reversal at the inception of the agreement. Due to the uncertainty in the achievement of the developmental and commercial milestones, the variable consideration associated with these future milestone payments has been fully constrained (excluded) from the transaction price until such time that we conclude that it is probable that a significant reversal of previously recognized revenue will not occur.

Amounts received prior to satisfying the above revenue recognition criteria were recognized as deferred revenue until all applicable revenue recognition criteria were met. Deferred revenue represented the portion of payments received that have not been earned. Refer to Note 6 to our consolidated financial statements included elsewhere in this Annual Report for quantitative disclosures related to revenue recognition.

Stock-Based Compensation

Stock-based compensation expense for employee and non-employee stock option grants and restricted stock units is recorded at the estimated fair value of the award as of the grant date and is recognized as expense on a straight-line basis over the requisite service period (usually the vesting period) of the stock-based award, and forfeitures are recognized as incurred. Stock-based compensation expense for employee stock purchases under the Employee Stock Purchase Plan, or the ESPP, is recorded at the estimated fair value of the purchase as of the plan enrollment date and is recognized as expense on a straight-line basis over the applicable six-month ESPP offering period.

We estimate the fair value of our stock-based awards using the Black-Scholes model. The Black-Scholes model requires the use of subjective assumptions, including the fair value of the underlying common stock on the date of grant, risk-free interest rate, expected volatility, expected term and expected dividend yield. Changes in the assumptions can materially affect the fair value and ultimately how much stock-based compensation expense is recognized. These inputs are subjective and generally require judgment to develop. See Note 9 to our consolidated financial statements included elsewhere in this Annual Report for information concerning certain of the specific assumptions we used in applying the Black-Scholes option pricing model to determine the estimated fair value

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of our stock options granted in the years ended December 31, 2022, 2021, and 2020. Stock-based compensation totaled approximately $20.9 million, $10.7 million, and $0.8 million for the years ended December 31, 2022, 2021, and 2020 respectively.

As of December 31, 2022, the unrecognized stock-based compensation expense related to stock options and restricted stock units was $105.8 million which is expected to be recognized as expense over a weighted-average period of approximately 3.25 years.

Common Stock Valuations

Prior to our IPO in March 2021, the fair value of the common stock underlying our equity awards was determined on each grant date by our board of directors, taking into account input from management and independent third-party valuation analyses. Following the completion of our IPO, the fair value of our common stock is based on the closing price as reported on the date of grant on the Nasdaq Global Select Market.

Research and Development and Clinical Trial Accruals

We are required to make estimates of our accrued expenses resulting from our obligations under contracts with CROs, manufacturers, vendors and consultants, in connection with conducting research and development activities. The financial terms of these contracts vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. We reflect research and development expenses in our financial statements by matching those expenses with the period in which services and efforts are expended.

We account for these expenses according to the progress of the preclinical study as measured by the timing of various aspects of the study or related activities. In accruing for these activities, we obtain information from various sources and estimates level of effort or expense allocated to each period. Although we do not expect our estimates to be materially different from amounts actually incurred, if our estimates of the status and timing of services performed differ from the actual status and timing of services performed, it could result in us reporting amounts that are too high or too low in any particular period. To date, there have been no material differences between our estimates of such expenses and the amounts actually incurred.

Contractual Obligations and Commitments

We have obligations related to our operating lease for office and laboratory space in San Diego, California. In March 2021, we executed a non-cancellable lease agreement for office and laboratory space, which commenced in March 2022. The lease was subsequently amended in October 2021 to allow for occupancy of an additional floor. The amended lease commenced in September 2022 for the expansion premises with an initial term of 127.5 months and an option to extend the lease term for an additional five-year term. Initial monthly rental payments are approximately $0.3 million with rent escalation and we are also responsible for certain operating expenses and taxes throughout the lease term. See Note 10 to our consolidated financial statements included elsewhere in this Annual Report.

We enter into contracts in the normal course of business for contract research services, contract manufacturing services, professional services and other services and products for operating purposes. These contracts generally provide for termination after a notice period, and, therefore, are cancelable contracts. Any related cancellation fees are not reasonably possible to estimate if and when these provisions would be triggered and, therefore, the amounts are not fixed and determinable at this time.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

Interest Rate Risk

Our cash, cash equivalents and short-term investments consist of cash held in readily available checking and money market accounts, as well as high-quality U.S. government and agency securities, corporate debt securities, and commercial paper. The primary objectives of our investment activities are to preserve principal, provide liquidity and maximize income without significantly increasing risk. Our primary exposure to market risk is interest rate sensitivity, which is affected by changes in the general level of United States interest rates. To minimize our exposure due to adverse shifts in interest rates, we ensure that the average maturity of our investments does not exceed 12 months. If a 1% change in interest rates were to have occurred on December 31, 2022, this change would not have had a material effect on the fair value of our investment portfolio as of that date. Due to the short holding period of our investments, we have concluded that we do not have a material financial market risk exposure.

Foreign Currency Exchange Risk

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Our expenses are generally denominated in U.S. dollars. However, we have entered into a limited number of contracts with vendors for research and development services that are denominated in foreign currencies. We are subject to foreign currency transaction gains or losses on our contracts denominated in foreign currencies. To date, foreign currency transaction gains and losses have not been material to our financial statements, and we have not had a formal hedging program with respect to foreign currency. A hypothetical 1% increase or decrease in exchange rates during any of the periods presented would not have had a material impact on our financial results.

Effects of Inflation

Inflation generally affects us by increasing our cost of labor and clinical trial costs. We do not believe that inflation has had a material effect on our financial results during the periods presented.

Item 8. Financial Statements and Supplementary Data.

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Stockholders and Board of Directors

Prometheus Biosciences, Inc.

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of Prometheus Biosciences, Inc. (the “Company”) as of December 31, 2022 and 2021, the related consolidated statements of operations and comprehensive loss, convertible preferred stock and stockholders’ equity (deficit), and cash flows for each of the three years in the period ended December 31, 2022, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2022 and 2021, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2022, in conformity with accounting principles generally accepted in the United States of America.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (“PCAOB”), the Company's internal control over financial reporting as of December 31, 2022, based on criteria established in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (“COSO”) and our report dated February 28, 2023 expressed an unqualified opinion thereon.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing separate opinions on the critical audit matter or on the accounts or disclosures to which it relates.

Clinical Trial Accruals

As described in Note 2 and Note 5 to the financial statements, the Company recognizes costs incurred pursuant to contracts with clinical research organizations (“CROs”) that conduct and manage clinical trials on the Company’s behalf as research and development expenses. When accruing for these services, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period based on communication with the CROs. As of December 31, 2022, the Company has recorded $4.4 million for accrued clinical trial expenses for the estimated costs incurred but not yet billed or paid.

We identified the auditing of the Company’s accrued clinical trial expenses as a critical audit matter. Due to the long duration of clinical trials and the timing of invoicing received from CROs, the estimate of the time period over which services will be performed and the level of effort expended each period requires significant management judgment. Auditing these elements involved subjective auditor judgment due to the nature and extent of the audit evidence and effort required to address these matters.

The primary procedures we performed to address this critical audit matter included:

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Discontinued Operations

As described in Note 7, in December 2020, the Company completed a spin-off of Prometheus Laboratories, Inc., which has been presented as discontinued operations in the accompanying consolidated financial statements.

/s/ BDO USA, LLP

We have served as the Company’s auditor since 2018.

San Diego, California

February 28, 2023

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Prometheus Biosciences, Inc.

Consolidated Balance Sheets

(in thousands, except share and par value amounts)

See accompanying notes to the consolidated financial statements.

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Prometheus Biosciences, Inc.

Consolidated Statements of Operations and Comprehensive Loss

(in thousands, except share and per share amounts)

See accompanying notes to the consolidated financial statements.

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Prometheus Biosciences, Inc.

Consolidated Statements of Convertible Preferred Stock and Stockholders’ Equity (Deficit)

(in thousands, except share amounts)