Lyra Therapeutics (LYRA) 10-K9 Mar 212020 FY Annual reportFinancial data

Company Profile

Document And Entity Information

Document And Entity Information - USD ($) $ in Thousands	12 Months Ended
Document And Entity Information - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 01, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Entity File Number	001-39273
Entity Registrant Name	Lyra Therapeutics, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-1700838
Entity Address, Address Line One	480 Arsenal Way
Entity Address, City or Town	Watertown
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02472
City Area Code	617
Local Phone Number	393-4600
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	LYRA
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 84,280,762
Entity Common Stock, Shares Outstanding		12,947,572
Documents Incorporated by Reference	None.
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Central Index Key	0001327273
Document Fiscal Period Focus	FY

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 74,593	$ 9,808
Prepaid expenses and other current assets	1,324	311
Total current assets	75,917	10,119
Property and equipment, net	2,165	237
Operating lease right-of-use assets	2,301	3,182
Restricted cash	329	329
Other assets	118	1,096
Total assets	80,830	14,963
Current liabilities:
Accounts payable	922	1,069
Accrued expenses and other current liabilities	2,977	3,240
Operating lease liabilities	985	899
Total current liabilities	4,884	5,208
Operating lease liabilities, net of current portion	1,454	2,427
Total liabilities	6,338	7,635
Commitments and contingencies (Note 11)
Total redeemable convertible preferred stock		130,666
Stockholders’ equity (deficit):
Common stock, $0.001 par value; 200,000,000 and 275,000,000 shares authorized at December 31, 2020 and 2019, respectively; 12,932,377 and 230,860 shares issued and outstanding at December 31, 2020 and 2019, respectively	13
Additional paid-in capital	224,363	4,419
Accumulated deficit	(149,884)	(127,757)
Total stockholders’ equity (deficit)	74,492	(123,338)
Total liabilities, redeemable convertible preferred stock and stockholders’ equity (deficit)	$ 80,830	14,963
Series A-1 Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock		39,742
Series A-2 Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock		18,393
Series A-3 Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock		38,114
Series A-4 Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock		6,000
Series B Redeemable Convertible Preferred Stock
Current liabilities:
Total redeemable convertible preferred stock		$ 28,417

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Common stock par value	$ 0.001	$ 0.001
Common stock shares authorized	200,000,000	275,000,000
Common stock shares issued	12,932,377	230,860
Common stock shares outstanding	12,932,377	230,860
Series A-1 Redeemable Convertible Preferred Stock
Temporary equity par value	$ 0.001	$ 0.001
Temporary equity shares authorized	0	34,017,033
Temporary equity shares issued	0	34,017,033
Temporary equity shares outstanding	0	34,017,033
Series A-2 Redeemable Convertible Preferred Stock
Temporary equity par value	$ 0.001	$ 0.001
Temporary equity shares authorized	0	26,680,202
Temporary equity shares issued	0	26,680,202
Temporary equity shares outstanding	0	26,680,202
Series A-3 Redeemable Convertible Preferred Stock
Temporary equity par value	$ 0.001	$ 0.001
Temporary equity shares authorized	0	30,070,487
Temporary equity shares issued	0	30,070,487
Temporary equity shares outstanding	0	30,070,487
Series A-4 Redeemable Convertible Preferred Stock
Temporary equity par value	$ 0.001	$ 0.001
Temporary equity shares authorized	0	19,999,999
Temporary equity shares issued	0	19,999,999
Temporary equity shares outstanding	0	19,999,999
Series B Redeemable Convertible Preferred Stock
Temporary equity par value	$ 0.001	$ 0.001
Temporary equity shares authorized	0	100,018,619
Temporary equity shares issued	0	98,351,953
Temporary equity shares outstanding	0	98,351,953
Series C Redeemable Convertible Preferred Stock
Temporary equity par value	$ 0.001	$ 0.001
Temporary equity shares authorized	0	0
Temporary equity shares issued	0	0
Temporary equity shares outstanding	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 12,522	$ 12,032
General and administrative	9,687	4,487
Total operating expenses	22,209	16,519
Loss from operations	(22,209)	(16,519)
Other income:
Interest income	82	213
Total other income	82	213
Net loss	(22,127)	(16,306)
Comprehensive loss	$ (22,127)	$ (16,306)
Net loss per share attributable to common stockholders—basic and diluted	$ (2.59)	$ (82.23)
Weighted-average common shares outstanding—basic and diluted	8,590,205	202,093

Condensed Consolidated Statemen

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (audited) - USD ($) $ in Thousands	Total	Redeemable Convertible Preferred Stock	Series C Redeemable Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings
Balance at Dec. 31, 2018	$ (107,074)				$ 4,377	$ (111,451)
Temporary equity balance, Shares at Dec. 31, 2018		209,119,674
Temporary equity balance, Value at Dec. 31, 2018		$ 130,353
Balance, Shares at Dec. 31, 2018				170,156
Exercise of common stock options	111				111
Exercise of common stock options, Shares				60,704
Accretion of convertible preferred stock to redemption value	(313)				(313)
Temporary equity, Accretion of convertible preferred stock to redemption value		$ 313
Stock-based compensation	244				244
Net loss	(16,306)					(16,306)
Balance at Dec. 31, 2019	(123,338)				4,419	(127,757)
Temporary equity balance, Shares at Dec. 31, 2019		209,119,674	0
Temporary equity balance, Value at Dec. 31, 2019	130,666	$ 130,666
Balance, Shares at Dec. 31, 2019				230,860
Exercise of common stock options	$ 8				8
Exercise of common stock options, Shares	2,814			2,814
Issuance of Series C redeemable convertiblepreferred stock, net of issuance costsof $201			$ 29,446
Issuance of Series C redeemable convertible preferred stock, net of issuance costs, Shares			78,306,611
Accretion of convertible preferred stock to redemption value	$ (115)				(115)
Temporary equity, Accretion of convertible preferred stock to redemption value		$ 115
Issuance of common stock warrants inconjunction with sale of Series Credeemable convertible preferred stock	740				740
Conversion of redeemable convertiblepreferred stock to common stockupon closing of initial public offering	160,227		$ (160,227)	$ 8	160,219
Conversion of redeemable convertible preferred stock to common stock upon closing of initial public offering, Shares			(287,426,285)	8,335,248
Issuance of common stock from initialpublic offering, net of issuancecosts of $7,116	57,284			$ 4	57,280
Issuance of common stock from initial public offering, net of issuance costs, Shares				4,025,000
Vesting of restricted common stock				24,661
Issuance of common stock upon exercise ofwarrants				$ 1	(1)
Issuance of common stock upon exercise of warrants, Shares				313,794
Stock-based compensation	1,813				1,813
Net loss	(22,127)					(22,127)
Balance at Dec. 31, 2020	$ 74,492			$ 13	$ 224,363	$ (149,884)
Temporary equity balance, Shares at Dec. 31, 2020			0
Balance, Shares at Dec. 31, 2020				12,932,377

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) (audited) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Common Stock
Payments Of Stock Issuance Costs	$ 7,116
Series C Redeemable Convertible Preferred Stock
Temporary equity, issuance costs	$ 201

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (22,127,000)	$ (16,306,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	1,813,000	244,000
Depreciation expense	95,000	27,000
Reserve for uncollectible accounts		167,000
Gain on disposal of assets	(45,000)
Changes in assets and liabilities:
Prepaid expenses and other current assets	(1,013,000)	561,000
Operating lease right-of-use assets	894,000	864,000
Other assets	(118,000)
Accounts payable	345,000	(205,000)
Accrued expenses and other current liabilities	(87,000)	1,734,000
Operating lease liabilities	(900,000)	(840,000)
Net cash used in operating activities	(21,143,000)	(13,754,000)
Cash flows from investing activities:
Purchases of property and equipment	(1,775,000)	(211,000)
Net cash used in investing activities	(1,775,000)	(211,000)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriting discount	59,892,000
Payment of initial public offering costs	(2,383,000)	(226,000)
Proceeds from exercise of stock options	8,000	111,000
Net cash provided by (used in) financing activities	87,703,000	(115,000)
Net increase (decrease) in cash and cash equivalents	64,785,000	(14,080,000)
Cash and cash equivalents and restricted cash, beginning of period	10,137,000	24,217,000
Cash and cash equivalents and restricted cash, end of period	74,922,000	10,137,000
Supplemental disclosure of non-cash financing and investing activities:
Property and equipment purchases included in accounts payable	205,000	2,000
Conversion of redeemable convertible preferred stock	160,227,000
Accretion of redeemable convertible preferred stock to redemption value	115,000	313,000
Right-of-use asset obtained in exchange of operating lease obligation	13,000	4,046,000
Deferred offering costs included in accounts payable and accrued expense		$ 870,000
Series C Preferred Stock
Cash flows from financing activities:
Proceeds from the sale of Series C redeemable convertible preferred stock	30,392,000
Payment of offering costs related to sale of Series C redeemable convertible preferred stock	(206,000)
Supplemental disclosure of non-cash financing and investing activities:
Allocation of Series C redeemable convertible preferred stock to common stock warrant	$ 740,000

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
Organization and Basis of Presentation	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation Lyra Therapeutics, Inc. (the “Company”) is a clinical-stage therapeutics company focused on the development and commercialization of novel integrated drug and delivery solutions for the localized treatment of patients with ear, nose and throat (“ENT”) diseases. The Company’s proprietary technology platform, XTreo, is designed to precisely and consistently deliver medicines directly to the affected tissue for sustained periods with a single administration. The Company’s initial product candidates, LYR-210 and LYR-220, are bioresorbable polymeric matrices designed to be administered in a brief, non-invasive, in-office procedure and intended to deliver up to six months of continuous drug therapy to the sinonasal passages for the treatment of chronic rhinosinusitis (“CRS”). The Company was incorporated as a Delaware corporation on November 21, 2005 and is located in Watertown, Massachusetts. On July 16, 2018, the Company formerly changed its name from 480 Biomedical, Inc. to Lyra Therapeutics, Inc. The Company is subject to risks common to companies in the therapeutics and pharmaceutical industry, including but not limited to, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for any drug product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development by competitors of technological innovations, reliance on third party manufacturers, ability to transition from pilot-scale manufacturing to large-scale production of products and the need to obtain adequate additional financing to fund the development of its product candidates. Since inception, the Company has funded its operations with proceeds from sales of redeemable convertible preferred stock and funding from government contracts. The Company has incurred recurring net losses since inception and had net losses of approximately $22.1 million and $16.3 million for the years ended December 31, 2020 and 2019, respectively. In addition, the Company has an accumulated deficit of approximately $149.9 million at December 31, 2020. The Company expects to continue to generate operating losses for the foreseeable future. At December 31, 2020, the Company had approximately $74.6 million of cash and cash equivalents. On May 5, 2020, the Company completed its initial public offering (“IPO”), in which the Company issued and sold 4,025,000 shares of its common stock, including 525,000 shares pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a public offering price of $16.00 per share, for aggregate gross proceeds of $64.4 million. The Company received approximately $57.3 million in net proceeds after deducting underwriting discounts and offering expenses paid by the Company. The Company believes that its cash and cash equivalents as of December 31, 2020 will be sufficient to fund the Company’s operating plan for a period of at least one year from the issuance date of the consolidated financial statements. The Company will need additional financing to support its continuing operations and pursue its growth strategy. Until such time as the Company can generate significant revenue from product sales, if ever, it expects to finance its operations through a combination of equity or debt financings, collaboration agreements, strategic alliances and licensing arrangements. The Company may be unable to raise additional funds or enter into such other agreements when needed on favorable terms or at all. The inability to obtain funding as and when needed would have a negative impact on the Company’s financial condition and ability to pursue its business strategies. If the Company is unable to obtain funding when needed, the Company could be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations. The Company will need to generate significant revenue to achieve profitability, and it may never do so. Upon the completion of the IPO of its common stock in May 2020, all outstanding redeemable convertible preferred stock of the Company converted into shares of common stock and all outstanding warrants to purchase common stock were automatically cashless exercised. COVID-19 Pandemic and CARES Act On January 30, 2020, the World Health Organization (“WHO”) announced a global health emergency because of a new strain of coronavirus originating in Wuhan, China (the “COVID-19 outbreak”) and the risks to the international community as the virus subsequently spread globally beyond its point of origin. On March 11, 2020, the WHO classified the COVID-19 outbreak as a pandemic, based on the rapid increase in exposure globally. The COVID-19 pandemic is affecting the United States and global economies and may affect the Company’s operations and those of third parties on which the Company relies, including by causing disruptions in the supply of the Company’s product candidates and the conduct of current and future clinical trials. In addition, the COVID-19 pandemic may affect the operations of the Food and Drug Administration and other health authorities, which could result in delays of reviews and approvals, including with respect to the Company’s product candidates. In light of developments relating to the COVID-19 pandemic, the Company discontinued enrollment at 67 patients in its Phase 2 LANTERN clinical trial and did not enroll patients in the United States. Additionally, while the potential economic impact brought by, and the duration of, the COVID-19 pandemic is difficult to assess or predict, the impact of the COVID-19 pandemic on the global financial markets may reduce the Company’s ability to access capital, which could negatively impact the Company’s short-term and long-term liquidity. The ultimate impact of the COVID-19 pandemic is highly uncertain and subject to change. The Company does not yet know the full extent of potential delays or impacts on its business, financing or clinical trial activities or on healthcare systems or the global economy as a whole. However, these effects could have a material impact on the Company’s liquidity, capital resources, operations and business and those of the third parties on which the Company relies. On March 27, 2020, President Trump signed into law the “Coronavirus Aid, Relief, and Economic Security (CARES) Act.” The CARES Act, among other things, includes provisions relating to refundable payroll tax credits, deferment of employer side social security payments, net operating loss carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations, increased limitations on qualified charitable contributions, and technical corrections to tax depreciation methods for qualified improvement property. The Company currently defers the employer side social security payments and also is evaluating whether it will take advantage of other provisions, if any. The CARES Act also appropriated funds for the SBA Paycheck Protection Program loans that are forgivable in certain situations to promote continued employment, as well as Economic Injury Disaster Loans to provide liquidity to small businesses harmed by COVID-19. On December 27, 2020, the Consolidated Appropriations Act, 2021 was signed into law in order to provide further stimulus and support to those affected by the COVID-19 pandemic. The Company has not and does not plan on obtaining funding from such loans. The Company does not believe the CARES Act or the Consolidated Appropriations Act, 2021 will have a material impact on its financial condition, results of operations, or liquidity. Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standard Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Principles of Consolidation The consolidated financial statements include the accounts of Lyra Therapeutics, Inc. and its wholly owned subsidiary Lyra Therapeutics Security Corporation, which was incorporated in December 2018. All intercompany transactions and balances have been eliminated. The accompanying consolidated financial statements reflect the application of certain significant accounting policies as described in this note and elsewhere in the accompanying consolidated financial statements and notes. Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, expenses and related disclosure of contingent assets and liabilities at the date of the consolidated financial statements and reported amounts of expenses during the reporting period. On an ongoing basis, the Company’s management evaluates its estimates, which include but are not limited to management’s judgments of accrued expenses, fair value of common stock, valuation of share-based awards warrants to purchase common stock and deferred income taxes. Due to the uncertainty inherent in such estimates, actual results may differ from these estimates. The Company utilizes significant estimates and assumptions in determining the fair value of its common stock. The Company has utilized various valuation methodologies to estimate the fair value of its common stock. Each valuation methodology includes estimates and assumptions that require the Company’s judgment. These estimates and assumptions include a number of objective and subjective factors, including external market conditions, the prices at which the Company sold shares of preferred stock, the superior rights and preferences of securities senior to the Company’s common stock at the time of, and the likelihood of, achieving a liquidity event, such as an initial public offering or sale. Significant changes to the key assumptions used in the valuations could result in different fair values of common stock at each valuation date. Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision-maker in deciding how to allocate resources and assess performance. The Company and the Company’s chief operating decision-maker, the Company’s chief executive officer, views the Company’s operations and manages its business as a single operating segment, which is the business of developing targeted medicines to address ENT diseases. Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. As the Company did not have any element of other comprehensive income (loss), its comprehensive loss is equal to its net loss for all periods presented. Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash and cash equivalents include cash held in banks and amounts held in money market funds. Cash equivalents are stated at cost, which approximates market value. Cash and cash equivalents consist of cash held in banks at December 31, 2020 and 2019. Restricted Cash The Company had restricted cash of approximately $0.3 million as of December 31, 2020 and 2019, which was held in certificates of deposit at the Company’s financial institution to secure the Company’s letter of credit for its facility lease. Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains all its cash and cash equivalents at a single accredited financial institution, in amounts that exceed federally insured limits. The Company has no significant off-balance sheet risk such as foreign exchange contracts, option contracts, or other foreign exchange hedging arrangements. Significant Suppliers The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the drug product and associated applicator related to these programs. These programs could be adversely affected by a significant interruption in the supply of the materials required to manufacture the drug product and associated applicator. Fair Value of Financial Instruments Fair value is defined as the price that would be received upon sale of an asset or paid to transfer a liability between market participants at a measurement date. ASC Topic 820, Fair Value Measurements Level 1 -Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 -Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3 -Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. An entity may elect to measure many financial instruments and certain other items at fair value at specified election dates. Subsequent unrealized gains and losses on items for which the fair value option has been elected will be reported in net loss. The Company did not elect to measure any financial instruments or other items at fair value. Derivative Liabilities In connection with certain debt and equity financings, the Company may issue financial instruments in which a derivative instrument is “embedded.” Upon issuing the financial instrument, the Company assesses whether the economic characteristics of the embedded derivative are clearly and closely related to the economic characteristics of the remaining component of the financial instrument (i.e., the host contract) and whether a separate, non-embedded instrument with the same terms as the embedded instrument would meet the definition of a derivative instrument. When it is determined that (1) the embedded derivative possesses economic characteristics that are not clearly and closely related to the economic characteristics of the host contract, and (2) a separate, stand-alone instrument with the same terms would qualify as a derivative instrument, the embedded derivative is separated from the host contract and carried at fair value until the derivative is settled. Changes in the fair value of the derivative liabilities are recognized as other income (expense) in the consolidated statement of operations and comprehensive loss. Classification and Accretion of Redeemable Convertible Preferred Shares The Company has classified the redeemable convertible preferred stock outside of stockholders’ deficit in the accompanying consolidated balance sheets in accordance with authoritative guidance for the classification and measurement of redeemable securities as the redeemable convertible preferred stock is redeemable at a determinable price on a fixed date or upon the occurrence of a deemed liquidation event. The carrying values of the redeemable convertible preferred shares are accreted to their redemption values from the date of issuance through the earliest date of redemption. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset as follows: Estimated Useful Life Laboratory equipment 5 years Computer software and equipment 3 years Office furniture and fixtures 7 years Leasehold improvements Shorter of useful life or remaining term of related lease Costs for capital assets not yet placed into service are capitalized as construction in progress and are depreciated in accordance with the above guidelines once placed into service. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are eliminated from the balance sheet and related gains or losses are reflected in the consolidated statement of operations and comprehensive loss. Repairs and maintenance that do not improve or extend the lives of the respective assets are expensed as incurred, while costs of major additions and betterments are capitalized. Impairment of Long-Lived Assets Long-lived assets consist of property and equipment. The Company continually evaluates long-lived assets for potential impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparing the book values of the assets to the expected future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book values of the assets exceed their fair value. The Company did not record any impairment losses on long-lived assets during the years ended December 31, 2020 and 2019. Leases ASU No. 2016-02, Leases (Topic 842) A lease qualifies as a finance lease if any of the following criteria are met at the inception of the lease: (i) there is a transfer of ownership of the leased asset to the Company by the end of the lease term, (ii) the Company holds an option to purchase the leased asset that it is reasonably certain to exercise, (iii) the lease term is for a major part of the remaining economic life of the leased asset, (iv) the present value of the sum of lease payments equals or exceeds substantially all of the fair value of the leased asset, (v) the nature of the leased asset is specialized to the point that it is expected to provide the lessor no alternative use at the end of the lease term. All other leases are recorded as operating leases. Finance and operating lease assets and liabilities are recognized at the lease commencement date based on the present value of the lease payments over the lease term using the discount rate implicit in the lease. If the rate implicit in the lease is not readily determinable, the Company utilizes its incremental borrowing rate at the lease commencement date. Operating lease assets are further adjusted for prepaid or accrued lease payments. Operating lease payments are expensed using the straight-line method as an operating expense over the lease term. Finance lease assets are amortized to depreciation expense using the straight-line method over the shorter of the useful life of the related asset or the lease term. Finance lease payments are bifurcated into (i) a portion that is recorded as imputed interest expense and (ii) a portion that reduces the finance liability associated with the lease. The Company separates lease and non-lease components when determining which lease payments to include in the calculation of its lease assets and liabilities. Variable lease payments are expensed as incurred. If a lease includes an option to extend or terminate the lease, the Company reflects the option in the lease term if it is reasonably certain it will exercise the option. Operating leases are recorded in “Operating lease right-of use assets,” “Operating lease liabilities” and “Operating lease liabilities, net of current portion” in the Company’s consolidated balance sheets. The Company did not have any finance leases recorded in its consolidated balance sheet as of December 31, 2020. Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses include salaries and benefits, materials and supplies, preclinical and clinical trial expenses, manufacturing expenses, stock-based compensation expense, depreciation of equipment, contract services and other outside expenses. Costs of certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the consolidated financial statements as prepaid or accrued research and development costs. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are deferred and capitalized. The capitalized amounts are expensed as the related goods are delivered or the services are performed. The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs. Patent Costs The Company expenses patent application and related legal costs as incurred and classifies such costs as general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss. Accounting for Stock-Based Compensation The Company accounts for its stock-based compensation in accordance with ASC Topic 718, Compensation—Stock Compensation The Black-Scholes option-pricing model uses the following inputs: the fair value of the Company’s common stock, the expected volatility of the Company’s common stock, the expected term of the Company’s stock options, the risk-free interest rate for a period that approximates the expected term of the Company’s stock options, and the Company’s expected dividend yield. Following the closing of the Company’s IPO, the fair value of the Company’s common stock is determined based on the quoted market price of its common stock. The Company has historically been a private company and lacks company-specific historical and implied volatility data. Therefore, the Company has based its computation of expected volatility on the historical volatility of a representative group of public companies with similar characteristics to it, including stage of product development, life science industry focus, length of trading history, and similar vesting provisions. The historical volatility data is calculated based on a period of time commensurate with the expected term assumption. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available or until circumstances change, such that the identified entities are no longer representative companies. In the latter case, more suitable, similar entities whose share prices are publicly available would be utilized in the calculation. The Company uses the simplified method as prescribed by the SEC Staff Accounting Bulletin No. 107, Share-Based Payment The Company has elected as a policy to recognize forfeitures as they occur as described in ASU No. 2016-09, Compensation—Stock Compensation The Company expenses the fair value of its stock-based compensation awards to employees on a straight-line basis over the requisite service period, which is generally the vesting period. The Company records the expense for stock-based compensation awards subject to performance-based milestone vesting when management determines that achievement of the milestone is probable. Management evaluates when the achievement of a performance-based milestone is probable based on the expected satisfaction of the performance conditions as of the reporting date. The Company follows the provisions of ASU No. 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting Income Taxes The Company accounts for income taxes using the liability method in accordance with ASC Topic 740, Income Taxes The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. Contingencies In accordance with ASC Topic 450, Contingencies If a loss contingency is not probable but is reasonably possible, or is probable but cannot be estimated, the nature of the contingent liability, together with an estimate of the range of possible loss if determinable and material, would be disclosed. Guarantees The Company has identified the guarantees described below as disclosable, in accordance with ASC Topic 460, Guarantees As permitted under Delaware law, the Company indemnifies its officers and directors for certain events or occurrences while the officer or director is, or was, serving at the Company’s request in such capacity. The maximum potential amount of future payments the Company could be required to make is unlimited; however, the Company has directors’ and officers’ insurance coverage that should limit its exposure and enable it to recover a portion of any future amounts paid. The Company is a party to a number of agreements entered into in the ordinary course of business that contain typical provisions that obligate the Company to indemnify the other parties to such agreements upon the occurrence of certain events. Such indemnification obligations are usually in effect from the date of execution of the applicable agreement for a period equal to the applicable statute of limitations. The aggregate maximum potential future liability of the Company under such indemnification provisions is uncertain. The Company leases office space under a noncancelable operating lease. The Company has standard indemnification arrangements under the lease that requires it to indemnify the landlord against all costs, expenses, fines, suits, claims, demands, liabilities, and actions directly resulting from any breach, violation, or nonperformance of any covenant or condition of the lease. As of December 31, 2020 and 2019, the Company had not experienced any losses related to these indemnification obligations, and no material claims with respect thereto were outstanding. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related reserves have been established. Deferred Offering Costs The Company capitalizes certain legal, professional, accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ deficit as a reduction of additional paid-in capital generated as a result of the offering. Should the planned equity financing be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the consolidated statement of operations and comprehensive loss. Deferred offering costs of $0 and $1.1 million are included in other assets in the consolidated balance sheets at December 31, 2020 and 2019, respectively. Net Loss per Share The Company has reported losses since inception and has computed basic net loss per share attributable to common stockholders by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. The Company has computed diluted net loss per common share after giving consideration to all potentially dilutive common shares, including options to purchase common stock, warrants to purchase common stock and redeemable convertible preferred stock, outstanding during the period determined using the treasury-stock and if-converted methods, except where the effect of including such securities would be antidilutive. Because the Company has reported net losses since inception, these potential common shares have been anti-dilutive and basic and diluted loss per share have been the same. Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share data): Year Ended December 31, 2020 2019 Numerator: Net loss $ (22,127 ) $ (16,306 ) Accretion of redeemable convertible preferred stock (115 ) (313 ) Net loss attributable to common stockholders $ (22,242 ) $ (16,619 ) Denominator: Weighted-average common shares—basic and diluted 8,590,205 202,093 Net loss per share attributable to common stockholders—basic and diluted $ (2.59 ) $ (82.23 ) The following table sets forth the potentially dilutive securities that have been excluded from the calculation of diluted net loss per share because to include them would be anti-dilutive (in common stock equivalent shares retroactively adjusted): Year Ended December 31, 2020 2019 Series A-1 redeemable convertible preferred stock — 986,466 Series A-2 redeemable convertible preferred stock — 773,712 Series A-3 redeemable convertible preferred stock — 872,031 Series A-4 redeemable convertible preferred stock — 579,993 Series B redeemable convertible preferred stock — 2,852,177 Stock options 1,428,886 792,439 Total 1,428,886 6,856,818 Recently Adopted Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract Recently Issued Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The Company did not have financial assets and liabilities measured at fair value at December 31, 2020 and 2019. There have been no changes to the valuation methods used during the years ended December 31, 2020 and 2019. There were no transfers within the fair value hierarchy during the years ended December 31, 2020 and 2019. The carrying values of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities. In connection with the Company’s sale of Series C redeemable convertible preferred stock (“Series C Preferred Stock”), the Company issued to investors warrants for the purchase of common stock (“Warrants”). The proceeds from the issuance of the Series C Preferred Stock were allocated between the Series C Preferred Stock and Warrants based on their relative fair values at the time of issuance.

Property and Equipment

Property and Equipment	12 Months Ended
Property and Equipment	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Property and Equipment	4. Property and Equipment Property and equipment consist of the following at December 31, 2020 and 2019 (in thousands): December 31, 2020 2019 Property and equipment: Laboratory equipment $ 3,277 $ 1,715 Computer software and equipment 650 595 Office furniture and fixtures 301 301 Leasehold improvements 317 317 Construction in progress 498 138 $ 5,043 $ 3,066 Accumulated depreciation (2,878 ) (2,829 ) Property and equipment, net $ 2,165 $ 237 The Company recognized approximately $0.1 million and $27,000 of depreciation expense for the years ended December 31, 2020 and 2019, respectively. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset as follows: Estimated Useful Life Laboratory equipment 5 years Computer software and equipment 3 years Office furniture and fixtures 7 years Leasehold improvements Shorter of useful life or remaining term of related lease Costs for capital assets not yet placed into service are capitalized as construction in progress and are depreciated in accordance with the above guidelines once placed into service. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are eliminated from the balance sheet and related gains or losses are reflected in the consolidated statement of operations and comprehensive loss. Repairs and maintenance that do not improve or extend the lives of the respective assets are expensed as incurred, while costs of major additions and betterments are capitalized.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
Accrued Expenses and Other Current Liabilities	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	5. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following at December 31, 2020 and 2019 (in thousands): December 31, 2020 2019 Payroll and employee related expenses $ 1,892 $ 885 Third-party research and development expenses 381 1,344 Professional and consulting fees 555 901 Other 149 110 Total accrued expenses and other current liabilities $ 2,977 $ 3,240

Redeemable Convertible Preferre

Redeemable Convertible Preferred Stock	12 Months Ended
Redeemable Convertible Preferred Stock	Dec. 31, 2020
Temporary Equity Disclosure [Abstract]
PreferredStockTextBlock	6. Redeemable Convertible Preferred Stock On January 10, 2020, the Company filed an amended and restated certificate of incorporation which authorized its Board of Directors to issue up to 299,300,288 shares of preferred stock, par value $0.001 per share. In January 2020, the Company issued 78,306,611 shares of Series C Preferred Stock for $0.38811 per share, in exchange for gross cash proceeds of approximately $30.4 million. Upon the completion of the IPO of its common stock in May 2020, all outstanding redeemable convertible preferred stock of the Company converted into shares of common stock.

Preferred and Common Stock

Preferred and Common Stock	12 Months Ended
Preferred and Common Stock	Dec. 31, 2020
Equity [Abstract]
Preferred and Common Stock	7. Preferred and Common Stock On January 10, 2020, the Company filed an amended and restated certificate of incorporation which authorized its Board of Directors to issue up to 400,000,000 shares of common stock, par value $0.001 per share. On May 5, 2020, the Company filed a restated certificate of incorporation which authorizes its Board of Directors to issue up to 200,000,000 shares of common stock, par value $0.001 per share and 10,000,000 shares of undesignated preferred stock, par value $0.001 per share. The holders of common stock are entitled to one vote for each share held. Common stockholders are not entitled to receive dividends, unless declared by the Board of Directors. The Company’s Board of Directors approved a one-for-34.483 reverse stock split of its issued and outstanding common stock and stock options and a proportional adjustment to the existing conversion ratios for the Company’s redeemable convertible preferred stock pursuant to an amendment to the Company’s amended and restated certificate of incorporation effective as of April 27, 2020. Accordingly, all common stock shares, per share amounts, and additional paid in capital amounts for all periods presented in the accompanying consolidated financial statements and notes thereto have been retroactively adjusted, where applicable, to reflect the reverse stock split. In May 2020, the Company completed its IPO in which the Company issued and sold 4,025,000 shares of its common stock, including 525,000 shares pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a public offering price of $16.00 per share, for aggregate gross proceeds of $64.4 million. The Company received approximately $57.3 million in net proceeds after deducting underwriting discounts and offering expenses paid by the Company. In connection with this financing, all outstanding shares of redeemable convertible preferred stock converted into 8,335,248 shares of the Company’s common stock, all outstanding Warrants were automatically cashless exercised resulting in the issuance of 313,794 shares of the Company’s stock and the issuance to one of our directors, in lieu of compensation payable by the Company under a consulting agreement, of 19,661 fully vested shares of the Company’s common stock. In December 2020, the Company issued as non-employee compensation 5,000 fully vested shares of the Company’s common stock. The Company has reserved for future issuances the following shares of common stock as of December 31, 2020: As of December 31, 2020 Stock options 2,888,653 Employee stock purchase plan 150,000 Total 3,038,653 Warrants In conjunction with the issuance of the Series C Preferred Stock, the Company issued Warrants to purchase 681,256 shares of common stock at an exercise price of $8.63 per share. The Company classified the Warrants as equity in the consolidated balance sheets in accordance with the guidance in ASC 815, Derivatives and Hedging Upon the completion of the IPO of the Company’s common stock in May 2020, all outstanding Warrants were automatically cashless exercised resulting in the issuance of 313,794 shares of the Company’s common stock.

Stock-Based Compensation Expens

Stock-Based Compensation Expense	12 Months Ended
Stock-Based Compensation Expense	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Expense	8. Stock-Based Compensation Expense The Company adopted the 2016 Equity Incentive Plan (“2016 Plan”) in February 2016 and amended it in June 2017 and June 2018. Upon adoption of the 2016 Plan, no further grants were made under the 2005 Equity Incentive Plan (“2005 Plan”). In April 2020, the Company’s Board of Directors adopted the Company’s 2020 Incentive Award Plan (“2020 Plan”, and together with the 2016 Plan and 2005 Plan, the “Plans”), and upon effectiveness of the 2020 Plan, the Company ceased granting equity-based awards under the 2016 Plan. The 2020 Plan provides for grant of incentive stock options and nonqualified stock options, stock appreciation rights, restricted stock, dividend equivalents, restricted stock units, performance awards and other share and cash-based awards to employees and consultants and members of the Board of Directors of the Company and its subsidiaries. The initial number of shares of the Company’s common stock that may be issued under the 2020 Plan is 2,100,000 shares plus the number of shares of the Company’s common stock underlying outstanding awards under the 2005 Plan and 2016 Plan as of the effective date of the 2020 Plan that expire, lapse or are terminated, exchanged for cash, surrendered, repurchased, canceled or forfeited following the effective date of the 2020 Plan. The number of shares available under the 2020 Plan will automatically increase on January 1st of each year from 2021 to 2030 by the lesser of (i) 4% of the number of shares of common stock outstanding on the final day of the immediately preceding calendar year and (ii) a smaller number of shares determined by the Company’s Board of Directors. However, no more than 8,800,000 shares may be issued under the 2020 Plan pursuant to the exercise of incentive stock options. As of December 31, 2020, the Company had 1,459,767 shares available for issuance under the 2020 Plan. All stock option grants are nonqualified stock options except option grants to employees and officers intended to qualify as incentive stock options under the Internal Revenue Code of 1986, as amended. Stock options may not be granted at less than the fair market value of the Company’s common stock on the date of grant. Vesting periods of awards are determined by the Board of Directors or its compensation committee. Vesting periods of awards granted to date range from vesting upon grant to vesting over a four-year period. Vesting conditions are generally based on continued service. Additionally, the Company has granted certain awards which vest upon the achievement of certain financing and revenue milestones. Stock options granted under the Plans expire no more than 10 years from the date of grant. Stock-based compensation expense included in the Company’s consolidated statements of operations and comprehensive loss was as follows (in thousands): Year Ended December 31, 2020 2019 Research and development $ 229 $ 26 General and administrative 1,584 218 Total $ 1,813 $ 244 The Company did not record any stock-based compensation associated with milestone-based awards in the years ended December 31, 2020 and 2019. The fair value of each stock option granted to employees, directors and non-employees was estimated on the date of grant using the Black-Scholes option-pricing model, with the following weighted-average assumptions: Year Ended December 31, 2020 2019 Risk-free interest rate 0.6 % 2.2 % Expected dividend yield — % — % Expected term (in years) 6.0 6.1 Expected volatility 80.7 % 76.8 % A summary of the stock option activity under the Plans for the year ended December 31, 2020 was as follows: Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Outstanding December 31, 2019 792,439 $ 6.59 7.3 $ 3,363 Granted 763,505 14.16 Exercised (2,814 ) 2.92 Cancelled (124,244 ) 9.30 Outstanding at December 31, 2020 1,428,886 $ 10.41 7.7 $ 5,165 Exercisable at December 31, 2020 626,578 $ 9.30 6.0 $ 3,099 Vested and expected to vest at December 31, 2020 1,428,886 $ 10.41 7.7 $ 5,165 The weighted-average fair value of options granted to employees, directors and non-employees during the years ended December 31, 2020 and 2019 was $9.66 and $3.45, respectively. The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The aggregate intrinsic value of stock options exercised during the years ended December 31, 2020 and 2019 was approximately $27,000 and $0.2 million, respectively. As of December 31, 2020, total unrecognized stock-based compensation expense relating to unvested stock options was approximately $6.2 million. This amount is expected to be recognized over a weighted-average period of 3.2 years. Additionally, as of December 31, 2020, there was approximately $36,000 of unrecognized stock-based compensation related to a stock option award related to the achievement of a revenue-based milestone. As the Company believes the achievement of the revenue-based milestone is currently not probable, it has not recorded any stock-based compensation related to this award. The Company will continue to assess the probability of achieving the revenue-based milestone at each reporting period. 2020 Employee Stock Purchase Plan In April 2020, the Company’s Board of Directors adopted the Company’s 2020 Employee Stock Purchase Plan (“2020 ESPP”). The 2020 ESPP is structured as a qualified employee stock purchase plan under Section 423 of the Internal Revenue Code of 1986, as amended, and is not subject to the provisions of the Employee Retirement Income Security Act of 1974. The Company initially reserved 150,000 shares of common stock for issuance under the 2020 ESPP. In addition, the number of shares available for issuance under the 2020 ESPP will be annually increased on January 1st of each year from 2021 to 2030 by the lesser of (i) 0.5% of the number of shares of common stock outstanding on the final day of the immediately preceding calendar year and (ii) such smaller number of shares as is determined by the Company’s Board of Directors, provided that no more than 987,500 shares of common stock may be issued under the 2020 ESPP. The 2020 ESPP permits eligible participants to purchase common stock through payroll deductions of up to a specified percentage of their eligible compensation. On the first trading day of each offering period, each participant will automatically be granted an option to purchase shares of the Company’s common stock. The option will expire at the end of the applicable offering period, and will be exercised at that time to the extent of the payroll deductions accumulated during the offering period, subject to the limits set forth in the 2020 ESPP. The purchase price of the shares, in the absence of a contrary designation, will be 85% of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the purchase date. As of December 31, 2020, no shares have been issued under the 2020 ESPP.

Related Parties

Related Parties	12 Months Ended
Related Parties	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Parties	9. Related Parties The Company had consulting agreements that expired in January 2020 with two of its founders who resigned as directors of the Company in October 2020. Total consulting expense related to these consulting agreements was $0 and $50,000 for the years ended December 31, 2020 and 2019, respectively. In 2011, the Company entered into a Contribution Agreement, Transition Services Agreement (as amended), Collaboration Agreement, Technology License Agreement and Trademark Coexistence Agreement with Arsenal Medical, Inc. (“Arsenal”), a company which shares certain common owners with the Company. During the year ended December 31, 2019, the Company invoiced Arsenal for an aggregate of $0.3, primarily for its share of rent and other overhead costs. The Transition Services Agreement expired in June 2019. All amounts receivable from Arsenal were collected as of December 31, 2019.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The Company records a provision or benefit for income taxes on pre-tax income or loss based on its estimated effective tax rate for the year. During the years ended December 31, 2020 and 2019, the Company recorded net losses of approximately $22.1 million and $16.3 million, respectively, and, since it maintains a full valuation allowance on its deferred tax assets, the Company did not record an income tax benefit for the years ended December 31, 2020 and 2019. A reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes reflected in the consolidated financial statements is as follows: Year Ended December 31, 2020 2019 Income tax computed at federal statutory tax rate 21.0 % 21.0 % Permanent differences (2.0 )% (0.2 )% State taxes, net of federal benefit 5.4 % 6.2 % Research and development and other tax credits 2.6 % 3.8 % Change in deferred tax asset valuation allowance (28.4 )% (30.7 )% Other 1.4 % (0.1 )% — % — % Net deferred tax assets as of December 31, 2020 and 2019 consist of the following (in thousands): December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 35,729 $ 30,006 Research and development credits 5,223 4,652 Stock-based compensation 322 173 Operating lease liabilities 661 909 Other 140 280 Total gross deferred tax assets 42,075 36,020 Less: Valuation allowance (41,451 ) (35,150 ) Total deferred tax assets 624 870 Deferred tax liabilities: Operating lease right-of-use assets (624 ) (870 ) Total deferred tax liabilities (624 ) (870 ) Net deferred taxes $ — $ — As of December 31, 2020, the Company had U.S. federal net operating loss carryforwards of approximately $91.4 million which may be able to offset future income tax liabilities and expire at various dates through 2037 and approximately $44.0 million of federal net operating loss carryforwards that may be carried forward indefinitely. As of December 31, 2020, the Company also had state net operating loss carryforwards of approximately $116.0 million which may be available to offset future income tax liabilities and expire at various dates through 2040. As of December 31, 2020 and 2019, the Company had federal research and development tax credit carryforwards of approximately $3.6 million and $3.2 million, respectively, available to reduce future tax liabilities which expire at various dates through 2040. As of December 31, 2020 and 2019, the Company had state research and development tax credit carryforwards of approximately $2.0 million and $1.8 million, respectively, available to reduce future tax liabilities which expire at various dates through 2035. The Company has generated research credits but has not conducted a study to document the qualified activity. This study may result in an adjustment to the Company’s research and development credit carryforwards; however, until a study is completed and any adjustment is known, no amounts are being presented as an uncertain tax position. A full valuation allowance has been provided against the Company’s research and development credits and, if an adjustment is required, this adjustment would be offset by an adjustment to the deferred tax asset established for the research and development credit carryforwards and the valuation allowance. Under the provisions of the Internal Revenue Code, the net operating loss and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. Net operating loss and tax credit carryforwards may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant shareholders over a three-year period in excess of 50%, as defined under Sections 382 and 383 of the Internal Revenue Code, respectively, as well as similar state provisions. This could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. The Company has not conducted a study to assess whether a change of control has occurred or whether there have been multiple changes of control since inception due to the significant complexity and cost associated with such a study. If the Company has experienced a change of control, as defined by Section 382, at any time since inception, utilization of the net operating loss carryforwards or research and development tax credit carryforwards would be subject to an annual limitation under Section 382, which is determined by first multiplying the value of the Company’s stock at the time of the ownership change by the applicable long-term tax-exempt rate, and then could be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the net operating loss carryforwards or research and development tax credit carryforwards before utilization. Further, until a study is completed by the Company and any limitation is known, no amounts are being presented as an uncertain tax position. ASC 740 requires a valuation allowance to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. After consideration of all the evidence, both positive and negative, the Company has recorded a valuation allowance against its deferred tax assets at December 31, 2020 and 2019 because the Company’s management has determined that it is more likely than not that the Company will not recognize the benefits of its federal and state deferred tax assets primarily due to its history of cumulative net losses incurred since inception and its lack of commercialization of any products or generation of any revenue from product sales since inception and, as a result, a valuation allowance of approximately $41.5 million and $35.2 million, respectively, has been established at December 31, 2020 and 2019. Management reevaluates the positive and negative evidence at each reporting period. The valuation allowance increased by approximately $6.3 million and $5.1 million, respectively, during the years ended December 31, 2020 and 2019 due primarily to the generation of net operating losses. The Company has recorded adjustments to deferred tax assets for unrecognized tax benefits as of December 31, 2020 and 2019. The Company’s policy is to record interest and penalties related to uncertain tax positions as part of its income tax provision. As of December 31, 2020 and 2019, the Company had no accrued interest or penalties related to uncertain tax positions and no such amounts have been recognized in the Company’s statement of operations and comprehensive loss. In many cases, the Company’s uncertain tax positions are related to years that remain subject to examination by relevant tax authorities. The statute of limitations for federal and state tax authorities is closed for years prior to December 31, 2017. However, since the Company is in a loss carryforward position, the Company is generally subject to examination by the U.S. federal, state and local income tax authorities for all tax years in which a loss carryforward is available. Income Taxes The Company accounts for income taxes using the liability method in accordance with ASC Topic 740, Income Taxes The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.

Leases

Leases	12 Months Ended
Leases	Dec. 31, 2020
Leases [Abstract]
Leases	11. Leases In August 2007, the Company entered into an operating lease, as amended, for approximately 22,343 square feet of office and laboratory space in Watertown, Massachusetts. In November 2017, the Company amended its lease (“2017 Amendment”) and extended the lease term through April 2023. Initial base rent under the 2017 Amendment was approximately $1.0 million per year. The 2017 Amendment includes annual rent escalations over the term of the operating lease. The Company maintains a letter of credit of approximately $0.3 million securing its obligations under the operating lease which is secured by approximately $0.3 million of certificate of deposits, which are included as restricted cash in the consolidated balance sheets. Rent expense is recognized on a straight-line basis over the terms of occupancy. In addition to the lease discussed above, the Company is party to an April 2020 lease for office equipment that expires in June 2024. The equipment lease is accounted for as an operating lease. The components of lease cost recorded in the Company’s consolidated financial statements were as follows (in thousands): Year Ended December 31, 2020 2019 Lease Cost: Operating lease cost $ 1,055 $ 1,053 Variable lease cost 726 727 Sublease income — (368 ) Total lease cost, net $ 1,781 $ 1,412 Variable lease payments include the Company’s allocated share of costs incurred and expenditures made by the landlord in the operation and management of the building. The Company’s sublease income during the year ended December 31, 2019 related to subleases for a portion of the Company’s office and lab space. The weighted-average remaining lease term and discount rate related to the Company’s operating leases were as follows: As of December 31, 2020 Weighted-average remaining lease term (in years) 2.3 Weighted-average discount rate 5.5 % Maturity of the Company’s operating lease liabilities in accordance with ASC 842 as of December 31, 2020 were as follows (in thousands): Year ending December 31, 2021 $ 1,095 2022 1,127 2023 382 2024 2 Total maturities 2,606 Less: Amount representing interest (167 ) Present value of operating lease liability 2,439 Less: Current portion of operating lease liability (985 ) Total operating lease liability, net of current portion $ 1,454

Retirement Plan

Retirement Plan	12 Months Ended
Retirement Plan	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Retirement Plan	12. Retirement Plan The Company has a defined-contribution plan under Section 401(k) of the Internal Revenue Code (“401(k) Plan”). The 401(k) Plan covers all employees who meet defined minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. As currently established, the Company is not required to make any contributions to the 401(k) Plan. For the year ended December 31, 2020, the Company made a discretionary match that matches 50% of employee contributions up to a maximum of 3% of employees’ salary. Matching contributions are fully vested at the time of contribution. During the year ended December 31, 2020, matching contribution costs incurred by the Company were $0.1 million. The Company did not make any matching contributions during the year ended December 31, 2019.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2020
Accounting Policies [Abstract]
COVID-19 Pandemic and CARES Act	COVID-19 Pandemic and CARES Act On January 30, 2020, the World Health Organization (“WHO”) announced a global health emergency because of a new strain of coronavirus originating in Wuhan, China (the “COVID-19 outbreak”) and the risks to the international community as the virus subsequently spread globally beyond its point of origin. On March 11, 2020, the WHO classified the COVID-19 outbreak as a pandemic, based on the rapid increase in exposure globally. The COVID-19 pandemic is affecting the United States and global economies and may affect the Company’s operations and those of third parties on which the Company relies, including by causing disruptions in the supply of the Company’s product candidates and the conduct of current and future clinical trials. In addition, the COVID-19 pandemic may affect the operations of the Food and Drug Administration and other health authorities, which could result in delays of reviews and approvals, including with respect to the Company’s product candidates. In light of developments relating to the COVID-19 pandemic, the Company discontinued enrollment at 67 patients in its Phase 2 LANTERN clinical trial and did not enroll patients in the United States. Additionally, while the potential economic impact brought by, and the duration of, the COVID-19 pandemic is difficult to assess or predict, the impact of the COVID-19 pandemic on the global financial markets may reduce the Company’s ability to access capital, which could negatively impact the Company’s short-term and long-term liquidity. The ultimate impact of the COVID-19 pandemic is highly uncertain and subject to change. The Company does not yet know the full extent of potential delays or impacts on its business, financing or clinical trial activities or on healthcare systems or the global economy as a whole. However, these effects could have a material impact on the Company’s liquidity, capital resources, operations and business and those of the third parties on which the Company relies. On March 27, 2020, President Trump signed into law the “Coronavirus Aid, Relief, and Economic Security (CARES) Act.” The CARES Act, among other things, includes provisions relating to refundable payroll tax credits, deferment of employer side social security payments, net operating loss carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations, increased limitations on qualified charitable contributions, and technical corrections to tax depreciation methods for qualified improvement property. The Company currently defers the employer side social security payments and also is evaluating whether it will take advantage of other provisions, if any. The CARES Act also appropriated funds for the SBA Paycheck Protection Program loans that are forgivable in certain situations to promote continued employment, as well as Economic Injury Disaster Loans to provide liquidity to small businesses harmed by COVID-19. On December 27, 2020, the Consolidated Appropriations Act, 2021 was signed into law in order to provide further stimulus and support to those affected by the COVID-19 pandemic. The Company has not and does not plan on obtaining funding from such loans. The Company does not believe the CARES Act or the Consolidated Appropriations Act, 2021 will have a material impact on its financial condition, results of operations, or liquidity.
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standard Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of Lyra Therapeutics, Inc. and its wholly owned subsidiary Lyra Therapeutics Security Corporation, which was incorporated in December 2018. All intercompany transactions and balances have been eliminated. The accompanying consolidated financial statements reflect the application of certain significant accounting policies as described in this note and elsewhere in the accompanying consolidated financial statements and notes.
Use of Estimates	Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, expenses and related disclosure of contingent assets and liabilities at the date of the consolidated financial statements and reported amounts of expenses during the reporting period. On an ongoing basis, the Company’s management evaluates its estimates, which include but are not limited to management’s judgments of accrued expenses, fair value of common stock, valuation of share-based awards warrants to purchase common stock and deferred income taxes. Due to the uncertainty inherent in such estimates, actual results may differ from these estimates. The Company utilizes significant estimates and assumptions in determining the fair value of its common stock. The Company has utilized various valuation methodologies to estimate the fair value of its common stock. Each valuation methodology includes estimates and assumptions that require the Company’s judgment. These estimates and assumptions include a number of objective and subjective factors, including external market conditions, the prices at which the Company sold shares of preferred stock, the superior rights and preferences of securities senior to the Company’s common stock at the time of, and the likelihood of, achieving a liquidity event, such as an initial public offering or sale. Significant changes to the key assumptions used in the valuations could result in different fair values of common stock at each valuation date.
Segment Information	Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision-maker in deciding how to allocate resources and assess performance. The Company and the Company’s chief operating decision-maker, the Company’s chief executive officer, views the Company’s operations and manages its business as a single operating segment, which is the business of developing targeted medicines to address ENT diseases.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. As the Company did not have any element of other comprehensive income (loss), its comprehensive loss is equal to its net loss for all periods presented.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash and cash equivalents include cash held in banks and amounts held in money market funds. Cash equivalents are stated at cost, which approximates market value. Cash and cash equivalents consist of cash held in banks at December 31, 2020 and 2019.
Restricted Cash	Restricted Cash The Company had restricted cash of approximately $0.3 million as of December 31, 2020 and 2019, which was held in certificates of deposit at the Company’s financial institution to secure the Company’s letter of credit for its facility lease.
Concentrations Of Credit Risk And Off Balance Sheet Risk	Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains all its cash and cash equivalents at a single accredited financial institution, in amounts that exceed federally insured limits. The Company has no significant off-balance sheet risk such as foreign exchange contracts, option contracts, or other foreign exchange hedging arrangements.
Significant Suppliers	Significant Suppliers The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the drug product and associated applicator related to these programs. These programs could be adversely affected by a significant interruption in the supply of the materials required to manufacture the drug product and associated applicator.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received upon sale of an asset or paid to transfer a liability between market participants at a measurement date. ASC Topic 820, Fair Value Measurements Level 1 -Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 -Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3 -Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. An entity may elect to measure many financial instruments and certain other items at fair value at specified election dates. Subsequent unrealized gains and losses on items for which the fair value option has been elected will be reported in net loss. The Company did not elect to measure any financial instruments or other items at fair value.
Derivative Liabilities	Derivative Liabilities In connection with certain debt and equity financings, the Company may issue financial instruments in which a derivative instrument is “embedded.” Upon issuing the financial instrument, the Company assesses whether the economic characteristics of the embedded derivative are clearly and closely related to the economic characteristics of the remaining component of the financial instrument (i.e., the host contract) and whether a separate, non-embedded instrument with the same terms as the embedded instrument would meet the definition of a derivative instrument. When it is determined that (1) the embedded derivative possesses economic characteristics that are not clearly and closely related to the economic characteristics of the host contract, and (2) a separate, stand-alone instrument with the same terms would qualify as a derivative instrument, the embedded derivative is separated from the host contract and carried at fair value until the derivative is settled. Changes in the fair value of the derivative liabilities are recognized as other income (expense) in the consolidated statement of operations and comprehensive loss.
Classification and Accretion of Redeemable Convertible Preferred Shares	Classification and Accretion of Redeemable Convertible Preferred Shares The Company has classified the redeemable convertible preferred stock outside of stockholders’ deficit in the accompanying consolidated balance sheets in accordance with authoritative guidance for the classification and measurement of redeemable securities as the redeemable convertible preferred stock is redeemable at a determinable price on a fixed date or upon the occurrence of a deemed liquidation event. The carrying values of the redeemable convertible preferred shares are accreted to their redemption values from the date of issuance through the earliest date of redemption.
Property and Equipment	4. Property and Equipment Property and equipment consist of the following at December 31, 2020 and 2019 (in thousands): December 31, 2020 2019 Property and equipment: Laboratory equipment $ 3,277 $ 1,715 Computer software and equipment 650 595 Office furniture and fixtures 301 301 Leasehold improvements 317 317 Construction in progress 498 138 $ 5,043 $ 3,066 Accumulated depreciation (2,878 ) (2,829 ) Property and equipment, net $ 2,165 $ 237 The Company recognized approximately $0.1 million and $27,000 of depreciation expense for the years ended December 31, 2020 and 2019, respectively. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset as follows: Estimated Useful Life Laboratory equipment 5 years Computer software and equipment 3 years Office furniture and fixtures 7 years Leasehold improvements Shorter of useful life or remaining term of related lease Costs for capital assets not yet placed into service are capitalized as construction in progress and are depreciated in accordance with the above guidelines once placed into service. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are eliminated from the balance sheet and related gains or losses are reflected in the consolidated statement of operations and comprehensive loss. Repairs and maintenance that do not improve or extend the lives of the respective assets are expensed as incurred, while costs of major additions and betterments are capitalized.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets consist of property and equipment. The Company continually evaluates long-lived assets for potential impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparing the book values of the assets to the expected future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book values of the assets exceed their fair value. The Company did not record any impairment losses on long-lived assets during the years ended December 31, 2020 and 2019.
Leases	Leases ASU No. 2016-02, Leases (Topic 842) A lease qualifies as a finance lease if any of the following criteria are met at the inception of the lease: (i) there is a transfer of ownership of the leased asset to the Company by the end of the lease term, (ii) the Company holds an option to purchase the leased asset that it is reasonably certain to exercise, (iii) the lease term is for a major part of the remaining economic life of the leased asset, (iv) the present value of the sum of lease payments equals or exceeds substantially all of the fair value of the leased asset, (v) the nature of the leased asset is specialized to the point that it is expected to provide the lessor no alternative use at the end of the lease term. All other leases are recorded as operating leases. Finance and operating lease assets and liabilities are recognized at the lease commencement date based on the present value of the lease payments over the lease term using the discount rate implicit in the lease. If the rate implicit in the lease is not readily determinable, the Company utilizes its incremental borrowing rate at the lease commencement date. Operating lease assets are further adjusted for prepaid or accrued lease payments. Operating lease payments are expensed using the straight-line method as an operating expense over the lease term. Finance lease assets are amortized to depreciation expense using the straight-line method over the shorter of the useful life of the related asset or the lease term. Finance lease payments are bifurcated into (i) a portion that is recorded as imputed interest expense and (ii) a portion that reduces the finance liability associated with the lease. The Company separates lease and non-lease components when determining which lease payments to include in the calculation of its lease assets and liabilities. Variable lease payments are expensed as incurred. If a lease includes an option to extend or terminate the lease, the Company reflects the option in the lease term if it is reasonably certain it will exercise the option. Operating leases are recorded in “Operating lease right-of use assets,” “Operating lease liabilities” and “Operating lease liabilities, net of current portion” in the Company’s consolidated balance sheets. The Company did not have any finance leases recorded in its consolidated balance sheet as of December 31, 2020.
Research And Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses include salaries and benefits, materials and supplies, preclinical and clinical trial expenses, manufacturing expenses, stock-based compensation expense, depreciation of equipment, contract services and other outside expenses. Costs of certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the consolidated financial statements as prepaid or accrued research and development costs. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are deferred and capitalized. The capitalized amounts are expensed as the related goods are delivered or the services are performed. The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs.
Patents Costs	Patent Costs The Company expenses patent application and related legal costs as incurred and classifies such costs as general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss.
Accounting for Stock-Based Compensation	Accounting for Stock-Based Compensation The Company accounts for its stock-based compensation in accordance with ASC Topic 718, Compensation—Stock Compensation The Black-Scholes option-pricing model uses the following inputs: the fair value of the Company’s common stock, the expected volatility of the Company’s common stock, the expected term of the Company’s stock options, the risk-free interest rate for a period that approximates the expected term of the Company’s stock options, and the Company’s expected dividend yield. Following the closing of the Company’s IPO, the fair value of the Company’s common stock is determined based on the quoted market price of its common stock. The Company has historically been a private company and lacks company-specific historical and implied volatility data. Therefore, the Company has based its computation of expected volatility on the historical volatility of a representative group of public companies with similar characteristics to it, including stage of product development, life science industry focus, length of trading history, and similar vesting provisions. The historical volatility data is calculated based on a period of time commensurate with the expected term assumption. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available or until circumstances change, such that the identified entities are no longer representative companies. In the latter case, more suitable, similar entities whose share prices are publicly available would be utilized in the calculation. The Company uses the simplified method as prescribed by the SEC Staff Accounting Bulletin No. 107, Share-Based Payment The Company has elected as a policy to recognize forfeitures as they occur as described in ASU No. 2016-09, Compensation—Stock Compensation The Company expenses the fair value of its stock-based compensation awards to employees on a straight-line basis over the requisite service period, which is generally the vesting period. The Company records the expense for stock-based compensation awards subject to performance-based milestone vesting when management determines that achievement of the milestone is probable. Management evaluates when the achievement of a performance-based milestone is probable based on the expected satisfaction of the performance conditions as of the reporting date. The Company follows the provisions of ASU No. 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting
Income Taxes	10. Income Taxes The Company records a provision or benefit for income taxes on pre-tax income or loss based on its estimated effective tax rate for the year. During the years ended December 31, 2020 and 2019, the Company recorded net losses of approximately $22.1 million and $16.3 million, respectively, and, since it maintains a full valuation allowance on its deferred tax assets, the Company did not record an income tax benefit for the years ended December 31, 2020 and 2019. A reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes reflected in the consolidated financial statements is as follows: Year Ended December 31, 2020 2019 Income tax computed at federal statutory tax rate 21.0 % 21.0 % Permanent differences (2.0 )% (0.2 )% State taxes, net of federal benefit 5.4 % 6.2 % Research and development and other tax credits 2.6 % 3.8 % Change in deferred tax asset valuation allowance (28.4 )% (30.7 )% Other 1.4 % (0.1 )% — % — % Net deferred tax assets as of December 31, 2020 and 2019 consist of the following (in thousands): December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 35,729 $ 30,006 Research and development credits 5,223 4,652 Stock-based compensation 322 173 Operating lease liabilities 661 909 Other 140 280 Total gross deferred tax assets 42,075 36,020 Less: Valuation allowance (41,451 ) (35,150 ) Total deferred tax assets 624 870 Deferred tax liabilities: Operating lease right-of-use assets (624 ) (870 ) Total deferred tax liabilities (624 ) (870 ) Net deferred taxes $ — $ — As of December 31, 2020, the Company had U.S. federal net operating loss carryforwards of approximately $91.4 million which may be able to offset future income tax liabilities and expire at various dates through 2037 and approximately $44.0 million of federal net operating loss carryforwards that may be carried forward indefinitely. As of December 31, 2020, the Company also had state net operating loss carryforwards of approximately $116.0 million which may be available to offset future income tax liabilities and expire at various dates through 2040. As of December 31, 2020 and 2019, the Company had federal research and development tax credit carryforwards of approximately $3.6 million and $3.2 million, respectively, available to reduce future tax liabilities which expire at various dates through 2040. As of December 31, 2020 and 2019, the Company had state research and development tax credit carryforwards of approximately $2.0 million and $1.8 million, respectively, available to reduce future tax liabilities which expire at various dates through 2035. The Company has generated research credits but has not conducted a study to document the qualified activity. This study may result in an adjustment to the Company’s research and development credit carryforwards; however, until a study is completed and any adjustment is known, no amounts are being presented as an uncertain tax position. A full valuation allowance has been provided against the Company’s research and development credits and, if an adjustment is required, this adjustment would be offset by an adjustment to the deferred tax asset established for the research and development credit carryforwards and the valuation allowance. Under the provisions of the Internal Revenue Code, the net operating loss and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. Net operating loss and tax credit carryforwards may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant shareholders over a three-year period in excess of 50%, as defined under Sections 382 and 383 of the Internal Revenue Code, respectively, as well as similar state provisions. This could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. The Company has not conducted a study to assess whether a change of control has occurred or whether there have been multiple changes of control since inception due to the significant complexity and cost associated with such a study. If the Company has experienced a change of control, as defined by Section 382, at any time since inception, utilization of the net operating loss carryforwards or research and development tax credit carryforwards would be subject to an annual limitation under Section 382, which is determined by first multiplying the value of the Company’s stock at the time of the ownership change by the applicable long-term tax-exempt rate, and then could be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the net operating loss carryforwards or research and development tax credit carryforwards before utilization. Further, until a study is completed by the Company and any limitation is known, no amounts are being presented as an uncertain tax position. ASC 740 requires a valuation allowance to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. After consideration of all the evidence, both positive and negative, the Company has recorded a valuation allowance against its deferred tax assets at December 31, 2020 and 2019 because the Company’s management has determined that it is more likely than not that the Company will not recognize the benefits of its federal and state deferred tax assets primarily due to its history of cumulative net losses incurred since inception and its lack of commercialization of any products or generation of any revenue from product sales since inception and, as a result, a valuation allowance of approximately $41.5 million and $35.2 million, respectively, has been established at December 31, 2020 and 2019. Management reevaluates the positive and negative evidence at each reporting period. The valuation allowance increased by approximately $6.3 million and $5.1 million, respectively, during the years ended December 31, 2020 and 2019 due primarily to the generation of net operating losses. The Company has recorded adjustments to deferred tax assets for unrecognized tax benefits as of December 31, 2020 and 2019. The Company’s policy is to record interest and penalties related to uncertain tax positions as part of its income tax provision. As of December 31, 2020 and 2019, the Company had no accrued interest or penalties related to uncertain tax positions and no such amounts have been recognized in the Company’s statement of operations and comprehensive loss. In many cases, the Company’s uncertain tax positions are related to years that remain subject to examination by relevant tax authorities. The statute of limitations for federal and state tax authorities is closed for years prior to December 31, 2017. However, since the Company is in a loss carryforward position, the Company is generally subject to examination by the U.S. federal, state and local income tax authorities for all tax years in which a loss carryforward is available. Income Taxes The Company accounts for income taxes using the liability method in accordance with ASC Topic 740, Income Taxes The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.
Contingencies	Contingencies In accordance with ASC Topic 450, Contingencies If a loss contingency is not probable but is reasonably possible, or is probable but cannot be estimated, the nature of the contingent liability, together with an estimate of the range of possible loss if determinable and material, would be disclosed.
Guarantees	Guarantees The Company has identified the guarantees described below as disclosable, in accordance with ASC Topic 460, Guarantees As permitted under Delaware law, the Company indemnifies its officers and directors for certain events or occurrences while the officer or director is, or was, serving at the Company’s request in such capacity. The maximum potential amount of future payments the Company could be required to make is unlimited; however, the Company has directors’ and officers’ insurance coverage that should limit its exposure and enable it to recover a portion of any future amounts paid. The Company is a party to a number of agreements entered into in the ordinary course of business that contain typical provisions that obligate the Company to indemnify the other parties to such agreements upon the occurrence of certain events. Such indemnification obligations are usually in effect from the date of execution of the applicable agreement for a period equal to the applicable statute of limitations. The aggregate maximum potential future liability of the Company under such indemnification provisions is uncertain. The Company leases office space under a noncancelable operating lease. The Company has standard indemnification arrangements under the lease that requires it to indemnify the landlord against all costs, expenses, fines, suits, claims, demands, liabilities, and actions directly resulting from any breach, violation, or nonperformance of any covenant or condition of the lease. As of December 31, 2020 and 2019, the Company had not experienced any losses related to these indemnification obligations, and no material claims with respect thereto were outstanding. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related reserves have been established.
Deferred Offering Costs	Deferred Offering Costs The Company capitalizes certain legal, professional, accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ deficit as a reduction of additional paid-in capital generated as a result of the offering. Should the planned equity financing be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the consolidated statement of operations and comprehensive loss. Deferred offering costs of $0 and $1.1 million are included in other assets in the consolidated balance sheets at December 31, 2020 and 2019, respectively.
Net Loss per Share	Net Loss per Share The Company has reported losses since inception and has computed basic net loss per share attributable to common stockholders by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. The Company has computed diluted net loss per common share after giving consideration to all potentially dilutive common shares, including options to purchase common stock, warrants to purchase common stock and redeemable convertible preferred stock, outstanding during the period determined using the treasury-stock and if-converted methods, except where the effect of including such securities would be antidilutive. Because the Company has reported net losses since inception, these potential common shares have been anti-dilutive and basic and diluted loss per share have been the same. Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share data): Year Ended December 31, 2020 2019 Numerator: Net loss $ (22,127 ) $ (16,306 ) Accretion of redeemable convertible preferred stock (115 ) (313 ) Net loss attributable to common stockholders $ (22,242 ) $ (16,619 ) Denominator: Weighted-average common shares—basic and diluted 8,590,205 202,093 Net loss per share attributable to common stockholders—basic and diluted $ (2.59 ) $ (82.23 ) The following table sets forth the potentially dilutive securities that have been excluded from the calculation of diluted net loss per share because to include them would be anti-dilutive (in common stock equivalent shares retroactively adjusted): Year Ended December 31, 2020 2019 Series A-1 redeemable convertible preferred stock — 986,466 Series A-2 redeemable convertible preferred stock — 773,712 Series A-3 redeemable convertible preferred stock — 872,031 Series A-4 redeemable convertible preferred stock — 579,993 Series B redeemable convertible preferred stock — 2,852,177 Stock options 1,428,886 792,439 Total 1,428,886 6,856,818
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2020
Accounting Policies [Abstract]
Property Plant And Equipment	Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset as follows: Estimated Useful Life Laboratory equipment 5 years Computer software and equipment 3 years Office furniture and fixtures 7 years Leasehold improvements Shorter of useful life or remaining term of related lease Property and equipment consist of the following at December 31, 2020 and 2019 (in thousands): December 31, 2020 2019 Property and equipment: Laboratory equipment $ 3,277 $ 1,715 Computer software and equipment 650 595 Office furniture and fixtures 301 301 Leasehold improvements 317 317 Construction in progress 498 138 $ 5,043 $ 3,066 Accumulated depreciation (2,878 ) (2,829 ) Property and equipment, net $ 2,165 $ 237
Summary of Basic and Diluted Net Loss per Share Attributable to Common Stockholders	Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share data): Year Ended December 31, 2020 2019 Numerator: Net loss $ (22,127 ) $ (16,306 ) Accretion of redeemable convertible preferred stock (115 ) (313 ) Net loss attributable to common stockholders $ (22,242 ) $ (16,619 ) Denominator: Weighted-average common shares—basic and diluted 8,590,205 202,093 Net loss per share attributable to common stockholders—basic and diluted $ (2.59 ) $ (82.23 )
Summary of Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss per Share	The following table sets forth the potentially dilutive securities that have been excluded from the calculation of diluted net loss per share because to include them would be anti-dilutive (in common stock equivalent shares retroactively adjusted): Year Ended December 31, 2020 2019 Series A-1 redeemable convertible preferred stock — 986,466 Series A-2 redeemable convertible preferred stock — 773,712 Series A-3 redeemable convertible preferred stock — 872,031 Series A-4 redeemable convertible preferred stock — 579,993 Series B redeemable convertible preferred stock — 2,852,177 Stock options 1,428,886 792,439 Total 1,428,886 6,856,818

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
Property and Equipment (Tables)	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Property Plant And Equipment	Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset as follows: Estimated Useful Life Laboratory equipment 5 years Computer software and equipment 3 years Office furniture and fixtures 7 years Leasehold improvements Shorter of useful life or remaining term of related lease Property and equipment consist of the following at December 31, 2020 and 2019 (in thousands): December 31, 2020 2019 Property and equipment: Laboratory equipment $ 3,277 $ 1,715 Computer software and equipment 650 595 Office furniture and fixtures 301 301 Leasehold improvements 317 317 Construction in progress 498 138 $ 5,043 $ 3,066 Accumulated depreciation (2,878 ) (2,829 ) Property and equipment, net $ 2,165 $ 237

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Dec. 31, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following at December 31, 2020 and 2019 (in thousands): December 31, 2020 2019 Payroll and employee related expenses $ 1,892 $ 885 Third-party research and development expenses 381 1,344 Professional and consulting fees 555 901 Other 149 110 Total accrued expenses and other current liabilities $ 2,977 $ 3,240

Preferred and Common Stock (Tab

Preferred and Common Stock (Tables)	12 Months Ended
Preferred and Common Stock (Tables)	Dec. 31, 2020
Equity [Abstract]
Schedule of Common Stock Reserved for Future Issuances	The Company has reserved for future issuances the following shares of common stock as of December 31, 2020: As of December 31, 2020 Stock options 2,888,653 Employee stock purchase plan 150,000 Total 3,038,653

Stock-Based Compensation Expe_2

Stock-Based Compensation Expense (Tables)	12 Months Ended
Stock-Based Compensation Expense (Tables)	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Stock-Based Compensation Expense	Stock-based compensation expense included in the Company’s consolidated statements of operations and comprehensive loss was as follows (in thousands): Year Ended December 31, 2020 2019 Research and development $ 229 $ 26 General and administrative 1,584 218 Total $ 1,813 $ 244
Schedule of Fair Value of Stock Option Estimated on Date of Grant Using Black-Scholes Option-Pricing Model	The fair value of each stock option granted to employees, directors and non-employees was estimated on the date of grant using the Black-Scholes option-pricing model, with the following weighted-average assumptions: Year Ended December 31, 2020 2019 Risk-free interest rate 0.6 % 2.2 % Expected dividend yield — % — % Expected term (in years) 6.0 6.1 Expected volatility 80.7 % 76.8 %
Summary of Stock Option Activity Under Plans	A summary of the stock option activity under the Plans for the year ended December 31, 2020 was as follows: Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Outstanding December 31, 2019 792,439 $ 6.59 7.3 $ 3,363 Granted 763,505 14.16 Exercised (2,814 ) 2.92 Cancelled (124,244 ) 9.30 Outstanding at December 31, 2020 1,428,886 $ 10.41 7.7 $ 5,165 Exercisable at December 31, 2020 626,578 $ 9.30 6.0 $ 3,099 Vested and expected to vest at December 31, 2020 1,428,886 $ 10.41 7.7 $ 5,165

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes reflected in the consolidated financial statements is as follows: Year Ended December 31, 2020 2019 Income tax computed at federal statutory tax rate 21.0 % 21.0 % Permanent differences (2.0 )% (0.2 )% State taxes, net of federal benefit 5.4 % 6.2 % Research and development and other tax credits 2.6 % 3.8 % Change in deferred tax asset valuation allowance (28.4 )% (30.7 )% Other 1.4 % (0.1 )% — % — %
Schedule of Deferred Tax Assets and Liabilities	Net deferred tax assets as of December 31, 2020 and 2019 consist of the following (in thousands): December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 35,729 $ 30,006 Research and development credits 5,223 4,652 Stock-based compensation 322 173 Operating lease liabilities 661 909 Other 140 280 Total gross deferred tax assets 42,075 36,020 Less: Valuation allowance (41,451 ) (35,150 ) Total deferred tax assets 624 870 Deferred tax liabilities: Operating lease right-of-use assets (624 ) (870 ) Total deferred tax liabilities (624 ) (870 ) Net deferred taxes $ — $ —

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2020
Leases [Abstract]
Components of Lease Cost	The components of lease cost recorded in the Company’s consolidated financial statements were as follows (in thousands): Year Ended December 31, 2020 2019 Lease Cost: Operating lease cost $ 1,055 $ 1,053 Variable lease cost 726 727 Sublease income — (368 ) Total lease cost, net $ 1,781 $ 1,412
Summary of Weighted-Average Remaining Lease Term and Discount Rate Related to Operating Leases	The weighted-average remaining lease term and discount rate related to the Company’s operating leases were as follows: As of December 31, 2020 Weighted-average remaining lease term (in years) 2.3 Weighted-average discount rate 5.5 %
Summary of Maturity of Operating Lease Liabilities	Maturity of the Company’s operating lease liabilities in accordance with ASC 842 as of December 31, 2020 were as follows (in thousands): Year ending December 31, 2021 $ 1,095 2022 1,127 2023 382 2024 2 Total maturities 2,606 Less: Amount representing interest (167 ) Present value of operating lease liability 2,439 Less: Current portion of operating lease liability (985 ) Total operating lease liability, net of current portion $ 1,454

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Details) $ / shares in Units, $ in Thousands	May 05, 2020USD ($)$ / sharesshares	Mar. 11, 2020Patient	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)
Organization And Basis Of Presentation [Line Items]
Entity incorporation, date of incorporation			Nov. 21, 2005
Net loss			$ (22,127)	$ (16,306)
Accumulated deficit			(149,884)	(127,757)
Cash and cash equivalents			74,593	$ 9,808
Net proceeds from initial public offering			$ 59,892
Number of patients \| Patient		67
Common Stock
Organization And Basis Of Presentation [Line Items]
Issuance of common stock from initial public offering, net of issuance costs, Shares \| shares			4,025,000
Gross proceeds from initial public offering	$ 64,400
Net proceeds from initial public offering	$ 57,300
IPO \| Common Stock
Organization And Basis Of Presentation [Line Items]
Issuance of common stock from initial public offering, net of issuance costs, Shares \| shares	4,025,000
Shares issued and sold, public offering price \| $ / shares	$ 16
Exercise of Underwriters' Option \| Common Stock
Organization And Basis Of Presentation [Line Items]
Issuance of common stock from initial public offering, net of issuance costs, Shares \| shares	525,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Restricted Cash	$ 300	$ 300
Lease liabilities	0	0
Finance lease liability	0	0
Deferred offering costs	$ 0	$ 1,100

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2020
Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	5 years
Computer software and equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	3 years
Office furniture and fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	7 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	Shorter of useful life or remaining term of related lease

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of Basic and Diluted Net Loss per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss	$ (22,127)	$ (16,306)
Accretion of redeemable convertible preferred stock	(115)	(313)
Net loss attributable to common stockholders	$ (22,242)	$ (16,619)
Denominator:
Weighted-average common shares outstanding—basic and diluted	8,590,205	202,093
Net loss per share attributable to common stockholders—basic and diluted	$ (2.59)	$ (82.23)

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Summary of Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss per Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	1,428,886	6,856,818
Series A-1 Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share		986,466
Series A-2 Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share		773,712
Series A-3 Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share		872,031
Series A-4 Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share		579,993
Series B Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share		2,852,177
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	1,428,886	792,439

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Financial assets, fair value	$ 0	$ 0
Financial liabilities, fair value	$ 0	$ 0
Alternative investment, change in valuation technique	false	false

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 5,043	$ 3,066
Accumulated depreciation	(2,878)	(2,829)
Property and equipment, net	2,165	237
Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	3,277	1,715
Computer Software and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	650	595
Office Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	301	301
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	317	317
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 498	$ 138

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Depreciation expense	$ 95,000	$ 27,000

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Payroll and employee related expenses	$ 1,892	$ 885
Third-party research and development expenses	381	1,344
Professional and consulting fees	555	901
Other	149	110
Total accrued expenses and other current liabilities	$ 2,977	$ 3,240

Redeemable Convertible Prefer_2

Redeemable Convertible Preferred Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Jan. 31, 2020	Dec. 31, 2020	Jan. 10, 2020	Dec. 31, 2019
Temporary Equity [Line Items]
Preferred stock, par value			$ 0.001
Series C Redeemable Convertible Preferred Stock
Temporary Equity [Line Items]
Preferred stock, shares authorized		0		0
Preferred stock, par value		$ 0.001		$ 0.001
Preferred stock, shares issued	78,306,611	0		0
Shares issued and sold, public offering price	$ 0.38811
Proceeds from the sale of Series C redeemable convertible preferred stock	$ 30.4
Maximum
Temporary Equity [Line Items]
Preferred stock, shares authorized			299,300,288

Preferred and Common Stock - Ad

Preferred and Common Stock - Additional Information (Details) $ / shares in Units, $ in Thousands	May 05, 2020USD ($)$ / sharesshares	Dec. 31, 2020USD ($)Vote$ / sharesshares	May 31, 2020shares	Jan. 31, 2020$ / shares	Jan. 10, 2020$ / sharesshares	Dec. 31, 2019$ / sharesshares
Class Of Stock [Line Items]
Common stock shares authorized	200,000,000	200,000,000			400,000,000	275,000,000
Common stock par value \| $ / shares	$ 0.001	$ 0.001			$ 0.001	$ 0.001
Preferred Stock, Shares Authorized	10,000,000
Preferred Stock, Par or Stated Value Per Share \| $ / shares	$ 0.001
Common stock, voting rights		The holders of common stock are entitled to one vote for each share held.
Number of common stock voting rights \| Vote		1
Reverse stock split of issued and outstanding common stock		one-for-34.483
Net proceeds from initial public offering \| $		$ 59,892
Common stock shares issued		12,932,377				230,860
Series C Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Shares issued and sold, public offering price \| $ / shares				$ 0.38811
IPO
Class Of Stock [Line Items]
Common stock shares issued			313,794
Non Employee Compensation
Class Of Stock [Line Items]
Common stock shares issued		5,000
Common Stock
Class Of Stock [Line Items]
Issuance of common stock from initial public offering, net of issuance costs, Shares		4,025,000
Gross proceeds from initial public offering \| $	$ 64,400
Net proceeds from initial public offering \| $	$ 57,300
Preferred stock converted into common stock	8,335,248
Number of warrants issued to purchase common stock	313,794	681,256
Warrants exercise price, per share \| $ / shares		$ 8.63
Common Stock \| Director
Class Of Stock [Line Items]
Vested share of common stock	19,661
Common Stock \| Exercise of Underwriters' Option
Class Of Stock [Line Items]
Issuance of common stock from initial public offering, net of issuance costs, Shares	525,000
Common Stock \| IPO
Class Of Stock [Line Items]
Issuance of common stock from initial public offering, net of issuance costs, Shares	4,025,000
Shares issued and sold, public offering price \| $ / shares	$ 16
Warrants \| Series C Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Net proceeds from issuance of preferred stock allocated to warrants \| $		$ 700

Preferred and Common Stock - Sc

Preferred and Common Stock - Schedule of Common Stock Reserved for Future Issuances (Details)	Dec. 31, 2020shares
Class Of Stock [Line Items]
Shares of common stock reserved for future issuances	3,038,653
Stock Options
Class Of Stock [Line Items]
Shares of common stock reserved for future issuances	2,888,653
Employee stock purchase plan
Class Of Stock [Line Items]
Shares of common stock reserved for future issuances	150,000

Stock-Based Compensation Expe_3

Stock-Based Compensation Expense - Additional Information (Details) - USD ($)	1 Months Ended		12 Months Ended
	Apr. 30, 2020	Feb. 29, 2016	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted			763,505
Shares of common stock reserved for future issuances			3,038,653
Stock-based compensation expense			$ 1,813,000	$ 244,000
Weighted-average fair value of options granted to employees, directors and consultants			$ 9.66	$ 3.45
Aggregate intrinsic value of stock options exercised			$ 27,000	$ 200,000
Unrecognized stock-based compensation expense relating to unvested stock options			$ 6,200,000
Unvested stock options expected to be recognized over a weighted-average period			3 years 2 months 12 days
Milestone-based Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense			$ 0	$ 0
Revenue Based Milestone Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense relating to unvested stock options			$ 36,000
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period			4 years
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option expiration period			10 years
2005 and 2016 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted		0
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuances	2,100,000
Maximum number of common shares issued	8,800,000
Percentage of common shares increase automatically in each year	4.00%
Number of shares available for future grant			1,459,767
2020 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuances	150,000
Maximum number of common shares issued	987,500
Annual increase in number of shares available for issuance as percentage of outstanding shares common stock on final day of immediately preceding fiscal year	0.50%
Purchase price of shares as percentage lower of fair market value of common stock	85.00%

Stock-Based Compensation Expe_4

Stock-Based Compensation Expense - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,813	$ 244
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	229	26
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,584	$ 218

Stock-Based Compensation Expe_5

Stock-Based Compensation Expense - Schedule of Fair Value of Stock Option Estimated on Date of Grant Using Black-Scholes Option-Pricing Model (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	0.60%	2.20%
Expected term (in years)	6 years	6 years 1 month 6 days
Expected volatility	80.70%	76.80%

Stock-Based Compensation Expe_6

Stock-Based Compensation Expense - Summary of Stock Option Activity Under Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Outstanding December 31, 2019	792,439
Number of shares granted	763,505
Shares, Exercised	(2,814)
Shares, Cancelled	(124,244)
Shares, Outstanding December 31, 2020	1,428,886	792,439
Shares, Exercisable at December 31, 2020	626,578
Shares, Vested and expected to vest at December 31, 2020	1,428,886
Weighted Average Exercise Price, Outstanding December 31, 2019	$ 6.59
Weighted Average Exercise Price, Granted	14.16
Weighted Average Exercise Price, Exercised	2.92
Weighted Average Exercise Price, Cancelled	9.30
Weighted Average Exercise Price, Outstanding December 31, 2020	10.41	$ 6.59
Weighted Average Exercise Price, Exercisable at December 31, 2020	9.30
Weighted Average Exercise Price,Vested and expected to vest at December 31, 2020	$ 10.41
Outstanding, Weighted Average Remaining Contractual Life (in years)	7 years 8 months 12 days	7 years 3 months 18 days
Exercisable, Weighted Average Remaining Contractual Life (in years)	6 years
Vested and expected to vest, Weighted Average Remaining Contractual Life (in years)	7 years 8 months 12 days
Aggregate Intrinsic Value, Outstanding December 31, 2019	$ 3,363
Aggregate Intrinsic Value, Outstanding December 31, 2020	5,165	$ 3,363
Aggregate Intrinsic Value, Exercisable at December 31, 2020	3,099
Aggregate Intrinsic Value, Vested and expected to vest at December 31, 2020	$ 5,165

Related Parties - Additional In

Related Parties - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Director
Related Party Transaction [Line Items]
Consulting expense related to consulting agreement	$ 0	$ 50,000
Arsenal
Related Party Transaction [Line Items]
Amounts receivable		$ 300

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
Income Taxes - Additional Information (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Net loss	$ (22,127,000)	$ (16,306,000)
Income Tax Expense (Benefit)	0	0
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit	0
Valuation allowance	41,451,000	35,150,000
Increase in valuation allowance	6,300,000	5,100,000
Unrecognized tax benefits income tax penalties accrued	0	0
U.S. federal jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 91,400,000
Operating loss carryforwards limitations on use	offset future income tax liabilities and expire at various dates through 2037
Deferred Tax Assets, Tax Credit Carryforwards, Research	$ 3,600,000	3,200,000
U.S. federal jurisdiction \| Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	44,000,000
State jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 116,000,000
Operating loss carryforwards limitations on use	offset future income tax liabilities and expire at various dates through 2040
Deferred Tax Assets, Tax Credit Carryforwards, Research	$ 2,000,000	$ 1,800,000

Income Taxes (Schedule of Effec

Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income tax computed at federal statutory tax rate	21.00%	21.00%
Permanent differences	(2.00%)	(0.20%)
State taxes, net of federal benefit	5.40%	6.20%
Research and development and other tax credits	2.60%	3.80%
Change in deferred tax asset valuation allowance	(28.40%)	(30.70%)
Other	1.40%	(0.10%)

Income Taxes (Schedule of Defer

Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 35,729	$ 30,006
Research and development credits	5,223	4,652
Stock-based compensation	322	173
Operating lease liabilities	661	909
Other	140	280
Total gross deferred tax assets	42,075	36,020
Less: Valuation allowance	(41,451)	(35,150)
Total deferred tax assets	624	870
Operating lease right-of-use assets	(624)	(870)
Total deferred tax liabilities	$ (624)	$ (870)

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	1 Months Ended	12 Months Ended
Leases - Additional Information (Details) $ in Thousands	Nov. 30, 2017USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Aug. 31, 2007ft²
Lessee Lease Description [Line Items]
Initial base rent	$ 1,000
Restricted cash		$ 329	$ 329
Extended lease term	2023-04
Office and Laboratory
Lessee Lease Description [Line Items]
Area of property \| ft²				22,343
Office furniture and fixtures
Lessee Lease Description [Line Items]
Lease initiation date		Apr. 30, 2020
Lease expiration date		Jun. 30, 2024
Certificate of Deposits
Lessee Lease Description [Line Items]
Restricted cash	$ 300
Letter of Credit
Lessee Lease Description [Line Items]
Secured debt obligations	$ 300

Leases - Schedule of Components

Leases - Schedule of Components of Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease Cost:
Operating lease cost	$ 1,055	$ 1,053
Variable lease cost	726	727
Sublease income		368
Total lease cost, net	$ 1,781	$ 1,412

Leases - Summary of Weighted-Av

Leases - Summary of Weighted-Average Remaining Lease Term and Discount Rate Related to Operating Leases (Details)	Dec. 31, 2020
Leases [Abstract]
Weighted-average remaining lease term (in years)	2 years 7 months 3 days
Weighted-average discount rate	5.50%

Leases - Summary of Maturity of

Leases - Summary of Maturity of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2021	$ 1,095
2022	1,127
2023	382
2024	2
Total maturities	2,606
Less: Amount representing interest	(167)
Present value of operating lease liability	2,439
Present value of operating lease liability	2,439
Less: Current portion of operating lease liability	(985)	$ (899)
Operating lease liabilities, net of current portion	$ 1,454	$ 2,427

Retirement Plan - Additional In

Retirement Plan - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Company match percentage	3.00%
Matching contribution costs	$ 0.1	$ 0