Eiger BioPharmaceuticals (EIGRQ) 10-K 8 Apr 24 2023 FY Annual report Financial data

Cover

Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Apr. 04, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-36183
Entity Registrant Name	Eiger BioPharmaceuticals, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0971591
Entity Address, Address Line One	2155 Park Boulevard
Entity Address, City or Town	Palo Alto
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94306
City Area Code	650
Local Phone Number	272 6138
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	EIGR
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 30
Entity Common Stock, Shares Outstanding		1,480,797
Documents Incorporated by Reference	Part III incorporates certain information by reference from the registrant’s proxy statement for the 2024 Annual Meeting of Shareholders or an amendment to this Form 10-K to be filed no later than 120 days after the close of the registrant’s fiscal year ended December 31, 2023.
Amendment Flag	false
Document Fiscal Period Focus	FY
Entity Central Index Key	0001305253
Document Fiscal Year Focus	2023

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2023
Audit Information [Abstract]
Auditor Firm ID	185
Auditor Name	KPMG LLP
Auditor Location	San Francisco, CA

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	[1]	$ 25,440	$ 25,798
Short-term debt securities	[1]	0	73,150
Accounts receivable, net	[1]	1,682	1,749
Inventories, net	[1]	1,556	2,853
Prepaid expenses and other current assets	[1]	9,161	13,985
Total current assets	[1]	37,839	117,535
Property and equipment, net	[1]	627	696
Other assets	[1]	360	1,908
Total assets	[1]	38,826	120,139
Current liabilities:
Accounts payable	[1]	2,115	8,975
Accrued liabilities	[1]	9,966	15,655
Current portion of operating lease liabilities	[1]	84	491
Current portion of long-term debt	[1]	41,119	0
Total current liabilities	[1]	53,284	25,121
Debt, net	[1]	0	39,625
Operating lease liabilities	[1]	0	83
Total liabilities	[1]	53,284	64,829
Commitments and contingencies (Note 12)	[1]
Stockholders’ (deficit) equity:
Common stock, $0.001 par value, 200,000,000 shares authorized as of December 31, 2023 and 2022; 1,479,483 and 1,469,149 shares issued and outstanding as of December 31, 2023 and 2022, respectively	[1]	1	1
Additional paid-in capital	[1]	497,866	492,802
Accumulated other comprehensive loss	[1]	(169)	(300)
Accumulated deficit	[1]	(512,156)	(437,193)
Total stockholders’ (deficit) equity	[1],[2]	(14,458)	55,310
Total liabilities and stockholders’ (deficit) equity	[1]	$ 38,826	$ 120,139
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information. for further information

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($)		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022
Revenues [Abstract]
Total revenue	[1]	$ 15,773,000		$ 13,484,000
Costs and operating expenses:
Cost of sales	[1]	24,000		1,837,000
Research and development	[1]	62,331,000		75,282,000
Selling, general and administrative	[1]	25,204,000		29,105,000
Total costs and operating expenses	[1]	87,559,000		106,224,000
Loss from operations	[1]	(71,786,000)		(92,740,000)
Interest expense	[1]	(5,466,000)		(4,132,000)
Interest income	[1]	2,208,000		1,082,000
Other (expense) income, net	[1]	87,000		(963,000)
Loss before provision for income taxes	[1]	(74,957,000)		(96,753,000)
Provision for income taxes	[1]	6,000		23,000
Net loss		$ (74,963,000)	[1]	$ (96,776,000)	[2]
Net loss per common share:
Basic (in USD per share)	[1]	$ (50.78)		$ (69.74)
Diluted (in USD per share)	[1]	$ (50.78)		$ (69.74)
Weighted-average common shares outstanding:
Basic (in shares)	[1]	1,476,247		1,387,632
Diluted (in shares)	[1]	1,476,247		1,387,632
Product revenue, net
Revenues [Abstract]
Total revenue	[1]	$ 15,523,000		$ 12,734,000
Other revenue
Revenues [Abstract]
Total revenue	[1]	$ 250,000		$ 750,000
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information for further information

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net loss		$ (74,963)	[1]	$ (96,776)	[2]
Other comprehensive loss:
Unrealized gain (loss) on available-for-sale debt securities, net	[2]	200		(51)
Foreign currency translation adjustment	[2]	(69)		(100)
Comprehensive loss		$ (74,832)		$ (96,927)
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information for further information

Consolidated Statements of Stoc

Consolidated Statements of Stockholders’ (Deficit) Equity - USD ($) $ in Thousands		Total		Common Stock		Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance, beginning of period (in shares) at Dec. 31, 2021	[1]			1,152,350
Balance, beginning of period at Dec. 31, 2021	[1]	$ 72,399		$ 1		$ 412,964	$ (149)	$ (340,417)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon offering at-the-market, net of issuance costs (in shares)	[1]			284,262
Issuance of common stock upon offering at-the-market, net of $2,068 of issuance costs	[1]	66,110				66,110
Issuance of common stock upon stock option exercise (in shares)	[1]			1,573
Issuance of common stock upon exercise of stock options	[1]	234				234
Issuance of common stock to lender (in shares)	[1]			24,967
Issuance of common stock to lender	[1]	5,000				5,000
Vesting of common stock issued under Product Development Agreement	[1]	19				19
Issuance of common stock upon ESPP purchase (in shares)	[1]			1,594
Issuance of common stock upon ESPP purchase	[1]	158				158
Issuance of common stock upon release of restricted stock units (in shares)	[1]			4,403
Stock-based compensation expense	[1]	8,317				8,317
Unrealized (loss) gain on available-for-sale debt securities, net	[1]	(51)					(51)
Cumulative translation adjustment	[1]	(100)					(100)
Net loss	[1]	$ (96,776)						(96,776)
Balance, end of period (in shares) at Dec. 31, 2022		1,469,149		1,469,149	[1]
Balance, end of period at Dec. 31, 2022	[1]	$ 55,310	[2]	$ 1		492,802	(300)	(437,193)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon ESPP purchase (in shares)	[1]			1,709
Issuance of common stock upon ESPP purchase	[1]	56				56
Issuance of common stock upon release of restricted stock units and performance stock units (in shares)	[1]			8,625
Stock-based compensation expense	[1]	5,008				5,008
Unrealized (loss) gain on available-for-sale debt securities, net	[1]	200					200
Cumulative translation adjustment	[1]	(69)					(69)
Net loss		$ (74,963)	[3]					(74,963)	[1]
Balance, end of period (in shares) at Dec. 31, 2023		1,479,483		1,479,483	[1]
Balance, end of period at Dec. 31, 2023	[1]	$ (14,458)	[2]	$ 1		$ 497,866	$ (169)	$ (512,156)
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information for further information. for further information

Consolidated Statements of St_2

Consolidated Statements of Stockholders’ (Deficit) Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Statement of Stockholders' Equity [Abstract]
Stock issuance costs	$ 2,068

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023		Dec. 31, 2022
Operating activities
Net loss	$ (74,963)	[1]	$ (96,776)	[2]
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	275		292
Inventory write down	8		1,043
Net amortization of premiums and accretion of discounts on investments	(1,112)		682
Loss on extinguishment of debt	0		1,144
Non-cash interest expense	1,494		1,238
Reduction in the carrying amount of right-of-use assets	475		550
Common stock issued under Product Development Agreement	0		19
Stock-based compensation	5,008		8,317
Change in operating assets and liabilities:
Accounts receivable	84		828
Inventories	1,626		(1,367)
Prepaid expenses and other current assets	4,169		(196)
Other assets	1,857		(1,265)
Accounts payable	(6,835)		1,152
Accrued liabilities	(6,145)		1,957
Operating lease liabilities	(489)		(628)
Net cash used in operating activities	(74,548)		(83,010)
Investing activities
Purchase of debt securities available-for-sale	(19,388)		(75,101)
Proceeds from maturities of debt securities available-for-sale	93,850		85,073
Purchase of property and equipment	(234)		(340)
Net cash provided by investing activities	74,228		9,632
Financing activities
Issuance of common stock upon offering at-the-market, net of commissions	0		66,402
Proceeds from issuance of common stock to lender	0		5,000
Proceeds from debt	0		39,841
Repayment of debt	0		(33,277)
Proceeds from issuance of common stock upon stock option exercises	0		234
Proceeds from issuance of common stock upon ESPP purchase	56		157
Payment of debt issuance costs	0		(1,116)
Common stock offering costs	(15)		(286)
Net cash provided by financing activities	41		76,955
Effect of foreign exchange on cash and cash equivalents	(79)		0
Net (decrease) increase in cash and cash equivalents	(358)		3,577
Cash and cash equivalents at beginning of the year	25,798		22,221
Cash and cash equivalents at end of the year	25,440		25,798
Supplemental disclosure of cash flow information:
Interest paid	3,972		2,885
Income taxes paid	269		64
Property and equipment purchases included in accounts payable and accrued liabilities	7		36
Common stock offering costs included in accounts payable and accrued liabilities	135		6
Right-of-use assets obtained in exchange for lease liabilities	$ 0		$ 458
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information for further information

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical)	Dec. 31, 2023 $ / shares shares	Dec. 31, 2022 $ / shares shares
Statement of Financial Position [Abstract]
Common stock, par value (in USD per share) | $ / shares	$ 0.001	$ 0.001
Common Stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, issued (in shares)	1,479,483	1,469,149
Common stock, outstanding (in shares)	1,479,483	1,469,149

Consolidated Statements of Op_2

Consolidated Statements of Operations (Parenthetical)	Jan. 05, 2024
Subsequent Event
Reverse stock split, conversion ratio	0.0333

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Eiger BioPharmaceuticals, Inc. (the Company or Eiger) was incorporated in the State of Delaware on November 6, 2008. Eiger is a commercial-stage biopharmaceutical company focused on the development of innovative therapies for rare metabolic diseases. Eiger’s lead product candidate, avexitide, is a well-characterized, first-in-class glucagon-like peptide-1 ( GLP-1) antagonist and is in development for the treatment of post-bariatric hypoglycemia (PBH) and other forms of hyperinsulinemic hypoglycemia (HH) arising after gastrointestinal surgeries. These disorders are characterized by exaggerated secretion of GLP-1 after meals, dysregulated secretion of insulin, followed by a rapid drop in blood sugar. Avexitide is the only drug in development for PBH with Breakthrough Therapy designation by the U.S. Food and Drug Administration (FDA). Avexitide is also in development for congenital hyperinsulinism (HI), an ultra-rare, life-threatening, pediatric disorder of persistent hypoglycemia that results in irreversible brain damage in up to 50% of children with the condition. Avexitide has completed Phase 2 for both PBH and HI, and Phase 3 study start-up activities for PBH and HI were initiated. However further Phase 3 activities have been paused until additional funding is secured. The FDA approved the Company’s first commercial product, Zokinvy ® (lonafarnib), to reduce risk of mortality of Hutchinson-Gilford progeria syndrome (HGPS) and for treatment of processing-deficient progeroid laminopathies (PL), with either heterozygous LMNA mutation with progerin-like protein accumulation, or homozygous or compound heterozygous ZMPSTE24 mutations, on November 20, 2020. Collectively known as progeria, HGPS and PL are ultra-rare, fatal, genetic premature aging diseases that accelerate mortality in young patients. In July 2022, the Company announced that the European Commission (EC) granted marketing authorization (MA) under exceptional circumstances for Zokinvy through the centralized procedure. The EC's MA is valid in all 27 European Union (EU) member states plus Iceland, Liechtenstein, and Norway. In May 2022, the Pharmaceutical Division at the Ministry of Health of Israel granted regulatory approval for Zokinvy in Israel. In August 2022, the Medicine and Healthcare products Regulatory Agency (MHRA) granted approval in the UK. The Company commercially launched Zokinvy in the U.S. in January 2021 and started to recognize product revenue in the first quarter of 2021. The first European sales were recognized in the fourth quarter of 2022. In June 2023, the Company announced that it is focusing its clinical development efforts on advancing avexitide in HH indications, including PBH. The Company will continue to commercialize Zokinvy (lonafarnib) for the treatment of HGPS and processing-deficient PL. In addition, Eiger is evaluating strategic partnering options for its virology assets, lonafarnib and peginterferon lambda. In June 2023, the Company also announced that it has appointed David Apelian, MD, PhD, MBA, who has served as interim Chief Executive Officer (CEO) since December 2022, as the Company's next CEO. The Company’s principal operations are based in Palo Alto, California, with subsidiaries in Delaware, Ireland, England and Wales. The Company operates in one segment. Reverse Stock Split In January 2024, following approval by the Company’s stockholders at a special meeting of stockholders held in December 2023, the Company's board of directors approved a certificate of amendment to the Company’s amended and restated certificate of incorporation to effect a reverse split of shares of the Company’s common stock on a 1-for-30 basis, which was effected on January 5, 2024. All share data and per share data amounts for all periods presented in the consolidated financial statements and notes thereto have been retrospectively adjusted to reflect the effect of the Reverse Stock Split. Liquidity As previously reported in the Company's Current Report on Form 8-K, filed with the U.S. Securities and Exchange Commission on April 1, 2024, and as discussed in Note 13, the Company and its wholly owned subsidiaries commenced voluntary proceedings under Chapter 11 of the United States Bankruptcy Code. See Note 13 for additional details. The Company expects to be delisted from Nasdaq on April 11, 2024, which will have a negative impact on the Company's ability to raise capital. As of December 31, 2023, the Company had $25.4 million of cash and cash equivalents. The Company had an accumulated deficit of $512.2 million and negative cash flows from operating activities as of December 31, 2023. As the Company continues to incur losses, its transition to profitability will depend on the successful development, approval, and commercialization of product candidates and on the achievement of sufficient revenues to support its cost structure. The Company may never achieve profitability, and until it does, the Company will need to continue to raise additional capital. Based on its recurring losses from operations incurred since inception, expectation of continuing operating losses and negative cash flows for the foreseeable future, need to raise additional capital to finance its future operations, and given the current cash, cash equivalents and short-term securities balance, the Company has concluded that there is substantial doubt regarding the Company’s ability to continue as a going concern beyond twelve months after the date that these consolidated financial statements are issued, which was a principal reason for our decision to seek bankruptcy protection under Chapter 11.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The consolidated financial statements include the accounts of Eiger BioPharmaceuticals, Inc. and its wholly owned subsidiaries, EBPI Merger Inc., EB Pharma LLC, Eiger BioPharmaceuticals Europe Limited, and EigerBio Europe Limited, have been prepared in accordance with accounting principles generally accepted in the United States of America, (U.S. GAAP) and follow the requirements of the Securities and Exchange Commission (SEC) for annual reporting. All intercompany balances and transactions have been eliminated in consolidation. Use of Estimates The preparation of 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 revenue and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates including, but not limited to, those related to the estimated useful lives of long-lived assets, clinical trial accruals, fair value of assets and liabilities, fair value of investments, and stock-based compensation. The Company bases its estimates on historical experience and on various other market-specific and relevant assumptions that the Company believes to be reasonable under the circumstances. Actual results could differ from those estimates. Concentrations of Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents and investments. The Company’s cash is held by financial institutions in the United States and Ireland. Amounts on deposit may at times exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents and investments and issuers of investments. The Company manages its credit risk by holding its cash, cash equivalents and investments in large financial institutions within the U.S. and Ireland. In addition, the Company’s investment policy limits investments to certain types of instruments such as money market funds, debt securities issued by the U.S. government and its agencies, corporate debt securities, commercial paper as well as asset-backed securities, and places restrictions on the credit ratings, maturities and concentration by type and issuer. The Company has not experienced any losses on its deposits of cash, cash equivalents and investments. The Company relies on one supply chain for each of its product candidates. If any of the single source suppliers in any of the supply chains fail to satisfy the Company’s requirements on a timely basis, the Company could suffer delays in its clinical development programs and activities which could adversely affect its operating results. Three customers accounted for approximately 48 percent, 37 percent and 15 percent of the Company’s accounts receivable as of December 31, 2023. Two customers accounted for approximately 73 percent and 26 percent of product revenue during the year ended December 31, 2023. Two customers accounted for approximately 58 percent and 42 percent of the Company’s accounts receivable as of December 31, 2022. One customer accounted for approximately 93 percent of product revenue during the year ended December 31, 2022. Foreign Currency Exchange Foreign Currency Transaction Risk The foreign currency transaction risk relates to changes in exchange rates on monetary assets, liabilities, revenues and expenses held at Eiger BioPharmaceuticals Europe Limited . Gains and losses on foreign currency transactions result primarily from monetary assets, liabilities, revenues and expenses denominated in Euro. Aggregated transaction gains for were $0.1 million for the years ended December 31, 2023 and 2022. The Company expects the foreign currency gain/loss to continue to fluctuate as long as the Company continues to hold monetary assets and liabilities at its subsidiaries in Ireland, England and Wales. Market uncertainty could potentially lead to significant volatility with foreign currency exchange rates, which could result in additional foreign currency gain/loss. Foreign Currency Translation Risk The foreign currency translation risk relates to the translation of the foreign consolidated subsidiaries' assets, liabilities, revenues and expenses from the subsidiaries’ functional currency to the U.S. dollar at each reporting date. Fluctuations in exchange rates may impact the amount of assets, liabilities, revenues and expenses reported on the consolidated balance sheets and consolidated statements of operations. The financial statements of the Company’s foreign subsidiaries, which have a functional currency other than the U.S. dollar, are translated into U.S. dollars using a current exchange rate. Gains and losses resulting from this translation are recognized as a foreign currency translation adjustment within accumulated other comprehensive loss, which is a component of stockholders' (deficit) equity and comprehensive loss. Aggregate translation losses, net of tax, were $0.1 million for the years ended December 31, 2023 and 2022. Cash and Cash Equivalents Cash and cash equivalents include all cash balances and highly liquid investments with original maturities of three months or less from the date of purchase. Cash equivalents consists primarily of amounts invested in money market funds held at financial institutions and corporate debt securities. The recorded carrying amount of cash equivalents approximates their fair value. Debt Securities All securities are short-term in nature and consist of debt securities classified as available-for-sale and have maturities greater than 90 days, but less than 365 days from the date of acquisition. The Company’s debt securities consist of available-for-sale securities that are classified as Level 2 because their value is based on valuations using significant inputs derived from, or corroborated by, observable market data. The Company evaluates, on a quarterly basis, its available-for-sale debt securities for potential impairment. For available-for-sale debt securities in an unrealized loss position, the Company assesses whether such declines are due to credit related factors such as changes to the rating of the security by a ratings agency, market conditions and supportable forecasts of economic and market conditions, among others. If the fair value of available-for-sale debt securities is less than the amortized cost basis, the Company assesses whether it has plans to sell the security or it is more likely than not it will be required to sell any available-for-sale debt security before recovery of its amortized cost basis. If either condition is met, the security’s amortized cost basis is written down to fair value and is recognized through other (expense) income, net. If neither condition is met, declines as a result of credit losses, if any, are recognized as an allowance for credit loss, limited to the amount of unrealized loss, through other (expense) income, net. Any portion of the unrealized loss that is not a result of a credit loss, is recognized in other comprehensive loss. The cost of available-for-sale securities sold is based on the specific-identification method . Realized gains and losses on the sale of debt securities are determined using the specific-identification method and recorded in other (expense) income, net. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Depreciation expense is computed using the straight-line method over the estimated useful lives of the assets. Depreciation begins at the time the asset is placed into service. Maintenance and repairs are charged to operations as incurred. Property and equipment purchased for specific research and development projects with no alternative uses are expensed as incurred. The useful lives of the property and equipment are as follows: Lab equipment 5 years Furniture 5 years Leasehold improvements Shorter of remaining lease term or 5 years Computer equipment and software 3 years Impairment of Long-Lived Assets The Company evaluates its long-lived assets, including property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. The Company assesses the recoverability of long-lived assets by determining whether or not the carrying value of such assets will be recovered through undiscounted expected future cash flows. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. Through December 31, 2023, the Company has not impaired any long-lived assets. Accounts Receivable Accounts receivable represent amounts billed to the Company’s customers, net of an allowance for credit losses. Trade accounts receivable are recorded at invoiced amounts and do not bear interest. The allowance for credit losses reflects the Company’s best estimate of probable losses inherent in the receivable portfolio determined based on various factors, including age of the outstanding invoice, credit quality of the customer, historical experience, current economic conditions, and management’s expectations of future economic conditions. The Company regularly reviews the adequacy of the allowance for credit losses by considering the age of each outstanding invoice and the collection history of each customer to determine the appropriate amount of allowance for credit losses. The Company had no allowance as of December 31, 2023 and 2022. The Company had no credit losses for the years ended December 31, 2023 and 2022. Inventories Inventories are stated at the lower of cost, determined based on actual costs, or estimated net realizable value, on a first-in, first-out basis. Inventories consist of raw materials, work-in-process, and finished goods. Prior to regulatory approval of the Company’s product candidates, expenses incurred to manufacture drug products are recorded as research and development expense. The Company begins capitalizing these expenses as inventory upon regulatory approval. The Company periodically assesses the recoverability of its inventory and reduces the carrying value of the inventory when items are determined to be obsolete, defective or in excess of forecasted sales requirements. Inventory write-downs for excess, defective, and obsolete inventory are recorded as a cost of sales. The Company wrote-down $8,000 and $1.0 million of inventories for the years ended December 31, 2023 and 2022, respectively. Revenue Recognition The Company recognizes revenue upon transfer of control of promised products to customers in an amount that reflects the consideration it expects to receive in exchange for those products. To determine revenue recognition for contracts with customers, the Company performs the following five-step approach: (i) identify the contract, or contracts, with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when, or as, the performance obligation is satisfied. The five-step model is only applied to contracts when it is probable that the Company will collect substantially all of the consideration it is entitled to in exchange for the goods transferred to a customer. Product Revenue The Company’s product revenue consists of sales of Zokinvy, which received FDA approval in November 2020 and was launched commercially in the United States in January 2021 and in Europe in November 2022. Prior to 2021, the Company had no product revenue. In the United States, the Company sells Zokinvy to a single specialty pharmacy provider that subsequently dispenses the product directly to patients. The Company discloses revenue on a total basis without further disaggregation. Additionally, the Company does not have any contract assets or liabilities, other than accounts receivable, related to its product revenue. In June 2021, the French National Agency for Medicines and Health Products Safety (ANSM) granted Zokinvy (lonafarnib) a Temporary Authorizations for Use (Autorisation Temporaire d'Utilisation or ATU) for an early access program for a term of one year. The Company has received a one year extension of the ATU program and expects the program to continue until commercial reimbursement of Zokinvy is approved in France. In the context of this program, the Company sells product to a distributor who in turn ships product to pharmacies after receiving requests from physicians for patients in France. In November 2021, the Company began distributing and recognizing revenue from sales of Zokinvy (lonafarnib) through a reimbursed early access program in France. The Company recorded revenue of $2.4 million and $0.2 million from sales of product under the ATU program for the years ended December 31, 2023 and 2022, respectively. The Company recognizes product revenue when a customer obtains control of its product, which occurs at a point in time, typically upon delivery to a customer as the delivery of the product is the Company’s only performance obligation. Shipping and handling activities are fulfillment activities rather than a separate performance obligation and are recorded in cost of sales. Product revenue is recorded at the net sales price (transaction price), which includes estimates of variable consideration resulting from rebates, prompt payment discounts, co-payment assistance, and returns. Amounts related to such items are estimated at contract inception and updated at the end of each reporting period as additional information becomes available. The amount of variable consideration may be constrained and is included in the transaction price only to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Product revenue is recorded after considering the impact of the following variable consideration amounts along with the constraint at the time of revenue recognition: Rebates: The Company’s product is subject to government mandated rebates for Medicaid Drug Rebate Program, Medicare Part D Prescription Drug Benefit Program, and other government health care programs in the United States. Rebate amounts are based upon contractual agreements or legal requirements with public sector benefit providers. The Company uses the expected-value method for estimating these rebates based on statutory discount rates and expected utilization. The expected utilization of rebates is estimated based on expected coverage of identified patients. Estimates for these rebates are adjusted quarterly to reflect the most recent information. The Company records an accrued liability for unpaid rebates related to products for which control has been transferred to a customer. Prompt payment discounts: The Company provides a discount to a customer if it pays for purchases within 30 days. The Company expects that its customers will earn prompt payment discounts and uses the most likely amount method for estimating such discounts. As a result, when revenues are recognized, the Company deducts the full amount of the prompt payment discounts from total product revenues and records these discounts as a reduction of accounts receivable. Co-payment assistance: The Company provides co-payment assistance to patients who have commercial insurance and meet certain eligibility requirements. The Company uses the expected-value method for estimating co-payment assistance based on estimates of program redemption using data provided by third-party administrators. Estimates for the co-payment assistance are adjusted quarterly to reflect actual experience. The Company records an accrued liability for unredeemed co-payment assistance related to products for which control has been transferred to a customer. Product returns: The Company offers limited product return rights and generally allows for the return of product that is damaged or defective, or within a few months prior to and up to a few months after the product expiration date. The Company considers several factors in the estimation of potential product returns, including expiration dates of the product shipped, the limited product return rights, third-party data in monitoring channel inventory levels, shelf life of the product, and other relevant factors. Other Revenue Other revenue consists of milestone payments from the Marketing and Distribution Agreement (MDA) with AnGes, Inc., which was executed in May 2022. The MDA provides AnGes with a right to use the Company's intellectual property (IP) and seek regulatory approval for and commercialization of Zokinvy in Japan. The Company will receive additional payments upon achievement of certain regulatory milestones. Cost of Sales Cost of sales consists primarily of direct and indirect costs related to the manufacturing of Zokinvy for commercial sale, including third-party manufacturing costs, packaging services, freight, storage costs, and write down of inventories. Accrued Research and Development Costs The Company accrues for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of preclinical and clinical studies, and contract manufacturing activities. The Company records the estimated costs of research and development activities based upon the estimated amount of services provided but not yet invoiced and includes these costs in accrued liabilities in the accompanying consolidated balance sheets and within research and development expenses in the accompanying consolidated statements of operations. The Company accrues for these costs based on factors such as estimates of the work completed made by its internal personnel and third-party service providers and in accordance with agreements established with its third-party service providers. The Company makes judgments and estimates in determining the accrued liabilities balance in each reporting period and although the Company does not expect its estimate to be materially different from amounts actually incurred, as actual costs become known the Company adjusts its accrued liabilities. Leases The Company determines if an arrangement is or contains a lease at inception. Material leases with a term greater than one year are recognized in right-of-use assets and current and noncurrent lease liabilities, as applicable, in the Company’s consolidated balance sheets. The Company had a real estate lease for its office space in Palo Alto, California that expired on February 28, 2024. In February 2024, the Company amended the lease to extend the lease term for an additional month from March 1, 2024 to April 1, 2024 with a month to month renew option. The Company determines the initial classification and measurement of its right-of-use assets (ROU assets) and lease liabilities at the lease commencement date and thereafter if modified. The lease term includes any renewal options and termination options that the Company is reasonably assured to exercise. The present value of lease payments is determined by using the interest rate implicit in the lease, if that rate is readily determinable; otherwise, the Company uses its incremental borrowing rate. The incremental borrowing rate is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment. Rent expense for operating leases is recognized on a straight-line basis, unless the operating lease ROU assets have been impaired, over the reasonably assured lease term based on the total lease payments and is included in operating expenses in the consolidated statements of operations. For operating leases that reflect impairment, the Company will recognize the amortization of the operating lease ROU assets on a straight-line basis over the remaining lease term with rent expense still included in selling, general and administrative expenses in the consolidated statements of operations. The Company has elected the practical expedient to not separate lease and non-lease components. The Company’s non-lease components are primarily related to property maintenance and insurance, which varies based on future outcomes, and thus is recognized in selling, general and administrative expenses when incurred. Debt Issuance Costs Financing costs incurred with securing a term debt are recorded in the Company’s consolidated balance sheets as an offset to the term debt and amortized to interest expense in the Company’s consolidated statements of operations over the contractual life of the loan using the effective interest method. Research and Development Costs Research and development costs are expensed as incurred and consist of payroll expenses, stock-based compensation expense, lab supplies and allocated facility costs, as well as fees paid to third parties that conduct certain research and development and manufacturing activities on the Company’s behalf. Amounts incurred in connection with license and asset purchase agreements are also included in research and development expenses. Manufacturing costs related to products undergoing regulatory approval are expensed as research and development costs until receipt of such approval. Non-refundable advance payments for research and development activities to be received or incurred in the future are deferred and recorded in prepaid expenses and other current assets. The prepaid amounts are expensed as the related services are performed or goods are delivered. Stock-Based Compensation Stock-based awards to employees and directors, including stock options, are recorded at fair value as of the grant date using the Black-Scholes option pricing model and recognized as expense on a straight line-basis over the employee’s or director’s requisite service period (generally the vesting period). Stock-based awards to non-employees are recorded at their fair value as of the grant date, using the Black-Scholes option pricing model and recognized as expense over the period in which the related services are received. The determination of fair value for stock-based awards on the date of grant using an option pricing model requires management to make certain assumptions for Black-Scholes option pricing model inputs. The Company accounts for forfeitures of stock-based awards when they occur. Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company must then assess the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. Due to the Company’s lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on their technical merits, as the largest amount of benefit that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to unrecognized tax benefits. Internal Revenue Code Section 382 limits the use of net operating loss and tax credit carryforwards in certain situations where changes occur in the stock ownership of a company. In the event that the Company experiences a change of ownership, utilization of the net operating loss and tax credit carryforwards may be restricted. Comprehensive Loss Comprehensive loss represents all changes in stockholders' (deficit) equity except those resulting from and distributions to stockholders. The Company’s unrealized gains and losses on debt securities and foreign currency translation adjustments represent the components of other comprehensive loss that are excluded from the reported net loss and that are presented in the consolidated statements of comprehensive loss. Net Loss per Share Basic net loss per share of common stock is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Since the Company was in a loss position for all periods presented, diluted net loss per share is the same as basic net loss per share for all periods as the inclusion of all potential common shares outstanding would have been anti-dilutive. The following table sets forth the outstanding potentially dilutive securities which have been excluded in the calculation of diluted net loss per share because including such securities would be anti-dilutive (in common stock equivalent shares): December 31, 2023 2022 Options to purchase common stock 180,151 204,656 ESPP 12,839 11,121 Restricted stock units (unvested) 5,998 21,337 Total 198,988 237,114 Recent Adopted Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Updates (ASU) No. 2016-13, Financial Instruments—Credit Losses (Topic 326) . ASU 2016-13 requires an entity to utilize a new impairment model that requires measurement and recognition of expected credit losses for most financial assets and certain other instruments, including but not limited to available-for-sale debt securities. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down to the security. The new guidance requires the use of forward-looking expected credit loss models based on historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount, which may result in earlier recognition of credit losses under the new guidance. In April 2019, the FASB issued ASU No. 2019-04, Codification Improvements to Topic 326, Financial Instruments – Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments, which clarifies and corrects certain unintended applications of the guidance contained in each of the amended Topics. Additionally, in May 2019, the FASB issued ASU No. 2019-05, Financial Instruments – Credit Losses (Topic 326), which provides an option to irrevocably elect to measure certain individual financial assets at fair value instead of amortized cost. In November 2019, the FASB issued ASU No. 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842) , which deferred the effective date for ASU No. 2016-13 for smaller reporting companies to fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. The Company adopted this guidance on a modified-retrospective basis effective January 1, 2023 and noted no material impact to the Company’s consolidated financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which requires an enhanced disclosure of significant segment expenses on an annual and interim basis. This guidance will be effective for the annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. Upon adoption, the guidance should be applied retrospectively to all prior periods presented in the financial statements. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures , which improves the transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the effective tax rate reconciliation and income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. This guidance will be effective for the annual periods beginning after December 15, 2024. Early adoption is permitted. Upon adoption, the guidance can be applied prospectively or retrospectively. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value accounting is applied for all financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis (at least annually). As of December 31, 2023 and 2022, the carrying amount of cash equivalents, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximated their estimated fair value due to their relatively short maturities. Management believes the terms of its long-term debt reflect current market conditions for an instrument with similar terms and maturity, therefore the carrying value of the Company’s debt approximated its fair value. Assets and liabilities recorded at fair value on a recurring basis in the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1 : Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2 : Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and Level 3 : Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. The Company’s money market funds are classified as Level 1 because they are valued using quoted market prices. The Company’s debt securities and commercial paper consist of available-for-sale securities and are classified as Level 2 because their value is based on valuations using significant inputs derived from or corroborated by observable market data. There were no assets or liabilities classified as Level 3 as of December 31, 2023 and 2022. There were no transfers into or out of Level 3 of the fair value hierarchy during the periods presented. The following tables present the fair value hierarchy for assets measured at fair value, and summarize the estimated value of the Company’s cash equivalents and debt securities and the gross unrealized holding gains and losses (in thousands): December 31, 2023 Level Amortized cost Unrealized gain Unrealized loss Estimated Fair Cash equivalents: Money market funds 1 $ 18,653 $ — $ — $ 18,653 Total cash equivalents $ 18,653 $ — $ — $ 18,653 December 31, 2022 Level Amortized cost Unrealized gain Unrealized loss Estimated Fair Cash equivalents: Money market funds 1 $ 11,546 $ — $ — $ 11,546 Commercial paper 2 3,968 — — 3,968 Total cash equivalents $ 15,514 $ — $ — $ 15,514 Short-term debt securities: U.S. government bonds 2 $ 39,646 $ 3 $ (86) $ 39,563 Corporate debt securities 2 28,759 — (117) 28,642 Commercial paper 2 4,945 — — 4,945 Total debt securities $ 73,350 $ 3 $ (203) $ 73,150 There were no financial liabilities to be remeasured on a recurring basis as of December 31, 2023 and 2022. During the year ended December 31, 2023, the Company did not recognize any credit losses. The Company determined that the decline in fair value of debt securities was not due to credit-related factors, and no allowance for expected credit losses was recorded as of December 31, 2023. There were no impairment losses on investments during the years ended December 31, 2023 and 2022.

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Balance Sheet Components Inventories Inventories consist of the following (in thousands): December 31, 2023 2022 Work-in-progress $ 940 $ 884 Raw materials 531 1,703 Finished goods 85 266 Total inventories $ 1,556 $ 2,853 Property and Equipment, Net Property and equipment, net consist of the following (in thousands): December 31, 2023 2022 Computer equipment and software $ 1,004 $ 736 Construction in progress 305 367 Lab equipment 271 271 Furniture 116 116 Leasehold improvements 101 101 Total property and equipment 1,797 1,591 Less: accumulated depreciation (1,170) (895) Property and equipment, net $ 627 $ 696 Depreciation expense for the years ended December 31, 2023 and 2022 was approximately $0.3 million. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): December 31, 2023 2022 Prepaid research costs $ 5,577 $ 2,822 Prepaid marketing 911 753 Prepaid contract manufacturing costs 577 3,542 Short term deposits 404 4,542 Prepaid insurance 403 586 Other 1,289 1,740 Total prepaid expenses and other current assets $ 9,161 $ 13,985 Accrued Liabilities Accrued liabilities consist of the following (in thousands): December 31, 2023 2022 Compensation and related benefits $ 3,046 $ 6,167 Contract research costs 2,909 4,579 Product revenue reserves 2,277 1,373 Contract manufacturing costs 818 2,101 Legal fees 438 562 Other 478 873 Total accrued liabilities $ 9,966 $ 15,655

License, Collaboration, and Pro

License, Collaboration, and Product Development Agreements	12 Months Ended
	Dec. 31, 2023
Product Development Agreement [Abstract]
License, Collaboration, and Product Development Agreements	License, Collaboration, and Product Development Agreements License Agreement with the Trustees of the University of Pennsylvania and the Children’s Hospital of Philadelphia In May 2019, the Company entered into a license agreement (the UPenn/CHOP Agreement) with the Trustees of the University of Pennsylvania (UPenn) and the Children’s Hospital of Philadelphia (CHOP), under which the Company obtained an exclusive, royalty-bearing, worldwide license to develop, manufacture and sell certain Glucagon Like Peptide-1 (GLP-1) receptor antagonist(s) products to treat all human and animal conditions. The Company also obtained an exclusive, royalty-bearing, sublicensable, worldwide license to certain data developed by CHOP. The Company is responsible for the development and commercialization of the licensed products at its sole cost and expense. As part of the consideration for the rights granted to the Company under the UPenn/CHOP Agreement, the Company paid UPenn a one-time, non-refundable issue fee of $1.0 million, which is recorded in research and development expenses for the year ended December 31, 2019. In addition, the Company is obligated to pay UPenn a specified annual license maintenance fee, up to $2.5 million upon marketing authorization in one or more countries, and up to $18.0 million in commercial milestones. The Company will also be required to pay UPenn a flat royalty in the low-single digits on net sales of all licensed products by the Company, subject to specified reductions and offsets, and specified minimum annual royalty payments. The Company’s obligation to pay royalties expires on a product-by-product and country-by-country basis, on the later of: (i) the expiration of the last valid claim in the licensed patents in any country, or (ii) the tenth anniversary of the first commercial sale of the product in such country. No milestones have been achieved as of December 31, 2023 . The Company may terminate the UPenn/CHOP Agreement in its entirety for any reason by providing prior written notice to UPenn and CHOP. UPenn or CHOP may terminate the UPenn/CHOP Agreement, upon a written notice, for the Company’s failure to achieve the specified diligence milestones within the specified periods, subject to the Company’s extension rights. Product Development Agreement On August 11, 2018, the Company entered into a Product Development Agreement and a First Project Agreement (the Product Agreements), pursuant to which the Company will receive development program support services for its HDV program. The services are to be provided from July 1, 2018 through the new drug application (NDA) filing. As consideration, the Company has committed to pay fees of approximately $10.0 million in cash and stock over four years, including approximately $0.8 million for expert consultant fees and pass through costs to vendors, plus certain incentive-based regulatory milestone fees up to $1.0 million. As part of the aggregate payment, the Company issued 3,848 shares (adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024) of common stock subject to quarterly vesting requirements related to successful performance of the services and achievement of budget timeline set forth in the Product Agreements. The Product Agreements can be terminated by either party due to material breach or by the Company without cause with 90 days prior written notice. For the year ended December 31, 2022, the Company recognized research and development expense of $19,000 related to the shares issued under the Product Agreements . As of December 31, 2022, the restricted shares were fully vested. No milestones have been achieved as of December 31, 2023. Progeria Research Foundation (PRF) Collaboration Agreement On May 15, 2018, the Company entered into a Collaboration and Supply Agreement (the PRF Collaboration Agreement) with PRF. Under the PRF Collaboration Agreement, the parties agreed to collaborate with respect to the development and pursuit of regulatory approval of lonafarnib for the treatment of HGPS and processing-deficient progeroid laminopathies, collectively called progeria, in humans. PRF granted the Company a non-exclusive, world-wide, royalty-free, sub-licensable license pertaining to all intellectual property and data controlled by PRF to prepare and file any NDA for a product containing lonafarnib for progeria. The Company is obligated to: (i) exclusively supply lonafarnib to PRF for use in clinical trials and non-clinical research in progeria at the Company’s expense, (ii) prepare and be the sponsor of any NDA submission for lonafarnib for the treatment of progeria to the FDA, (iii) use commercially reasonable efforts to file a NDA for progeria by a specified date, (iv) submit a Rare Pediatric Disease designation and a request for expedited approval in connection with a NDA filing, (v) establish a patient support program in progeria, and (vi) use commercially reasonable efforts to develop a pediatric formulation of lonafarnib for use in progeria. Under the PRF Collaboration Agreement, the Company is solely responsible for any additional studies necessary for obtaining an NDA for progeria and is also responsible for any additional costs for such studies up to $2.0 million. The PRF Collaboration Agreement continues for an initial term of ten years and automatically renews for subsequent renewal terms of two years each unless either party terminates earlier. No milestones have been achieved as of December 31, 2023. Bristol-Meyers Squibb License Agreement On April 20, 2016, the Company and Bristol-Myers Squibb Company (BMS) entered into a License Agreement (the BMS License Agreement) and a Common Stock Purchase Agreement (the BMS Purchase Agreement). Under the BMS License Agreement, BMS granted the Company an exclusive, worldwide, license to research, develop, manufacture, and sell products containing PEG-interferon Lambda-1a (peginterferon lambda or the Licensed Product) for all therapeutic and diagnostic uses in humans and animals. The Company is responsible for the development and commercialization of the Licensed Product at its sole cost and expense. The Company paid BMS $2.0 million and issued 5,252 shares of its common stock (adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024) at an aggregate fair value of $3.2 million in April 2016. The BMS License Agreement also includes development and regulatory milestone payments totaling $61.0 million and commercial sales milestones of up to $128.0 million. The Company is obligated to pay BMS annual net sales royalties in the range of mid-single to mid-teens, depending on net sales levels. In fourth quarter of 2020, the Company recorded a $3.0 million milestone in research and development expense, triggered on successful demonstration of proof of concept, as defined by the BMS License Agreement, in a Phase 2 clinical trial. In March 2022, the Company recorded a $5.0 million milestone expense in research and development, which was related to the initiation of a Phase 3 clinical trial, as defined under the BMS License Agreement. No milestones have been achieved in 2023. Merck License Agreement In September 2010, the Company entered into an exclusive license agreement with Schering Corporation, subsequently acquired by Merck & Co., Inc. (Merck), which provides the Company with the exclusive right to develop, manufacture, and sell products containing the compounds lonafarnib for the treatment of all human viruses except certain specified viruses such as hepatitis B and hepatitis C alone. As part of consideration, the Company issued 911 shares of common stock (adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024) with a fair value of $0.5 million. The Company is obligated to pay Merck up to an aggregate of $27.0 million in development milestones and will be required to pay tiered royalties based on aggregate annual net sales of all licensed products ranging from mid-single to low double-digit royalties on net sales. In May 2015, the first regulatory milestone was achieved and the Company paid the related milestone payment of $1.0 million to Merck. In September 2023, the Phase 3 study was completed and the $1.0 million related milestone expense was recorded in accrued liabilities on the consolidated balance sheet. On May 15, 2018, the Company entered into an amendment to the exclusive license agreement with Merck, which provides for expansion of the existing exclusively licensed field of use under the license agreement with Merck to include all uses of lonafarnib related to the treatment of Hutchinson-Gilford progeria syndrome (HGPS) in humans at no cost to the Company. On November 3, 2020, the Company entered into an amendment to the exclusive license agreement with Merck which expanded the indication to also include progeroid laminopathies, collectively called progeria. The Company has the sole responsibility and the continuing obligation for the manufacture and supply of lonafarnib to the PRF. Merck will not receive milestone payments in relation to lonafarnib for the treatment of progeria or any royalty payments for sales of a specified quantity of lonafarnib to treat the currently estimated progeria patient population worldwide.

Asset Purchase Agreements and R

Asset Purchase Agreements and Related License Agreements	12 Months Ended
	Dec. 31, 2023
Asset Purchase Agreements And Related License Agreements [Abstract]
Asset Purchase Agreements and Related License Agreements	Asset Purchase Agreements and Related License Agreements Avexitide Purchase Agreement and Related Stanford License Agreement In September 2015, the Company entered into an asset purchase agreement with two individuals, Dr. Tracey McLaughlin and Dr. Colleen Craig, (the Sellers), whereby the Company purchased all of the assets related to the compound avexitide (formerly known as exendin 9-39) including any related intellectual property from the Sellers (the Exendin APA). The Company also entered into a consulting agreement with the Sellers as part of the agreement. The Company issued 512 shares of common stock (adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024) that were valued at $0.2 million. In addition, the Company granted the Sellers options to purchase an aggregate 3,155 shares of common stock (adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024) at exercise prices of $61.80 and $517.80 that vest based on certain service and milestone-based performance vesting conditions. As of December 31, 2023, the service vesting conditions were met and the performance conditions were not deemed probable of achievement. No expense was recognized for the milestone-based options during the years ended December 31, 2023 and 2022. The Company is also obligated to pay development milestone payments in an aggregate amount of up to $1.0 million to each Seller. Additionally, the Company is obligated to pay each Seller royalties of low single-digits based on aggregate annual net sales of all products developed based on avexitide, subject to certain reductions and exceptions. The Company’s obligation to pay royalties expires on the expiration of the last to expire valid claim as defined in the agreement. Additionally, the Company has assumed the license agreement the Sellers had previously entered into with the Board of Trustees of the Leland Stanford Junior University (Stanford). The Company is obligated to pay a royalty to Stanford in the low single-digits on annual net sales after the first commercial sale of any products developed based on avexitide. As of December 31, 2023, the Company has paid a total of $0.1 million in milestone payments to each of the Sellers related to the successful completion of the Phase 2 trials.

Debt

Debt	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Debt	Debt Innovatus Term Loan On June 1, 2022 (Closing Date), the Company entered into a term loan and security agreement (Innovatus Loan) with Innovatus Life Sciences Lending Fund I, LP (Innovatus), providing for up to $75.0 million funded in three tranches with a maturity date of August 31, 2027. The floating per annum interest rate of the Innovatus Loan is equal to the sum of (a) the greater of (i) the Prime Rate published in the Money Rates section of the Wall Street Journal (or any successor thereto) and (ii) 3.5%, plus (b) 3.75%; provided that, at the election of the Borrower, up to 2.25% of such rate shall be payable in-kind until the third anniversary of the closing date. The Company is required to make monthly interest-only payments through July 1, 2027, after which the Company is required to make monthly amortizing payments, with the remaining balance of the principal plus accrued and unpaid interest due at maturity. 2.25% of the interest is payable in-kind for the first three years of the term by increasing the principal balance. Prepayments of the loan, in whole or in part, will be subject to an early prepayment fee which ranges between 3% and 0% of the principal amount repaid and declines each year until the third anniversary date of the Closing Date, after which no prepayment fee is required. The Company is also required to pay an exit fee upon any payment or prepayment equal to 6.5% of the aggregate principal amount of the tranches funded under the Innovatus Loan. The Innovatus Loan contains customary representations, warranties, events of default, including failure to pay amounts due, breaches of covenants and warranties, material adverse change events, certain cross defaults and judgements, and insolvency, and covenants of the Company and its subsidiaries, including a requirement to maintain a cash balance of not less than 5% of the aggregate principal amount of funded and outstanding loan terms at all times. Should the Company be unable to comply with these covenants or if the Company defaults on any portion of its outstanding borrowings, the lender can also impose a 5% interest rate penalty, restrict access to additional borrowings under the loan and security agreement, and accelerate the maturity of the debt to be immediately due and payable. The Innovatus Loan is secured by perfected first priority liens on the Company's assets, including a commitment by the Company to not allow any liens to be placed upon the Company's intellectual property. The Company was funded $40.0 million in June 2022 on the Closing Date under Tranche A. The remaining $35.0 million is divided into two tranches (Tranche B and Tranche C). The $17.5 million under each of Tranche B and Tranche C was available for a period commencing on the later of (a) the first date that the Company achieves certain development and regulatory milestones applicable to each Tranche and (b) November 1, 2022. Both Tranche B and Tranche C draw periods end on the earlier of (a) June 30, 2024 or (b) an event of default. Tranches B and C are no longer available to the Company following the filing of the Bankruptcy Petitions. In connection with the issuance of the Innovatus Loan, the Company recorded a debt discount of $0.2 million and capitalized debt issuance costs of $1.1 million. The discount and issuance costs will be amortized over the life of the loan. Interest expense for the Innovatus Loan for the year ended December 31, 2023 was $5.5 million, and is inclusive of non-cash amortization of the debt discount and debt issuance costs and accretion of final payment. The carrying amount of the Innovatus Loan approximates fair value given the interest rate is based on the prime rate. The effective interest rate for the Innovatus Loan was 13.84% as of December 31, 2023. Additionally, in connection with entering into the Innovatus Loan, the Company entered into a Stock Purchase Agreement with Innovatus for the sale of common stock with an aggregate value of $5.0 million. On June 1, 2022, the Company issued 24,967 shares of common stock (adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024) to Innovatus at a per share purchase price of $200.25, the preceding five-day volume weighted average price per share. A portion of the loan proceeds was used to repay in full the approximately $33.5 million of aggregate principal amount, unpaid interest, and exit fees in connection with loans outstanding owed to Oxford Finance LLC by the Company. The Company reclassified its long term debt to current liabilities on its consolidated balance sheet as of December 31, 2023, as there is substantial doubt regarding the Company's ability to continue as a going concern and in connection with its recent filing under Chapter 11, as discussed in Note 13. The Innovatus Loan provides that upon the filing of the Bankruptcy Petitions, the principal amount together with accrued and unpaid fees and interest thereon shall become immediately due and payable. However, any efforts to enforce such payment obligations under the Innovatus Loan are automatically stayed as a result of the Bankruptcy Petitions, and the creditors’ rights of enforcement in respect of the Innovatus Loan are subject to the applicable provisions of the Bankruptcy Code. Oxford Term Loan On June 1, 2022, upon entering into the Innovatus Loan, the Company repaid the loan from Oxford Finance LLC (Oxford Loan) including (i) the $30.0 million outstanding principal balances, (ii) $0.2 million in accrued and unpaid interest, and (iii) other final payments consisting of $3.3 million, for a total payment of $33.5 million. The Company recorded a loss of $1.1 million on early extinguishment of the debt related to the unamortized debt premium, discount, and cost of issuance, which was recognized as a component of other (expense) income, net in the consolidated statement of operations. The Company is also required to pay a 5.0% success fee of the total amount drawn under the Amended Oxford Loan within 30 days following the FDA’s approval of the Company’s first product, excluding Zokinvy for treatment of Progeria processing-deficient progeroid laminopathies. This fee is enforceable through March 2029. The Company determined that the success fee met the scope exemption from derivative accounting and should be accounted for under the guidance for contingencies. Accordingly, the Company will record a liability for the success fee upon receipt of approval from the FDA. No success fee liability was recognized as of December 31, 2023 and 2022. The Company accounts for the amortization of the debt discount utilizing the effective interest method. Debt and unamortized discount balances are as follows (in thousands): December 31, 2023 2022 Face value of debt $ 41,452 $ 40,531 Exit fee 2,600 2,600 Unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees (2,933) (3,506) Current portion of long-term debt $ 41,119 $ 39,625 As of December 31, 2023, future minimum payments of principal, paid in kind interest and exit fee under the Innovatus Loan were as follows (in thousands): Year ending December 31, 2024 45,393 2025 — 2026 — 2027 — Total future payments 45,393 Less: paid in kind interest (1,341) Less: unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees (2,933) Current portion of long-term debt $ 41,119

Stockholders_ Equity

Stockholders’ Equity	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stockholders’ Equity	Stockholders’ Equity Common Stock The holders of the Company’s common stock have one vote for each share of common stock. Common stockholders are entitled to dividends when, as, and if declared by the Board of Directors, subject to the prior rights of the convertible preferred stockholders. As of December 31, 2023, no dividends had been declared by the Board of Directors. In December 2020, the Company filed a shelf registration statement on Form S-3 (File No. 333-251497) with the Securities and Exchange Commission, which permits the offering, issuance and sale by the Company up to a maximum aggregate offering price of $200.0 million of its common stock, preferred stock, debt securities and warrants. Up to a maximum of $50.0 million of the maximum aggregate offering price of $200.0 million may be issued and sold pursuant to an ATM financing facility (the 2020 ATM Facility) under a sales agreement with Jefferies. In January and March 2022, the Company completed ATM offerings for a total of 194,723 shares of common stock (adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024) under the 2020 ATM Facility. The offerings were made under the Company’s effective shelf registration statement and resulted in net proceeds to the Company of $45.6 million, after deducting commissions. As of December 31, 2022, the Company completed the sale of all shares available for sale under the 2020 ATM Facility, and the 2020 ATM Facility was terminated. On March 25, 2022, the Company entered into a new Open Market Sale Agreement SM with Jefferies, pursuant to which the Company can sell up to a maximum of $50.0 million of our common stock in offerings that are deemed “at the market” offerings as defined in Rule 415 under the Securities Act, under the Company’s effective shelf registration statement (the 2022 ATM Facility). In April 2022, the Company completed offerings from the 2022 ATM facility for a total of 89,539 shares of its common stock (adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024) resulting in net proceeds of $20.8 million , after deducting commissions costs. No additional offerings were completed since April 2022. The registration statement registering the offer and sale of shares pursuant to the 2022 ATM Facility expired in December 2023. The Company had reserved shares of common stock for issuance as follows: December 31, 2023 2022 Options issued and outstanding 180,151 204,656 Awards available for future issuance 203,891 65,882 Shares available for issuance under ESPP 24,587 26,296 Restricted and performance stock units outstanding 5,998 21,337 Total 414,627 318,171

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Restated 2013 Equity Incentive Plan In June 2016, the Company’s Board of Directors adopted and in August 2016 the Company’s stockholders approved the Amended and Restated 2013 Equity Incentive Plan (the Restated 2013 Plan). Under the terms of the Restated 2013 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and other awards to individuals who are then employees, officers, non-employee directors or consultants of the Company. Under the terms of the Restated 2013 Plan, options may be granted at an exercise price not less than fair market value. For employees holding more than 10% of the voting rights of all classes of stock, the exercise prices for incentive and non-statutory stock options may not be less than 110% of fair market value, as determined by the Board of Directors. The terms of options granted under the Restated 2013 Plan may not exceed ten years. The vesting schedule of newly issued option grants is generally four years. As of December 31, 2023, the Company is authorized to issue up to 344,380 shares under the Restated 2013 Plan. 2021 Inducement Plan During the second quarter of 2021, the Company approved the 2021 Inducement Plan to reserve 28,333 shares of its common stock to be used exclusively for grants of awards to individuals that were not previously employees or directors of the Company as a material inducement to such individuals’ entry into employment with the Company within the meaning of Rule 5635(c)(4) of the Nasdaq Listing Rules. As of December 31, 2023, there were 22,539 shares remaining and available to be issued under the 2021 Inducement Plan. The following table summarizes stock option activity under the Company’s stock-based compensation plans during the year ended December 31, 2023 (in thousands, except option and share data): Number of Weighted- Weighted- Aggregate Outstanding as of December 31, 2022 204,656 $ 270.00 6.00 $ — Granted 119,623 $ 46.89 Forfeited (144,128) $ 221.28 Outstanding as of December 31, 2023 180,151 $ 167.68 6.56 $ — Vested and exercisable as of December 31, 2023 97,601 $ 248.27 5.36 $ — As of December 31, 2023, there were 203,891 shares remaining and available to be issued under the plans, including stock options, restricted stock units (RSUs) and performance stock units (PSUs). The aggregate intrinsic values of options outstanding, exercisable, vested and expected to vest were calculated as the difference between the exercise price of the options and the closing price of the Company’s common stock of $6.75 as of December 31, 2023. The aggregate intrinsic value of stock options exercised in 2023 and 2022 was $0 and $0.1 million, respectively. During the years ended December 31, 2023 and 2022, the weighted-average grant date fair value of options granted were $28.97 and $109.53 per share, respectively. The total grant date fair value of options that vested during the years ended December 31, 2023 and 2022 was $5.8 million and $7.3 million, respectively. The Company records stock-based compensation of stock options granted by estimating the fair value of stock-based awards using the Black-Scholes option pricing model and amortizes the fair value of the stock-based awards granted over the applicable vesting period of the awards on a straight-line basis. The fair value of stock options was estimated using the following weighted-average assumptions: Year Ended December 31, 2023 2022 Expected term (in years) 0.86-6.08 5.27-6.08 Volatility 90.21%-156.25% 68.71%-88.51% Risk free interest rate 3.50%-4.86% 1.76%-4.23% Dividend yield — — Expected Term : The expected term represents the number of years the Company estimates, based primarily on historical experience, that the options will be outstanding prior to exercise. Expected Volatility : The expected volatility for stock options is based on the Company's historical stock price volatility. Risk-Free Interest Rate : The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of option. Expected Dividend : The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero. 2013 Employee Stock Purchase Plan In 2013, the Company’s board of directors adopted and in 2016, upon the merger with Celladon, the Company amended and approved the 2013 Employee Stock Purchase Plan (2013 ESPP). The 2013 ESPP is intended to qualify as an employee stock purchase plan under Section 423 of the U.S. Internal Revenue Code and is administered by the Company’s board of directors. The number of shares of common stock initially reserved for issuance under the 2013 ESPP was 3,333 shares with an automatic annual increase to the shares issuable under the 2013 ESPP to the lower of (i) 1% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, and (ii) 5,500 shares of common stock, unless a lower number determined by the board of directors. As of December 31, 2023, a total of 31,626 shares are reserved for issuance and 24,587 shares available for future issuance under the 2013 ESPP. During the years ended December 31, 2023 and 2022, employees purchased 1,709 shares for $0.1 million and 1,594 shares for $0.2 million, respectively, under the 2013 ESPP. Restricted Stock Units and Performance Stock Units In the first quarter of 2020, the Company revised its non-employee director compensation policy to approve the granting of RSUs and PSUs in accordance with the Restated 2013 Equity Incentive Plan (the Restated 2013 Plan). Each eligible director who has served for at least six months during the prior calendar year and continues to serve as a non-employee member of the board of Directors (the Board) is granted RSUs. Each eligible director who has served on the Board for less than six months during the prior calendar year and who continues to serve as a non-employee member of the Board, is granted RSUs which are pro-rated for the period served during the prior calendar year. The RSUs granted to non-employee directors will vest on the one-year anniversary of the grant date, subject to the eligible director’s continuous services through the vesting date, and will vest in full upon a change in control, as defined under the Restated 2013 Plan. The RSUs granted to employees will vest annually on the one-year, two-year, and three-year anniversaries of the grant date. The fair value of all RSUs is measured at the grant date based on the closing market price of the Company’s common stock and is recognized as stock-based compensation expense on a straight-line basis over the vesting period. Each PSU, which is a stock award, is earned through the achievement of performance-based metrics over a defined performance period. The length of the defined performance period, the performance-based metric to be achieved during the defined performance period, and the measure of whether and to what degree such performance-based metric has been achieved will be conclusively determined by the compensation committee of the Company’s Board, in its sole discretion. The estimated fair value of equity awards that contain performance conditions is expensed over the term of the award once the Company has determined that it is probable that performance conditions will be satisfied. During the years ended December 31, 2023 and 2022 the Company granted 500 and 1,000 PSUs, with a weighted-average grant date fair value of $67.80 and $206.10 per share, respectively. The performance-based metrics include the achievement of certain revenue targets and clinical and regulatory milestones. During the years ended December 31, 2023 and 2022, the Company recorded $0.4 million and $0.5 million, respectively, of stock-based compensation expense related to the PSUs as it is expected at the beginning of the period that all milestones would be achieved by the target dates. This expense is included in selling, general and administrative expenses. On June 30, 2023, the Company reassessed the probability of the performance-based metrics being achieved. The Company concluded that some of the performance-based metrics are no longer probable of being achieved but are still more than improbable. As such, starting July 2023 the Company discontinued recognizing the related expense on a prospective basis and will not reverse the previously recognized expenses. In May 2023, four employees were terminated who had outstanding PSU awards. As the performance-based metrics were not achieved at time of termination, the stock compensation expense related to these awards of $0.4 million was reversed. As of December 31, 2023, other than 500 PSUs for which vesting was accelerated in connection with the modification noted below, 1,349 PSUs have vested as the performance-based metrics of the PSUs were met upon the achievement of $35 million in cumulative net sales of Zokinvy. During the years ended December 31, 2023 and 2022, the Company granted 1,305 and 9,925 RSUs, respectively, with a weighted-average grant date fair value of $67.80 and $156.58 per share, respectively. In relation to the RSUs granted, the Company recognized $0.7 million and $1.2 million in stock-based compensation expense for the years ended December 31, 2023 and 2022, respectively, which were included in selling, general and administrative expenses. The following table summarizes RSU and PSU activity and weighted average grant date fair value for the year ended December 31, 2023: Shares Weighted- Unvested shares as of December 31, 2022 21,337 $ 220.40 Granted 1,805 $ 67.80 Vested (8,625) $ 176.10 Forfeited (8,519) $ 236.55 Unvested shares as of December 31, 2023 5,998 $ 215.24 Awards Modification On February 6, 2023, the Company entered into a separation agreement and general release with David Cory, the Company's former President and CEO. Pursuant to the separation agreement, 50% of Mr. Cory's unvested equity awards were accelerated to vest on the date the separation agreement was executed. Additionally, the exercise period for Mr. Cory's vested awards was extended, including his accelerated awards. The stock compensation recognized related to these modifications was $0.9 million for the year ended December 31, 2023, which is reflected in selling, general and administrative expenses. Stock-Based Compensation Expense Total stock-based compensation expense recognized was as follows (in thousands): Year Ended December 31, 2023 2022 Research and development $ 2,391 $ 3,159 Selling, general and administrative 2,617 5,158 Total $ 5,008 $ 8,317 As of December 31, 2023, the total unrecognized compensation expense related to unvested awards was $10.9 million, which the Company expects to recognize over an estimated weighted average period of 2.6 years.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company’s provision for income taxes was approximately $6,000 and $23,000 for the years ended December 31, 2023 and 2022, respectively, with an effective tax rate of 0.01% and (0.02)% for the years ended December 31, 2023 and 2022, respectively. The effective tax rate in each period differs from the U.S. statutory tax rate primarily due to the valuation allowance on the Company’s deferred tax assets as it is more likely than not that some or all of the Company’s deferred tax assets will not be realized. The tax expense recorded for the year ended December 31, 2023 relates to foreign taxes. The following table presents loss before provision for income taxes as follows (in thousands): Year Ended December 31, 2023 2022 Domestic $ (75,002) $ (96,769) Foreign 45 16 Total loss before provision for income taxes $ (74,957) $ (96,753) The state and foreign income tax provisions for the years ended December 31, 2023 and 2022 are summarized as follows (in thousands): Year Ended December 31, 2023 2022 Current: State $ — $ 21 Foreign 6 2 Total current $ 6 $ 23 Deferred: State $ — $ — Foreign — — Total deferred $ — $ — Total provision for income taxes $ 6 $ 23 The effective tax rate of the provision for income taxes differs from the federal statutory rate as follows: Year Ended December 31, 2023 2022 Federal statutory income tax rate 21.00 % 21.00 % Change in valuation allowance (27.82) (25.99) Tax credits 6.24 4.15 State income taxes, net of federal benefit 4.12 2.39 Stock-based compensation (3.47) (0.98) Other, net (0.06) (0.59) Provision for income taxes 0.01 % (0.02) % The components of the deferred tax assets and liabilities are as follows (in thousands): December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 69,417 $ 63,069 Tax credits 15,194 9,985 Depreciation and amortization 2,775 2,920 Stock-based compensation 1,905 3,429 Section 174 capitalization 26,668 15,581 Accruals and reserves 884 1,431 Lease liabilities 20 131 Gross deferred tax assets 116,863 96,546 Valuation allowance (116,842) (96,418) Total deferred tax assets 21 128 Deferred tax liabilities: Right-of-use assets (21) (128) Total deferred tax liabilities (21) (128) Net deferred tax assets $ — $ — Due to the Company’s lack of earnings history, the deferred tax assets have been fully offset by a valuation allowance as of December 31, 2023 and 2022. The net change in the valuation allowance for the years ended December 31, 2023 and 2022 was an increase of $20.4 million and $25.1 million, respectively. As of December 31, 2023, the Company had approximately $322.5 million and $47.1 million, respectively of federal and state operating loss carryforwards available to reduce future taxable income that will begin to expire in 2030 and 2028, respectively, for federal and state tax purposes. The Company had $15.5 million of federal Orphan Drug credit carryforwards available to reduce future taxable income that will begin to expire in 2041. As of December 31, 2023, the Company also had research and development tax credit carryforwards of approximately $1.6 million and $4.0 million for federal and state purposes available to offset future taxable income tax, respectively. If not utilized, the federal carryforwards will expire beginning in 2043, and the state credits can be carried forward indefinitely. The Company’s ability to utilize NOL carryforwards or other tax attributes, such as research tax credits, in any taxable year may be limited if the Company has experienced an ownership change under Section 382 of the Internal Revenue Code (the Code) of 1986, as amended. The Company’s merger with Celladon resulted in such an ownership change and, accordingly, Celladon’s NOL carryforwards and certain other tax attributes will be subject to further limitations on their use. The Company assessed whether it had an ownership change, as defined by Section 382 of the Code from its formation through December 31, 2023. Based upon this assessment, the Company experienced ownership changes on April 20, 2016, October 18, 2018 and December 31, 2020. Due to the April 20, 2016 and October 18, 2018 ownership changes, reductions were made to the Company’s NOL and tax credit carryforwards under these rules. Additional ownership changes could result in additional limitations on the Company’s NOL and tax credit carryforwards. Tax benefits from uncertain tax positions are recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. The amount recognized is measured as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon effective settlement. Uncertain Tax Positions A reconciliation of the Company’s unrecognized tax benefits for the years ended December 31, 2023 and 2022 is as follows (in thousands): Year Ended December 31, 2023 2022 Balance at beginning of year $ 3,492 $ 1,950 Additions based on tax positions related to current year 1,784 1,586 Reductions based on tax positions related to prior year — (44) Balance at end of year $ 5,276 $ 3,492 If the $5.3 million of unrecognized tax benefits is recognized, there would not be an effect on the effective tax rate. The Company does not expect the unrecognized tax benefits to change significantly over the next 12 months. As of December 31, 2023, the unrecognized tax benefits for uncertain tax positions were offset against deferred tax assets and would not affect the income tax rate if recognized due to the Company being in a full valuation allowance position. The Company’s policy is to account for interest and penalties in tax expense on the consolidated statements of operations. The Company files income tax returns in the U.S. federal and state jurisdictions. All periods since inception are subject to examination by U.S. federal and state jurisdictions. There were no such interest or penalties during the years ended December 31, 2023 and 2022.

Legal Matters

Legal Matters	12 Months Ended
	Dec. 31, 2023
Legal Matters [Abstract]
Legal Matters	Legal Matters From time to time in the ordinary course of business, the Company may be involved in various legal claims and litigation, including those pertaining to the defense and enforcement of the Company's patent or other intellectual property rights and contractual rights. The Company is defending all current litigation matters, including the litigation matters discussed below. Although there can be no assurances and the outcome of these matters is currently not determinable, the Company currently believes that none of these claims or proceedings are likely to have a material adverse effect on the Company's financial position. The Company records accruals for outstanding legal proceedings, claims or investigations when it is probable that a liability will be incurred, and the amount of loss can be reasonably estimated. The Company evaluated developments in legal proceedings, claims or investigations that could affect the amount of any accrual, as well as any developments that would result in a loss contingency to become both probable and reasonably estimable. The Company has not recorded any accrual for loss contingencies associated with such legal claims or litigation discussed herein as they are in the early stages and an estimate of loss, if any, cannot be made. Legal fees and other costs associated with such actions will be expensed as incurred. Schoen v. Eiger BioPharmaceuticals, Inc., et al. , Case No. 22-cv-06985 On November 8, 2022 a putative securities class action complaint was filed in the United States District Court for the Northern District of California alleging that the company and two former executives violated Sections 10(b) and 20(a) of the Securities Exchange Act and SEC Rule 10b-5. The complaint alleged generally that between March 2021 and October 2022, material misstatements and omissions were made to shareholders regarding the TOGETHER study of peginterferon lambda for the treatment of COVID-19 as well as the likelihood of FDA approval of an Emergency Use Authorization for peginterferon lambda. The Court appointed a lead plaintiff on March 2, 2023. On April 10, 2023, the lead plaintiff filed a notice of voluntary dismissal without prejudice. The Progeria Research Foundation, Inc. v. Eiger BioPharmaceuticals, Inc. Arbitration On November 15, 2022, the Company received a demand for arbitration (Demand) from claimant The Progeria Research Foundation, Inc. (PRF) asserting two claims under a May 15, 2018 Collaboration and Supply Agreement (the PRF Collaboration Agreement) between the parties. The terms of the PRF Collaboration Agreement are discussed in Note 5 of our consolidated financial statements. PRF has alleged that the Company breached an obligation to supply quantities of a drug as requested by PRF. PRF also has a claim for declaratory relief regarding the grant of licenses under the PRF Collaboration Agreement. On January 18, 2023, the Company filed a response to the Demand denying PRF’s claims, contesting the arbitrability of PRF’s claim for declaratory relief, and asserting a counterclaim for declaratory relief related

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Commitments and Contingencies	Commitments and Contingencies Indemnification Agreements for Directors and Officers In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions and has never accrued any liabilities related to such obligations in its consolidated financial statements. The Company has also entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance. Other The Company enters into contracts in the normal course of business with various third parties for clinical trials, preclinical research studies and testing, manufacturing and other services and products for operating purposes. These contracts generally provide for termination upon notice. Payments due upon cancellation consist only of payments for services provided or expenses incurred, including non-cancellable obligations of our service providers, up to the date of cancellation.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Voluntary Filing Under Chapter 11 As previously reported in the Company's Current Report on Form 8-K, filed with the U.S. Securities and Exchange Commission on April 1, 2024, the Company and its wholly owned subsidiaries commenced voluntary proceedings under Chapter 11 of the United States Bankruptcy Code in the United States Bankruptcy Court for the Northern District of Texas (Bankruptcy Court). The Chapter 11 proceedings are jointly administered under the caption In re Eiger BioPharmaceuticals, Inc., et al , Case No. 24-80040 . (Chapter 11 Cases). The Company continues to operate its business in accordance with the applicable provisions of the Bankruptcy Code and orders of the Bankruptcy Court. On March 31, 2024, we entered into a “stalking horse” asset purchase agreement (Asset Purchase Agreement) with Sentynl Therapeutics, Inc. (Purchaser), pursuant to which the Purchaser has agreed to acquire substantially all of the rights of the Company to its Zokinvy® program, including the Company’s in-license from Merck Sharp & Dohme Corp. (successor-in-interest of Schering Corporation) (Transferred Assets). The acquisition of the Transferred Assets by the Purchaser pursuant to the Asset Purchase Agreement is subject to approval of the Bankruptcy Court and one or more auctions, if necessary, to solicit higher or otherwise better bids. On April 1, 2024, we filed a motion (Bidding Procedures Motion) seeking approval of, among other things, certain bidding procedures (Bidding Procedures), which will establish procedures for the selection of the highest or otherwise best bids for the sale of the Transfer Assets and other assets. Other interested bidders would be permitted to participate in the auction if they submit qualifying bids that are higher or otherwise better than the Asset Purchase Agreement. The Asset Purchase Agreement acts as a baseline for competitive bids for the acquisition of the Transferred Assets. The Bidding Procedures Motion additionally seeks the Bankruptcy Court’s approval of the Asset Purchase Agreement and designation of the Purchaser as the “stalking horse” bidder for the Transferred Assets. Under the Asset Purchase Agreement, the Purchaser has agreed, subject to the Bankruptcy Court’s approval and absent any higher or otherwise better bid, to acquire the Transferred Assets from the Debtors for $26 million, subject to certain adjustments, including per diem reductions if the sale closes after April 24, 2024, in accordance with the terms and conditions of the Asset Purchase Agreement, plus the assumption of specified liabilities related to the Transferred Assets. The Asset Purchase Agreement includes customary representations and warranties and various customary covenants under the circumstances that are subject to certain limitations, including, without limitation, a termination fee, expense reimbursement and the right to designate executory contracts and unexpired leases to assume or reject. On April 3, 2024, the Purchaser increased the purchase price to $30.0 million, subject to certain adjustments, including per diem reductions if the sale closes after April 24, 2024. Subject to certain specific exceptions under the Bankruptcy Code, the Chapter 11 Cases automatically stayed most judicial or administrative actions against the Company and its direct subsidiaries and efforts by creditors to collect on or otherwise exercise rights or remedies with respect to obligations of the Company and its direct subsidiaries incurred prior to the petition date. Nasdaq Listing On April 2, 2024, the Company received written notice (Delisting Notice) from the Listing Qualifications Department of the Nasdaq Stock Market LLC (Nasdaq) notifying the Company that, as a result of the Chapter 11 Cases and in accordance with Nasdaq Listing Rules 5101, 5110(b) and IM-5101-1, Nasdaq had determined that the Company’s common stock will be delisted from Nasdaq. The Delisting Notice also advises the Company of its right to appeal Nasdaq’s determination pursuant to procedures set forth in Nasdaq Listing Rule 5800 Series. The Company does not intend to pursue an appeal.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023		Dec. 31, 2022
Pay vs Performance Disclosure
Net loss	$ (74,963)	[1]	$ (96,776)	[2]
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information for further information

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
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

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of Eiger BioPharmaceuticals, Inc. and its wholly owned subsidiaries, EBPI Merger Inc., EB Pharma LLC, Eiger BioPharmaceuticals Europe Limited, and EigerBio Europe Limited, have been prepared in accordance with accounting principles generally accepted in the United States of America, (U.S. GAAP) and follow the requirements of the Securities and Exchange Commission (SEC) for annual reporting. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of 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 revenue and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates including, but not limited to, those related to the estimated useful lives of long-lived assets, clinical trial accruals, fair value of assets and liabilities, fair value of investments, and stock-based compensation. The Company bases its estimates on historical experience and on various other market-specific and relevant assumptions that the Company believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Concentrations of Risk	Concentrations of Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents and investments. The Company’s cash is held by financial institutions in the United States and Ireland. Amounts on deposit may at times exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents and investments and issuers of investments. The Company manages its credit risk by holding its cash, cash equivalents and investments in large financial institutions within the U.S. and Ireland. In addition, the Company’s investment policy limits investments to certain types of instruments such as money market funds, debt securities issued by the U.S. government and its agencies, corporate debt securities, commercial paper as well as asset-backed securities, and places restrictions on the credit ratings, maturities and concentration by type and issuer. The Company has not experienced any losses on its deposits of cash, cash equivalents and investments. The Company relies on one supply chain for each of its product candidates. If any of the single source suppliers in any of the supply chains fail to satisfy the Company’s requirements on a timely basis, the Company could suffer delays in its clinical development programs and activities which could adversely affect its operating results.
Foreign Currency Exchange	Foreign Currency Exchange Foreign Currency Transaction Risk The foreign currency transaction risk relates to changes in exchange rates on monetary assets, liabilities, revenues and expenses held at Eiger BioPharmaceuticals Europe Limited . Gains and losses on foreign currency transactions result primarily from monetary assets, liabilities, revenues and expenses denominated in Euro. Aggregated transaction gains for were $0.1 million for the years ended December 31, 2023 and 2022. The Company expects the foreign currency gain/loss to continue to fluctuate as long as the Company continues to hold monetary assets and liabilities at its subsidiaries in Ireland, England and Wales. Market uncertainty could potentially lead to significant volatility with foreign currency exchange rates, which could result in additional foreign currency gain/loss. Foreign Currency Translation Risk
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include all cash balances and highly liquid investments with original maturities of three months or less from the date of purchase. Cash equivalents consists primarily of amounts invested in money market funds held at financial institutions and corporate debt securities. The recorded carrying amount of cash equivalents approximates their fair value.
Debt Securities	Debt Securities All securities are short-term in nature and consist of debt securities classified as available-for-sale and have maturities greater than 90 days, but less than 365 days from the date of acquisition. The Company’s debt securities consist of available-for-sale securities that are classified as Level 2 because their value is based on valuations using significant inputs derived from, or corroborated by, observable market data. The Company evaluates, on a quarterly basis, its available-for-sale debt securities for potential impairment. For available-for-sale debt securities in an unrealized loss position, the Company assesses whether such declines are due to credit related factors such as changes to the rating of the security by a ratings agency, market conditions and supportable forecasts of economic and market conditions, among others. If the fair value of available-for-sale debt securities is less than the amortized cost basis, the Company assesses whether it has plans to sell the security or it is more likely than not it will be required to sell any available-for-sale debt security before recovery of its amortized cost basis. If either condition is met, the security’s amortized cost basis is written down to fair value and is recognized through other (expense) income, net. If neither condition is met, declines as a result of credit losses, if any, are recognized as an allowance for credit loss, limited to the amount of unrealized loss, through other (expense) income, net. Any portion of the unrealized loss that is not a result of a credit loss, is recognized in other comprehensive loss. The cost of available-for-sale securities sold is based on the specific-identification method . Realized gains and losses on the sale of debt securities are determined using the specific-identification method and recorded in other (expense) income, net.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Depreciation expense is computed using the straight-line method over the estimated useful lives of the assets. Depreciation begins at the time the asset is placed into service. Maintenance and repairs are charged to operations as incurred. Property and equipment purchased for specific research and development projects with no alternative uses are expensed as incurred. The useful lives of the property and equipment are as follows: Lab equipment 5 years Furniture 5 years Leasehold improvements Shorter of remaining lease term or 5 years Computer equipment and software 3 years
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
Accounts Receivable	Accounts Receivable Accounts receivable represent amounts billed to the Company’s customers, net of an allowance for credit losses. Trade accounts receivable are recorded at invoiced amounts and do not bear interest. The allowance for credit losses reflects the Company’s best estimate of probable losses inherent in the receivable portfolio determined based on various factors, including age of the outstanding invoice, credit quality of the customer, historical experience, current economic conditions, and management’s expectations of future economic conditions. The Company regularly reviews the adequacy of the allowance for credit losses by considering the age of each outstanding invoice and the collection history of each customer to determine the appropriate amount of allowance for credit losses.
Inventories	Inventories Inventories are stated at the lower of cost, determined based on actual costs, or estimated net realizable value, on a first-in, first-out basis. Inventories consist of raw materials, work-in-process, and finished goods. Prior to regulatory approval of the Company’s product candidates, expenses incurred to manufacture drug products are recorded as research and development expense. The Company begins capitalizing these expenses as inventory upon regulatory approval.
Revenue Recognition	Revenue Recognition The Company recognizes revenue upon transfer of control of promised products to customers in an amount that reflects the consideration it expects to receive in exchange for those products. To determine revenue recognition for contracts with customers, the Company performs the following five-step approach: (i) identify the contract, or contracts, with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when, or as, the performance obligation is satisfied. The five-step model is only applied to contracts when it is probable that the Company will collect substantially all of the consideration it is entitled to in exchange for the goods transferred to a customer. Product Revenue The Company’s product revenue consists of sales of Zokinvy, which received FDA approval in November 2020 and was launched commercially in the United States in January 2021 and in Europe in November 2022. Prior to 2021, the Company had no product revenue. In the United States, the Company sells Zokinvy to a single specialty pharmacy provider that subsequently dispenses the product directly to patients. The Company discloses revenue on a total basis without further disaggregation. Additionally, the Company does not have any contract assets or liabilities, other than accounts receivable, related to its product revenue. In June 2021, the French National Agency for Medicines and Health Products Safety (ANSM) granted Zokinvy (lonafarnib) a Temporary Authorizations for Use (Autorisation Temporaire d'Utilisation or ATU) for an early access program for a term of one year. The Company has received a one year extension of the ATU program and expects the program to continue until commercial reimbursement of Zokinvy is approved in France. In the context of this program, the Company sells product to a distributor who in turn ships product to pharmacies after receiving requests from physicians for patients in France. In November 2021, the Company began distributing and recognizing revenue from sales of Zokinvy (lonafarnib) through a reimbursed early access program in France. The Company recorded revenue of $2.4 million and $0.2 million from sales of product under the ATU program for the years ended December 31, 2023 and 2022, respectively. The Company recognizes product revenue when a customer obtains control of its product, which occurs at a point in time, typically upon delivery to a customer as the delivery of the product is the Company’s only performance obligation. Shipping and handling activities are fulfillment activities rather than a separate performance obligation and are recorded in cost of sales. Product revenue is recorded at the net sales price (transaction price), which includes estimates of variable consideration resulting from rebates, prompt payment discounts, co-payment assistance, and returns. Amounts related to such items are estimated at contract inception and updated at the end of each reporting period as additional information becomes available. The amount of variable consideration may be constrained and is included in the transaction price only to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Product revenue is recorded after considering the impact of the following variable consideration amounts along with the constraint at the time of revenue recognition: Rebates: The Company’s product is subject to government mandated rebates for Medicaid Drug Rebate Program, Medicare Part D Prescription Drug Benefit Program, and other government health care programs in the United States. Rebate amounts are based upon contractual agreements or legal requirements with public sector benefit providers. The Company uses the expected-value method for estimating these rebates based on statutory discount rates and expected utilization. The expected utilization of rebates is estimated based on expected coverage of identified patients. Estimates for these rebates are adjusted quarterly to reflect the most recent information. The Company records an accrued liability for unpaid rebates related to products for which control has been transferred to a customer. Prompt payment discounts: The Company provides a discount to a customer if it pays for purchases within 30 days. The Company expects that its customers will earn prompt payment discounts and uses the most likely amount method for estimating such discounts. As a result, when revenues are recognized, the Company deducts the full amount of the prompt payment discounts from total product revenues and records these discounts as a reduction of accounts receivable. Co-payment assistance: The Company provides co-payment assistance to patients who have commercial insurance and meet certain eligibility requirements. The Company uses the expected-value method for estimating co-payment assistance based on estimates of program redemption using data provided by third-party administrators. Estimates for the co-payment assistance are adjusted quarterly to reflect actual experience. The Company records an accrued liability for unredeemed co-payment assistance related to products for which control has been transferred to a customer. Product returns: The Company offers limited product return rights and generally allows for the return of product that is damaged or defective, or within a few months prior to and up to a few months after the product expiration date. The Company considers several factors in the estimation of potential product returns, including expiration dates of the product shipped, the limited product return rights, third-party data in monitoring channel inventory levels, shelf life of the product, and other relevant factors. Other Revenue
Cost of Sales	Cost of Sales
Accrued Research and Development Costs	Accrued Research and Development Costs The Company accrues for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of preclinical and clinical studies, and contract manufacturing activities. The Company records the estimated costs of research and development activities based upon the estimated amount of services provided but not yet invoiced and includes these costs in accrued liabilities in the accompanying consolidated balance sheets and within research and development expenses in the accompanying consolidated statements of operations. The Company accrues for these costs based on factors such as estimates of the work completed made by its internal personnel and third-party service providers and in accordance with agreements established with its third-party service providers. The Company makes judgments and estimates in determining the accrued liabilities balance in each reporting period and although the Company does not expect its estimate to be materially different from amounts actually incurred, as actual costs become known the Company adjusts its accrued liabilities. Research and Development Costs
Leases	Leases The Company determines if an arrangement is or contains a lease at inception. Material leases with a term greater than one year are recognized in right-of-use assets and current and noncurrent lease liabilities, as applicable, in the Company’s consolidated balance sheets. The Company had a real estate lease for its office space in Palo Alto, California that expired on February 28, 2024. In February 2024, the Company amended the lease to extend the lease term for an additional month from March 1, 2024 to April 1, 2024 with a month to month renew option. The Company determines the initial classification and measurement of its right-of-use assets (ROU assets) and lease liabilities at the lease commencement date and thereafter if modified. The lease term includes any renewal options and termination options that the Company is reasonably assured to exercise. The present value of lease payments is determined by using the interest rate implicit in the lease, if that rate is readily determinable; otherwise, the Company uses its incremental borrowing rate. The incremental borrowing rate is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment. Rent expense for operating leases is recognized on a straight-line basis, unless the operating lease ROU assets have been impaired, over the reasonably assured lease term based on the total lease payments and is included in operating expenses in the consolidated statements of operations. For operating leases that reflect impairment, the Company will recognize the amortization of the operating lease ROU assets on a straight-line basis over the remaining lease term with rent expense still included in selling, general and administrative expenses in the consolidated statements of operations. The Company has elected the practical expedient to not separate lease and non-lease components. The Company’s non-lease components are primarily related to property maintenance and insurance, which varies based on future outcomes, and thus is recognized in selling, general and administrative expenses when incurred.
Debt Issuance Costs	Debt Issuance Costs
Stock-Based Compensation	Stock-Based Compensation
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company must then assess the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. Due to the Company’s lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on their technical merits, as the largest amount of benefit that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to unrecognized tax benefits. Internal Revenue Code Section 382 limits the use of net operating loss and tax credit carryforwards in certain situations where changes occur in the stock ownership of a company. In the event that the Company experiences a change of ownership, utilization of the net operating loss and tax credit carryforwards may be restricted.
Comprehensive Loss	Comprehensive Loss
Net Loss per Share	Net Loss per Share
Recent Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements Not Yet Adopted	Recent Adopted Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Updates (ASU) No. 2016-13, Financial Instruments—Credit Losses (Topic 326) . ASU 2016-13 requires an entity to utilize a new impairment model that requires measurement and recognition of expected credit losses for most financial assets and certain other instruments, including but not limited to available-for-sale debt securities. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down to the security. The new guidance requires the use of forward-looking expected credit loss models based on historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount, which may result in earlier recognition of credit losses under the new guidance. In April 2019, the FASB issued ASU No. 2019-04, Codification Improvements to Topic 326, Financial Instruments – Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments, which clarifies and corrects certain unintended applications of the guidance contained in each of the amended Topics. Additionally, in May 2019, the FASB issued ASU No. 2019-05, Financial Instruments – Credit Losses (Topic 326), which provides an option to irrevocably elect to measure certain individual financial assets at fair value instead of amortized cost. In November 2019, the FASB issued ASU No. 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842) , which Recently Issued Accounting Pronouncements Not Yet Adopted In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which requires an enhanced disclosure of significant segment expenses on an annual and interim basis. This guidance will be effective for the annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. Upon adoption, the guidance should be applied retrospectively to all prior periods presented in the financial statements. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures , which improves the transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the effective tax rate reconciliation and income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. This guidance will be effective for the annual periods beginning after December 15, 2024. Early adoption is permitted. Upon adoption, the guidance can be applied prospectively or retrospectively. The Company does not expect the adoption of this guidance to have a material impact on the consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives of Property and Equipment	The useful lives of the property and equipment are as follows: Lab equipment 5 years Furniture 5 years Leasehold improvements Shorter of remaining lease term or 5 years Computer equipment and software 3 years
Schedule of Potentially Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share	The following table sets forth the outstanding potentially dilutive securities which have been excluded in the calculation of diluted net loss per share because including such securities would be anti-dilutive (in common stock equivalent shares): December 31, 2023 2022 Options to purchase common stock 180,151 204,656 ESPP 12,839 11,121 Restricted stock units (unvested) 5,998 21,337 Total 198,988 237,114

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Estimated Value of Cash Equivalents and Debt Securities and Gross Unrealized Holding Gains and Losses	The following tables present the fair value hierarchy for assets measured at fair value, and summarize the estimated value of the Company’s cash equivalents and debt securities and the gross unrealized holding gains and losses (in thousands): December 31, 2023 Level Amortized cost Unrealized gain Unrealized loss Estimated Fair Cash equivalents: Money market funds 1 $ 18,653 $ — $ — $ 18,653 Total cash equivalents $ 18,653 $ — $ — $ 18,653 December 31, 2022 Level Amortized cost Unrealized gain Unrealized loss Estimated Fair Cash equivalents: Money market funds 1 $ 11,546 $ — $ — $ 11,546 Commercial paper 2 3,968 — — 3,968 Total cash equivalents $ 15,514 $ — $ — $ 15,514 Short-term debt securities: U.S. government bonds 2 $ 39,646 $ 3 $ (86) $ 39,563 Corporate debt securities 2 28,759 — (117) 28,642 Commercial paper 2 4,945 — — 4,945 Total debt securities $ 73,350 $ 3 $ (203) $ 73,150

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Schedule of Inventory	Inventories consist of the following (in thousands): December 31, 2023 2022 Work-in-progress $ 940 $ 884 Raw materials 531 1,703 Finished goods 85 266 Total inventories $ 1,556 $ 2,853
Schedule of Property, Plant and Equipment	Property and equipment, net consist of the following (in thousands): December 31, 2023 2022 Computer equipment and software $ 1,004 $ 736 Construction in progress 305 367 Lab equipment 271 271 Furniture 116 116 Leasehold improvements 101 101 Total property and equipment 1,797 1,591 Less: accumulated depreciation (1,170) (895) Property and equipment, net $ 627 $ 696
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following (in thousands): December 31, 2023 2022 Prepaid research costs $ 5,577 $ 2,822 Prepaid marketing 911 753 Prepaid contract manufacturing costs 577 3,542 Short term deposits 404 4,542 Prepaid insurance 403 586 Other 1,289 1,740 Total prepaid expenses and other current assets $ 9,161 $ 13,985
Schedule of Components of Accrued Liabilities	Accrued liabilities consist of the following (in thousands): December 31, 2023 2022 Compensation and related benefits $ 3,046 $ 6,167 Contract research costs 2,909 4,579 Product revenue reserves 2,277 1,373 Contract manufacturing costs 818 2,101 Legal fees 438 562 Other 478 873 Total accrued liabilities $ 9,966 $ 15,655

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Schedule of Long-Term Debt and Unamortized Discount Balances	Debt and unamortized discount balances are as follows (in thousands): December 31, 2023 2022 Face value of debt $ 41,452 $ 40,531 Exit fee 2,600 2,600 Unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees (2,933) (3,506) Current portion of long-term debt $ 41,119 $ 39,625
Schedule of Maturities of Long-term Debt	As of December 31, 2023, future minimum payments of principal, paid in kind interest and exit fee under the Innovatus Loan were as follows (in thousands): Year ending December 31, 2024 45,393 2025 — 2026 — 2027 — Total future payments 45,393 Less: paid in kind interest (1,341) Less: unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees (2,933) Current portion of long-term debt $ 41,119

Stockholders_ Equity (Tables)

Stockholders’ Equity (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Common Stock Reserved For Future Issuances	The Company had reserved shares of common stock for issuance as follows: December 31, 2023 2022 Options issued and outstanding 180,151 204,656 Awards available for future issuance 203,891 65,882 Shares available for issuance under ESPP 24,587 26,296 Restricted and performance stock units outstanding 5,998 21,337 Total 414,627 318,171

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Stock Option Activity	The following table summarizes stock option activity under the Company’s stock-based compensation plans during the year ended December 31, 2023 (in thousands, except option and share data): Number of Weighted- Weighted- Aggregate Outstanding as of December 31, 2022 204,656 $ 270.00 6.00 $ — Granted 119,623 $ 46.89 Forfeited (144,128) $ 221.28 Outstanding as of December 31, 2023 180,151 $ 167.68 6.56 $ — Vested and exercisable as of December 31, 2023 97,601 $ 248.27 5.36 $ —
Schedule of Weighted-average assumptions used in Black-Scholes Model to estimate fair value of stock options granted	The fair value of stock options was estimated using the following weighted-average assumptions: Year Ended December 31, 2023 2022 Expected term (in years) 0.86-6.08 5.27-6.08 Volatility 90.21%-156.25% 68.71%-88.51% Risk free interest rate 3.50%-4.86% 1.76%-4.23% Dividend yield — —
Schedule of Nonvested Restricted Stock Units and Performance Stock Units Activity and Weighted Average Grant Date Fair Value	The following table summarizes RSU and PSU activity and weighted average grant date fair value for the year ended December 31, 2023: Shares Weighted- Unvested shares as of December 31, 2022 21,337 $ 220.40 Granted 1,805 $ 67.80 Vested (8,625) $ 176.10 Forfeited (8,519) $ 236.55 Unvested shares as of December 31, 2023 5,998 $ 215.24
Schedule of Non-cash Stock Based Compensation Expense	Total stock-based compensation expense recognized was as follows (in thousands): Year Ended December 31, 2023 2022 Research and development $ 2,391 $ 3,159 Selling, general and administrative 2,617 5,158 Total $ 5,008 $ 8,317

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The following table presents loss before provision for income taxes as follows (in thousands): Year Ended December 31, 2023 2022 Domestic $ (75,002) $ (96,769) Foreign 45 16 Total loss before provision for income taxes $ (74,957) $ (96,753)
Schedule of State and Foreign Income Tax Provisions	The state and foreign income tax provisions for the years ended December 31, 2023 and 2022 are summarized as follows (in thousands): Year Ended December 31, 2023 2022 Current: State $ — $ 21 Foreign 6 2 Total current $ 6 $ 23 Deferred: State $ — $ — Foreign — — Total deferred $ — $ — Total provision for income taxes $ 6 $ 23
Schedule of Effective Income Tax Rate Reconciliation	The effective tax rate of the provision for income taxes differs from the federal statutory rate as follows: Year Ended December 31, 2023 2022 Federal statutory income tax rate 21.00 % 21.00 % Change in valuation allowance (27.82) (25.99) Tax credits 6.24 4.15 State income taxes, net of federal benefit 4.12 2.39 Stock-based compensation (3.47) (0.98) Other, net (0.06) (0.59) Provision for income taxes 0.01 % (0.02) %
Schedule of Deferred Tax Assets and Liabilities	The components of the deferred tax assets and liabilities are as follows (in thousands): December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 69,417 $ 63,069 Tax credits 15,194 9,985 Depreciation and amortization 2,775 2,920 Stock-based compensation 1,905 3,429 Section 174 capitalization 26,668 15,581 Accruals and reserves 884 1,431 Lease liabilities 20 131 Gross deferred tax assets 116,863 96,546 Valuation allowance (116,842) (96,418) Total deferred tax assets 21 128 Deferred tax liabilities: Right-of-use assets (21) (128) Total deferred tax liabilities (21) (128) Net deferred tax assets $ — $ —
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the Company’s unrecognized tax benefits for the years ended December 31, 2023 and 2022 is as follows (in thousands): Year Ended December 31, 2023 2022 Balance at beginning of year $ 3,492 $ 1,950 Additions based on tax positions related to current year 1,784 1,586 Reductions based on tax positions related to prior year — (44) Balance at end of year $ 5,276 $ 3,492

Description of Business - Addit

Description of Business - Additional Information (Detail) $ in Thousands			12 Months Ended
		Jan. 05, 2024	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of operating segments | segment			1
Cash and cash equivalents	[1]		$ 25,440	$ 25,798
Accumulated deficit	[1]		$ 512,156	$ 437,193
Subsequent Event
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reverse stock split, conversion ratio		0.0333
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)		1 Months Ended	12 Months Ended
		Jun. 30, 2021	Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2020
Product Information [Line Items]
Aggregated transaction gains			$ 100,000		$ 100,000
Foreign currency translation adjustment	[1]		(69,000)		(100,000)
Impairment, Long-Lived Asset, Held-for-Use			0
Accounts receivable, allowance for doubtful accounts			0		0
Credit losses			0		0
Inventory write down			8,000		1,043,000
Total revenue	[2]		$ 15,773,000		$ 13,484,000
Early access program term (in years)		1 year
Early access program extension term (in years)			1 year
Anti-dilutive securities (in shares)			198,988		237,114
Options to purchase common stock
Product Information [Line Items]
Anti-dilutive securities (in shares)			180,151		204,656
ESPP
Product Information [Line Items]
Anti-dilutive securities (in shares)			12,839		11,121
Restricted stock units (unvested)
Product Information [Line Items]
Anti-dilutive securities (in shares)			5,998		21,337
Customer A | Customer Concentration Risk | Financing Receivable
Product Information [Line Items]
Concentration risk			48%		58%
Customer A | Customer Concentration Risk | Revenue Benchmark
Product Information [Line Items]
Concentration risk			73%		93%
Customer B | Customer Concentration Risk | Financing Receivable
Product Information [Line Items]
Concentration risk			37%		42%
Customer B | Customer Concentration Risk | Revenue Benchmark
Product Information [Line Items]
Concentration risk			26%
Customer C | Customer Concentration Risk | Financing Receivable
Product Information [Line Items]
Concentration risk			15%
Product revenue, net
Product Information [Line Items]
Total revenue			$ 15,523,000	[2]	$ 12,734,000	[2]	$ 0
Autorisation Temporaire D Utlisation Member
Product Information [Line Items]
Total revenue			$ 2,400,000		$ 200,000
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information for further information

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Property and Equipment (Details)	Dec. 31, 2023
Lab equipment
Property, Plant and Equipment [Line Items]
Useful life	5 years
Furniture
Property, Plant and Equipment [Line Items]
Useful life	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Useful life	5 years
Computer equipment and software
Property, Plant and Equipment [Line Items]
Useful life	3 years

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Allowance for credit loss, not previously recorded	$ 0
Allowance for expected credit losses	0
Unrealized loss		$ 203,000
Unrealized loss position for more than 12 months		21,000
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Financial liabilities	0	0
Transfers in or out of level 3	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Estimated Value of Cash Equivalents and Debt Securities and Gross Unrealized Holding Gains and Losses (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Cash Equivalents and Investment Securities [Line Items]
Cash equivalents, amortized cost	$ 18,653	$ 15,514
Cash equivalents, estimated fair value	18,653	15,514
Debt securities, amortized cost		73,350
Debt securities, unrealized gain		3
Unrealized loss		(203)
Debt securities, estimated fair value		73,150
Commercial paper | Level 2
Cash Equivalents and Investment Securities [Line Items]
Debt securities, amortized cost		4,945
Debt securities, unrealized gain		0
Unrealized loss		0
Debt securities, estimated fair value		4,945
U.S. government bonds | Level 2
Cash Equivalents and Investment Securities [Line Items]
Debt securities, amortized cost		39,646
Debt securities, unrealized gain		3
Unrealized loss		(86)
Debt securities, estimated fair value		39,563
Corporate debt securities | Level 2
Cash Equivalents and Investment Securities [Line Items]
Debt securities, amortized cost		28,759
Debt securities, unrealized gain		0
Unrealized loss		(117)
Debt securities, estimated fair value		28,642
Money market funds | Level 1
Cash Equivalents and Investment Securities [Line Items]
Cash equivalents, amortized cost	18,653	11,546
Cash equivalents, estimated fair value	$ 18,653	11,546
Commercial paper | Level 2
Cash Equivalents and Investment Securities [Line Items]
Cash equivalents, amortized cost		3,968
Cash equivalents, estimated fair value		$ 3,968

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Inventory (Detail) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Work-in-progress		$ 940	$ 884
Raw materials		531	1,703
Finished goods		85	266
Total inventories	[1]	$ 1,556	$ 2,853
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information.

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 1,797	$ 1,591
Less: accumulated depreciation		(1,170)	(895)
Property and equipment, net	[1]	627	696
Depreciation		300	300
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment		1,004	736
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment		305	367
Lab equipment
Property, Plant and Equipment [Line Items]
Total property and equipment		271	271
Furniture
Property, Plant and Equipment [Line Items]
Total property and equipment		116	116
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 101	$ 101
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information.

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Prepaid research costs		$ 5,577	$ 2,822
Prepaid marketing		911	753
Prepaid contract manufacturing costs		577	3,542
Short term deposits		404	4,542
Prepaid insurance		403	586
Other		1,289	1,740
Total prepaid expenses and other current assets	[1]	$ 9,161	$ 13,985
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information.

Balance Sheet Components - Sc_4

Balance Sheet Components - Schedule of Components of Accrued Liabilities (Detail) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Compensation and related benefits		$ 3,046	$ 6,167
Contract research costs		2,909	4,579
Product revenue reserves		2,277	1,373
Contract manufacturing costs		818	2,101
Legal fees		438	562
Other		478	873
Total accrued liabilities	[1]	$ 9,966	$ 15,655
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information.

License, Collaboration, and P_2

License, Collaboration, and Product Development Agreements - Additional Information (Detail)

1 Months Ended

3 Months Ended

12 Months Ended

Jan. 05, 2024

Aug. 11, 2018 USD ($) shares

May 15, 2018 USD ($)

Mar. 31, 2022 USD ($)

Apr. 30, 2016 USD ($) shares

Sep. 30, 2010 USD ($) shares

Dec. 31, 2020 USD ($)

Dec. 31, 2023 USD ($)

Dec. 31, 2022 USD ($) shares

Dec. 31, 2019 USD ($)

Sep. 30, 2023 USD ($)

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Research and development

[1]

$ 62,331,000

$ 75,282,000

Value of common stock issued during period

[2]

66,110,000

Common stock, value, issued

[3]

1,000

1,000

Accrued liabilities

[3]

9,966,000

15,655,000

Subsequent Event

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Reverse stock split, conversion ratio

0.0333

UPennCHOPAgreement

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Non refundable issue fee

$ 1,000,000

Research and development

2,000,000

Product Development Agreement

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Product development fees

$ 10,000,000

Period of committed payment of fees

4 years

Expert consultant fees and pass through costs

$ 800,000

Incentive-based regulatory milestone fees

$ 1,000,000

Number of common stock issued subject to quarterly vesting requirements (in shares) | shares

3,848

Research and development

$ 19,000

Progeria Research Foundation (PRF) Collaboration Agreement

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Collaboration agreement initial term

10 years

Collaborative arrangement renewal term

2 years

Maximum | UPennCHOPAgreement

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

License maintenance fee

2,500,000

Commercial Sales | Maximum | UPennCHOPAgreement

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Milestone obligations

$ 0

$ 18,000,000

Common Stock

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Issuance of common stock (in shares) | shares

[2]

284,262

Licensing Agreements

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Up front cash payments

$ 2,000,000

Licensing Agreements | Merck Transaction

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Milestone payments

$ 1,000,000

Accrued liabilities

$ 1,000,000

Licensing Agreements | Research and development | Maximum | Merck Transaction

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Development milestone obligations

$ 27,000,000

Contract-Based Intangible Assets | Merck Transaction

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Issuance of common stock (in shares) | shares

911

Common stock, value, issued

$ 500,000

BMS Transaction | Common Stock | Purchase Agreement

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Issuance of common stock (in shares) | shares

5,252

Value of common stock issued during period

$ 3,200,000

BMS Transaction | Licensing Agreements | Development And Regulatory Milestones

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Milestone obligations

61,000,000

BMS Transaction | Licensing Agreements | Commercial Sales | Maximum

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Milestone obligations

$ 128,000,000

BMS Transaction | Licensing Agreements | Development Phase Two

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Milestone obligations

$ 3,000,000

BMS Transaction | Licensing Agreements | Development Phase Three

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Milestone obligations

$ 5,000,000

[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information for further information for further information.

Asset Purchase Agreements and_2

Asset Purchase Agreements and Related License Agreements - Additional Information (Detail) $ / shares in Units, $ in Millions		1 Months Ended	100 Months Ended
	Jan. 05, 2024	Sep. 30, 2015 USD ($) $ / shares shares	Dec. 31, 2023 USD ($)
Subsequent Event
Asset Purchase Agreement And Related License Agreement [Line Items]
Reverse stock split, conversion ratio	0.0333
Avexitide Purchase Agreement
Asset Purchase Agreement And Related License Agreement [Line Items]
Issued stocks (in shares) | shares		512
Stock issued during period		$ 0.2
Options to purchase of common stock (in shares) | shares		3,155
License agreement milestone payments paid			$ 0.1
Avexitide Purchase Agreement | Service-Based Performance Vesting Condition
Asset Purchase Agreement And Related License Agreement [Line Items]
Exercise price (in USD per share) | $ / shares		$ 61.80
Avexitide Purchase Agreement | Milestone-Based Performance Vesting Condition
Asset Purchase Agreement And Related License Agreement [Line Items]
Exercise price (in USD per share) | $ / shares		$ 517.80
Avexitide Purchase Agreement | Maximum
Asset Purchase Agreement And Related License Agreement [Line Items]
License agreement potential milestone payments		$ 1

Debt - Additional Information (

Debt - Additional Information (Detail) $ / shares in Units, $ in Thousands				12 Months Ended
		Jan. 05, 2024	Jun. 01, 2022 USD ($) tranche $ / shares shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jun. 30, 2022 USD ($) tranche
Debt Instrument [Line Items]
Face value of term loan				$ 41,452	$ 40,531
Interest expense	[1]			5,466	4,132
Issuance of common stock upon offering at-the-market, net of $2,068 of issuance costs	[2]				66,110
Loss on extinguishment of debt				0	1,144
Subsequent Event
Debt Instrument [Line Items]
Reverse stock split, conversion ratio		0.0333
Secured Debt | Line of Credit | Innovatus Stock Purchase Agreement
Debt Instrument [Line Items]
Issuance of common stock upon offering at-the-market, net of $2,068 of issuance costs			$ 5,000
Sale of common stock, shares issued (in shares) | shares			24,967
Sale of common stock (in USD per share) | $ / shares			$ 200.25
Secured Debt | Innovatus Loan | Line of Credit
Debt Instrument [Line Items]
Loan agreement, aggregate borrowing capacity			$ 75,000
Number of tranches | tranche			3
Debt instrument, percent of interest due (in percent)			0.0225
Interest due timeframe			3 years
Percentage of exit fee on principal balance			6.50%
Minimum cash balance of face value of loan (in percent)			0.05
Debt instrument, penalty percentage			5%
Debt discount			$ 200
Capitalized debt issuance costs			$ 1,100
Interest expense				$ 5,500
Effective interest rate				13.84%
Secured Debt | Innovatus Loan | Line of Credit | Minimum
Debt Instrument [Line Items]
Prepayment fee			3%
Secured Debt | Innovatus Loan | Line of Credit | Maximum
Debt Instrument [Line Items]
Prepayment fee			0%
Secured Debt | Innovatus Loan | Line of Credit | Variable Rate Component One | Minimum
Debt Instrument [Line Items]
Minimum prime rate			3.50%
Secured Debt | Innovatus Loan | Line of Credit | Variable Rate Component Two
Debt Instrument [Line Items]
Minimum prime rate			3.75%
Secured Debt | Oxford Loan | Line of Credit
Debt Instrument [Line Items]
Face value of term loan			$ 33,500
Secured Debt, Tranche A | Innovatus Loan | Line of Credit
Debt Instrument [Line Items]
Face value of term loan						$ 40,000
Secured Debt, Tranche B and C | Innovatus Loan | Line of Credit
Debt Instrument [Line Items]
Number of tranches | tranche						2
Face value of term loan						$ 35,000
Secured Debt, Tranche B | Innovatus Loan | Line of Credit
Debt Instrument [Line Items]
Face value of term loan						$ 17,500
Amended Tranche A | Amended Oxford Loan | Line of Credit
Debt Instrument [Line Items]
Loan agreement, aggregate borrowing capacity			30,000
Accrued and unpaid interest			200
Other final payments			3,300
Repayments of loan agreement exit fee			$ 33,500
Loss on extinguishment of debt					$ 1,100
Success fee, percentage			5%
Debt instrument success fee, number of days to pay			30 days
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information for further information

Debt - Schedule of Long-Term De

Debt - Schedule of Long-Term Debt and Unamortized Discount Balances (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Face value of debt	$ 41,452	$ 40,531
Exit fee	2,600	2,600
Unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees	(2,933)	(3,506)
Current portion of long-term debt	$ 41,119	$ 39,625

Debt - Schedule of Maturities o

Debt - Schedule of Maturities of Long-term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Less: unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees	$ (2,933)	$ (3,506)
Current portion of long-term debt	41,119	$ 39,625
Amended Tranche A | Innovatus Loan
Debt Instrument [Line Items]
2024	45,393
2025	0
2026	0
2027	0
Total future payments	45,393
Less: paid in kind interest	(1,341)
Less: unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees	(2,933)
Current portion of long-term debt	$ 41,119

Stockholders_ Equity - Addition

Stockholders’ Equity - Additional Information (Detail)			1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 05, 2024	Mar. 25, 2022 USD ($) shares	Dec. 31, 2020 USD ($)	Mar. 31, 2022 USD ($) shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividends declared					$ 0
Aggregate offering amount			$ 200,000,000
Issuance of common stock upon offering at-the-market, net of commissions					$ 0	$ 66,402,000
Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Reverse stock split, conversion ratio	0.0333
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock available for future issuance		$ 50,000,000
At The Market Offering
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate offering amount			200,000,000
Maximum shares issued during the period			$ 50,000,000
Issuance of common stock upon offering at-the-market, net of issuance costs (in shares) | shares				194,723
Issuance of common stock upon offering at-the-market, net of commissions				$ 45,600,000
Sale of common stock, shares issued (in shares) | shares		89,539
Consideration received on sale of stock		$ 20,800,000

Stockholders_ Equity - Common S

Stockholders’ Equity - Common Stock Reserved For Future Issuances (Details) - shares	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Options issued and outstanding (in shares)	180,151	204,656
Awards available for future issuance (in shares)	203,891	65,882
Shares available for issuance under ESPP (in shares)	24,587	26,296
Restricted and performance stock units outstanding (in shares)	5,998	21,337
Total (in shares)	414,627	318,171

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended	12 Months Ended
		May 31, 2023 USD ($)	Mar. 31, 2020	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2016 shares	Feb. 06, 2023	Jun. 30, 2021 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards available for future grants (in shares)				203,891	65,882
Closing price of common stock (in USD per share) | $ / shares				$ 6.75
Aggregate intrinsic value of options exercised | $				$ 0	$ 100
Aggregate intrinsic value of options exercised | $				$ 5,800	$ 7,300
Total (in shares)				414,627	318,171
Percentage increase in number of shares of common stock reserved for issuance						1%
Additional options authorized (in shares)						5,500
Issuance of common stock upon ESPP purchase | $	[1]			$ 56	$ 158
Total stock-based compensation expense | $				5,008	$ 8,317
Total unrecognized compensation expense | $				$ 10,900
Weighted-average period for recognition (in years)				2 years 7 months 6 days
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock upon ESPP purchase (in shares)	[1]			1,709	1,594
Additional Paid-In Capital
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock upon ESPP purchase | $	[1]			$ 56	$ 158
Options to purchase common stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of employee option grants (in USD per share) | $ / shares				$ 28.97	$ 109.53
Restricted stock units (unvested)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period of service threshold			6 months
Common stock available for grant (in shares)				1,305	9,925
Weighted-average grant date fair value of employee option grants (in USD per share) | $ / shares				$ 67.80	$ 156.58
Total stock-based compensation expense | $				$ 700	$ 1,200
Restricted stock units (unvested) | Director
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of new grants			1 year
Restricted stock units (unvested) | Share-based Payment Arrangement, Tranche One | Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of new grants			1 year
Restricted stock units (unvested) | Share-based Payment Arrangement, Tranche Two | Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of new grants			2 years
Restricted stock units (unvested) | Share-based Payment Arrangement, Tranche Three | Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of new grants			3 years
Performance Stock Units (PSU)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock available for grant (in shares)				500	1,000
Weighted-average grant date fair value of employee option grants (in USD per share) | $ / shares				$ 67.80	$ 206.10
Total stock-based compensation expense | $				$ 400	$ 500
Share-based compensation arrangement by share-based payment award, accelerated vesting, number (in shares)				500
Vested (in shares)				1,349
Share-based compensation arrangement by share-based payment award, equity instruments other than options, performance based metric, net sales threshold | $				$ 35,000
Performance Stock Units (PSU) | Four Terminated Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee benefits and share-based compensation expense (reversal) | $		$ (400)
Unvested Stock Options, Performance-Based Restricted Stock Units, And Time-Based RSUs | Former CEO
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee benefits and share-based compensation expense (reversal) | $				$ 900
Accelerated vesting							0.50
Restated Two Thousand Thirteen Equity Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of new grants				4 years
Number of shares available to be issued (in shares)				344,380
Inducement Plan 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available to be issued (in shares)								28,333
Awards available for future grants (in shares)				22,539
Two Thousand Thirteen Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards available for future grants (in shares)				24,587
Total (in shares)				31,626		3,333
Minimum | Restated Two Thousand Thirteen Equity Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Threshold ownership percentage of shareholder for grant of options at pre determined exercise price				0.10
Minimum | Restated Two Thousand Thirteen Equity Incentive Plan Member | Holders Of Ten Percent Or More Of Voting Power
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee holding percentage				110%
Maximum | Restated Two Thousand Thirteen Equity Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Contractual terms of options granted under the Plan				10 years
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Number of Options
Outstanding, beginning balance (in shares)	204,656
Granted (in shares)	119,623
Forfeited (in shares)	(144,128)
Outstanding, ending balance (in shares)	180,151	204,656
Vested and exercisable (in shares)	97,601
Weighted- Average Exercise Price
Weighted-average exercise price, outstanding, beginning balance (in USD per share)	$ 270
Weighted-average exercise price, granted (in USD per share)	46.89
Weighted-average exercise price, forfeited (in USD per share)	221.28
Weighted-average exercise price, outstanding, ending balance (in USD per share)	167.68	$ 270
Weighted-average exercise price, vested and exercisable (in USD per share)	$ 248.27
Stock Options Additional Disclosures
Weighted- Average Remaining Contractual Life (in Years)	6 years 6 months 21 days	6 years
Aggregate Intrinsic Value	$ 0	$ 0
Weighted average remaining contractual life, vested and exercisable (in years)	5 years 4 months 9 days
Aggregate intrinsic value, vested and exercisable	$ 0

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted-average assumptions used in Black-Scholes Model to estimate fair value of stock options granted (Detail) - Stock Options	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility, minimum	90.21%	68.71%
Volatility, maximum	156.25%	88.51%
Risk free interest rate, minimum	3.50%	1.76%
Risk free interest rate, maximum	4.86%	4.23%
Dividend yield	0%	0%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	10 months 9 days	5 years 3 months 7 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 29 days	6 years 29 days

Stock Based Compensation - Sche

Stock Based Compensation - Schedule of Nonvested Restricted Stock Units and Performance Stock Units Activity and Weighted Average Grant Date Fair Value (Detail)	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Shares
Unvested shares, beginning balance (in shares)	21,337
Unvested shares, ending balance (in shares)	5,998
Restricted Stock Units and Performance Stock Unit
Shares
Unvested shares, beginning balance (in shares)	21,337
Stock options granted (in shares)	1,805
Vested (in shares)	(8,625)
Forfeited (in shares)	(8,519)
Unvested shares, ending balance (in shares)	5,998
Weighted- Average Grant Date Fair Value
Weighted average grant-date fair value of options beginning balance (in USD per share) | $ / shares	$ 220.40
Weighted-average grant date fair value of employee option grants (in USD per share) | $ / shares	67.80
Weighted average grant-date fair value of options vested (in USD per share) | $ / shares	176.10
Weighted average grant-date fair value of options forfeited (in USD per share) | $ / shares	236.55
Weighted average grant-date fair value of options ending balance (in USD per share) | $ / shares	$ 215.24

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Non-cash Stock Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 5,008	$ 8,317
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	2,391	3,159
Selling, general and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,617	$ 5,158

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Tax Credit Carryforward [Line Items]
Provision for income taxes	[1]	$ 6,000	$ 23,000
Provision for income taxes		0.01%	(0.02%)
Increase in valuation allowance		$ 20,400,000	$ 25,100,000
Unrecognized tax benefits impact on effective tax rate		5,300,000
Unrecognized tax benefits, income tax penalties and interest expense		0	$ 0
State and Local Jurisdiction
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards		47,100,000
Research and development tax credit carryforwards		4,000,000
Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards		322,500,000
Research and development tax credit carryforwards		1,600,000
Domestic Tax Authority | Orphan Drug Credit Carryforward
Tax Credit Carryforward [Line Items]
Research and development tax credit carryforwards		$ 15,500,000
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income before Income Tax, Domestic and Foreign (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Domestic		$ (75,002)	$ (96,769)
Foreign		45	16
Loss before provision for income taxes	[1]	$ (74,957)	$ (96,753)
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information

Income Taxes - Schedule of Stat

Income Taxes - Schedule of State and Foreign Income Tax Provisions (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Current:
State		$ 0	$ 21
Foreign		6	2
Total current		6	23
Deferred:
State		0	0
Foreign		0	0
Total deferred		0	0
Total provision for income taxes	[1]	$ 6	$ 23
[1]All periods presented have been retroactively adjusted to reflect the 1-for-30 reverse stock split effected on January 5, 2024. Refer to Note 1 for further information

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21%	21%
Change in valuation allowance	(27.82%)	(25.99%)
Tax credits	6.24%	4.15%
State income taxes, net of federal benefit	4.12%	2.39%
Stock-based compensation	(3.47%)	(0.98%)
Other, net	(0.06%)	(0.59%)
Provision for income taxes	0.01%	(0.02%)

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 69,417	$ 63,069
Tax credits	15,194	9,985
Depreciation and amortization	2,775	2,920
Stock-based compensation	1,905	3,429
Section 174 capitalization	26,668	15,581
Accruals and reserves	884	1,431
Lease liabilities	20	131
Gross deferred tax assets	116,863	96,546
Valuation allowance	(116,842)	(96,418)
Total deferred tax assets	21	128
Right-of-use assets	(21)	(128)
Total deferred tax liabilities	(21)	(128)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 3,492	$ 1,950
Additions based on tax positions related to current year	1,784	1,586
Reductions based on tax positions related to prior year	0	(44)
Balance at end of year	$ 5,276	$ 3,492

Legal Matters (Details)

Legal Matters (Details)	Nov. 15, 2022 claim	Nov. 08, 2022 executive
Schoen v. Eiger BioPharmaceuticals
Loss Contingencies [Line Items]
Number of former executives | executive		2
The Progeria Research Foundation v. Eiger BioPharmaceuticals
Loss Contingencies [Line Items]
Number of claims | claim	2

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ in Millions	Apr. 03, 2024	Mar. 31, 2024
Subsequent Event | Zokinvy Program | Disposal Group, Held-for-Sale, Not Discontinued Operations
Subsequent Event [Line Items]
Purchase price	$ 30	$ 26