Eiger BioPharmaceuticals (EIGRQ) 10-Q 5 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 02, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Trading Symbol	EIGR
Entity Registrant Name	Eiger BioPharmaceuticals, Inc.
Entity Central Index Key	0001305253
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		43,216,126
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-36183
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
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock (par value $0.001 per share)
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 46,562	$ 22,221
Short-term debt securities	86,155	66,594
Accounts receivable, net	2,287	2,576
Inventories	1,910	2,612
Prepaid expenses and other current assets	10,442	9,361
Total current assets	147,356	103,364
Long-term debt securities		17,262
Property and equipment, net	545	613
Operating lease right-of-use assets	521	653
Other assets	4,907	4,510
Total assets	153,329	126,402
Current liabilities:
Accounts payable	9,218	7,765
Accrued liabilities	14,255	13,699
Current portion of operating lease liabilities	590	628
Current portion of long-term debt, net	12,549	7,809
Total current liabilities	36,612	29,901
Long-term debt, net	19,446	23,986
Operating lease liabilities	4	116
Total liabilities	56,062	54,003
Stockholders’ equity:
Common stock	41	35
Additional paid-in capital	460,808	412,930
Accumulated other comprehensive loss	(522)	(149)
Accumulated deficit	(363,060)	(340,417)
Total stockholders’ equity	97,267	72,399
Total liabilities and stockholders’ equity	$ 153,329	$ 126,402

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Product revenue, net	$ 2,673,000	$ 3,646,000
Costs and operating expenses:
Cost of sales	110,000	53,000
Research and development	17,570,000	13,842,000
Selling, general and administrative	6,813,000	5,564,000
Total costs and operating expenses	24,493,000	19,459,000
Loss from operations	(21,820,000)	(15,813,000)
Interest expense	(886,000)	(885,000)
Interest income	45,000	51,000
Other income, net	27,000	45,914,000
(Loss) income before provision for income taxes	(22,634,000)	29,267,000
Provision for income taxes	9,000	19,000
Net (loss) income	$ (22,643,000)	$ 29,248,000
Net (loss) income per common share:
Basic	$ (0.64)	$ 0.86
Diluted	$ (0.64)	$ 0.85
Weighted-average common shares outstanding:
Basic	35,253,147	33,886,896
Diluted	35,253,147	34,220,895

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive (Loss) Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (22,643)	$ 29,248
Other comprehensive (loss) income:
Unrealized (loss) gain on available-for-sale debt securities, net	(373)	3
Comprehensive (loss) income	$ (23,016)	$ 29,251

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2020	$ 95,035	$ 34	$ 401,509	$ (8)	$ (306,500)
Balance, beginning of period, Shares at Dec. 31, 2020		33,878,486
Issuance of common stock upon exercise of stock options	166		166
Issuance of common stock upon exercise of stock options, Shares		19,150
Vesting of common stock issued under Product Development Agreement	53		53
Issuance of common stock upon ESPP purchase	136		136
Issuance of common stock upon ESPP purchase, Shares		19,928
Issuance of common stock upon release of restricted stock units, Shares		33,750
Stock-based compensation expense	1,549		1,549
Unrealized (loss) gain on available-for-sale debt securities, net	3			3
Net (loss) income	29,248				29,248
Balance at Mar. 31, 2021	126,190	$ 34	403,413	(5)	(277,252)
Balance, end of period, Shares at Mar. 31, 2021		33,951,314
Balance at Dec. 31, 2021	72,399	$ 35	412,930	(149)	(340,417)
Balance, beginning of period, Shares at Dec. 31, 2021		34,568,821
Issuance of common stock upon offering at-the-market, net of commissions	45,610	$ 6	45,604
Issuance of common stock upon offering at-the-market, net of commissions, shares		5,841,786
Issuance of common stock upon exercise of stock options	$ 144		144
Issuance of common stock upon exercise of stock options, Shares	15,995	15,995
Vesting of common stock issued under Product Development Agreement	$ 19		19
Issuance of common stock upon ESPP purchase	64		64
Issuance of common stock upon ESPP purchase, Shares		18,130
Issuance of common stock upon release of restricted stock units, Shares		85,106
Stock-based compensation expense	2,047		2,047
Unrealized (loss) gain on available-for-sale debt securities, net	(373)			(373)
Net (loss) income	(22,643)				(22,643)
Balance at Mar. 31, 2022	$ 97,267	$ 41	$ 460,808	$ (522)	$ (363,060)
Balance, end of period, Shares at Mar. 31, 2022		40,529,838

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Statement Of Stockholders Equity [Abstract]
Issuance of common stock upon public offering, commissions	$ 1,288

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net (loss) income	$ (22,643)	$ 29,248
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Gain from sale of priority review voucher		(46,493)
Income related to asset purchase agreement		(281)
Depreciation and amortization	73	67
Stock-based compensation	2,047	1,549
Amortization of debt securities premiums and discounts	330	191
Non-cash interest expense	200	199
Amortization of operating lease right-of-use assets	132	127
Common stock issued under Product Development Agreement	19	53
Change in operating assets and liabilities:
Accounts receivable	289	(639)
Inventories	666	(1,304)
Prepaid expenses and other current assets	(854)	1,529
Other assets	(397)	(18)
Accounts payable	1,269	3,175
Accrued liabilities	560	(2,205)
Operating lease liabilities	(150)	(131)
Net cash used in operating activities	(18,459)	(14,933)
Investing activities
Purchase of debt securities available-for-sale	(10,902)	(2,049)
Proceeds from maturities of debt securities available-for-sale	7,900	49,755
Proceeds from sale of priority review voucher		95,000
Payments related to priority review voucher		(48,507)
Proceeds related to asset purchase agreement		281
Purchase of property and equipment		(16)
Net cash (used in) provided by investing activities	(3,002)	94,464
Financing activities
Issuance of common stock upon offering at-the-market, net of commissions	45,610
Proceeds from issuance of common stock upon stock option exercises	144	166
Proceeds from issuance of common stock upon ESPP purchase	64	146
Common stock offering costs	(16)	(122)
Payment of debt issuance costs		(175)
Net cash provided by financing activities	45,802	15
Net increase in cash and cash equivalents	24,341	79,546
Cash and cash equivalents at beginning of period	22,221	28,864
Cash and cash equivalents at end of period	46,562	108,410
Supplemental disclosure of cash flow information:
Interest paid	686	$ 686
Income taxes paid	$ 41

Description of Business

Description of Business	3 Months Ended
	Mar. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	1. 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 to treat and cure Hepatitis Delta Virus (HDV), the most severe form of viral hepatitis, and other serious diseases. All five of the Company’s rare disease programs have FDA Breakthrough Therapy Designation. The Eiger HDV platform includes two first-in-class therapies in Phase 3 that target critical host processes involved in viral replication. Lonafarnib is a first-in-class oral farnesylation inhibitor and peginterferon lambda (lambda) is a first-in-class, type III, well-tolerated interferon. Both lonafarnib and lambda are in global Phase 3 trials. Eiger is also developing lambda for COVID-19 and is preparing to submit an emergency use authorization to FDA based on data from a Phase 3 investigator sponsored study. The FDA approved the Company’s first commercial product, Zokinvy (lonafarnib) for treatment of Progeria and processing-deficient progeroid laminopathies, ultra-rare and rapidly fatal genetic conditions of accelerated aging in children, on November 20, 2020. Eiger’s Marketing Authorization Application (MAA) is under review with the European Medicines Agency (EMA), with a CHMP opinion expected in the first half of 2022 . The Company is also developing avexitide, a well-characterized peptide, as a treatment for congenital hyperinsulinism (HI), an ultra-rare pediatric metabolic disorder and post-bariatric hypoglycemia (PBH), a debilitating and potentially life-threatening condition for which there is currently no approved therapy. The Company’s principal operations are based in Palo Alto, California and it operates in one segment. Liquidity As of March 31, 2022, the Company had $132.7 million of cash, cash equivalents and short-term securities, comprised of $46.6 million of cash and cash equivalents and $86.1 million of short-term debt securities available-for-sale. The Company had an accumulated deficit of $363.1 million and negative cash flows from operating activities as of March 31, 2022. 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 Management believes that the currently available resources will be sufficient to fund its planned operations for at least the next 12 months following the issuance date of these condensed consolidated financial statements. However, if the Company’s anticipated operating results are not achieved in future periods, the Company believes that planned expenditures may need to be reduced or it would be required to raise funding in order to fund the operations. Additionally, the Company’s ability to raise additional capital may be adversely impacted by potential worsening global economic conditions and disruptions to, and volatility in, the credit and financial markets in the United States and worldwide resulting from the ongoing COVID-19 pandemic.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The unaudited condensed 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 (the “SEC”) for annual reporting. All intercompany balances and transactions have been eliminated in consolidation. Use of Estimates The preparation of unaudited condensed 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. 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. Debt Securities Short-term securities 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. Long-term securities consist of debt securities classified as available-for-sale and have maturities greater than 365 days from the date of acquisition. All short-term and long-term securities are carried at fair value based upon quoted market prices. Unrealized gains and losses on available-for-sale securities are excluded from earnings and are reported as a component of accumulated other comprehensive (loss) income. The cost of available-for-sale securities sold is based on the specific-identification method . Accounts Receivable Accounts receivable represent amounts billed to the Company’s customers, net of an allowance for doubtful accounts. Trade accounts receivable are recorded at invoiced amounts and do not bear interest. The expectation of collectability is based on a review of credit profiles of customers, contractual terms and conditions, current economic trends, and historical payment experience. The Company regularly reviews the adequacy of the allowance for doubtful accounts by considering the age of each outstanding invoice and the collection history of each customer to determine the appropriate amount of allowance for doubtful accounts. The Company had no allowance as of March 31, 2022 and 2021. The Company had no bad debt expense for the three months ended March 31, 2022 and 2021. 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. There have been no write-downs of inventories for the periods presented. 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. 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. 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. 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. There was no revenue from sale of product under the ATU program for the three months ended March 31, 2022. 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. 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 unaudited condensed consolidated balance sheets and within research and development expenses in the accompanying unaudited condensed consolidated statements of operations. The Company accrues for these costs based on factors such as estimates of the work completed 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. As actual costs become known, the Company adjusts its accrued liabilities. Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) Codification Improvements to Topic 326, Financial Instruments – Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments, Financial Instruments – Credit Losses (Topic 326), 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) defers 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 is evaluating the impact of the guidance on its unaudited condensed consolidated financial statements. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) The pronouncement is effective for all entities as of March 12, 2020 through December 31, 2022. In October 2021, the Company amended its Oxford Loan to replace its floating interest rate with the LIBOR replacement rate (see Note 7). The Company will adopt this standard when LIBOR is discontinued and does not expect the adoption to have a material impact on its unaudited condensed consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. 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 March 31, 2022 and December 31, 2021 Assets and liabilities recorded at fair value on a recurring basis in the unaudited condensed 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 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 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 and liabilities measured at fair value (in thousands): March 31, 2022 Level 1 Level 2 Level 3 Total Financial assets: Money market funds $ 40,483 $ — $ — $ 40,483 Corporate debt securities — 33,264 — 33,264 Commercial paper — 10,904 — 10,904 U.S. government bonds — 41,987 — 41,987 Total $ 40,483 $ 86,155 $ — $ 126,638 December 31, 2021 Level 1 Level 2 Level 3 Total Financial assets: Money market funds $ 13,520 $ — $ — $ 13,520 Corporate debt securities — 41,511 — 41,511 U.S. government bonds — 42,345 — 42,345 Total $ 13,520 $ 83,856 $ — $ 97,376 There were no financial liabilities as of March 31, 2022 and December 31, 2021 The following tables summarize the estimated value of the Company’s cash equivalents and debt securities and the gross unrealized holding gains and losses (in thousands): March 31, 2022 Amortized cost Unrealized gain Unrealized loss Estimated Fair Value Cash equivalents: Money market funds $ 40,483 $ — $ — $ 40,483 Total cash equivalents $ 40,483 $ — $ — $ 40,483 Debt securities: Corporate debt securities $ 33,461 $ — $ (197 ) $ 33,264 Commercial paper 10,904 — — 10,904 U.S. government bonds 42,312 — (325 ) 41,987 Total debt securities $ 86,677 $ — $ (522 ) $ 86,155 Classified as: Cash equivalents $ 40,483 Short-term debt securities 86,155 $ 126,638 December 31, 2021 Amortized cost Unrealized gain Unrealized loss Estimated Fair Value Cash equivalents: Money market funds $ 13,520 $ — $ — $ 13,520 Total cash equivalents $ 13,520 $ — $ — $ 13,520 Debt securities: Corporate debt securities $ 41,576 $ — $ (65 ) $ 41,511 U.S. government bonds 42,429 — (84 ) 42,345 Total debt securities $ 84,005 $ — $ (149 ) $ 83,856 Classified as: Cash equivalents $ 13,520 Short-term debt securities 66,594 Long-term debt securities 17,262 $ 97,376 The Company periodically reviews the available-for-sale securities for other-than-temporary impairment loss. The Company considers factors such as the duration, severity and the reason for the decline in value, the potential recovery period and its intent to sell. For debt securities, it also considers whether (i) it is more likely than not that the Company will be required to sell the debt securities before recovery of their amortized cost basis, and (ii) the amortized cost basis cannot be recovered as a result of credit losses. During the three months ended March 31, 2022, the Company did not recognize any other-than-temporary impairment losses. All debt securities with unrealized losses have been in a loss position for less than 12 months.

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	4. Balance Sheet Components Inventories Inventories consist of the following (in thousands): March 31, December 31, 2022 2021 Raw materials $ 1,056 $ 1,056 Work-in-progress 781 1,468 Finished goods 73 88 Total inventories $ 1,910 $ 2,612 Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): March 31, December 31, 2022 2021 Prepaid contract manufacturing costs $ 4,429 $ 3,695 Prepaid research costs 3,850 3,253 Prepaid insurance 163 631 Other 2,000 1,782 Total prepaid expenses and other current assets $ 10,442 $ 9,361 Accrued Liabilities Accrued liabilities consist of the following (in thousands): March 31, December 31, 2022 2021 Contract research costs $ 8,801 $ 4,760 Product revenue reserves 2,005 1,846 Compensation and related benefits 1,583 3,131 Contract manufacturing costs 929 3,288 Other 937 674 Total accrued liabilities $ 14,255 $ 13,699

Bristol-Meyers Squibb License A

Bristol-Meyers Squibb License Agreement	3 Months Ended
	Mar. 31, 2022
Product Development Agreement [Abstract]
Bristol-Meyers Squibb License Agreement	5 . 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 (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 157,587 shares of its common stock 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 in research and development expense a $3.0 million milestone, 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 i n research and development , which was related to the initiation of a Phase 3 clinical trial, as defined under the BMS License Agreement.

Asset Purchase Agreements

Asset Purchase Agreements	3 Months Ended
	Mar. 31, 2022
Asset Purchase Agreements [Abstract]
Asset Purchase Agreements	6 . Asset Purchase Agreements On November 20, 2020, Eiger entered into an asset purchase agreement (the APA) with AbbVie, Inc. (AbbVie) to sell its rare pediatric disease priority review voucher (the PRV), which was awarded on November 20, 2020 upon FDA approval of Zokinvy. The APA contains customary representations, warranties, covenants, and indemnification provisions subject to certain limitations. In consideration for the PRV, AbbVie agreed to pay the Company $95.0 million. The transaction closed in January 2021. Such consideration was shared with the Progeria Research Foundation (PRF) in accordance with the terms of the PRF Collaboration and Supply Agreement, pursuant to which the Company and PRF will equally share any net proceeds from the sale of a priority review voucher that the Company may receive as the sponsor of a rare pediatric disease product application. The Company retained $46.5 million of proceeds from the sale of the PRV, net of related payments, and recorded the amount in other income, net in the unaudited condensed consolidated statement of operations for the three months ended March 31, 2021.

Debt

Debt	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Debt	7. Debt In December 2016, the Company entered into an aggregate $25.0 million loan with Oxford Finance LLC (the Oxford Loan) with a maturity date of July 1, 2021. The Company borrowed $15.0 million in December 2016 (Tranche A). In May 2018, the Company entered into an amendment to the Oxford Loan and borrowed $5.0 million (Tranche B). On August 3, 2018, the Company On March 5, 2019, the Company entered into the third amendment to the Oxford Loan (the Amended Oxford Loan) to refinance the Oxford Loan. The Amended Oxford Loan increased the aggregate amount available to be borrowed to $35.0 million and extended the maturity date to March 1, 2024. On March 5, 2019, prior to entering into the Amended Oxford Loan, the outstanding balance of the Oxford Loan was $23.3 million. At the time of entering into the Amended Oxford Loan, the Company borrowed an additional $6.7 million in principal under the Amended Oxford Loan, which increased the total amount borrowed to $30.0 million (Amended Tranche A). The remaining $5.0 million (Amended Tranche B) was available to the Company provided that certain milestones are achieved by February 2021. The Company did not draw down the Amended Tranche B. On February 23, 2021, the Company entered into the fifth amendment to the Oxford Loan. The amendment extended the interest only period by 17 months until September 1, 2022, followed by 19 equal monthly payments of principal and interest. Upon the receipt of the Amended Tranche B, the interest only period for borrowed funds will be extended by six months until March 1, 2023, followed by 13 equal monthly payments of principal plus accrued interest. In addition, the Company paid an amendment fee of $0.2 million to the lender on the effective date of the fifth amendment, which was recorded as an additional debt discount and is being amortized over the remaining term of the Amended Oxford Loan. The Amended Tranche B is now available to the Company provided certain milestones are achieved by August 2022. On October 6, 2021, the Company entered into the sixth amendment to the Oxford Loan. Prior to the sixth amendment, the Amended Oxford Loan bore interest at a floating rate per annum equal to the greater of either the 30-day U.S. Dollar LIBOR reported in the Wall Street Journal plus 6.64% or 9.15%. The latest amendment replaces this rate with the LIBOR replacement rate upon a LIBOR transition event. As a result, the Amended Oxford Loan will bear interest at the LIBOR replacement rate which is the sum of the alternate benchmark rate and the LIBOR replacement spread . At the time of final payment, the Company is required to pay an exit fee of 7.5% of the original principal balance of borrowed funds, or $2.3 million. In addition, the Company is required to pay an additional exit fee of $1.0 million The Company is also required to pay a 5.0% success fee of the total amount drawn under the Amended Oxford Loan The Amended Oxford Loan includes contingent interest features and mandatory prepayment features upon an event of default that meet the definition of a derivative but were not bifurcated from the debt instrument as their fair value was deemed to be insignificant . The refinancing of the Oxford Loan did not have a material impact on terms, conditions, representations, warranties, covenants or agreements set forth in the Oxford Loan. The loan is secured by the 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 loan includes customary events of default, including failure to pay amounts due, breaches of covenants and warranties, material adverse effect events, certain cross defaults and judgments, and insolvency. As of March 31, 2022, the Company was in compliance with all covenants. The Company is permitted to make voluntary prepayments of the Amended Oxford Loan with a prepayment fee, calculated as of the loan origination date, equal to (i) 2.0% of the loan prepaid during the first 12 months and (ii) 1.0% of the loan prepaid in months 13-24. The Company is required to make mandatory prepayments of the outstanding loan upon the acceleration by lender following the occurrence of an event of default, along with a payment of the final payment, the prepayment fee and any other obligations that are due and payable at the time of prepayment. The Company accounts for the amortization of the debt discount utilizing the effective interest method. Long-term debt and unamortized discount balances are as follows (in thousands): March 31, December 31, 2022 2021 Face value of long-term debt $ 30,000 $ 30,000 Exit fee 3,277 3,277 Unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees (1,282 ) (1,482 ) Total long-term debt, net 31,995 31,795 Less: current portion of long-term debt (12,549 ) (7,809 ) long-term debt, net $ 19,446 $ 23,986

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	8 . Stock-Based Compensation During the second quarter of 2021, the Company approved the 2021 Inducement Plan to reserve 850,000 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 March 31, 2022, there were 670,000 shares remaining available to be issued under the 2021 Inducement Plan. The following table summarizes stock option activity under the Company’s stock-based compensation plan during the three months ended March 31, 2022 (in thousands, except option and share data): Shares Available for Grant Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in Years) Aggregate Intrinsic Value Outstanding as of December 31, 2021 1,327,645 5,262,185 $ 10.24 7.25 $ 530 Additional shares authorized 1,728,441 — Granted (1,353,300 ) 1,353,300 $ 5.17 Restricted stock units granted (298,150 ) — Exercised — (15,995 ) $ 8.98 Forfeited or cancelled 109,039 (109,039 ) $ 12.06 Restricted stock units forfeited 33,225 — Outstanding as of March 31, 2022 1,546,900 6,490,451 $ 9.16 7.75 $ 7,636 Vested and exercisable as of March 31, 2022 3,115,184 $ 11.07 6.22 $ 1,934 During the three months ended March 31, 2022 and 2021, the weighted-average grant date fair value of options granted were $3.23 and $7.76 per share, 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: Three Months Ended March 31, 2022 2021 Expected term (in years) 5.27-6.08 5.27-6.08 Volatility 68.71%-70.75% 72.39%-100.87% Risk free interest rate 1.76%-2.41% 0.62%-1.16% Dividend yield — — 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 restricted stock units (RSUs) 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. The performance stock units (PSUs) are also available for grant pursuant to the Restated 2013 Plan. 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 of directors, 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. There was no PSUs granted during the three months ended March 31, 2022. As of March 31, 2022, no PSUs have vested as the performance-based metrics of the PSUs have not yet been achieved. During the three months ended March 31, 2022 and 2021, the Company granted 298,150 and 203,500 RSUs, respectively, with a weighted-average grant date fair value of $5.22 and $9.99 per share, respectively. In relation to the RSUs granted, the Company recognized $0.4 million and $0.1 million in stock-based compensation expense for the three months ended March 31, 2022 and 2021, respectively, which were included in selling, general and administrative expenses. As of March 31, 2022, the total unrecognized compensation expense related to unvested RSUs and PSUs was $5.1 million, which the Company expects to recognize over an estimated weighted-average period of 2.7 years. The following table summarizes RSU and PSU activity and weighted average grant date fair value for the three months ended March 31, 2022: Shares Weighted- Average Grant Date Fair Value Unvested shares as of December 31, 2021 623,000 $ 8.63 Granted 298,150 $ 5.22 Vested (85,106 ) $ 10.09 Forfeited (33,225 ) $ 8.33 Unvested shares as of March 31, 2022 802,819 $ 7.22 Stock-Based Compensation Expense Total stock-based compensation expense recognized was as follows (in thousands): Three Months Ended March 31, 2022 2021 Research and development $ 625 $ 391 Selling, general and administrative 1,422 1,158 Total $ 2,047 $ 1,549 As of March 31, 2022, the total unrecognized compensation expense related to unvested options was $15.2 million, which the Company expects to recognize over an estimated weighted average period of 2.9 years.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	9 . Income Taxes The Company’s provision for income taxes was $9,000 and $19,000 for the three months ended March 31, 2022 and 2021, with an effective tax rate of 0.04% and 0.1% for the three months ended March 31, 2022 and 2021, respectively. The effective tax rate in each period differs from the U.S. statutory tax rate primarily due to the valuation allowances 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 three months ended March 31, 2022 and March 31, 2021, respectively, relates to state taxes.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2022
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	10 . Commitments and Contingencies Lease Agreements In October 2017, the Company entered into a non-cancelable operating facility lease agreement for 8,029 square feet of office space located at 2155 Park Blvd. in Palo Alto, California. The lease commenced on March 1, 2018 and expires in February 2023. The lease has a three-year The maturity of the Company’s operating lease liabilities as of March 31, 2022, were as follows (in thousands): Undiscounted lease payments March 31, 2022 Remaining in 2022 501 2023 115 2024 1 2025 1 Total undiscounted payments 618 Less: imputed interest 24 Present value of future lease payments 594 Less: current portion of operating lease liabilities 590 Operating lease liabilities $ 4 Rent expense recognized for the Company’s operating leases was $0.1 million and $0.2 million for the three months ended March 31, 2022 and 2021, respectively. Under the terms of the lease agreements, the Company is also responsible for certain variable lease payments that are not included in the measurement of the lease liability. Variable lease payments for the operating leases was $23,000 for each of the three months ended March 31, 2022 and 2021. The operating cash outflows for the operating lease liabilities were $0.2 million and $0.2 million for the three months ended March 31, 2022 and 2021, respectively. As of March 31, 2022 and December 31, 2021, the weighted-average remaining lease terms were 0.9 years and 1.2 years, and weighted-average discount rates were 9.15% and 9.15%, respectively.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Net (Loss) Income Per Share	1 1 . Net (Loss) Income 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 the three months ended March 31, 2022, diluted net loss per share is the same as basic net loss per share as the inclusion of all potential common shares outstanding would have been anti-dilutive. Diluted net income per share for the three months ended March 31, 2021 is computed by dividing net income by the weighted-average number of shares of common stock and dilutive potential common stock equivalents then outstanding. Dilutive potential common stock equivalents include the assumed exercise, vesting and issuance of employee stock awards using the treasury stock method. The following table sets forth the computation of basic and diluted net (loss) income per common share for the periods presented (in thousands, except share amounts): Three Months Ended March 31, 2022 2021 Numerator: Net (loss) income $ (22,643 ) $ 29,248 Denominator: Weighted-average shares outstanding for basic net (loss) income per share 35,253,147 33,886,896 Effect of dilutive securities — 333,999 Weighted-average shares outstanding for diluted net (loss) income per share 35,253,147 34,220,895 Net (loss) income per share: Basic $ (0.64 ) $ 0.86 Diluted $ (0.64 ) $ 0.85 The following table sets forth the outstanding potentially dilutive securities which have been excluded in the calculation of diluted net (loss) income per share because including such securities would be anti-dilutive (in common stock equivalent shares): Three Months Ended March 31, 2022 2021 Options to purchase common stock 6,490,451 2,895,223 Restricted stock units (unvested) 802,819 — ESPP 87,553 3,789 Total 7,380,823 2,899,012

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	1 2 . Subsequent Event On March 25, 2022, the Company entered into a new Open Market Sale Agreement SM .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The unaudited condensed 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 (the “SEC”) for annual reporting. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of unaudited condensed 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. 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.
Debt Securities	Debt Securities Short-term securities 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. Long-term securities consist of debt securities classified as available-for-sale and have maturities greater than 365 days from the date of acquisition. All short-term and long-term securities are carried at fair value based upon quoted market prices. Unrealized gains and losses on available-for-sale securities are excluded from earnings and are reported as a component of accumulated other comprehensive (loss) income. The cost of available-for-sale securities sold is based on the specific-identification method .
Accounts Receivable	Accounts Receivable Accounts receivable represent amounts billed to the Company’s customers, net of an allowance for doubtful accounts. Trade accounts receivable are recorded at invoiced amounts and do not bear interest. The expectation of collectability is based on a review of credit profiles of customers, contractual terms and conditions, current economic trends, and historical payment experience. The Company regularly reviews the adequacy of the allowance for doubtful accounts by considering the age of each outstanding invoice and the collection history of each customer to determine the appropriate amount of allowance for doubtful accounts. The Company had no allowance as of March 31, 2022 and 2021. The Company had no bad debt expense for the three months ended March 31, 2022 and 2021.
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. 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. There have been no write-downs of inventories for the periods presented.
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. 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. 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. 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. There was no revenue from sale of product under the ATU program for the three months ended March 31, 2022. 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.
Cost of Sales	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	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 unaudited condensed consolidated balance sheets and within research and development expenses in the accompanying unaudited condensed consolidated statements of operations. The Company accrues for these costs based on factors such as estimates of the work completed 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. As actual costs become known, the Company adjusts its accrued liabilities.
Accounting Pronouncements Not Yet Adopted	Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) Codification Improvements to Topic 326, Financial Instruments – Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments, Financial Instruments – Credit Losses (Topic 326), 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) defers 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 is evaluating the impact of the guidance on its unaudited condensed consolidated financial statements. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) The pronouncement is effective for all entities as of March 12, 2020 through December 31, 2022. In October 2021, the Company amended its Oxford Loan to replace its floating interest rate with the LIBOR replacement rate (see Note 7). The Company will adopt this standard when LIBOR is discontinued and does not expect the adoption to have a material impact on its unaudited condensed consolidated financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Measured at Fair Value	The following tables present the fair value hierarchy for assets and liabilities measured at fair value (in thousands): March 31, 2022 Level 1 Level 2 Level 3 Total Financial assets: Money market funds $ 40,483 $ — $ — $ 40,483 Corporate debt securities — 33,264 — 33,264 Commercial paper — 10,904 — 10,904 U.S. government bonds — 41,987 — 41,987 Total $ 40,483 $ 86,155 $ — $ 126,638 December 31, 2021 Level 1 Level 2 Level 3 Total Financial assets: Money market funds $ 13,520 $ — $ — $ 13,520 Corporate debt securities — 41,511 — 41,511 U.S. government bonds — 42,345 — 42,345 Total $ 13,520 $ 83,856 $ — $ 97,376
Summary of Estimated Value of Cash Equivalents and Debt Securities and Gross Unrealized Holding Gains and Losses	The following tables summarize the estimated value of the Company’s cash equivalents and debt securities and the gross unrealized holding gains and losses (in thousands): March 31, 2022 Amortized cost Unrealized gain Unrealized loss Estimated Fair Value Cash equivalents: Money market funds $ 40,483 $ — $ — $ 40,483 Total cash equivalents $ 40,483 $ — $ — $ 40,483 Debt securities: Corporate debt securities $ 33,461 $ — $ (197 ) $ 33,264 Commercial paper 10,904 — — 10,904 U.S. government bonds 42,312 — (325 ) 41,987 Total debt securities $ 86,677 $ — $ (522 ) $ 86,155 Classified as: Cash equivalents $ 40,483 Short-term debt securities 86,155 $ 126,638 December 31, 2021 Amortized cost Unrealized gain Unrealized loss Estimated Fair Value Cash equivalents: Money market funds $ 13,520 $ — $ — $ 13,520 Total cash equivalents $ 13,520 $ — $ — $ 13,520 Debt securities: Corporate debt securities $ 41,576 $ — $ (65 ) $ 41,511 U.S. government bonds 42,429 — (84 ) 42,345 Total debt securities $ 84,005 $ — $ (149 ) $ 83,856 Classified as: Cash equivalents $ 13,520 Short-term debt securities 66,594 Long-term debt securities 17,262 $ 97,376

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Schedule of Inventory	Inventories consist of the following (in thousands): March 31, December 31, 2022 2021 Raw materials $ 1,056 $ 1,056 Work-in-progress 781 1,468 Finished goods 73 88 Total inventories $ 1,910 $ 2,612
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following (in thousands): March 31, December 31, 2022 2021 Prepaid contract manufacturing costs $ 4,429 $ 3,695 Prepaid research costs 3,850 3,253 Prepaid insurance 163 631 Other 2,000 1,782 Total prepaid expenses and other current assets $ 10,442 $ 9,361
Schedule of Components of Accrued Liabilities	Accrued liabilities consist of the following (in thousands): March 31, December 31, 2022 2021 Contract research costs $ 8,801 $ 4,760 Product revenue reserves 2,005 1,846 Compensation and related benefits 1,583 3,131 Contract manufacturing costs 929 3,288 Other 937 674 Total accrued liabilities $ 14,255 $ 13,699

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Schedule of Long-Term Debt and Unamortized Discount Balances	Long-term debt and unamortized discount balances are as follows (in thousands): March 31, December 31, 2022 2021 Face value of long-term debt $ 30,000 $ 30,000 Exit fee 3,277 3,277 Unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees (1,282 ) (1,482 ) Total long-term debt, net 31,995 31,795 Less: current portion of long-term debt (12,549 ) (7,809 ) long-term debt, net $ 19,446 $ 23,986

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2022
Stock Option Activity	The following table summarizes stock option activity under the Company’s stock-based compensation plan during the three months ended March 31, 2022 (in thousands, except option and share data): Shares Available for Grant Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in Years) Aggregate Intrinsic Value Outstanding as of December 31, 2021 1,327,645 5,262,185 $ 10.24 7.25 $ 530 Additional shares authorized 1,728,441 — Granted (1,353,300 ) 1,353,300 $ 5.17 Restricted stock units granted (298,150 ) — Exercised — (15,995 ) $ 8.98 Forfeited or cancelled 109,039 (109,039 ) $ 12.06 Restricted stock units forfeited 33,225 — Outstanding as of March 31, 2022 1,546,900 6,490,451 $ 9.16 7.75 $ 7,636 Vested and exercisable as of March 31, 2022 3,115,184 $ 11.07 6.22 $ 1,934
Summary of Non-cash Stock Based Compensation Expense	Total stock-based compensation expense recognized was as follows (in thousands): Three Months Ended March 31, 2022 2021 Research and development $ 625 $ 391 Selling, general and administrative 1,422 1,158 Total $ 2,047 $ 1,549
Employees and Non Employees Stock Option [Member]
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: Three Months Ended March 31, 2022 2021 Expected term (in years) 5.27-6.08 5.27-6.08 Volatility 68.71%-70.75% 72.39%-100.87% Risk free interest rate 1.76%-2.41% 0.62%-1.16% Dividend yield — —
Restricted Stock Units (RSU) [Member]
Schedule of Nonvested Restricted 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 three months ended March 31, 2022: Shares Weighted- Average Grant Date Fair Value Unvested shares as of December 31, 2021 623,000 $ 8.63 Granted 298,150 $ 5.22 Vested (85,106 ) $ 10.09 Forfeited (33,225 ) $ 8.33 Unvested shares as of March 31, 2022 802,819 $ 7.22

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2022
Commitments And Contingencies Disclosure [Abstract]
Maturity of Operating Leases Liabilities and Future Minimum Lease Payments	The maturity of the Company’s operating lease liabilities as of March 31, 2022, were as follows (in thousands): Undiscounted lease payments March 31, 2022 Remaining in 2022 501 2023 115 2024 1 2025 1 Total undiscounted payments 618 Less: imputed interest 24 Present value of future lease payments 594 Less: current portion of operating lease liabilities 590 Operating lease liabilities $ 4

Net (Loss) Income Per Share (Ta

Net (Loss) Income Per Share (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net (Loss) Income Per Common Share	The following table sets forth the computation of basic and diluted net (loss) income per common share for the periods presented (in thousands, except share amounts): Three Months Ended March 31, 2022 2021 Numerator: Net (loss) income $ (22,643 ) $ 29,248 Denominator: Weighted-average shares outstanding for basic net (loss) income per share 35,253,147 33,886,896 Effect of dilutive securities — 333,999 Weighted-average shares outstanding for diluted net (loss) income per share 35,253,147 34,220,895 Net (loss) income per share: Basic $ (0.64 ) $ 0.86 Diluted $ (0.64 ) $ 0.85
Summary of Potentially Dilutive Shares Excluded from Computation of Diluted Net (Loss) Income Per Share	The following table sets forth the outstanding potentially dilutive securities which have been excluded in the calculation of diluted net (loss) income per share because including such securities would be anti-dilutive (in common stock equivalent shares): Three Months Ended March 31, 2022 2021 Options to purchase common stock 6,490,451 2,895,223 Restricted stock units (unvested) 802,819 — ESPP 87,553 3,789 Total 7,380,823 2,899,012

Description of Business - Addit

Description of Business - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)Segment	Dec. 31, 2021USD ($)
Description Of Business [Abstract]
Entity incorporation, date of incorporation	Nov. 6, 2008
Number of operating segments | Segment	1
Cash, Cash Equivalents, and Investments	$ 132,700
Cash and cash equivalents	46,562	$ 22,221
Debt securities, available-for-sale	86,100
Accumulated deficit	$ (363,060)	$ (340,417)

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Significant Accounting Policies [Line Items]
Accounts receivable, allowance for doubtful accounts	$ 0	$ 0
Bad debt expense	0	0
Inventory Write-down	0
Revenues from sale of product	2,673,000	$ 3,646,000
ATU [Member]
Significant Accounting Policies [Line Items]
Revenues from sale of product	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	$ 126,638,000	$ 97,376,000
Financial liabilities	0	0
Level 3 [Member]
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 - Summa

Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value (Detail) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Financial assets:
Assets, Fair Value	$ 126,638,000	$ 97,376,000
Corporate Debt Securities [Member]
Financial assets:
Assets, Fair Value	33,264,000	41,511,000
US Government Bonds [Member]
Financial assets:
Assets, Fair Value	41,987,000	42,345,000
Money Market Funds [Member]
Financial assets:
Assets, Fair Value	40,483,000	13,520,000
Commercial Paper [Member]
Financial assets:
Assets, Fair Value	10,904,000
Level 1 [Member]
Financial assets:
Assets, Fair Value	40,483,000	13,520,000
Level 1 [Member] | Money Market Funds [Member]
Financial assets:
Assets, Fair Value	40,483,000	13,520,000
Level 2 [Member]
Financial assets:
Assets, Fair Value	86,155,000	83,856,000
Level 2 [Member] | Corporate Debt Securities [Member]
Financial assets:
Assets, Fair Value	33,264,000	41,511,000
Level 2 [Member] | US Government Bonds [Member]
Financial assets:
Assets, Fair Value	41,987,000	42,345,000
Level 2 [Member] | Commercial Paper [Member]
Financial assets:
Assets, Fair Value	10,904,000
Level 3 [Member]
Financial assets:
Assets, Fair Value	$ 0	$ 0

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Value of Cash Equivalents and Debt Securities and Gross Unrealized Holding Gains and Losses (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Cash Equivalents and Investment Securities [Line Items]
Cash equivalents, Amortized cost	$ 40,483	$ 13,520
Cash equivalents, Estimated Fair Value	40,483
Debt securities, Amortized cost	86,677	84,005
Debt securities, Unrealized loss	(522)	(149)
Debt securities, Estimated Fair Value	86,155	83,856
Assets, Fair Value	126,638	97,376
Short-Term Debt [Member]
Cash Equivalents and Investment Securities [Line Items]
Debt securities, Estimated Fair Value	86,155	66,594
Long-term Debt
Cash Equivalents and Investment Securities [Line Items]
Debt securities, Estimated Fair Value		17,262
Corporate Debt Securities [Member]
Cash Equivalents and Investment Securities [Line Items]
Debt securities, Amortized cost	33,461	41,576
Debt securities, Unrealized loss	(197)	(65)
Debt securities, Estimated Fair Value	33,264	41,511
Assets, Fair Value	33,264	41,511
US Government Bonds [Member]
Cash Equivalents and Investment Securities [Line Items]
Debt securities, Amortized cost	42,312	42,429
Debt securities, Unrealized loss	(325)	(84)
Debt securities, Estimated Fair Value	41,987	42,345
Assets, Fair Value	41,987	42,345
Money Market Funds [Member]
Cash Equivalents and Investment Securities [Line Items]
Cash equivalents, Amortized cost	40,483	13,520
Cash equivalents, Estimated Fair Value	40,483
Assets, Fair Value	40,483	13,520
Commercial Paper [Member]
Cash Equivalents and Investment Securities [Line Items]
Debt securities, Amortized cost	10,904
Debt securities, Estimated Fair Value	10,904
Assets, Fair Value	10,904
Cash Equivalents [Member]
Cash Equivalents and Investment Securities [Line Items]
Cash equivalents, Estimated Fair Value	$ 40,483	$ 13,520

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Raw materials	$ 1,056	$ 1,056
Work-in-progress	781	1,468
Finished goods	73	88
Total inventories	$ 1,910	$ 2,612

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Prepaid Expense And Other Assets Current [Abstract]
Prepaid contract manufacturing costs	$ 4,429	$ 3,695
Prepaid research costs	3,850	3,253
Prepaid insurance	163	631
Other	2,000	1,782
Total prepaid expenses and other current assets	$ 10,442	$ 9,361

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Components of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables And Accruals [Abstract]
Contract research costs	$ 8,801	$ 4,760
Product revenue reserves	2,005	1,846
Compensation and related benefits	1,583	3,131
Contract manufacturing costs	929	3,288
Other	937	674
Total accrued liabilities	$ 14,255	$ 13,699

Bristol-Meyers Squibb License_2

Bristol-Meyers Squibb License Agreement - Additional Information (Detail) - USD ($) $ in Thousands	Apr. 20, 2016	Mar. 31, 2022	Dec. 31, 2020	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Aggregate fair value of shares issued		$ 41		$ 35
Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Sale of common stock		5,841,786
BMS Transaction [Member] | Licensing Agreements [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment	$ 2,000
BMS Transaction [Member] | Common Stock [Member] | BMS Purchase Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Sale of common stock	157,587
Aggregate fair value of shares issued	$ 3,200
BMS Transaction [Member] | Development and Regulatory Milestones [Member] | Licensing Agreements [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment obligations	61,000
BMS Transaction [Member] | Commercial Sales [Member] | Maximum [Member] | Licensing Agreements [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment obligations	$ 128,000
BMS Transaction [Member] | Development Phase 2 [Member] | Licensing Agreements [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment obligations			$ 3,000
BMS Transaction [Member] | Development Phase 3 [Member] | Licensing Agreements [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment obligations		$ 5,000

Asset Purchase Agreements - Add

Asset Purchase Agreements - Additional Information (Detail) - AbbVie Asset Purchase Agreement [Member] $ in Millions	Nov. 20, 2020USD ($)
Asset Purchase Agreements [Line Items]
Payment for asset purchase agreement	$ 95
Progeria Research Foundation (PRF) Collaboration Agreement [Member]
Asset Purchase Agreements [Line Items]
Proceeds from sale	$ 46.5

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($) $ in Thousands	Oct. 06, 2021	Feb. 23, 2021	Mar. 05, 2019	Dec. 31, 2016	Mar. 31, 2022	Dec. 31, 2021	Aug. 03, 2018	May 31, 2018
Debt Instrument [Line Items]
Face value of term loan					$ 30,000	$ 30,000
Loan final repayment exit fees payable					$ (3,277)	$ (3,277)
Loan agreement, covenant noncompliance penalty					5.00%
Loan agreement, covenant description					The loan includes customary events of default, including failure to pay amounts due, breaches of covenants and warranties, material adverse effect events, certain cross defaults and judgments, and insolvency
Loan agreement, covenant compliance					and accelerate the maturity of the debt.
Oxford Loan [Member]
Debt Instrument [Line Items]
Loan agreement, aggregate borrowing capacity				$ 25,000
Loan, maturity period				Jul. 1, 2021
Repayments of loan agreement exit fee					$ 900
Oxford Loan [Member] | Tranche A [Member]
Debt Instrument [Line Items]
Face value of term loan				$ 15,000
Amendment [Member] | Tranche B [Member]
Debt Instrument [Line Items]
Face value of term loan								$ 5,000
Amendment [Member] | Tranche C [Member]
Debt Instrument [Line Items]
Face value of term loan							$ 5,000
Amended Oxford Loan [Member]
Debt Instrument [Line Items]
Loan agreement, aggregate borrowing capacity			$ 35,000
Loan, maturity period					Mar. 1, 2024
Loan outstanding			23,300
Borrowings from loan agreement			6,700
Loan agreement, floating rate terms					floating rate per annum equal to the greater of either the 30-day U.S. Dollar LIBOR reported in the Wall Street Journal plus 6.64% or 9.15%
Percentage of exit fee on principal balance					7.50%
Loan final repayment exit fees payable					$ 2,300
Loan final repayment additional exit fees payable					$ 1,000
Prepayment of loan fee, description					calculated as of the loan origination date, equal to (i) 2.0% of the loan prepaid during the first 12 months and (ii) 1.0% of the loan prepaid in months 13-24.
Amended Oxford Loan [Member] | Loan Prepaid During First 12 Months [Member]
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage					2.00%
Amended Oxford Loan [Member] | Loan Prepaid During 13 to 24 Months [Member]
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage					1.00%
Amended Oxford Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Loan agreement, interest rate	9.15%
Amended Oxford Loan [Member] | Food and Drug Administration [Member]
Debt Instrument [Line Items]
Percentage of success fee					5.00%
Success fees payable maximum period after approval					30 days
Amended Oxford Loan [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Loan agreement, percentage to be added to the interest rate under condition	6.64%
Amended Oxford Loan [Member] | Amended Tranche A [Member]
Debt Instrument [Line Items]
Loan agreement, aggregate borrowing capacity			30,000
Amended Oxford Loan [Member] | Amended Tranche A [Member] | Food and Drug Administration [Member]
Debt Instrument [Line Items]
Fee payable maximum period from funding					10 years
Amended Oxford Loan [Member] | Amended Tranche B [Member]
Debt Instrument [Line Items]
Loan agreement, remaining borrowing capacity			$ 5,000
Fifth Amended Oxford Loan [Member]
Debt Instrument [Line Items]
Principal and interest payment period		19 years
Interest payment period		17 months
Amendment fees payment		$ 200
Fifth Amended Oxford Loan [Member] | Tranche B [Member]
Debt Instrument [Line Items]
Principal and interest payment period		13 years
Interest payment period		6 months

Debt - Schedule of Long-Term De

Debt - Schedule of Long-Term Debt and Unamortized Discount Balances (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Face value of long-term debt	$ 30,000	$ 30,000
Exit fee	3,277	3,277
Unamortized debt discount associated with exit fee, debt issuance costs and loan origination fees	(1,282)	(1,482)
Total long-term debt, net	31,995	31,795
Less: current portion of long-term debt	(12,549)	(7,809)
Long-term debt, net	$ 19,446	$ 23,986

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted	1,353,300
Total unrecognized compensation expense	$ 15,200
Weighted average period expected to recognized compensation expense (in years)	2 years 10 months 24 days
Stock-based compensation expense	$ 2,047	$ 1,549
Weighted average period expected to recognized compensation expense (in years)	2 years 10 months 24 days
Employees Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of employee option grants	$ 3.23	$ 7.76
Performance Stock Units (PSU) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted	0
PSUs vested during the period	0
Restricted Stock Units (RSU) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of employee option grants	$ 5.22	$ 9.99
Stock options granted	298,150	203,500
Weighted average period expected to recognized compensation expense (in years)	2 years 8 months 12 days
Stock-based compensation expense	$ 400	$ 100
Weighted average period expected to recognized compensation expense (in years)	2 years 8 months 12 days
Restricted Stock Units and Performance Stock Unit [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of employee option grants	$ 5.22
Stock options granted	298,150
Total unrecognized compensation expense	$ 5,100
Inducement Plan 2021 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock available for grant	850,000
Number of shares available to be issued	670,000

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Exercise Price And Additional Disclosures [Abstract]
Shares Available for Grant, Outstanding, Beginning balance	1,327,645
Additional shares authorized	1,728,441
Shares Available for Grant, Granted	(1,353,300)
Shares Available for Grant, Restricted stock units granted	(298,150)
Shares Available for Grant, Forfeited or cancelled	109,039
Restricted stock units forfeited	33,225
Shares Available for Grant, Outstanding, Ending balance	1,546,900	1,327,645
Vested and exercisable as of March 31, 2022	3,115,184
Number of Options, Outstanding, Beginning balance	5,262,185
Number of Options, Granted	1,353,300
Shares Available for Grant, Restricted stock units granted	298,150
Number of Options, Exercised	(15,995)
Number of Options, Forfeited or cancelled	(109,039)
Number of Options, Outstanding, Ending balance	6,490,451	5,262,185
Weighted-Average Exercise Price, Outstanding, Beginning balance	$ 10.24
Weighted-Average Exercise Price, Granted	5.17
Weighted-Average Exercise Price, Exercised	8.98
Weighted Average Exercise Price Per Option, Forfeited or cancelled	12.06
Weighted-Average Exercise Price, Outstanding, Ending balance	9.16	$ 10.24
Weighted-Average Exercise Price, vested and exercisable	$ 11.07
Weighted Average Remaining Contractual Life, Ending balance	7 years 9 months	7 years 3 months
Vested and exercisable as of March 31, 2022	6 years 2 months 19 days
Aggregate Intrinsic Value	$ 7,636	$ 530
Aggregate Intrinsic Value, Vested and exercisable	$ 1,934

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted-average assumptions used in Black-Scholes Model to estimate fair value of stock options granted (Detail)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Employees Stock Option [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 3 months 7 days	5 years 3 months 7 days
Employees Stock Option [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 29 days	6 years 29 days
Employees and Non Employees Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility, minimum	68.71%	72.39%
Volatility, maximum	70.75%	100.87%
Risk free interest rate, minimum	1.76%	0.62%
Risk free interest rate, maximum	2.41%	1.16%

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)	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted	1,353,300
Restricted Stock Units and Performance Stock Unit [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested shares, beginning balance	623,000
Stock options granted	298,150
Vested, shares	(85,106)
Forfeited	(33,225)
Unvested shares, ending balance	802,819
Weighted average grant-date fair value of options begining balance | $ / shares	$ 8.63
Weighted-average grant date fair value of employee option grants | $ / shares	5.22
Weighted average grant-date fair value of options vested | $ / shares	10.09
Weighted average grant-date fair value of options forfeited | $ / shares	8.33
Weighted average grant-date fair value of options ending balance | $ / shares	$ 7.22

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Non-cash Stock Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,047	$ 1,549
Research and Development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	625	391
Selling General And Administrative Expenses [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,422	$ 1,158

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 9,000	$ 19,000
Effective tax rate	0.04%	0.10%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended	3 Months Ended
	Oct. 31, 2017USD ($)ft²	Mar. 31, 2022USD ($)	Mar. 31, 2021USD ($)	Dec. 31, 2021
Other Commitments [Line Items]
Rent expense recognized for company's operating leases		$ 100,000	$ 200,000
Variable lease payments for operating leases		23,000	23,000
Operating cash outflows for operating lease liabilities		$ 200,000	$ 200,000
Weighted-average remaining lease term		10 months 24 days		1 year 2 months 12 days
Weighted-average discount rate		9.15%		9.15%
Palo Alto, California [Member]
Other Commitments [Line Items]
Total leased space | ft²	8,029
Lease commencement date	Mar. 1, 2018
Long-term operating lease expiry period month and year	2023-02
Lease renewal term	3 years
Security deposit of collateral for lease	$ 300,000

Commitments and Contingencies_2

Commitments and Contingencies - Maturity of Operating Leases Liabilities and Future Minimum Lease Payments (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Operating leases minimum payments, remaining in 2022	$ 501
Operating leases minimum payments, 2023	115
Operating leases minimum payments, 2024	1
Operating leases minimum payments, 2025	1
Total undiscounted payments	618
Less: imputed interest	24
Present value of future lease payments	594
Less: current portion of operating lease liabilities	590	$ 628
Operating lease liabilities	$ 4	$ 116

Net (Loss) Income Per Share - S

Net (Loss) Income Per Share - Schedule of Computation of Basic and Diluted Net (Loss) Income Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net (loss) income	$ (22,643)	$ 29,248
Denominator:
Weighted-average shares outstanding for basic net (loss) income per share	35,253,147	33,886,896
Effect of dilutive securities		333,999
Weighted-average shares outstanding for diluted net (loss) income per share	35,253,147	34,220,895
Net (loss) income per share:
Basic	$ (0.64)	$ 0.86
Diluted	$ (0.64)	$ 0.85

Net Income (Loss) Per Share - S

Net Income (Loss) Per Share - Summary of Potentially Dilutive Shares Excluded from Computation of Diluted Net (Loss) Income Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities	7,380,823	2,899,012
Options Granted to Employees and Non Employees [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities	6,490,451	2,895,223
Restricted Stock Units (Unvested) [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities	802,819
ESPP [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities	87,553	3,789

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - 2022 ATM Facility [Member] - USD ($)	Mar. 25, 2022	Apr. 30, 2022
Subsequent Event [Line Items]
Equity, debt, warrants and units, maximum issued and sale	$ 50,000,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Issuance of common stock upon public offering, net of issuance costs, shares		2,686,288
Net proceeds from issuance of common stock, Net of commissions		$ 20,800