Rocket Pharmaceuticals (RCKT) 10-Q7 May 242024 Q1 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2024	May 01, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Document Transition Report	false
Entity File Number	001-36829
Entity Registrant Name	Rocket Pharmaceuticals, Inc.
Entity Central Index Key	0001281895
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3475813
Entity Address, Address Line One	9 Cedarbrook Drive
Entity Address, City or Town	Cranbury
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08512
City Area Code	609
Local Phone Number	659-8001
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	RCKT
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		90,782,211

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 35,276	$ 55,904
Investments	295,037	317,271
Prepaid expenses and other current assets	14,846	5,047
Total current assets	345,159	378,222
Property and equipment, net	39,337	39,172
Goodwill	39,154	39,154
Intangible assets	25,150	25,150
Restricted cash	1,362	1,372
Deposits	533	533
Investments	0	34,320
Operating lease right-of-use assets, net	4,768	3,901
Finance lease right-of-use asset, net	43,979	44,517
Total assets	499,442	566,341
Current liabilities:
Accounts payable and accrued expenses	30,085	45,789
Operating lease liabilities, current	1,064	925
Finance lease liability, current	1,808	1,791
Total current liabilities	32,957	48,505
Operating lease liabilities, non-current	3,714	2,973
Finance lease liability, non-current	19,363	19,353
Other liabilities	1,906	2,936
Total liabilities	57,940	73,767
Commitments and contingencies (Note 13)
Stockholders' equity:
Common stock, $0.01 par value, 120,000,000 shares authorized; 90,646,590 and 90,282,267 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	906	903
Additional paid-in capital	1,462,155	1,450,722
Accumulated other comprehensive income (loss)	(135)	319
Accumulated deficit	(1,021,424)	(959,370)
Total stockholders' equity	441,502	492,574
Total liabilities and stockholders' equity	499,442	566,341
Series A Convertible Preferred Shares
Stockholders' equity:
Preferred stock
Series B Convertible Preferred Shares
Stockholders' equity:
Preferred stock

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	120,000,000	120,000,000
Common stock, shares issued (in shares)	90,646,590	90,282,267
Common stock, shares outstanding (in shares)	90,646,590	90,282,267
Series A Convertible Preferred Shares
Stockholders' equity:
Preferred stock, shares authorized (in shares)	300,000	300,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series B Convertible Preferred Shares
Stockholders' equity:
Preferred stock, shares authorized (in shares)	300,000	300,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Consolidated Statements of Operations [Abstract]
Revenue	$ 0	$ 0
Operating expenses:
Research and development	45,227	46,371
General and administrative	22,148	15,823
Total operating expenses	67,375	62,194
Loss from operations	(67,375)	(62,194)
Interest expense	(471)	(468)
Interest and other income, net	3,029	1,908
Accretion of discount on investments, net	2,763	2,419
Net loss	$ (62,054)	$ (58,335)
Net loss per share - basic (in dollars per share)	$ (0.66)	$ (0.73)
Net loss per share - diluted (in dollars per share)	$ (0.66)	$ (0.73)
Weighted-average common shares outstanding - basic (in shares)	93,549,884	79,453,519
Weighted-average common shares outstanding - diluted (in shares)	93,549,884	79,453,519

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Consolidated Statements of Comprehensive Loss [Abstract]
Net loss	$ (62,054)	$ (58,335)
Other comprehensive loss
Net unrealized (loss) gain on investments	(454)	272
Total comprehensive loss	$ (62,508)	$ (58,063)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock, Common	Additional Paid-In Capital	Accumulated Other Comprehensive Income / (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2022	$ 489,686	$ 791	$ (47)	$ 1,203,074	$ (357)	$ (713,775)
Beginning Balance (in shares) at Dec. 31, 2022		79,123,312
Issuance of common stock pursuant to exercise of stock options	1,114	$ 1		1,113
Issuance of common stock pursuant to exercise of stock options (in shares)		88,429
Issuance of common stock pursuant to vesting of restricted stock units		$ 1		(1)
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		126,060
Issuance of common stock pursuant to exercise of warrants	7	$ 1		6
Issuance of common stock pursuant to exercise of warrant (in shares)		126,093
Issuance of common stock pursuant to the at-the-market offering program, net of issuance costs	17,222	$ 10		17,212
Issuance of common stock pursuant to the at-the-market offering program, net of issuance costs (in shares)		948,300
Unrealized comprehensive gain (loss) on investments	267				267
Stock-based compensation	8,915			8,915
Net loss	(58,335)					(58,335)
Ending Balance at Mar. 31, 2023	458,876	$ 804	$ (47)	1,230,319	(90)	(772,110)
Ending Balance (in shares) at Mar. 31, 2023		80,412,194
Beginning Balance at Dec. 31, 2023	492,574	$ 903		1,450,722	319	(959,370)
Beginning Balance (in shares) at Dec. 31, 2023		90,282,267
Issuance of common stock pursuant to exercise of stock options	1,184			1,184
Issuance of common stock pursuant to exercise of stock options (in shares)		73,745
Issuance of common stock pursuant to vesting of restricted stock units		$ 3		(3)
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		290,578
Unrealized comprehensive gain (loss) on investments	(454)				(454)
Stock-based compensation	10,252			10,252
Net loss	(62,054)					(62,054)
Ending Balance at Mar. 31, 2024	$ 441,502	$ 906		$ 1,462,155	$ (135)	$ (1,021,424)
Ending Balance (in shares) at Mar. 31, 2024		90,646,590

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating activities:
Net loss	$ (62,054)	$ (58,335)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization of property and equipment	1,716	1,135
Amortization of finance lease right of use asset	538	538
Stock-based compensation	10,252	8,915
Accretion of discount on investments, net	(2,754)	(2,343)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,151)	866
Accounts payable and accrued expenses	(2,413)	(7,750)
Operating lease liabilities and right of use assets, net	13	97
Finance lease liability	27	37
Other liabilities	(1,030)	(720)
Net cash used in operating activities	(56,856)	(57,560)
Investing activities:
Purchases of investments	(63,947)	(96,034)
Proceeds from maturities of investments	101,016	62,335
Payments made to acquire right of use asset	0	(7)
Purchases of property and equipment	(2,035)	(3,015)
Net cash provided by (used in) investing activities	35,034	(36,721)
Financing activities:
Issuance of common stock, pursuant to exercise of stock options	1,184	1,114
Issuance of common stock pursuant to the at-the-market offering program, net of issuance costs	0	17,222
Issuance of common stock, pursuant to exercise of warrants	0	7
Net cash provided by financing activities	1,184	18,343
Net change in cash, cash equivalents and restricted cash	(20,638)	(75,938)
Cash, cash equivalents and restricted cash at beginning of period	57,276	141,857
Cash, cash equivalents and restricted cash at end of period	36,638	65,919
Supplemental disclosure of non-cash financing and investing activities:
Accrued purchases of property and equipment, ending balance	923	1,794
Investment maturity receivables and purchase payables, ending balance	8,648	0
Operating lease liabilities	1,134	0
Unrealized loss on investments	$ (454)	$ 267

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (62,054)	$ (58,335)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Nature of Business

Nature of Business	3 Months Ended
Nature of Business	Mar. 31, 2024
Nature of Business [Abstract]
Nature of Business	1. Nature of Business Rocket Pharmaceuticals, Inc. is a fully integrated, late-stage biotechnology company focused on the development of first, only and best in class gene therapies, with direct on-target mechanism of action and clear clinical endpoints, for rare and devastating diseases. The Company has three clinical-stage ex vivo lentiviral vector programs, which include programs for: • Fanconi Anemia, a genetic defect in the bone marrow that reduces production of blood cells or promotes the production of faulty blood cells; • Leukocyte Adhesion Deficiency-I, a genetic disorder that causes the immune system to malfunction; and • Pyruvate Kinase Deficiency, a red blood cell autosomal recessive disorder that results in chronic non-spherocytic hemolytic anemia. In September 2023, the FDA accepted the Biologics License Application and granted priority review for RP-L201 for the treatment of severe LAD-I. Treatments in the FA Phase 2 studies were completed in 2023 with regulatory filings in the U.S. and EU for FA anticipated in 2024. Additional work on a gene therapy program for the less common FA subtypes C and G is ongoing. In the U.S., the Company also has two clinical stage and one pre-clinical stage in vivo adeno-associated virus programs, which include programs for: • Danon Disease, a multi-organ lysosomal-associated disorder leading to early death due to heart failure. The DD program is currently in an ongoing Phase 2 trial. • Plakophilin-2 Arrhythmogenic Cardiomyopathy, an inheritable cardiac disorder that is characterized by a progressive loss of cardiac muscle mass, severe right ventricular dilation, dysplasia, fibrofatty replacement of the myocardium and a high propensity to arrhythmias and sudden death. This program received FDA clearance of an Investigational New Drug application and the Company has initiated a Phase 1 study. • BAG3 Dilated Cardiomyopathy, which is the most common form of cardiomyopathy and is characterized by progressive thinning of the walls of the heart resulting in enlarged heart chambers that are unable to pump blood. The Company utilizes recombinant AAV9-based gene therapy designed to slow or halt progression of BAG3-DCM. The Company has global commercialization and development rights to all of these product candidates under royalty-bearing license agreements.

Risks and Liquidity

Risks and Liquidity	3 Months Ended
Risks and Liquidity	Mar. 31, 2024
Risks and Liquidity [Abstract]
Risks and Liquidity	2. Risks and Liquidity The Company has not generated any revenue and has incurred losses since inception. Operations of the Company are subject to certain risks and uncertainties, including, among others, uncertainty of drug candidate development, technological uncertainty, uncertainty regarding patents and proprietary rights, having no commercial manufacturing experience, marketing or sales capability or experience, dependency on key personnel, compliance with government regulations and the need to obtain additional financing. Drug candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure, and extensive compliance-reporting capabilities. The Company’s product candidates are in the development and clinical stage. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies. The Company’s consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities in the ordinary course of business. The Company has experienced negative cash flows from operations and had an accumulated deficit of $ 1.02 billion as of March 31, 2024. As of March 31, 2024, the Company had $ 330.3 million of cash, cash equivalents and investments. Excluded from the $ 330.3 million of cash, cash equivalent and investments are receivables from maturity of securities that have yet to be received of $ 8.6 million recorded as part of prepaid expenses and other current assets. The net balance of cash, cash equivalents and investments when adjusting for this receivable would have been $ 338.9 million. The Company expects such resources will be sufficient to fund the Company’s operating expenses and capital expenditure requirements into 2026. On February 28, 2022, the Company entered into a sales agreement (the “Sales Agreement”), with Cowen and Company, LLC (“Cowen”), with respect to an at-the-market offering program pursuant to which the Company may offer and sell, from time to time at its sole discretion, shares of its common stock, par value $ 0.01 per share, having an aggregate offering price of up to $ 200 million (the “Shares”) through Cowen as its sales agent. On September 12, 2023, the Company and Cowen entered into an amendment (the “Amended Sales Agreement”) pursuant to which the aggregate offering amount available under the at-the-market offering program was reduced to $ 180.0 million. Through March 31, 2024 , the Company has sold 4.2 million shares of common stock for net proceeds of $ 63.8 million pursuant to the at-the-market offering program (see Note 8 “Stockholders’ Equity”). The Company did not sell any shares under the at-the-market offering program during the three months ended March 31, 2024. In the longer term, the future viability of the Company is dependent on its ability to generate cash from operating activities or to raise additional capital to finance its operations. The Company’s failure to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies.

Basis of Presentation, Principl

Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies [Abstract]
Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies	3. Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited interim consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements for the year ended December 31, 2023 included in the Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 27, 2024. The unaudited interim consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s consolidated financial position as of March 31, 2024 and the results of its operations and its cash flows for the three months ended March 31, 2024. The financial data and other information disclosed in these consolidated notes related to the three months ended March 31, 2024 and 2023 are unaudited. The results for the three months ended March 31, 2024 are not necessarily indicative of results to be expected for the year ending December 31, 2024 and any other interim periods or any future year or period. Significant Accounting Policies The significant accounting policies used in the preparation of these consolidated financial statements for the three months ended March 31, 2024 are consistent with those disclosed in Note 3 to the consolidated financial statements in the 2023 Form 10-K with most significant policies also being listed here. Principles of Consolidation The consolidated financial statements represent the consolidation of the accounts of the Company and its subsidiaries in conformity with U.S. GAAP. All intercompany accounts have been eliminated in consolidation. Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions reflected in these consolidated financial statements include but are not limited to goodwill and intangible asset impairments, the accrual of R&D expenses, and the valuation of equity transactions and stock-based awards. Changes in estimates and assumptions are reflected in reported results in the period in which they become known. Actual results could differ from those estimates. Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consists of bank deposits, certificates of deposit and money market accounts with financial institutions. Cash equivalents are carried at cost which approximates fair value due to their short-term nature and which the Company believes do not have a material exposure to credit risk. The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents. The Company’s cash and cash equivalent accounts, at times, exceed federally insured limits. The Company has not experienced any losses in such accounts. Restricted cash consists of deposits collateralizing letters of credit issued by a bank in connection with the Company’s operating leases (see Note 12 “Leases” for additional disclosures) and a deposit collateralizing a letter of credit issued by a bank supporting the Company’s corporate credit cards. Cash, cash equivalents and restricted cash consist of the following: March 31, 2024 December 31, 2023 Cash and cash equivalents $ 35,276 $ 55,904 Restricted cash 1,362 1,372 Total cash, cash equivalents and restricted cash $ 36,638 $ 57,276 Concentrations of credit risk and off-balance sheet risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents and available-for-sale securities. The Company maintains its cash and cash equivalent balances with high quality financial institutions and, consequently, the Company believes that such funds are subject to minimal credit risk. The Company’s marketable securities consist of U.S. Treasury Securities and Corporate Bonds. The Company’s investment policy limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to be at least AA-/Aa3 rated, thereby reducing credit risk exposure. Investments Investments consist of U.S. Treasury Securities and Corporate Bonds. Management determines the appropriate classification of these securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company classifies its investments as available-for-sale pursuant to FASB ASC 320, Investments-Debt and Equity Securities. Investments are recorded at fair value, with unrealized gains and losses included as a component of accumulated other comprehensive income (loss) in stockholders’ equity and a component of total comprehensive loss in the consolidated statements of comprehensive loss, until realized. Realized gains and losses are included in investment income on a specific-identification basis. The Company estimates expected credit losses for investments when unrealized losses exist. Unrealized losses that are credit related are recognized in the Company’s Consolidated Statements of Operations and unrealized losses that are not credit related are recognized in accumulated other comprehensive income (loss). For the three months ended March 31, 2024 and 2023, there were no unrealized losses that were credit related. For the three months ended March 31, 2024, there was $ 0.5 million of net unrealized loss on investments. For the three months ended March 31, 2023 there was $ 0.3 million of net unrealized gains on investments. Intangible Assets Intangible assets related to in process research and development projects are considered to be indefinite-lived until the completion or abandonment of the associated R&D efforts. If and when development is complete, which generally occurs if and when regulatory approval to market a product is obtained, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time. IPR&D intangible assets which are determined to have had a decrease in their fair value are adjusted downward and an expense is recognized in R&D expenses in the Consolidated Statements of Operations. These IPR&D intangible assets are tested at least annually or when a triggering event occurs that could indicate a potential impairment based on indicators including progress of R&D activities, changes in projected development of assets, and changes in regulatory environment and future commercial markets. If a triggering event occurs that would indicate a potential impairment, the Company will perform a quantitative analysis to determine whether it is more likely than not that the fair value is below carrying amount. Fair Value Measurements The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. FASB ASC 820, Fair Value Measurements and Disclosures, establishes a hierarchy of inputs used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported fair value of the investments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy are described below: • Level 1 - Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. • Level 2 - Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. • Level 3 - Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable. To the extent that 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. The fair value of the Company’s financial instruments, including cash and cash equivalents, restricted cash, deposits, accounts payable and accrued expenses approximate their respective carrying values due to the short-term nature of most of these instruments. Warrants The Company accounts for stock warrants as either equity instruments, liabilities or derivative liabilities in accordance with FASB ASC 480, Distinguishing Liabilities from Equity and/or FASB ASC 815, Derivatives and Hedging, depending on the specific terms of the warrant agreement. Liability-classified warrants are recorded at their estimated fair values at each reporting period until they are exercised, terminated, reclassified or otherwise settled. Changes in the estimated fair value of liability-classified warrants are included in interest and other income in the Company’s Consolidated Statement of Operations. Stock-Based Compensation The Company issues stock-based awards to employees and non-employees, generally in the form of stock options, RSUs and PSUs. The Company measures the compensation expense of employee and non-employee services received in exchange for an award of equity instruments based on the fair value of the award on the grant date. That cost of stock options and RSUs is recognized over the requisite service period of the awards on a straight-line basis with forfeitures recognized as they occur. The vesting condition for PSUs is performance based and the cost of PSUs is recognized when it is likely that the performance goals associated with the PSUs will be achieved and the awards will vest. The Company classifies stock-based compensation expense in its Consolidated Statements of Operations in the same manner in which the award recipient’s payroll costs and services are classified or in which the award recipient’s service payments are classified. Recent Accounting Pronouncements Accounting Pronouncements Not Adopted as of March 31, 2024 ASU 2023-09: Income Taxes Topic 740 - Improvements to Income Tax Disclosures. This update standardizes categories for the effective tax rate reconciliation, requires disaggregation of income taxes and additional income tax-related disclosures. This update is required to be effective for the Company for fiscal periods beginning after December 15, 2024. As this accounting standard only impacts disclosures, it will not have a material impact on the Company's Consolidated Financial Statements. ASU 2023-07: Segment Reporting Topic 280 - Improvements to Reportable Segment Disclosures. This update requires expanded annual and interim disclosures for significant segment expenses that are regularly provided to the chief operating decision maker and included within each reported measure of segment profit or loss. This update will be effective for fiscal years beginning after December 15, 2023, and is to be applied retrospectively to all periods presented in the financial statements. Early adoption is permitted. As this accounting standard only impacts disclosures, it will not have a material impact on the Company’s consolidated financial statements.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
Fair Value of Financial Instruments	Mar. 31, 2024
Fair Value of Financial Instruments [Abstract]
Fair Value of Financial Instruments	4. Fair Value of Financial Instruments Items measured at fair value on a recurring basis are the Company’s investments and warrant liability. The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy: Fair Value Measurements as of March 31, 2024 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market mutual funds $ 17,107 $ - $ - $ 17,107 17,107 - - 17,107 Investments: U.S. Treasury securities - 273,846 - 273,846 Corporate Bonds - 21,191 - 21,191 - 295,037 - 295,037 Total assets $ 17,107 $ 295,037 $ - $ 312,144 Liabilities: Warrant liability $ - $ - $ 765 $ 765 Total liabilities $ - $ - $ 765 $ 765 Fair Value Measurements as of December 31, 2023 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market mutual funds $ 50,737 $ - $ - $ 50,737 U.S. Treasury Securities - 2,487 - 2,487 50,737 2,487 - 53,224 Investments: U.S. Treasury securities - 312,696 - 312,696 Corporate Bonds - 38,895 - 38,895 - 351,591 - 351,591 Total assets $ 50,737 $ 354,078 $ - $ 404,815 Liabilities: Warrant liability $ - $ - $ 1,876 $ 1,876 Total liabilities $ - $ - $ 1,876 $ 1,876 The Company classifies its money market mutual funds as Level 1 assets under the fair value hierarchy, as these assets have been valued using quoted market prices in active markets without any valuation adjustment. The Company classifies its U.S. Treasury Securities and Corporate Bonds as Level 2 assets as these assets are not traded in an active market and have been valued through a third-party pricing service based on quoted prices for similar assets. The reconciliation of the Company’s warrant liability, which is recorded as part of other liabilities in the Consolidated Balance Sheets, measured at fair value on a recurring basis using unobservable inputs (Level 3) is as follows: Warrant Liability Balance, December 31, 2023 $ 1,876 Fair value adjustments ( 1,111 ) Balance, March 31, 2024 $ 765 The Company utilizes a Black-Scholes model to value the warrant liability (see Note 10 “Warrants”) at each reporting period, with changes in fair value recognized in the Consolidated Statements of Operations. The estimated fair value of the warrant liability is determined using Level 3 inputs. Inherent in an options pricing model are assumptions related to expected share-price volatility, expected life, risk-free interest rate and dividend yield. The Company estimates the expected volatility of its common stock based on historical volatility of the Company and of a peer group, considering the expected remaining life of the warrants. The risk-free interest rate is based on the U.S. Treasury zero-coupon yield curve on the valuation date for a maturity similar to the expected remaining life of the warrants. The expected life of the warrants is assumed to be equivalent to their remaining contractual term. The dividend rate is based on the historical rate, which the Company anticipates will remain at zero . The fair value of the warrant liability has been estimated with the following assumptions: March 31, 2024 December 31, 2023 Stock price $ 26.94 $ 29.50 Exercise price $ 65.23 $ 65.23 Expected volatility 63.34 % 68.83 % Risk-free interest rate 5.04 % 4.70 % Expected dividend yield - - Expected life (years) 1.06 1.31 Fair value per warrant $ 1.24 $ 3.04

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
Property and Equipment, Net	Mar. 31, 2024
Property and Equipment, Net [Abstract]
Property and Equipment, Net	5. Property and Equipment, Net The Company’s property and equipment consisted of the following: March 31, 2024 December 31, 2023 Laboratory equipment $ 30,777 $ 29,232 Machinery and equipment 12,508 12,325 Computer equipment 244 244 Furniture and fixtures 2,777 2,777 Leasehold improvements 6,876 6,723 Internal use software 1,903 1,903 55,085 53,204 Less: accumulated depreciation and amortization ( 15,748 ) ( 14,032 ) Total property and equipment, net $ 39,337 $ 39,172 During the three months ended March 31, 2024 and 2023, the Company recognized $ 1.7 million and $ 1.1 million of depreciation and amortization expense, respectively.

Intangible Assets and Goodwill

Intangible Assets and Goodwill	3 Months Ended
Intangible Assets and Goodwill	Mar. 31, 2024
Intangible Assets and Goodwill [Abstract]
Intangible Assets and Goodwill	6. Intangible Assets and Goodwill The Company’s indefinite lived intangible assets consist of an acquired IPR&D asset received in the acquisition of Renovacor on December 1, 2022. Intangible assets as of March 31, 2024 and December 31, 2023 are summarized as follows: March 31, 2024 Gross Carrying Value Accumulated Amortization Intangible Assets, Net In process research & development $ 25,150 $ - $ 25,150 Total intangible assets $ 25,150 $ - $ 25,150 December 31, 2023 Gross Carrying Value Accumulated Amortization Intangible Assets, Net In process research & development $ 25,150 $ - $ 25,150 Total intangible assets $ 25,150 $ - $ 25,150 The carrying value of Goodwill as of March 31, 2024 and December 31, 2023 was $ 39.2 million.

Accounts Payable and Accrued Ex

Accounts Payable and Accrued Expenses	3 Months Ended
Accounts Payable and Accrued Expenses	Mar. 31, 2024
Accounts Payable and Accrued Expenses [Abstract]
Accounts Payable and Accrued Expenses	7. Accounts Payable and Accrued Expenses The Company’s accounts payable and accrued expenses consisted of the following: March 31, 2024 December 31, 2023 Research and development $ 15,216 $ 13,867 Investment payable - 13,137 Employee compensation 4,192 9,930 Property and equipment 923 1,077 Professional fees 7,003 6,006 Other 2,751 1,772 Total accounts payable and accrued expenses $ 30,085 $ 45,789 The $ 13.1 million investment payable at December 31, 2023 was related to investment purchases of available-for-sale securities in 2023 that settled in 2024.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
Stockholders' Equity	Mar. 31, 2024
Stockholders' Equity [Abstract]
Stockholders' Equity	8. Stockholders’ Equity At-the-Market Offering Program On February 28, 2022, the Company entered into the Sales Agreement with Cowen with respect to an at-the-market offering program pursuant to which the Company may offer and sell, from time to time at its sole discretion, shares through Cowen as its sales agent. The shares to be offered and sold under the Sales Agreement, if any, will be offered and sold pursuant to the Company’s shelf registration statement on Form S-3. The Company filed a prospectus supplement with the SEC on February 28, 2022 in connection with the offer and sale of the shares pursuant to the Sales Agreement. The Company will pay Cowen a cash commission of 3.0 % of gross proceeds from the sale of the shares pursuant to the Sales Agreement. The Company has provided Cowen with customary indemnification and contribution rights. The Company has reimbursed Cowen for certain expenses incurred in connection with the Sales Agreement. On September 12, 2023, the Company and Cowen entered into the Amended Sales Agreement pursuant to which the aggregate offering amount available under the at-the-market offering program was reduced to $ 180.0 million. Through March 31, 2024 , the Company sold 4.2 million shares under the at-the-market offering program for gross proceeds of $ 65.8 million, less commissions of $ 2.0 million for net proceeds of $ 63.8 million. The Company did no t sell any shares under the at-the-market offering program during the three months ended March 31, 2024 .

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
Stock-Based Compensation	Mar. 31, 2024
Stock-Based Compensation [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation Stock Option Valuation The weighted average assumptions that the Company used in a Black-Scholes pricing model to determine the fair value of stock options granted to employees, non-employees and directors were as follows: Three Months Ended March 31, 2024 2023 Risk-free interest rate 5.16 % 4.02 % Expected term (in years) 5.88 5.88 Expected volatility 73.62 % 73.54 % Expected dividend yield 0.00 % 0.00 % Exercise price $ 29.46 $ 20.17 Fair value of common stock $ 29.46 $ 20.17 The following table summarizes stock option activity for the three months ended March 31, 2024: Weighted Weighted Average Average Aggregate Number of Exercise Contractual Intrinsic Shares Price Term (Years) Value Outstanding as of December 31, 2023 14,863,996 $ 15.07 5.16 $ 250,602 Granted 1,174,939 29.46 9.88 Exercised ( 73,745 ) 16.05 956 Cancelled or forfeited ( 41,384 ) 18.18 Outstanding as of March 31, 2024 15,923,806 $ 16.12 5.24 $ 208,603 Options vested and exercisable as of March 31, 2024 12,351,611 $ 14.14 4.14 $ 190,665 Options unvested as of March 31, 2024 3,572,195 $ 22.94 9.04 $ 17,937 The weighted average grant-date fair value per share of stock options granted during the three months ended March 31, 2024, and 2023 was $ 19.92 and $ 13.50 , respectively. The total fair value of options vested during the three months ended March 31, 2024 and 2023 was $ 11.5 million and $ 11.4 million, respectively. Restricted Stock Units The following table summarizes the Company’s RSU activity for the three months ended March 31, 2024: Weighted Average Number of Grant Date Shares Fair Value Unvested as of December 31, 2023 1,490,357 $ 18.53 Granted 566,366 29.24 Vested ( 290,578 ) 19.38 Forfeited ( 25,400 ) 17.04 Unvested as of March 31, 2024 1,740,745 $ 21.89 Performance Stock Units The following table summarizes the Company’s PSU activity for the three months ended March 31, 2024: Weighted Average Number of Grant Date Shares Fair Value Unvested as of December 31, 2023 - $ - Granted 139,323 28.71 Vested - - Forfeited - - Unvested as of March 31, 2024 139,323 $ 28.71 PSU vesting and expense recognition is based on achievement of specific performance goals within certain time periods. PSU awards that are not achieved within specific time periods are forfeited. No performance goals were probable of achievement and no time periods had expired on grant date and as of March 31, 2024. Stock-Based Compensation Expense Stock-based compensation expense recognized by award type was as follows: Three Months Ended March 31, 2024 2023 Stock options $ 6,938 $ 6,985 Restricted stock units 3,314 1,930 Total stock-based compensation expense $ 10,252 $ 8,915 Stock-based compensation expense by classification included within the Consolidated Statements of Operations and Comprehensive Loss was as follows: Three Months Ended March 31, 2024 2023 Research and development $ 4,637 $ 3,819 General and administrative 5,615 5,096 Total stock-based compensation expense $ 10,252 $ 8,915 As of March 31, 2024, the Company had an aggregate of $ 85.3 million of unrecognized stock-based compensation expense related to stock options, RSU and PSU grants. The stock options and RSU grants had an aggregate of $ 81.3 million of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted average period of 1.98 years.

Warrants

Warrants	3 Months Ended
Warrants	Mar. 31, 2024
Warrants [Abstract]
Warrants	10. Warrants A summary of the warrants outstanding as of March 31, 2024 is as follows: Exercise Price Outstanding Grant/Assumption Date Expiration Date $ 57.11 603,386 December 21, 2020 December 21, 2030 33.63 301,291 August 9, 2021 August 9, 2031 22.51 153,155 December 17, 2021 December 17, 2031 22.51 153,155 December 17, 2021 December 17, 2031 65.23 617,050 December 1, 2022 April 23, 2025 65.23 760,086 December 1, 2022 December 1, 2026 $ 0.01 3,126,955 September 15, 2023 N/A Total 5,715,078 The following table is a summary of changes in warrants to purchase common stock for the three months ended March 31, 2024: Number of Warrant Shares Outstanding and Exercisable Exercise Price per Share Balance as of December 31, 2023 5,715,078 Issued - $ - Exercised - - Expired - $ - Balance as of March 31, 2024 5,715,078 Warrants Issued in Public Offering On September 15, 2023, the Company completed a public offering that included pre-funded warrants to purchase 3,126,955 shares of common shares at a price of $ 0.01 per share (see Note 8 “Stockholders’ Equity” and Note 17 “Related Party Transactions”). Assumed Renovacor Public Warrants In conjunction with the acquisition of Renovacor, Rocket assumed pre-acquisition public warrants (“Public Warrants”) that were converted into Rocket warrants with a right to purchase 760,086 of Rocket common shares at an exercise price of $ 65.23 per share. The Company determined that the Public Warrants met all of the criteria for equity classification. Accordingly, upon closing of the acquisition, the Public Warrants were recorded as a component of additional paid-in capital of $ 3.4 million. Assumed Renovacor Private Warrants In conjunction with the acquisition of Renovacor, Rocket assumed pre-acquisition private warrants (“Private Warrants”) that were converted into Rocket warrants with a right to purchase 617,050 of Rocket common shares at an exercise price of $ 65.23 per share. The Company determined that the Private Warrants did not meet all of the criteria for equity classification. Accordingly, the Company classifies the Private Warrants as derivative liabilities in its Consolidated Balance Sheets. The Company measures the fair value of the warrants at the end of each reporting period and recognizes changes in the fair value from the prior period in the Company’s operating results for the current period. See Note 4 “Fair Value of Financial Instruments” for discussion of fair value measurement of the warrant liability.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
Net Loss Per Share	Mar. 31, 2024
Net Loss Per Share [Abstract]
Net Loss Per Share	11. Net Loss Per Share Basic and diluted net loss per share attributable to common stockholders was calculated as follows: Three Months Ended March 31, 2024 2023 Numerator: Net loss attributable to common stockholders $ ( 62,054 ) $ ( 58,335 ) Denominator: Weighted-average common shares outstanding - basic and diluted 93,549,884 79,453,519 Net loss per share attributable to common stockholders - basic and diluted $ ( 0.66 ) $ ( 0.73 ) For the three months ended March 31, 2024 , the Company included the 3,126,955 potential shares from the pre-funded warrants acquired by RTW as it was determined that these met the definition for equity classification as the holder is only required to pay $ 0.01 per share upon exercise of the pre-funded warrants . The Company excluded the following potential shares of common stock, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended March 31, 2024 2023 Warrants exercisable for common shares 2,588,123 2,595,174 Restricted stock units 1,740,745 1,622,457 Performance stock units 139,323 - Options to purchase common shares 15,923,806 14,651,390 Total potential shares excluded from diluted net loss per share 20,391,997 18,869,021

Leases

Leases	3 Months Ended
Leases	Mar. 31, 2024
Leases [Abstract]
Leases	12. Leases Finance Lease The Company has a lease for a facility in Cranbury, New Jersey, consisting of 103,720 square feet of space including areas for offices, process development, research, and development laboratories and 50,000 square feet dedicated to AAV cGMP manufacturing facilities to support the Company’s pipeline (such lease, as amended, the “NJ Lease Agreement”). The NJ Lease Agreement has a 15 -year term from September 1, 2019, with an option to renew for two consecutive five-year renewal terms. Estimated rent payments for the NJ Lease Agreement are $ 1.2 million per annum, payable in monthly installments, depending upon the nature of the leased space, and subject to annual base rent increases of 3 %. The total commitment under the lease is estimated to be approximately $ 29.3 million over the 15 -year term of the lease. The Company paid a cash security deposit of $ 0.3 million to the landlord in connection with the NJ Lease Agreement which has been reflected as part of deposits in the Consolidated Balance Sheets as of March 31, 2024 and December 31, 2023. Operating Leases On June 7, 2018, the Company entered into a three-year lease agreement for office space in the Empire State Building in New York, NY (the “ESB Lease Agreement”). In connection with the ESB Lease Agreement, the Company established an irrevocable standby letter of credit (the “Empire LOC”) for $ 0.8 million. On March 26, 2021, the Company entered into Amendment No. 1 to the ESB Lease Agreement (“ESB Lease Amendment”) that extended the term of the lease agreement to June 30, 2024 , reduced the rent payments going forward, and reduced the Empire LOC to $ 0.8 million. On March 29, 2024, the Company entered into Amendment No. 2 to the ESB Lease Agreement that extended the term of the lease agreement to July 31, 2027. The Empire LOC serves as the Company’s security deposit on the lease in which the landlord is the beneficiary and expires September 30, 2027 . The Company has a certificate of deposit of $ 0.8 million with a bank as collateral for the Empire LOC which is classified as part of restricted cash in the Consolidated Balance Sheets as of March 31, 2024 and December 31, 2023. On November 15, 2022, the Company entered into a lease agreement with a lease term until October 31, 2024 , for laboratory space in Madrid, Spain. The lease commenced on April 1, 2023 and the Company recognized a right-of-use asset and corresponding lease liability of approximately $ 0.2 million each. On December 1, 2022, in connection with the acquisition of Renovacor, the Company acquired the Renovacor operating leases for space at facilities in Hopewell, New Jersey and Cambridge, Massachusetts with remaining lease terms of approximately 10.3 and 1.3 years, respectively. The Company recognized total right-of-use assets of $ 3.8 million with corresponding total lease liabilities of $ 3.6 million at lease commencement dates. The Company signed an agreement to sublease one of these facilities in January 2024 and intends to sublease the other remaining facilities. Rental income received under the sublease agreement totaled $ 0.1 million for the three months ended March 31, 2024. Rent expense under operating leases was $ 0.6 million and $ 0.6 million for the three months ended March 31, 2024 and 2023, respectively. The total restricted cash balance for the Company’s operating and finance leases as of March 31, 2024 and December 31, 2023 was $ 0.8 million. Operating lease cost was $ 0.4 million and $ 0.4 million for the three months ended March 31, 2024 and 2023, respectively. The following table summarizes lease cost for the three months ended March 31, 2024 and 2023: Three Months Ended March 31, Lease cost 2024 2023 Operating lease cost $ 369 $ 358 Finance lease cost: Amortization of right of use assets 538 538 Interest on lease liabilities 471 468 Total lease cost $ 1,378 $ 1,364 The following table summarizes the future lease payments of the Company’s operating and finance lease liabilities on an undiscounted cash flow basis : Fiscal Year Ending December 31, March 31, 2024 2024 (nine months) $ 815 2025 1,001 2026 1,005 2027 759 2028 522 Thereafter 2,420 Total lease payments $ 6,522 Less: interest ( 1,744 ) Total operating lease liabilities $ 4,778 Fiscal Year Ending December 31, March 31, 2024 2024 (nine months) $ 1,348 2025 1,856 2026 1,911 2027 1,969 2028 2,028 Thereafter 41,003 Total lease payments $ 50,115 Less: interest ( 28,944 ) Total finance lease liability $ 21,171 The following table summarizes the operating and financing lease liabilities and right-of-use assets as of March 31, 2024 and December 31, 2023: Leases March 31, 2024 December 31, 2023 Operating right-of-use assets $ 4,768 $ 3,901 Operating current lease liabilities $ 1,064 $ 925 Operating noncurrent lease liabilities 3,714 2,973 Total operating lease liabilities $ 4,778 $ 3,898 Finance right-of-use assets $ 43,979 $ 44,517 Finance current lease liability $ 1,808 $ 1,791 Finance noncurrent lease liability 19,363 19,353 Total finance lease liability $ 21,171 $ 21,144 Three Months Ended March 31, Other Information 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 333 $ 261 Cash flows from finance lease $ 443 $ 431 Weighted-average remaining lease term - operating leases 7.1 years 8.2 years Weighted-average remaining lease term - finance lease 20.4 years 21.4 years Weighted-average discount rate - operating leases 8.82 % 8.08 % Weighted-average discount rate - finance lease 8.96 % 8.96 %

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2024
Commitments and Contingencies [Abstract]
Commitments and Contingencies	13. Commitments and Contingencies Litigation From time to time, the Company may be subject to various legal proceedings and claims that arise in the ordinary course of its business activities. Although the results of litigation and claims cannot be predicted with certainty, the Company does not believe it is party to any other claim or litigation the outcome of which, if determined adversely to the Company, would individually or in the aggregate be reasonably expected to have a material adverse effect on its business. Regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors. Indemnification Arrangements Pursuant to its bylaws and as permitted under Delaware law, the Company has indemnification obligations to directors, officers, employees or agents of the Company or anyone serving in these capacities. The maximum potential amount of future payments the Company could be required to pay is unlimited. The Company has insurance that reduces its monetary exposure and would enable it to recover a portion of any future amounts paid. As a result, the Company believes that the estimated fair value of these indemnification commitments is minimal. Throughout the normal course of business, the Company has agreements with vendors that provide goods and services required by the Company to run its business. In some instances, vendor agreements include language that requires the Company to indemnify the vendor from certain damages caused by the Company’s use of the vendor’s goods and/or services. The Company has insurance that would allow it to recover a portion of any future amounts that could arise from these indemnifications. As a result, the Company believes that the estimated fair value of these indemnification commitments is minimal.

Agreements Related to Intellect

Agreements Related to Intellectual Property	3 Months Ended
Agreements Related to Intellectual Property	Mar. 31, 2024
Agreements Related to Intellectual Property [Abstract]
Agreements Related to Intellectual Property	14. Agreements Related to Intellectual Property The Company, directly and through its subsidiary Spacecraft Seven, LLC, has various license and research and collaboration arrangements. The transactions principally resulted in the acquisition of rights to intellectual property which is in the preclinical phase and has not been tested for safety or feasibility. In all cases, the Company did not acquire tangible assets, processes, protocols, or operating systems. The Company expenses the acquired intellectual property rights as of the acquisition date on the basis that the cost of intangible assets purchased from others for use in R&D activities has no alternative future uses.

CIRM Grants

CIRM Grants	3 Months Ended
CIRM Grants	Mar. 31, 2024
CIRM Grants [Abstract]
CIRM Grants	15. CIRM Grants LAD-I CIRM Grant On April 30, 2019, the California Institute for Regenerative Medicine awarded the Company up to $ 7.5 million under a CLIN2 grant award to support the clinical development of its LV-based gene therapy for RP-L201. Proceeds from the grant would help fund clinical trial costs as well as manufactured drug product for Phase 1/2 patients enrolled at the U.S. clinical site, University of California, Los Angeles Mattel Children’s Hospital, led by principal investigator Donald Kohn, M.D., UCLA Professor of Microbiology, Immunology and Molecular Genetics, Pediatrics (Hematology/Oncology), Molecular and Medical Pharmacology and member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA. As of March 31, 2024, the Company has received $ 5.9 million in total RP-L201 grants from CIRM. T he Company received a final milestone grant of $ 0.05 million on January 2, 2024 and no additional payments are available under the grant awards program as of March 31, 2024.

Related Party Transactions

Related Party Transactions	3 Months Ended
Related Party Transactions	Mar. 31, 2024
Related Party Transactions [Abstract]
Related Party Transactions	16. Related Party Transactions In June 2023, the Company entered into a consulting agreement with the spouse of one of the Company’s executive officers for information technology advisory services. The Company incurred expenses of approximately $ 0.002 million for the three months ended March 31, 2024, relating to services provided under this agreement. In September 2023, in connection with a public offering, the Company sold approximately 3.1 million pre-funded warrants to purchase shares of the Company’s common stock to funds affiliated with RTW Investments, LP, the Company’s largest shareholder (see Note 8 “Stockholders’ Equity”).

401(k) Savings Plan

401(k) Savings Plan	3 Months Ended
401(k) Savings Plan	Mar. 31, 2024
401(k) Savings Plan [Abstract]
401(k) Savings Plan	17. 401(k) Savings Plan The Company has a defined contribution savings plan (the “Plan”) under Section 401(k) of the Internal Revenue Code of 1986. This Plan covers substantially all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. Company contributions to the Plan may be made at the discretion of the Company’s Board of Directors. The Company has elected the safe harbor match of 4 % of employee contributions to the Plan, subject to certain limitations. The Company’s matching contribution for the three months ended March 31, 2024 and 2023, was $ 0.4 million and $ 0.3 million, respectively.

Basis of Presentation, Princi_2

Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements for the year ended December 31, 2023 included in the Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 27, 2024. The unaudited interim consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s consolidated financial position as of March 31, 2024 and the results of its operations and its cash flows for the three months ended March 31, 2024. The financial data and other information disclosed in these consolidated notes related to the three months ended March 31, 2024 and 2023 are unaudited. The results for the three months ended March 31, 2024 are not necessarily indicative of results to be expected for the year ending December 31, 2024 and any other interim periods or any future year or period.
Significant Accounting Policies	Significant Accounting Policies The significant accounting policies used in the preparation of these consolidated financial statements for the three months ended March 31, 2024 are consistent with those disclosed in Note 3 to the consolidated financial statements in the 2023 Form 10-K with most significant policies also being listed here.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements represent the consolidation of the accounts of the Company and its subsidiaries in conformity with U.S. GAAP. All intercompany accounts have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions reflected in these consolidated financial statements include but are not limited to goodwill and intangible asset impairments, the accrual of R&D expenses, and the valuation of equity transactions and stock-based awards. Changes in estimates and assumptions are reflected in reported results in the period in which they become known. Actual results could differ from those estimates.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consists of bank deposits, certificates of deposit and money market accounts with financial institutions. Cash equivalents are carried at cost which approximates fair value due to their short-term nature and which the Company believes do not have a material exposure to credit risk. The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents. The Company’s cash and cash equivalent accounts, at times, exceed federally insured limits. The Company has not experienced any losses in such accounts. Restricted cash consists of deposits collateralizing letters of credit issued by a bank in connection with the Company’s operating leases (see Note 12 “Leases” for additional disclosures) and a deposit collateralizing a letter of credit issued by a bank supporting the Company’s corporate credit cards. Cash, cash equivalents and restricted cash consist of the following: March 31, 2024 December 31, 2023 Cash and cash equivalents $ 35,276 $ 55,904 Restricted cash 1,362 1,372 Total cash, cash equivalents and restricted cash $ 36,638 $ 57,276
Concentrations of Credit Risk and Off-balance Sheet Risk	Concentrations of credit risk and off-balance sheet risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents and available-for-sale securities. The Company maintains its cash and cash equivalent balances with high quality financial institutions and, consequently, the Company believes that such funds are subject to minimal credit risk. The Company’s marketable securities consist of U.S. Treasury Securities and Corporate Bonds. The Company’s investment policy limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to be at least AA-/Aa3 rated, thereby reducing credit risk exposure.
Investments	Investments Investments consist of U.S. Treasury Securities and Corporate Bonds. Management determines the appropriate classification of these securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company classifies its investments as available-for-sale pursuant to FASB ASC 320, Investments-Debt and Equity Securities. Investments are recorded at fair value, with unrealized gains and losses included as a component of accumulated other comprehensive income (loss) in stockholders’ equity and a component of total comprehensive loss in the consolidated statements of comprehensive loss, until realized. Realized gains and losses are included in investment income on a specific-identification basis. The Company estimates expected credit losses for investments when unrealized losses exist. Unrealized losses that are credit related are recognized in the Company’s Consolidated Statements of Operations and unrealized losses that are not credit related are recognized in accumulated other comprehensive income (loss). For the three months ended March 31, 2024 and 2023, there were no unrealized losses that were credit related. For the three months ended March 31, 2024, there was $ 0.5 million of net unrealized loss on investments. For the three months ended March 31, 2023 there was $ 0.3 million of net unrealized gains on investments.
Intangible Assets	Intangible Assets Intangible assets related to in process research and development projects are considered to be indefinite-lived until the completion or abandonment of the associated R&D efforts. If and when development is complete, which generally occurs if and when regulatory approval to market a product is obtained, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time. IPR&D intangible assets which are determined to have had a decrease in their fair value are adjusted downward and an expense is recognized in R&D expenses in the Consolidated Statements of Operations. These IPR&D intangible assets are tested at least annually or when a triggering event occurs that could indicate a potential impairment based on indicators including progress of R&D activities, changes in projected development of assets, and changes in regulatory environment and future commercial markets. If a triggering event occurs that would indicate a potential impairment, the Company will perform a quantitative analysis to determine whether it is more likely than not that the fair value is below carrying amount.
Fair Value Measurements	Fair Value Measurements The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. FASB ASC 820, Fair Value Measurements and Disclosures, establishes a hierarchy of inputs used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported fair value of the investments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy are described below: • Level 1 - Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. • Level 2 - Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. • Level 3 - Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable. To the extent that 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. The fair value of the Company’s financial instruments, including cash and cash equivalents, restricted cash, deposits, accounts payable and accrued expenses approximate their respective carrying values due to the short-term nature of most of these instruments.
Warrants	Warrants The Company accounts for stock warrants as either equity instruments, liabilities or derivative liabilities in accordance with FASB ASC 480, Distinguishing Liabilities from Equity and/or FASB ASC 815, Derivatives and Hedging, depending on the specific terms of the warrant agreement. Liability-classified warrants are recorded at their estimated fair values at each reporting period until they are exercised, terminated, reclassified or otherwise settled. Changes in the estimated fair value of liability-classified warrants are included in interest and other income in the Company’s Consolidated Statement of Operations.
Stock-Based Compensation	Stock-Based Compensation The Company issues stock-based awards to employees and non-employees, generally in the form of stock options, RSUs and PSUs. The Company measures the compensation expense of employee and non-employee services received in exchange for an award of equity instruments based on the fair value of the award on the grant date. That cost of stock options and RSUs is recognized over the requisite service period of the awards on a straight-line basis with forfeitures recognized as they occur. The vesting condition for PSUs is performance based and the cost of PSUs is recognized when it is likely that the performance goals associated with the PSUs will be achieved and the awards will vest. The Company classifies stock-based compensation expense in its Consolidated Statements of Operations in the same manner in which the award recipient’s payroll costs and services are classified or in which the award recipient’s service payments are classified.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Pronouncements Not Adopted as of March 31, 2024 ASU 2023-09: Income Taxes Topic 740 - Improvements to Income Tax Disclosures. This update standardizes categories for the effective tax rate reconciliation, requires disaggregation of income taxes and additional income tax-related disclosures. This update is required to be effective for the Company for fiscal periods beginning after December 15, 2024. As this accounting standard only impacts disclosures, it will not have a material impact on the Company's Consolidated Financial Statements. ASU 2023-07: Segment Reporting Topic 280 - Improvements to Reportable Segment Disclosures. This update requires expanded annual and interim disclosures for significant segment expenses that are regularly provided to the chief operating decision maker and included within each reported measure of segment profit or loss. This update will be effective for fiscal years beginning after December 15, 2023, and is to be applied retrospectively to all periods presented in the financial statements. Early adoption is permitted. As this accounting standard only impacts disclosures, it will not have a material impact on the Company’s consolidated financial statements.

Basis of Presentation, Princi_3

Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2024
Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies [Abstract]
Cash, Cash Equivalents and Restricted Cash	Restricted cash consists of deposits collateralizing letters of credit issued by a bank in connection with the Company’s operating leases (see Note 12 “Leases” for additional disclosures) and a deposit collateralizing a letter of credit issued by a bank supporting the Company’s corporate credit cards. Cash, cash equivalents and restricted cash consist of the following: March 31, 2024 December 31, 2023 Cash and cash equivalents $ 35,276 $ 55,904 Restricted cash 1,362 1,372 Total cash, cash equivalents and restricted cash $ 36,638 $ 57,276

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
Fair Value of Financial Instruments (Tables)	Mar. 31, 2024
Fair Value of Financial Instruments [Abstract]
Measured on Recurring Basis	Items measured at fair value on a recurring basis are the Company’s investments and warrant liability. The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy: Fair Value Measurements as of March 31, 2024 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market mutual funds $ 17,107 $ - $ - $ 17,107 17,107 - - 17,107 Investments: U.S. Treasury securities - 273,846 - 273,846 Corporate Bonds - 21,191 - 21,191 - 295,037 - 295,037 Total assets $ 17,107 $ 295,037 $ - $ 312,144 Liabilities: Warrant liability $ - $ - $ 765 $ 765 Total liabilities $ - $ - $ 765 $ 765 Fair Value Measurements as of December 31, 2023 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market mutual funds $ 50,737 $ - $ - $ 50,737 U.S. Treasury Securities - 2,487 - 2,487 50,737 2,487 - 53,224 Investments: U.S. Treasury securities - 312,696 - 312,696 Corporate Bonds - 38,895 - 38,895 - 351,591 - 351,591 Total assets $ 50,737 $ 354,078 $ - $ 404,815 Liabilities: Warrant liability $ - $ - $ 1,876 $ 1,876 Total liabilities $ - $ - $ 1,876 $ 1,876
Changes in Level 3 Liabilities Measured at Fair Value	The reconciliation of the Company’s warrant liability, which is recorded as part of other liabilities in the Consolidated Balance Sheets, measured at fair value on a recurring basis using unobservable inputs (Level 3) is as follows: Warrant Liability Balance, December 31, 2023 $ 1,876 Fair value adjustments ( 1,111 ) Balance, March 31, 2024 $ 765
Level 3 Fair Value of the Private Warrants	The fair value of the warrant liability has been estimated with the following assumptions: March 31, 2024 December 31, 2023 Stock price $ 26.94 $ 29.50 Exercise price $ 65.23 $ 65.23 Expected volatility 63.34 % 68.83 % Risk-free interest rate 5.04 % 4.70 % Expected dividend yield - - Expected life (years) 1.06 1.31 Fair value per warrant $ 1.24 $ 3.04

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
Property and Equipment, Net (Tables)	Mar. 31, 2024
Property and Equipment, Net [Abstract]
Summary of Property and Equipment	The Company’s property and equipment consisted of the following: March 31, 2024 December 31, 2023 Laboratory equipment $ 30,777 $ 29,232 Machinery and equipment 12,508 12,325 Computer equipment 244 244 Furniture and fixtures 2,777 2,777 Leasehold improvements 6,876 6,723 Internal use software 1,903 1,903 55,085 53,204 Less: accumulated depreciation and amortization ( 15,748 ) ( 14,032 ) Total property and equipment, net $ 39,337 $ 39,172

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	3 Months Ended
Intangible Assets and Goodwill (Tables)	Mar. 31, 2024
Intangible Assets and Goodwill [Abstract]
Summary of Intangible Assets	Intangible assets as of March 31, 2024 and December 31, 2023 are summarized as follows: March 31, 2024 Gross Carrying Value Accumulated Amortization Intangible Assets, Net In process research & development $ 25,150 $ - $ 25,150 Total intangible assets $ 25,150 $ - $ 25,150 December 31, 2023 Gross Carrying Value Accumulated Amortization Intangible Assets, Net In process research & development $ 25,150 $ - $ 25,150 Total intangible assets $ 25,150 $ - $ 25,150

Accounts Payable and Accrued _2

Accounts Payable and Accrued Expenses (Tables)	3 Months Ended
Accounts Payable and Accrued Expenses (Tables)	Mar. 31, 2024
Accounts Payable and Accrued Expenses [Abstract]
Schedule of Accounts Payable and Accrued Expenses	The Company’s accounts payable and accrued expenses consisted of the following: March 31, 2024 December 31, 2023 Research and development $ 15,216 $ 13,867 Investment payable - 13,137 Employee compensation 4,192 9,930 Property and equipment 923 1,077 Professional fees 7,003 6,006 Other 2,751 1,772 Total accounts payable and accrued expenses $ 30,085 $ 45,789

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
Stock-Based Compensation (Tables)	Mar. 31, 2024
Stock-Based Compensation [Abstract]
Weighted-Average Assumptions for Stock Options	The weighted average assumptions that the Company used in a Black-Scholes pricing model to determine the fair value of stock options granted to employees, non-employees and directors were as follows: Three Months Ended March 31, 2024 2023 Risk-free interest rate 5.16 % 4.02 % Expected term (in years) 5.88 5.88 Expected volatility 73.62 % 73.54 % Expected dividend yield 0.00 % 0.00 % Exercise price $ 29.46 $ 20.17 Fair value of common stock $ 29.46 $ 20.17
Stock Option Activity	The following table summarizes stock option activity for the three months ended March 31, 2024: Weighted Weighted Average Average Aggregate Number of Exercise Contractual Intrinsic Shares Price Term (Years) Value Outstanding as of December 31, 2023 14,863,996 $ 15.07 5.16 $ 250,602 Granted 1,174,939 29.46 9.88 Exercised ( 73,745 ) 16.05 956 Cancelled or forfeited ( 41,384 ) 18.18 Outstanding as of March 31, 2024 15,923,806 $ 16.12 5.24 $ 208,603 Options vested and exercisable as of March 31, 2024 12,351,611 $ 14.14 4.14 $ 190,665 Options unvested as of March 31, 2024 3,572,195 $ 22.94 9.04 $ 17,937
RSU Activity	The following table summarizes the Company’s RSU activity for the three months ended March 31, 2024: Weighted Average Number of Grant Date Shares Fair Value Unvested as of December 31, 2023 1,490,357 $ 18.53 Granted 566,366 29.24 Vested ( 290,578 ) 19.38 Forfeited ( 25,400 ) 17.04 Unvested as of March 31, 2024 1,740,745 $ 21.89
PSU Activity	The following table summarizes the Company’s PSU activity for the three months ended March 31, 2024: Weighted Average Number of Grant Date Shares Fair Value Unvested as of December 31, 2023 - $ - Granted 139,323 28.71 Vested - - Forfeited - - Unvested as of March 31, 2024 139,323 $ 28.71 PSU vesting and expense recognition is based on achievement of specific performance goals within certain time periods. PSU awards that are not achieved within specific time periods are forfeited. No performance goals were probable of achievement and no time periods had expired on grant date and as of March 31, 2024.
Stock-Based Compensation Expense by Award Type	Stock-based compensation expense recognized by award type was as follows: Three Months Ended March 31, 2024 2023 Stock options $ 6,938 $ 6,985 Restricted stock units 3,314 1,930 Total stock-based compensation expense $ 10,252 $ 8,915
Stock-Based Compensation Expense	Stock-based compensation expense by classification included within the Consolidated Statements of Operations and Comprehensive Loss was as follows: Three Months Ended March 31, 2024 2023 Research and development $ 4,637 $ 3,819 General and administrative 5,615 5,096 Total stock-based compensation expense $ 10,252 $ 8,915

Warrants (Tables)

Warrants (Tables)	3 Months Ended
Warrants (Tables)	Mar. 31, 2024
Warrants [Abstract]
Warrants Outstanding and Changes in Warrants to Purchase Common Stock	A summary of the warrants outstanding as of March 31, 2024 is as follows: Exercise Price Outstanding Grant/Assumption Date Expiration Date $ 57.11 603,386 December 21, 2020 December 21, 2030 33.63 301,291 August 9, 2021 August 9, 2031 22.51 153,155 December 17, 2021 December 17, 2031 22.51 153,155 December 17, 2021 December 17, 2031 65.23 617,050 December 1, 2022 April 23, 2025 65.23 760,086 December 1, 2022 December 1, 2026 $ 0.01 3,126,955 September 15, 2023 N/A Total 5,715,078 The following table is a summary of changes in warrants to purchase common stock for the three months ended March 31, 2024: Number of Warrant Shares Outstanding and Exercisable Exercise Price per Share Balance as of December 31, 2023 5,715,078 Issued - $ - Exercised - - Expired - $ - Balance as of March 31, 2024 5,715,078

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
Net Loss Per Share (Tables)	Mar. 31, 2024
Net Loss Per Share [Abstract]
Basic and Diluted Net Loss Per Share	Basic and diluted net loss per share attributable to common stockholders was calculated as follows: Three Months Ended March 31, 2024 2023 Numerator: Net loss attributable to common stockholders $ ( 62,054 ) $ ( 58,335 ) Denominator: Weighted-average common shares outstanding - basic and diluted 93,549,884 79,453,519 Net loss per share attributable to common stockholders - basic and diluted $ ( 0.66 ) $ ( 0.73 )
Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share	The Company excluded the following potential shares of common stock, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended March 31, 2024 2023 Warrants exercisable for common shares 2,588,123 2,595,174 Restricted stock units 1,740,745 1,622,457 Performance stock units 139,323 - Options to purchase common shares 15,923,806 14,651,390 Total potential shares excluded from diluted net loss per share 20,391,997 18,869,021

Leases (Tables)

Leases (Tables)	3 Months Ended
Leases (Tables)	Mar. 31, 2024
Leases [Abstract]
Lease Cost	The following table summarizes lease cost for the three months ended March 31, 2024 and 2023: Three Months Ended March 31, Lease cost 2024 2023 Operating lease cost $ 369 $ 358 Finance lease cost: Amortization of right of use assets 538 538 Interest on lease liabilities 471 468 Total lease cost $ 1,378 $ 1,364
Future Lease Payments of Operating Lease Liabilities	The following table summarizes the future lease payments of the Company’s operating and finance lease liabilities on an undiscounted cash flow basis : Fiscal Year Ending December 31, March 31, 2024 2024 (nine months) $ 815 2025 1,001 2026 1,005 2027 759 2028 522 Thereafter 2,420 Total lease payments $ 6,522 Less: interest ( 1,744 ) Total operating lease liabilities $ 4,778
Future Lease Payments of Finance Lease Liability	Fiscal Year Ending December 31, March 31, 2024 2024 (nine months) $ 1,348 2025 1,856 2026 1,911 2027 1,969 2028 2,028 Thereafter 41,003 Total lease payments $ 50,115 Less: interest ( 28,944 ) Total finance lease liability $ 21,171
Balance Sheet Information Related to Leases	The following table summarizes the operating and financing lease liabilities and right-of-use assets as of March 31, 2024 and December 31, 2023: Leases March 31, 2024 December 31, 2023 Operating right-of-use assets $ 4,768 $ 3,901 Operating current lease liabilities $ 1,064 $ 925 Operating noncurrent lease liabilities 3,714 2,973 Total operating lease liabilities $ 4,778 $ 3,898 Finance right-of-use assets $ 43,979 $ 44,517 Finance current lease liability $ 1,808 $ 1,791 Finance noncurrent lease liability 19,363 19,353 Total finance lease liability $ 21,171 $ 21,144
Lease Related to Cash Flow Information, Lease Term and Discount Rate	Three Months Ended March 31, Other Information 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 333 $ 261 Cash flows from finance lease $ 443 $ 431 Weighted-average remaining lease term - operating leases 7.1 years 8.2 years Weighted-average remaining lease term - finance lease 20.4 years 21.4 years Weighted-average discount rate - operating leases 8.82 % 8.08 % Weighted-average discount rate - finance lease 8.96 % 8.96 %

Nature of Business - Additional

Nature of Business - Additional Information (Details)	3 Months Ended
Nature of Business - Additional Information (Details)	Mar. 31, 2024 Program
LV Member
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of clinical-stage programs	3
AAV Member
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of clinical-stage programs	2
Number of pre clinical-stage programs	1

Risks and Liquidity - Additiona

Risks and Liquidity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended
	Sep. 15, 2023	Sep. 30, 2023	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Sep. 12, 2023	Feb. 28, 2022
Class of Stock [Line Items]
Accumulated deficit			$ (1,021,424)		$ (959,370)
Cash, cash equivalents and investments			330,300
Cash			$ 338,900
Shareholders' Equity Disclosure [Abstract]
Common stock, par value (in dollars per share)			$ 0.01		$ 0.01
Net proceeds from offering			$ 0	$ 17,222
Pre-Funded Warrants \| Common Stock
Shareholders' Equity Disclosure [Abstract]
Number of stock warrants issued to purchase shares	3,126,955
Warrant to purchase shares of common stock price per share (in dollars per share)	$ 0.01
Investments in Securities
Class of Stock [Line Items]
Cash, cash equivalents and investments			$ 8,600
At-the-Market Offering Program
Shareholders' Equity Disclosure [Abstract]
Common stock shares issued and sold (in shares)			0
At-the-Market Offering Program \| Cowen and Company, LLC
Shareholders' Equity Disclosure [Abstract]
Common stock, par value (in dollars per share)							$ 0.01
Common stock shares issued and sold (in shares)			4,200,000
Net proceeds from offering			$ 63,800
At-the-Market Offering Program \| Cowen and Company, LLC \| Common Stock
Shareholders' Equity Disclosure [Abstract]
Net proceeds from offering			$ 63,800
At-the-Market Offering Program \| Cowen and Company, LLC \| Maximum
Shareholders' Equity Disclosure [Abstract]
Aggregate offering price						$ 180,000	$ 200,000
Public Offering \| Pre-Funded Warrants \| Common Stock
Shareholders' Equity Disclosure [Abstract]
Number of stock warrants issued to purchase shares		3,100,000

Basis of Presentation, Princi_4

Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Cash, Cash Equivalents and Restricted Cash [Abstract]
Cash and cash equivalents	$ 35,276	$ 55,904
Restricted cash	1,362	1,372
Total cash, cash equivalents and restricted cash	$ 36,638	$ 57,276	$ 65,919	$ 141,857

Basis of Presentation, Princi_5

Basis of Presentation, Principles of Consolidation and Summary of Significant Accounting Policies - Investments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Investments [Abstract]
Net unrealized loss on credit investments	$ 0	$ 0
Net unrealized gains (losses) on investments	$ (454,000)	$ 267,000

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Measured on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets [Abstract]
Cash equivalents	$ 17,107	$ 53,224
Investments	295,037	351,591
Fair value of financial instruments	312,144	404,815
Liabilities [Abstract]
Total liabilities	765	1,876
Warrant Liability
Liabilities [Abstract]
Total liabilities	765	1,876
Money Market Mutual Funds
Assets [Abstract]
Cash equivalents	17,107	50,737
U.S. Treasury securities
Assets [Abstract]
Cash equivalents		2,487
Investments	273,846	312,696
Corporate Bonds
Assets [Abstract]
Investments	21,191	38,895
Level 1
Assets [Abstract]
Cash equivalents	17,107	50,737
Investments	0	0
Fair value of financial instruments	17,107	50,737
Liabilities [Abstract]
Total liabilities	0	0
Level 1 \| Warrant Liability
Liabilities [Abstract]
Total liabilities	0	0
Level 1 \| Money Market Mutual Funds
Assets [Abstract]
Cash equivalents	17,107	50,737
Level 1 \| U.S. Treasury securities
Assets [Abstract]
Cash equivalents		0
Investments	0	0
Level 1 \| Corporate Bonds
Assets [Abstract]
Investments	0	0
Level 2
Assets [Abstract]
Cash equivalents	0	2,487
Investments	295,037	351,591
Fair value of financial instruments	295,037	354,078
Liabilities [Abstract]
Total liabilities	0	0
Level 2 \| Warrant Liability
Liabilities [Abstract]
Total liabilities	0	0
Level 2 \| Money Market Mutual Funds
Assets [Abstract]
Cash equivalents	0	0
Level 2 \| U.S. Treasury securities
Assets [Abstract]
Cash equivalents		2,487
Investments	273,846	312,696
Level 2 \| Corporate Bonds
Assets [Abstract]
Investments	21,191	38,895
Level 3
Assets [Abstract]
Cash equivalents	0	0
Investments	0	0
Fair value of financial instruments	0	0
Liabilities [Abstract]
Total liabilities	765	1,876
Level 3 \| Warrant Liability
Liabilities [Abstract]
Total liabilities	765	1,876
Level 3 \| Money Market Mutual Funds
Assets [Abstract]
Cash equivalents	0	0
Level 3 \| U.S. Treasury securities
Assets [Abstract]
Cash equivalents		0
Investments	0	0
Level 3 \| Corporate Bonds
Assets [Abstract]
Investments	$ 0	$ 0

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Changes in Level 3 Liabilities Measured at Fair Value (Details) - Recurring - Level 3 - Warrant Liability $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Changes in Fair Value of Warrant Liabilities [Roll Forward]
Fair value, beginning of period	$ 1,876
Fair value adjustments	(1,111)
Fair value, end of period	$ 765

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Level 3 Fair Value of the Private Warrants (Details) - Private Warrants	Mar. 31, 2024 USD ($) $ / shares	Dec. 31, 2023 USD ($) $ / shares
Fair Value of the Private Warrants, Assumptions [Abstract]
Term	1 year 21 days	1 year 3 months 21 days
Fair value per warrant (in dollars per share) \| $ / shares	$ 1.24	$ 3.04
Stock Price
Fair Value of the Private Warrants, Assumptions [Abstract]
Measurement input	26.94	29.5
Exercise Price
Fair Value of the Private Warrants, Assumptions [Abstract]
Measurement input	65.23	65.23
Expected Volatility
Fair Value of the Private Warrants, Assumptions [Abstract]
Measurement input	63.34	68.83
Risk-Free Interest Rate
Fair Value of the Private Warrants, Assumptions [Abstract]
Measurement input	5.04	4.7
Expected Dividend Yield
Fair Value of the Private Warrants, Assumptions [Abstract]
Measurement input	0	0

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property and Equipment [Abstract]
Property and equipment, gross	$ 55,085	$ 53,204
Less: accumulated depreciation and amortization	(15,748)	(14,032)
Total property and equipment, net	39,337	39,172
Laboratory Equipment
Property and Equipment [Abstract]
Property and equipment, gross	30,777	29,232
Machinery and Equipment
Property and Equipment [Abstract]
Property and equipment, gross	12,508	12,325
Computer Equipment
Property and Equipment [Abstract]
Property and equipment, gross	244	244
Furniture and Fixtures
Property and Equipment [Abstract]
Property and equipment, gross	2,777	2,777
Leasehold Improvements
Property and Equipment [Abstract]
Property and equipment, gross	6,876	6,723
Internal use Software
Property and Equipment [Abstract]
Property and equipment, gross	$ 1,903	$ 1,903

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Property and Equipment, Net [Abstract]
Depreciation and amortization	$ 1.7	$ 1.1

Intangible Assets and Goodwil_2

Intangible Assets and Goodwill - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Intangible Assets, Net [Abstract]
Gross Carrying Value	$ 25,150	$ 25,150
Intangible assets, net	25,150	25,150
In Process Research & Development
Intangible Assets, Net [Abstract]
Gross Carrying Value	25,150	25,150
Intangible assets, net	$ 25,150	$ 25,150

Intangible Assets and Goodwil_3

Intangible Assets and Goodwill - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Indefinite-Lived Intangible Assets [Line Items]
Goodwill	$ 39,154	$ 39,154

Accounts Payable and Accrued _3

Accounts Payable and Accrued Expenses - Schedule of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accounts Payable and Accrued Expenses [Abstract]
Research and development	$ 15,216	$ 13,867
Investment payable	0	13,137
Employee compensation	4,192	9,930
Property and equipment	923	1,077
Professional fees	7,003	6,006
Other	2,751	1,772
Total accounts payable and accrued expenses	$ 30,085	$ 45,789

Accounts Payable and Accrued _4

Accounts Payable and Accrued Expenses - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accounts Payable and Accrued Expenses [Abstract]
Investment payable	$ 0	$ 13,137

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Sep. 12, 2023	Feb. 28, 2022
At-the-Market Offering Program [Abstract]
Net proceeds from offering	$ 0	$ 17,222
At-the-Market Offering Program
At-the-Market Offering Program [Abstract]
Issuance of common stock, net of issuance costs (in shares)	0
At-the-Market Offering Program \| Cowen and Company, LLC
At-the-Market Offering Program [Abstract]
Percentage of cash commission				3%
Issuance of common stock, net of issuance costs (in shares)	4,200,000
Gross proceeds, offering amount	$ 65,800
Commissions	2,000
Net proceeds from offering	63,800
At-the-Market Offering Program \| Cowen and Company, LLC \| Common Stock
At-the-Market Offering Program [Abstract]
Net proceeds from offering	$ 63,800
At-the-Market Offering Program \| Cowen and Company, LLC \| Maximum
At-the-Market Offering Program [Abstract]
Aggregate offering price			$ 180,000	$ 200,000

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted-Average Assumptions for Stock Options (Details) - Employees, Non-employees and Directors - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Weighted-Average Assumptions [Abstract]
Risk-free interest rate	5.16%	4.02%
Expected term	5 years 10 months 17 days	5 years 10 months 17 days
Expected volatility	73.62%	73.54%
Expected dividend yield	0%	0%
Exercise price (in dollars per share)	$ 29.46	$ 20.17
Fair value of common stock (in dollars per share)	$ 29.46	$ 20.17

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) - Employee Stock Option - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of period (in shares)	14,863,996
Granted (in shares)	1,174,939
Exercised (in shares)	(73,745)
Cancelled or forfeited (in shares)	(41,384)
Outstanding at end of period (in shares)	15,923,806	14,863,996
Options vested and exercisable at end of period (in shares)	12,351,611
Options unvested at ending of period (in shares)	3,572,195
Weighted Average Exercise Price [Abstract]
Outstanding at beginning of period (in dollars per share)	$ 15.07
Granted (in dollars per share)	29.46
Exercised (in dollars per share)	16.05
Cancelled or forfeited (in dollars per share)	18.18
Outstanding at end of period (in dollars per share)	16.12	$ 15.07
Options vested and exercisable at end of period (in dollars per share)	14.14
Options unvested at ending (in dollars per share)	$ 22.94
Weighted-Average Remaining Contractual Term [Abstract]
Outstanding	5 years 2 months 26 days	5 years 1 month 28 days
Granted	9 years 10 months 17 days
Options vested and exercisable	4 years 1 month 20 days
Options unvested	9 years 14 days
Aggregate Intrinsic Value [Abstract]
Outstanding at beginning of period	$ 250,602
Exercised	956
Outstanding at end of period	208,603	$ 250,602
Options vested and exercisable	190,665
Options unvested	$ 17,937

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value of shares granted (in dollars per share)	$ 19.92	$ 13.5
Total fair value of options vested	$ 11.5	$ 11.4
Stock Options Performance Stock Units and Restricted Stock Units Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	85.3
Stock Options and Restricted Stock Units Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 81.3
Weighted average period expected to recognize unrecognized share-based compensation cost	1 year 11 months 23 days

Stock-Based Compensation - RSU

Stock-Based Compensation - RSU Activity (Details) - Restricted Stock Units	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Number of Shares [Roll Forward]
Beginning balance (in shares) \| shares	1,490,357
Granted (in shares) \| shares	566,366
Vested (in shares) \| shares	(290,578)
Forfeited (in shares) \| shares	(25,400)
Ending balance (in shares) \| shares	1,740,745
Weighted Average Grant Date Fair Value [Abstract]
Beginning balance (in dollars per share) \| $ / shares	$ 18.53
Granted (in dollars per share) \| $ / shares	29.24
Vested (in dollars per share) \| $ / shares	19.38
Forfeited (in dollars per share) \| $ / shares	17.04
Ending balance (in dollars per share) \| $ / shares	$ 21.89

Stock-Based Compensation - PSU

Stock-Based Compensation - PSU Activity (Details) - Performance Stock Units	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Number of Shares [Roll Forward]
Beginning balance (in shares) \| shares	0
Granted (in shares) \| shares	139,323
Vested (in shares) \| shares	0
Forfeited (in shares) \| shares	0
Ending balance (in shares) \| shares	139,323
Weighted Average Grant Date Fair Value [Abstract]
Beginning balance (in dollars per share) \| $ / shares	$ 0
Granted (in dollars per share) \| $ / shares	28.71
Vested (in dollars per share) \| $ / shares	0
Forfeited (in dollars per share) \| $ / shares	0
Ending balance (in dollars per share) \| $ / shares	$ 28.71

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Stock-Based Compensation Expense [Abstract]
Total stock-based compensation expense	$ 10,252	$ 8,915
Research and Development
Stock-Based Compensation Expense [Abstract]
Total stock-based compensation expense	4,637	3,819
General and Administrative
Stock-Based Compensation Expense [Abstract]
Total stock-based compensation expense	5,615	5,096
Employee Stock Option
Stock-Based Compensation Expense [Abstract]
Total stock-based compensation expense	6,938	6,985
Restricted Stock Units
Stock-Based Compensation Expense [Abstract]
Total stock-based compensation expense	$ 3,314	$ 1,930

Warrants - Summary of Warrants

Warrants - Summary of Warrants Outstanding (Details)	3 Months Ended
Warrants - Summary of Warrants Outstanding (Details)	Mar. 31, 2024 $ / shares shares
Warrants [Abstract]
Outstanding (in shares)	5,715,078
57.11
Warrants [Abstract]
Exercise price per share (in dollars per share) \| $ / shares	$ 57.11
Outstanding (in shares)	603,386
Grant date	Dec. 21, 2020
Expiration date	Dec. 21, 2030
33.63
Warrants [Abstract]
Exercise price per share (in dollars per share) \| $ / shares	$ 33.63
Outstanding (in shares)	301,291
Grant date	Aug. 09, 2021
Expiration date	Aug. 09, 2031
22.51
Warrants [Abstract]
Exercise price per share (in dollars per share) \| $ / shares	$ 22.51
Outstanding (in shares)	153,155
Grant date	Dec. 17, 2021
Expiration date	Dec. 17, 2031
22.51
Warrants [Abstract]
Exercise price per share (in dollars per share) \| $ / shares	$ 22.51
Outstanding (in shares)	153,155
Grant date	Dec. 17, 2021
Expiration date	Dec. 17, 2031
65.23
Warrants [Abstract]
Exercise price per share (in dollars per share) \| $ / shares	$ 65.23
Outstanding (in shares)	617,050
Grant date	Dec. 01, 2022
Expiration date	Apr. 23, 2025
65.23
Warrants [Abstract]
Exercise price per share (in dollars per share) \| $ / shares	$ 65.23
Outstanding (in shares)	760,086
Grant date	Dec. 01, 2022
Expiration date	Dec. 01, 2026
0.01
Warrants [Abstract]
Exercise price per share (in dollars per share) \| $ / shares	$ 0.01
Outstanding (in shares)	3,126,955
Grant date	Sep. 15, 2023

Warrants - Summary of Changes i

Warrants - Summary of Changes in Warrants to Purchase Common Stock (Details) - Warrants	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Number of Warrant Shares Outstanding and Exercisable [Abstract]
Beginning balance (in shares)	5,715,078
Issued (in shares)	0
Exercised (in shares)	0
Expired (in shares)	0
Ending balance (in shares)	5,715,078
Exercise Price Per Share [Abstract]
Issued (in dollars per share) \| $ / shares	$ 0
Exercised (in dollars per share) \| $ / shares	0
Expired (in dollars per share) \| $ / shares	$ 0

Warrants - Additional Informati

Warrants - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 15, 2023	Mar. 31, 2024	Dec. 31, 2023
Warrants [Abstract]
Additional paid-in capital		$ 1,462,155	$ 1,450,722
Public Warrants
Warrants [Abstract]
Additional paid-in capital		$ 3,400
Public Warrants \| Common Stock
Warrants [Abstract]
Warrant to purchase shares of common stock (in shares)		760,086
Warrant to purchase shares of common stock price per share (in dollars per share)		$ 65.23
Private Warrants
Warrants [Abstract]
Warrant to purchase shares of common stock price per share (in dollars per share)		$ 1.24	$ 3.04
Private Warrants \| Common Stock
Warrants [Abstract]
Warrant to purchase shares of common stock (in shares)		617,050
Warrant to purchase shares of common stock price per share (in dollars per share)		$ 65.23
Pre-Funded Warrants \| Common Stock
Warrants [Abstract]
Number of stock warrants issued to purchase shares	3,126,955
Warrant to purchase shares of common stock price per share (in dollars per share)	$ 0.01

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Numerator [Abstract]
Net loss attributable to common stockholders	$ (62,054)	$ (58,335)
Denominator [Abstract]
Weighted-average common shares outstanding - basic (in shares)	93,549,884	79,453,519
Weighted-average common shares outstanding - diluted (in shares)	93,549,884	79,453,519
Net loss per share attributable to common stockholders - basic (in dollars per share)	$ (0.66)	$ (0.73)
Net loss per share attributable to common stockholders - diluted (in dollars per share)	$ (0.66)	$ (0.73)

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Details) - Pre-Funded Warrants [Member]	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential shares included in the calculation of EPS \| shares	3,126,955
Warrants exercise price per share \| $ / shares	$ 0.01

Net Loss Per Share - Antidiluti

Net Loss Per Share - Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Weighted Average Number of Shares Outstanding, Diluted, Adjustment [Abstract]
Warrants exercisable for common shares	2,588,123	2,595,174
Restricted stock units	1,740,745	1,622,457
Performance stock units	139,323	0
Options to purchase common shares	15,923,806	14,651,390
Total potential shares excluded from diluted net loss per share	20,391,997	18,869,021

Leases - Finance Lease - Additi

Leases - Finance Lease - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) ft² Leaseagreement	Dec. 31, 2023 USD ($)
Finance Lease [Abstract]
Total lease payments	$ 50,115
Cash security deposit	$ 533	$ 533
NJ Lease Agreement [Member]
Finance Lease [Abstract]
Area of lease \| ft²	103,720
Term of finance lease agreement	15 years
Number of options to renew lease agreement \| Leaseagreement	2
Term of renewal of finance lease agreement	5 years
Estimated rent payments	$ 1,200
Percentage of annual increase in base rent	3%
Total lease payments	$ 29,300
Cash security deposit	$ 300
AAV Current Good Manufacturing Practice (cGMP) [Member]
Finance Lease [Abstract]
Area of lease \| ft²	50,000

Leases - Operating Leases - Add

Leases - Operating Leases - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended
	Mar. 26, 2021	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Jun. 07, 2018
Operating Leases [Abstract]
Lease expiration date		Oct. 31, 2024
Total right-of-use asset		$ 4,768		$ 3,901
Total lease liabilities		3,714	$ 200	2,973
Operating lease cost		369	358
Rent expense under operating leases		600	$ 600
Restricted cash		1,362		1,372
Operating and Finance Leases [Member]
Operating Leases [Abstract]
Restricted cash		800		800
Renovacor, Inc. [Member]
Operating Leases [Abstract]
Rental income received under sublease agreements		$ 100
Remaining lease term		1 year 3 months 18 days
Total right-of-use asset		$ 3,800
Total lease liabilities		$ 3,600
Hopewell, New Jersey and Cambridge [Member] \| Renovacor, Inc. [Member]
Operating Leases [Abstract]
Remaining lease term		10 years 3 months 18 days
ESB Lease Agreement [Member]
Operating Leases [Abstract]
Term of lease agreement		3 years
Letter of credit					$ 800
Lease expiration date		Sep. 30, 2027
Certificate of deposit		$ 800		$ 800
ESB Lease Agreement Amendment [Member]
Operating Leases [Abstract]
Letter of credit		$ 800
Lease expiration date	Jun. 30, 2024

Leases - Leases Cost (Details)

Leases - Leases Cost (Details) - USD ($) $ in Thousands	3 Months Ended
Leases - Leases Cost (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Lease cost [Abstract]
Operating lease cost	$ 369	$ 358
Finance Lease Costs [Abstract]
Amortization of right of use assets	538	538
Interest on lease liabilities	471	468
Total lease cost	$ 1,378	$ 1,364

Leases - Future Lease Payments

Leases - Future Lease Payments of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Future Lease Payments of Operating Lease Liabilities [Abstract]
2024 (nine months)	$ 815
2025	1,001
2026	1,005
2027	759
2028	522
Thereafter	2,420
Total lease payments	6,522
Less: interest	(1,744)
Total operating lease liabilities	$ 4,778	$ 3,898

Leases - Future Lease Payment_2

Leases - Future Lease Payments of Finance Lease Liability (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Finance Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
2024 (nine months)	$ 1,348
2025	1,856
2026	1,911
2027	1,969
2028	2,028
Thereafter	41,003
Total lease payments	50,115
Less: interest	(28,944)
Total finance lease liability	$ 21,171	$ 21,144

Leases - Balance Sheet Informat

Leases - Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Lease assets and liabilities [Abstract]
Operating right-of-use assets	$ 4,768	$ 3,901
Operating current lease liabilities	1,064	925
Operating noncurrent lease liabilities	3,714	2,973	$ 200
Total operating lease liabilities	4,778	3,898
Finance right-of-use assets	43,979	44,517
Finance current lease liability	1,808	1,791
Finance noncurrent lease liability	19,363	19,353
Total finance lease liability	$ 21,171	$ 21,144

Leases - Lease Related to Cash

Leases - Lease Related to Cash Flow Information, Lease Term and Discount Rate (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash Flow, Operating and Financing Activities, Lessee [Abstract]
Operating cash flows from operating leases	$ 333	$ 261
Cash flows from finance lease	$ 443	$ 431
Weighted-average remaining lease term - operating leases	7 years 1 month 6 days	8 years 2 months 12 days
Weighted-average remaining lease term - finance lease	20 years 4 months 24 days	21 years 4 months 24 days
Weighted-average discount rate - operating leases	8.82%	8.08%
Weighted-average discount rate - finance lease	8.96%	8.96%

CIRM Grants - Additional Inform

CIRM Grants - Additional Information (Details) - LAD-1 CIRM Grant - USD ($)	Mar. 31, 2024	Jan. 02, 2024	Apr. 30, 2019
CIRM Grants [Abstract]
Grant award for clinical development support			$ 7,500,000
Milestone payments received	$ 5,900,000	$ 50,000
Additional payments available under grant awards program	$ 0

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended
	Sep. 15, 2023	Sep. 30, 2023	Mar. 31, 2024
Related Party Transaction [Abstract]
Related party expenses			$ 2
Common Stock \| Pre-Funded Warrants
Related Party Transaction [Abstract]
Number of stock warrants issued to purchase shares	3,126,955
Public Offering \| Common Stock \| Pre-Funded Warrants
Related Party Transaction [Abstract]
Number of stock warrants issued to purchase shares		3,100,000

401(k) Savings Plan - Additiona

401(k) Savings Plan - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
401(k) Savings Plan [Abstract]
Percentage of matching employee contributions	4%
Matching employee contributions	$ 0.4	$ 0.3