Cymabay Therapeutics (CBAY) 10-K 17 Mar 22 2021 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2021	Feb. 28, 2022	Jun. 30, 2021
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Trading Symbol	CBAY
Entity Registrant Name	CYMABAY THERAPEUTICS, INC.
Entity Central Index Key	0001042074
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		84,677,939
Entity Shell Company	false
Entity File Number	001-36500
Entity Tax Identification Number	94-3103561
Entity Address, Address Line One	7575 Gateway Blvd
Entity Address, Address Line Two	Suite 110
Entity Address, City or Town	Newark
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94560
City Area Code	510
Local Phone Number	293-8800
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common stock, $0.0001 par value per share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Annual Report	true
Document Transition Report	false
Entity Public Float			$ 298,401,478
ICFR Auditor Attestation Flag	false
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	Redwood City, California

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 125,806	$ 28,193
Marketable securities	60,729	118,130
Prepaid research and development expenses	2,371	2,221
Other prepaid expenses and current assets	2,193	3,041
Total current assets	191,099	151,585
Property and equipment, net	1,178	1,761
Non-current marketable securities	8,067
Operating lease right-of-use asset	254	272
Other assets	1,720	207
Total assets	202,318	153,825
Current liabilities:
Accounts payable	2,728	231
Accrued research and development expenses	9,752	4,698
Other accrued liabilities	5,886	4,928
Total current liabilities	18,366	9,857
Development financing liability	50,320
Long-term portion of operating lease liability	695	1,262
Commitments and contingencies
Total liabilities	69,381	11,119
Stockholders' equity:
Preferred stock, $0.0001 par value: 10,000,000 shares authorized; no shares issued and outstanding
Common stock, $0.0001 par value: 200,000,000 shares authorized; 84,677,939 and 68,946,092 shares issued and outstanding as of December 31, 2021 and December 31, 2020, respectively	8	7
Additional paid-in capital	899,798	819,549
Accumulated other comprehensive (loss) income	(13)	8
Accumulated deficit	(766,856)	(676,858)
Total stockholders' equity	132,937	142,706
Total liabilities and stockholders' equity	$ 202,318	$ 153,825

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	84,677,939	68,946,092
Common stock, shares outstanding	84,677,939	68,946,092

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating expenses:
Research and development	$ 64,542	$ 35,882
General and administrative	23,040	16,720
Total operating expenses	87,582	52,602
Loss from operations	(87,582)	(52,602)
Other income (expense), net:
Interest income	167	1,616
Interest expense	(2,583)
Total other income (expense), net	(2,416)	1,616
Net loss	(89,998)	(50,986)
Other comprehensive loss:
Unrealized loss on marketable securities	(21)	(72)
Total other comprehensive loss	(21)	(72)
Comprehensive loss	$ (90,019)	$ (51,058)
Basic and diluted net loss per common share	$ (1.27)	$ (0.74)
Weighted average common shares outstanding used to calculate basic and diluted net loss per common share	71,055,331	68,893,127

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]
Balance at beginning of period at Dec. 31, 2019	$ 186,348	$ 7	$ 812,133	$ 80	$ (625,872)
Balance at beginning of period (in shares) at Dec. 31, 2019		68,882,459
Issuance of common stock upon exercise of stock options	92		92
Issuance of common stock upon exercise of stock options (Shares)		63,633
Stock-based compensation expense	7,324		7,324
Net loss	(50,986)				(50,986)
Net unrealized gain (loss) on marketable securities	(72)			(72)
Balance at end of period at Dec. 31, 2020	142,706	$ 7	819,549	8	(676,858)
Balance at end of period (in shares) at Dec. 31, 2020		68,946,092
Issuance of common stock upon exercise of stock options	$ 219		219
Issuance of common stock upon exercise of stock options (Shares)	106,847	106,847
Stock-based compensation expense	$ 9,996		9,996
Issuance of common stock and pre-funded warrants, net of issuance costs	70,035	$ 1	70,034
Issuance of common stock and pre-funded warrants, net of issuance costs Shares		15,625,000
Net loss	(89,998)				(89,998)
Net unrealized gain (loss) on marketable securities	(21)			(21)
Balance at end of period at Dec. 31, 2021	$ 132,937	$ 8	$ 899,798	$ (13)	$ (766,856)
Balance at end of period (in shares) at Dec. 31, 2021		84,677,939

Consolidated Statement of Sto_2

Consolidated Statement of Stockholders' Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Statement of Stockholders' Equity [Abstract]
Stock issuance cost	$ 4,965

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net loss	$ (89,998)	$ (50,986)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	688	632
Stock-based compensation expense	9,996	7,324
Accretion of development financing liability	2,583
Write-off of deferred financing costs	312
Net accretion and amortization of investments in marketable securities	637	(104)
Changes in assets and liabilities:
Other prepaid expenses and current assets	386	6,716
Other assets	(1,513)	(47)
Accounts payable	2,309	(2,272)
Accrued research and development expenses	5,054	(4,520)
Other accrued liabilities	115	(1,468)
Net cash used in operating activities	(69,431)	(44,725)
Investing activities
Purchases of property and equipment	(87)	(21)
Purchases of marketable securities	(78,084)	(176,300)
Proceeds from maturities of marketable securities	126,760	224,278
Net cash provided by investing activities	48,589	47,957
Financing activities
Proceeds from issuance of common stock and pre-funded warrants, net of issuance costs	70,499
Proceeds from development financing, net of transaction costs	47,737
Proceeds from issuance of common stock pursuant to equity award plans	219	92
Net cash provided by financing activities	118,455	92
Net increase in cash and cash equivalents	97,613	3,324
Cash and cash equivalents at beginning of period	28,193	24,869
Cash and cash equivalents at end of period	125,806	28,193
Supplemental disclosure
Cash paid for amounts included in the measurement of lease liabilities	666	647
Supplemental non-cash investing and financing activities
Unpaid financing costs	$ 464

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business CymaBay Therapeutics, Inc. (the Company or CymaBay) is a clinical-stage biopharmaceutical company focused on developing and providing access to innovative therapies for patients with liver and other chronic diseases with high unmet medical need. The Company’s key clinical development candidate is seladelpar. Seladelpar has been primarily under development for the treatment primary biliary cholangitis (PBC), a rare liver disease. The Company was incorporated in Delaware in October 1988 as Transtech Corporation. The Company’s headquarters and operations are located in Newark, California and it operates in one segment. Liquidity The Company has incurred net operating losses and negative cash flows from operations since its inception. During the year ended December 31, 2021, the Company incurred a net loss of $90.0 million and used $69.4 million of cash in operations. At December 31, 2021, the Company had an accumulated deficit of $766.9 million. Historically, the Company has incurred substantial research and development expenses in the course of studying its product candidates in clinical trials. To date, none of the Company’s product candidates have been approved for marketing and sale, and the Company has not recorded any revenue from product sales. Generally, the Company’s ability to achieve profitability is dependent on its ability to successfully develop, acquire or in-license During the year ended December 31, 2021, the Company completed certain financing transactions as follows: • On July 30, 2021, the Company entered into a Development Financing Agreement (the PBC in installment Note 6—Development Financing Agreement • On November 22, 2021, the Company sold 15,625,000 shares of common stock at $4.00 per share and pre-funded Note 9 — . As of December 31, 2021, the Company had cash, cash equivalents and marketable securities totaling $194.6 million, which the Company believes is sufficient to fund its current operating plan for at least twelve months from the issuance date of its financial statements. The Company has historically obtained, and expects to obtain in the future, additional financing to fund its business strategy through: equity offerings; debt financing; one or more possible licenses, collaborations or other similar arrangements with respect to development and/or commercialization rights of the Company’s product candidates; or a combination of the above. It is unclear if or when any such transactions will occur, on satisfactory terms or at all. The Company’s failure to raise capital as and when needed could have a negative impact on its financial condition and its ability to pursue its business strategies. If adequate funds are not available to the Company, it could have a material adverse effect on the Company’s business, results of operations, and financial condition. Market volatility resulting from the global novel coronavirus disease (COVID-19)

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Use of Estimates The accompanying consolidated financial statements are comprised of the accounts of CymaBay and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The Company has no unconsolidated subsidiaries or investments accounted for under the equity method. These consolidated statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP), which requires management to make informed estimates and assumptions that impact the amounts and disclosures reported in the consolidated financial statements and accompanying notes. Accounting estimates and assumptions are inherently uncertain. Management bases its estimates on historical experience and on assumptions believed to be reasonable under the circumstances. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes, and management must select an amount that falls within that range of reasonable estimates. Actual results could differ materially from those estimates and assumptions. These estimates form the basis for making judgments about the carrying values of assets and liabilities when these values are not readily apparent from other sources. Estimates are assessed each reporting period and updated to reflect current information and any changes in estimates will generally be reflected in the period first identified. Fair Value of Financial Instruments The Company’s financial instruments during the periods reported consist of cash, cash equivalents, marketable securities, accounts payable, certain accrued liabilities, and the development financing liability. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Assets and liabilities that are measured at fair value are reported using a three-level fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs and is as follows: Level 1—Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Inputs other than quoted prices in active markets that are observable for the asset or liability, either directly or indirectly. Level 3—Inputs that are significant to the fair value measurement and are unobservable (i.e. supported by little market activity), which requires the reporting entity to develop its own valuation techniques and assumptions. The carrying amounts of cash, accounts payable, and certain accrued liabilities approximate their related fair values due to the short-term nature of these instruments. Cash is classified as level 1 and accounts payable and accrued liabilities as level 2 under the fair value hierarchy. The following tables present the Company’s financial assets that are measured at fair value on a recurring basis using the above input categories (in thousands): As of December 31, 2021 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 85,638 $ — $ — $ 85,638 Total cash equivalents 85,638 — — 85,638 Marketable securities: U.S. and foreign commercial paper — 28,760 — 28,760 U.S. and foreign corporate debt securities — 23,535 — 23,535 Asset-backed securities — 8,522 — 8,522 U.S. treasury securities — 7,979 — 7,979 Total marketable securities — 68,796 — 68,796 Total assets measured at fair value $ 85,638 $ 68,796 $ — $ 154,434 As of December 31, 2020 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 22,415 $ — $ — $ 22,415 Total cash equivalents 22,415 — — 22,415 Marketable securities: U.S. treasury securities — 15,499 — 15,499 U.S. and foreign commercial paper — 38,561 — 38,561 U.S. and foreign corporate debt securities — 29,189 — 29,189 U.S. agency securities — 23,994 — 23,994 Asset-backed securities — 7,885 — 7,885 Supranational debt securities — 3,002 — 3,002 Total marketable securities — 118,130 — 118,130 Total assets measured at fair value $ 22,415 $ 118,130 $ — $ 140,545 The Company estimates the fair value of its money market funds, corporate debt, asset backed securities, commercial paper U.S. treasury and agency securities and supranational debt securities by taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs. The fair value of the Company’s development financing liability is consistent with its carrying value, which is recorded at amortized cost. The development financing liability is classified as level 3 under the fair value hierarchy as its valuation is based on a discounted cash flow model that uses unobservable inputs such as the estimated timing of regulatory approval and attainment of certain sales milestones. Cash, Cash Equivalents, and Marketable Securities The Company considers all highly liquid investments with an original maturity of 90 days or less at the time of purchase to be cash equivalents. Cash and cash equivalents consist of deposits with commercial banks in checking, interest-bearing, and money market funds. The Company invests excess cash in marketable securities with high credit ratings . “available-for-sale.” Realized gains and losses from the sale of marketable securities, if any, are calculated using the specific-identification method. Realized gains and losses and declines in value judged to be other-than-temporary are included in interest income or expense in the consolidated statements of operations and comprehensive loss. Unrealized holding gains and losses are reported in accumulated other comprehensive loss in the consolidated balance sheets. To date, the Company has not recorded any impairment charges on its marketable securities related to other-than-temporary declines in market value. In determining whether a decline in market value is other-than-temporary, various factors are considered, including the cause, duration of time and severity of the impairment, any adverse changes in the investees’ financial condition, and the Company’s intent and ability to hold the security for a period of time sufficient to allow for an anticipated recovery in market value. Concentration of Risk Cash, cash equivalents, and marketable securities consist of financial instruments that potentially subject the Company to a concentration of credit risk to the extent of the fair value recorded on the balance sheet. The Company invests cash that is not required for immediate operating needs primarily in highly liquid instruments that bear minimal risk. The Company has established guidelines relating to the quality, diversification, and maturities of securities to enable the Company to manage its credit risk. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash, cash equivalents and investments and issuers of investments to the extent recorded on the consolidated balance sheets. Certain materials and key components that the Company utilizes in its operations are obtained through single suppliers. Since the suppliers of key components and materials must be named in an NDA filed with the FDA for a product, significant delays can occur if the qualification of a new supplier is required. If delivery of material from the Company’s suppliers were interrupted for any reason, the Company may be unable to supply any of its product candidates for clinical trials. Other Risks and Uncertainties In March 2020, the World Health Organization declared the global novel coronavirus disease (COVID-19) COVID-19 COVID-19 COVID-19 COVID-19 Property and Equipment Property and equipment are recorded at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated non-cancelable Long-Lived Assets The Company reviews the carrying value long-lived assets, including right-of-use Leases The Company has one lease, a non-cancelable right-of-use right-of-use The operating lease right-of-use non-lease non-lease Research and Development Expenses Research and development expenses consist of costs incurred in identifying, developing, and testing product candidates. These expenses consist primarily of costs for research and development personnel, including related stock-based compensation; contract research organizations (CRO) and other third parties that assist in managing, monitoring, and analyzing clinical trials; investigator and site fees; laboratory services; consultants; contract manufacturing services; non-clinical development costs are expensed as incurred, including expenses that may or may not be reimbursed under research and development funding arrangements. Payments made prior to the receipt of goods or services to be used in research and development are recorded as prepaid assets until the goods are received or services are rendered. Such payments are evaluated for current or long-term classification based on when they will be realized. Additionally, if expectations change such that the Company does not expect goods to be delivered or services to be rendered, such prepayments are charged to expense . The Company records expenses related to clinical studies and manufacturing development activities based on its estimates of the services received and efforts expended pursuant to contracts with multiple CROs and manufacturing vendors that conduct and manage these activities on its behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract, and may result in uneven payment flows. There may be instances in which payments made to the Company’s vendors will exceed the level of services provided and result in a prepayment. Payments under some of these contracts depend on factors such as the successful enrollment of subjects and the completion of clinical trial milestones. In amortizing or accruing service fees, the Company estimates the time period over which services will be performed, enrollment of subjects, number of sites activated and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the Company’s estimate, the Company will adjust the accrued or prepaid expense balance accordingly. To date, there have been no material differences from the Company’s estimates to the amounts actually incurred. Development Financing Agreement The Company accounts for the Financing Agreement (see Note 6) as a debt instrument. Accordingly, the Company has recorded payments received under the Financing Agreement as part of a development financing liability in the Company’s consolidated balance sheet. The liability is recorded at amortized cost and accreted to the contractual success fee amounts based on the estimated timing of regulatory approval and attainment of certain sales milestones using an imputed interest rate. Certain transaction fees incurred specifically to complete the Financing Agreement were capitalized and recorded as a reduction to the carrying amount of the development financing liability and are being amortized to interest expense using the effective interest rate method. There are several factors that could affect the estimated timing of regulatory approval and attainment of sales milestones, some of which are not entirely within the Company’s control. Therefore, the Company periodically reassesses the estimated timing of regulatory approval and attainment of sales milestones, and the expected contractual success fee payments due therefrom. If the timing and/or amount of such expected payments is materially different than original estimates, the Company will prospectively adjust the accretion of the development financing liability and the imputed interest rate. The Company identified certain contingent repayment features in the Financing Agreement that are required to be bifurcated from the debt host instrument as embedded derivative liabilities; however, the Company determined the fair value of these features, both individually and in the aggregate, was immaterial at inception and as of December 31, 2021. The fair value of these features will be assessed at each reporting date and will be marked to market, if material. To determine the amount to record for the embedded derivative liabilities, the Company must assess the probability of occurrence of various potential future events that could affect the timing and/or amount of future cash flows related to the Financing Agreement. Pre-funded Warrants Pursuant to the Company’s public equity offering completed in November 2021 , the Company issued pre-funded warrants to purchase 3,125,000 shares of common stock at a price of $3.9999 per share. These pre-funded warrants have an exercise price of $0.0001 per share, were fully exercisable upon issuance, and have no expiration date. The Company determined that the pre-funded warrants should be equity classified because they are freestanding financial instruments, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, permit the holders to receive a fixed number of shares of common stock upon exercise, are indexed to the Company’s common stock and meet the equity classification criteria. In addition, such pre-funded paid-in Note 9—Stockholders’ Equity . Stock-Based Compensation Stock-based compensation is measured at fair value on the grant date of the award. Compensation cost is recognized as expense on a straight-line basis over the vesting period for options with service conditions and forfeitures are accounted for as they occur. The Company uses the Black-Scholes option-pricing model to determine the fair value of stock option awards. The determination of fair value for stock-based awards using an option-pricing model requires management to make certain assumptions regarding subjective input variables such as expected term, dividends, volatility and risk-free rate. If actual results are not consistent with the Company’s assumptions used in making these estimates, the Company may be required to increase or decrease compensation expense, which could be material to the Company’s results of operations. Income Taxes The Company utilizes the liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on differences between the financial reporting and the tax bases of assets and liabilities and are measured using enacted tax rates and laws that will be in effect when the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. A valuation allowance is recorded when it is more likely than not that all or part of a deferred tax asset will not be realized. When the Company establishes or reduces the valuation allowance related to the deferred tax assets, the provision for income taxes will increase or decrease, respectively, in the period such determination is made. The accounting guidance for uncertainty in income taxes prescribes a recognition threshold and measurement attribute criteria for the financial recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination based on the technical merits of the position. The Company is required to file federal and state income tax returns in the United States. The preparation of these income tax returns requires the Company to interpret the applicable tax laws and regulations in effect that could affect the amount of tax paid to these jurisdictions. The Company records interest related to income tax reserves, if any, as interest expense, and any penalties would be recorded as other expense in the consolidated statements of operations and comprehensive loss. Comprehensive Loss Comprehensive loss includes net loss and net unrealized gains and losses on marketable securities, which are presented in a single continuous statement. Other comprehensive (loss) gain is also disclosed in the consolidated balance sheets and statements of stockholders’ equity in accumulated other comprehensive income (loss), and is stated net of related tax effects, if any. Net Loss Per Common Share Basic net loss per share of common stock is based on the weighted average number of shares of common stock outstanding equivalents during the period. The weighted-average common shares outstanding as of December 31, 2021 includes pre-funded 3,125,000 shares of common stock that were issued in connection with the November 2021 public offering, as discussed in Note 9— Stockholders’ Equity The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share amounts): Year Ended December 31, 2021 2020 Numerator: Net loss $ (89,998 ) $ (50,986 ) Denominator: Weighted average number of common stock shares outstanding 71,055,331 68,893,127 Net loss per share $ (1.27 ) $ (0.74 ) The following table shows the total outstanding securities considered anti-dilutive and therefore excluded from the computation of diluted net loss per share (in thousands): Year Ended 2021 2020 Common stock options 10,791 8,812 Incentive awards 101 101 Total 10,892 8,913 Recently Adopted Accounting Pronouncements ASU 2019-12 In December 2019, the FASB issued ASU 2019-12, step-up Recently Issued Accounting Pronouncements ASU 2016-13 In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments available-for-sale No. 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842)

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Marketable Securities	3. Marketable Securities Marketable available-for-sale Amortized Gross Gross Estimated As of December 31, 2021: Cash equivalents: Money market funds $ 85,638 $ — $ — $ 85,638 Total cash equivalents 85,638 — — 85,638 Current marketable securities: U.S. and foreign commercial paper 28,760 — — 28,760 U.S. and foreign corporate debt securities 15,476 — (8 ) 15,468 Asset-backed securities 8,524 1 (3 ) 8,522 U.S. treasury securities 7,982 — (3 ) 7,979 Total current marketable securities 60,742 1 (14 ) 60,729 Non-current U.S. corporate debt securities 8,067 2 (2 ) 8,067 Total marketable securities $ 154,447 $ 3 $ (16 ) $ 154,434 Amortized Gross Gross Estimated As of December 31, 2020: Cash equivalents: Money market funds $ 22,415 $ — $ — $ 22,415 Total cash equivalents 22,415 — — 22,415 Current marketable securities: U.S. and foreign commercial paper 38,561 — — 38,561 U.S. and foreign corporate debt securities 29,186 7 (4 ) 29,189 Asset-backed securities 7,883 2 — 7,885 U.S. treasury securities 23,991 3 — 23,994 U.S. agency securities 15,498 1 — 15,499 Supranational debt securities 3,003 — (1 ) 3,002 Total current marketable securities 118,122 13 (5 ) 118,130 Total marketable securities $ 140,537 $ 13 $ (5 ) $ 140,545 The Company’s commercial paper and corporate debt securities consist of U.S. and foreign securities from issuers in various sectors, including finance and industry and have similar credit quality and risk characteristics. The Company’s asset-backed securities are collateralized by credit card receivables and have investment-grade ratings. The Company’s government securities are issued by the U.S. treasury and certain U.S. government-backed agencies. Supranational debt securities consist of securities issued with funding from various national governments, including the U.S. There were no realized gains and losses for the years ended December 31, 2021 and 2020. None of these investments have been in a continuous unrealized loss position for more than 12 months as of December 31, 2021 and 2020. The Company may sell certain of its marketable securities prior to their stated maturities for reasons including, but not limited to, managing liquidity, credit risk, duration and asset allocation. The following table shows the fair value of the Company’s marketable securities, by contractual maturity, as of December 31, 2021 (in thousands): Due less than 1 year $ 146,367 Due between 1 and 2 years 8,067 Total fair value $ 154,434

Certain Balance Sheet Items

Certain Balance Sheet Items	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Certain Balance Sheet Items	4. Certain Balance Sheet Items Property and equipment consist of the following (in thousands): December 31, 2021 2020 Leasehold improvements $ 2,429 $ 2,430 Office and computer equipment 290 290 Purchased software 44 44 Furniture and fixtures 539 451 Total 3,302 3,215 Less: Accumulated depreciation and amortization (2,124 ) (1,454 ) Property and equipment, net $ 1,178 $ 1,761 Depreciation and amortization exp e e Other accrued liabilities consist of the following (in thousands): December 31, 2021 2020 Accrued compensation $ 3,986 $ 3,769 Accrued professional fees and other 1,333 677 Current portion of operating lease liability 567 482 Total other accrued liabilities $ 5,886 $ 4,928

License Agreement

License Agreement	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License Agreement	5. License Agreement Janssen Pharmaceutical NV and Janssen Pharmaceuticals, Inc. In June 2006, the Company entered into an exclusive worldwide, royalty-bearing license to seladelpar and certain other PPAR d d right to grant sublicenses to third parties to make, use and sell such PPAR d d d d d d

Development Financing Agreement

Development Financing Agreement	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Development Financing Agreement	6. Development Financing Agreement On July 30, 2021 (the Effective Date), the Company entered into a Development Financing Agreement (the Financing Agreement) with Abingworth to provide funding to the Company to support its development of seladelpar for the treatment of primary biliary cholangitis (PBC). The Financing Agreement provides the Company up to $ million in funding, of which $ million was provided in , $ million was provided in , and $ million was provided in January . The Company has an option to receive an additional $ million (the Optional Funding) within approximately months of enrollment completion of the Company’s Phase RESPONSE clinical trial. The Optional Funding is subject to certain customary funding conditions. The use of proceeds from the funding is limited to PBC “Development Program” costs incurred or paid as defined in the Financing Agreement. In return, the Company will pay to Abingworth: (1) contingent upon the first to occur of regulatory approval of seladelpar for the treatment of PBC in the U.S., U.K., Germany, Spain, Italy or France (Regulatory Approval), fixed success payments equal to 2.0x of the funding provided, consisting of $10 million payable in 90 days after the Regulatory Approval and thereafter, payments due on the first six anniversaries of the Regulatory Approval in the amounts of $15.0 million, $22.5 million, $22.5 million, $25.0 million, $27.5 million and $27.5 million, respectively (or if the Optional Funding is provided, 133% of such payments) and (2) variable success payments equal to 1.1x of the funding provided, consisting of sales milestone payments of (x) $17.5 million and $27.5 million, respectively (or if the Optional Funding is provided, 133% of such payments) upon first reaching certain cumulative U.S. product sales thresholds, and (y) $37.5 million (or if the Optional Funding is provided, 133% of such payment) upon first reaching a specified U.S. product sales run rate. Promptly following receipt of Regulatory Approval, the Company is required to and deliver a promissory note to business days to convert the fixed and variable success payments into a note payable. At the time that Abingworth receives, collectively, an aggregate of x of the funding provided (approximately $ million (or $ million if the Optional Funding is provided)), the Company’s payment obligations under the Financing Agreement will be fully satisfied. The Company has the option to satisfy its payment obligations to Abingworth upon Regulatory Approval, or a change of control of the Company, by paying an amount equal to the remaining payments payable to Abingworth subject to a mid-single-digit discount rate. Upon a change of control of the Company, an acceleration payment of x of the funding provided is payable, net of payments already made to Abingworth and creditable against future payments to Abingworth. Pursuant to the Financing Agreement, the Company granted Abingworth a security interest in all its assets (other than intellectual property not related to seladelpar), provided that the Company is permitted to incur certain indebtedness. The security interest will terminate when the Company has paid Abingworth 2.0x of the funding provided or upon certain terminations of the Financing Agreement. The Financing Agreement provides for negative, affirmative and additional covenants, which the Company must comply with for the duration of the Financing Agreement term. As of December 31, 2021, the Company was in compliance with all covenants stipulated in the Financing Agreement. In certain instances, upon the termination of the Financing Agreement, the Company will be obligated to pay Abingworth a multiple of the amounts paid to the Company under the Financing Agreement, including specifically: (i) 310% of such amounts in the event that Abingworth terminates the Financing Agreement due to (x) a Fundamental Breach, as defined in the Financing Agreement, (y) the bankruptcy of the Company, or (z) a safety concern resulting from gross negligence on the part of the Company or due to a safety concern that was material on the Effective Date and the material data showing such safety concern was not publicly known, disclosed to Abingworth, or in the diligence room made available to Abingworth, (ii) 200% of such amounts in the event the Financing Agreement is terminated due to (x) Material Breach, as defined in the Financing Agreement, by the Company or (y) the security interests of Abingworth being invalidated or terminated other than as set forth in the Financing Agreement, and (iii) 100% of such amounts in the event of certain irresolvable disagreements within the executive review committee overseeing the Company’s development of seladelpar. In addition, if, following certain terminations, the Company continues to develop seladelpar for the treatment of PBC and obtains regulatory approval, it will make the payments to Abingworth as if the Financing Agreement had not been terminated, less any payments made upon termination. The Company shall not be obligated to make any payments to Abingworth under certain instances of technical or regulatory failure of the PBC development program as defined in the Financing Agreement. As part of the arrangement, an executive review committee was established between the Company and Abingworth to discuss the Company’s development of seladelpar. The Company evaluated the Financing Agreement and determined it to be a research and development funding arrangement with the characteristics of a debt instrument as the transfer of financial risk to Abingworth was not considered substantive and genuine. Accordingly, the Company has recorded payments received under the Financing Agreement as part of a development financing liability in its consolidated balance sheets. The Company accounts for the overall development financing liability at amortized cost based on the estimated timing of regulatory approval and attainment of certain sales milestones and the contractual success fee payments expected to be due therefrom, as discounted using an imputed interest rate. The development financing liability will be accreted as interest expense to its expected future repayment amount over the expected life of the agreement using the effective interest rate method. Certain legal and financial advisory fees incurred specifically to complete the Financing Agreement were capitalized and recorded as a reduction to the carrying amount of the development financing liability and will also be amortized to interest expense using the effective interest method. There are several factors that could affect the estimated timing of regulatory approval and attainment of sales milestones, some of which are not entirely within the Company’s control. Therefore, the Company periodically reassesses the estimated timing of regulatory approval and attainment of sales milestones, and the expected contractual success fee payments due therefrom. If the timing and/or amount of such expected payments is materially different than original estimates, the Company will prospectively adjust the accretion of the development financing liability and the imputed interest rate. The Company identified certain contingent repayment features in the agreement that are required to be bifurcated from the debt host instrument as embedded derivative liabilities; however, the fair value of these features was immaterial at the Effective Date and as of December 31, 2021. The fair value of the embedded derivative liabilities will be assessed at subsequent reporting dates if material. The following table sets forth a summary of the changes in the carrying value of the Company’s development financing liability (in thousands): Balance at December 31, 2020 $ — Cash received 50,000 Debt discount (2,263 ) Accretion of development financing liability 2,583 Balance at December 31, 2021 $ 50,320 As of December 31, 2021, the development financing liability was classified as a long-term liability as the Company expects the related repayments to take place between 2024 and 2030 for purposes of the model used to calculate its carrying value. The imputed interest rate on the unamortized portion of the development financing liability was approximately 20% as of December 31, 2021.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Indemnification In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnification, including indemnification associated with product liability or infringement of intellectual property rights. The Company’s exposure under these agreements is unknown because it involves future claims that may be made against the Company that may be, but have not yet been, made. To date, the Company has not paid any claims or been required to defend any action related to these indemnification obligations, and no amounts have been accrued in the accompanying consolidated balance sheets related to these indemnification obligations. The Company has agreed to indemnify its officers and directors for losses and costs incurred in connection with certain events or occurrences, including advancing money to cover certain costs, subject to certain limitations. The maximum potential amount of future payments the Company could be required to make under this indemnification is unlimited; however, the Company maintains insurance policies that may limit its exposure and may enable it to recover a portion of any future amounts paid. Assuming the applicability of coverage, the willingness of the insurer to assume coverage, and subject to certain retention, loss limits, and other policy provisions, the Company believes the fair value of these indemnification obligations is not material. Accordingly, the Company has not recognized any liabilities relating to these obligations as of December 31, 2021 and 2020. No assurances can be given that the covering insurers will not attempt to dispute the validity, applicability, or amount of coverage without expensive litigation against these insurers, in which case the Company may incur substantial liabilities as a result of these indemnification obligations. Litigation On January 15, 2021, Genfit S.A. (Genfit) filed a complaint against the Company in the U.S. District Court for the Northern District of California, alleging misappropriation of trade secrets and related causes of action based on the Company’s receipt of a Genfit protocol synopsis for Genfit’s Phase 3 clinical trial of its drug candidate elafibranor in patients with primary biliary cholangitis. An Amended Complaint was filed on April 16, 2021 with substantially the same allegations. Genfit seeks damages in an unspecified amount as well as injunctive relief. On March 12, 2021, the Court granted a Temporary Restraining Order (later converted to a Preliminary Injunction), prohibiting the Company from accessing or disseminating the protocol synopsis, using any Genfit trade secrets contained therein or destroying any evidence related thereto. The Company filed a Motion to Dismiss the Amended Complaint that was granted on September 9, 2021, with leave to amend. Genfit filed a Second Amended Complaint on October 15, 2021 with substantially the same allegations and claims for relief as in the original complaint. The Company filed a Motion to Dismiss most of the Second Amended Complaint that was granted on January 21, 2022, without further leave to amend. What remains in the complaint is an alleged misappropriation of the protocol synopsis as a whole. The Company filed its Answer to what remained of the Second Amended Complaint on February 4, 2022. The Company intends to defend itself vigorously. While the outcome of any litigation is inherently uncertain, based on currently available information, management does not currently believe a loss associated with this matter is probable, nor is any amount reasonably estimable, and accordingly no amounts have been recorded or disclosed.

Leases

Leases	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Leases	8. Leases The Company has one operating lease pertaining to 17,698 square feet of corporate office space in Newark, California pursuant to a lease agreement that commenced January 16, 2014 and was amended on April 16, 2018. At December 31, 2021 and December 31, 2020, the Company’s lease portfolio had a weighted average remaining term of 2.1 years, and 3.1 years, respectively, with an option to extend for an additional 5 years. The lease requires monthly lease payments that are subject to annual increases throughout the lease term. The optional period has not been considered in the determination of the right-of-use The Company cannot determine the implicit rate in its lease, and therefore the Company uses its incremental borrowing rate as the discount rate The incremental borrowing rate represents an estimate of the interest rate the Company would incur at lease commencement to borrow an amount equal to the lease payments on a collateralized basis over the term of a lease within a particular currency environment. The Company used an incremental borrowing rate as of the date of adoption for leases that commenced prior to January 1, 2019. For the years ended December 31, 2021 and 2020, the Company incurred $0.6 million and $0.5 million, respectively, of lease costs included in operating expenses in the consolidated statements of operations and comprehensive loss in relation to its operating lease, a portion of which was variable rent expense and not included within the measurement of the Company’s operating ROU assets and lease liabilities. The variable rent expense consists primarily of the Company’s proportionate share of operating expenses, property taxes, and insurance and is classified as lease expense due to the Company’s election to not separate lease and non-lease right-of-use Year ending December 31, 2022 $ 686 2023 707 2024 30 Total undiscounted future minimum lease payments 1,423 Less imputed interest 161 Total operating lease liability 1,262 Less: current portion of operating lease liability 567 Long-term portion of lease liability $ 695

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Stockholders' Equity	9. Stockholders’ Equity Preferred and Common Stock Authorized The Company is authorized to issue 10,000,000 shares of preferred stock as of December 31, 2021 and 2020, and 200,000,000 shares of common stock as of December 31, 2021 and 2020. Common Stock Reserved for Future Issuance As of December 31, 2021 and 2020, the Company had reserved shares of common stock for future issuances as follows: December 31, 2021 2020 Prefunded warrants to purchase common stock 3,125,000 — Equity award plans: Options and incentive awards outstanding, all equity plans 10,892,613 8,913,071 Equity awards available for future grant—2013 Plan 1,588,613 167,159 Equity awards available for future grant—2020 Plan — 750,000 Total shares of common stock reserved for future issuance 15,606,226 9,830,230 Sale of Common Stock and Prefunded Warrants On November 22, 2021, pursuant to a shelf registration statement on Form S-3, pre-funded pre-funded pre-funded 30 , pre-funded pre-funded pre-funded In the event of certain fundamental transactions, the holders of the pre-funded pre-funded pre-funded pre-funded The pre-funded paid-in pre-funded At-the-Market In July 2020, the Company filed a $200.0 million registration statement on Form S-3 at-the-market

Stock Plans and Stock-Based Com

Stock Plans and Stock-Based Compensation	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock Plans and Stock-Based Compensation	10. Stock Plans and Stock-Based Compensation Stock Plans In September 2013, the Company’s stockholders approved the 2013 Equity Incentive Plan (the 2013 Plan), under which shares of common stock are reserved for the granting of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards and other stock awards by the Company. These awards may be granted to employees, members of the Board of Directors, and consultants. The 2013 Plan has a term of ten years and replaced the 2003 Equity Incentive Plan, which had similar terms. The 2013 Plan permits the Company to (i) grant incentive stock options to directors and employees at not less than 100% of the fair value of common stock on the date of grant; (ii) grant nonqualified options to employees, directors, and consultants at not less than 85% of fair value; (iii) award stock bonuses; and (iv) grant rights to acquire restricted stock at not less than 85% of fair value. Options generally vest over a four year period and have a term of ten years. Options granted to 10% stockholders have a maximum term of five years and require an exercise price equal to at least 110% of the fair value on the date of grant. The exercise price of all options granted to date has been at least equal to the fair value of common stock on the date of grant. Stock option exercises are settled with shares reserved under the 2013 Plan. The share reserve under the 2013 Plan will automatically increase on January 1 st st st In October 2020, the Company’s board of directors approved the 2020 New Hire Plan (the 2020 Plan), under which shares of common stock are reserved for the granting of nonqualified stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards and other stock awards by the Company as an inducement to prospective new hire employees of the Company. The 2020 Plan has a term of ten years. The 2020 Plan permits the Company to (i) grant nonqualified options to new hire employees at not less than 85% of fair value; (ii) award stock bonuses; and (iii) grant rights to acquire restricted stock at not less than 85% of fair value. Options generally vest over a four year period and have a term of ten years. The share reserve under the 2020 Plan may be increased at the discretion of and approval by the board of directors. Stock Plan Activity As of December , , there were and shares available for grant under the and Plans, respectively. On January , , in accordance with the annual share increase provision in the Plan, the Company added shares to the Plan share reserve. 93 The following table summarizes activity in the Company’s stock option grants: Shares Weighted- Weighted- Aggregate Intrinsic Outstanding as of December 31, 2020 8,811,630 $ 6.35 Options granted 2,660,965 4.84 Options exercised (106,847 ) 2.05 Options forfeited (307,018 ) 5.89 Options expired (267,299 ) 7.60 Outstanding as of December 31, 2021 10,791,431 $ 6.01 7.28 $ 1,514 Vested and expected to vest as of December 31, 2021 10,791,431 $ 6.01 7.28 $ 1,514 Exercisable as of December 31, 2021 6,327,680 $ 6.62 6.22 $ 1,510 The total intrinsic value of options exercised was $0.2 million and $0.4 million for the years ended December 31, 2021 and 2020, respectively. The total fair value of options vested was $0.7 million and $3.3 million for the years ended December 31, 2021 and 2020, respectively. As of December 31, 2021, unamortized stock-based compensation expense of $16.9 million is expected to be recognized over a weighted average period of 2.6 years. Incentive Awards In December 2013, January 2014, and April 2014, as permitted by the 2013 Plan, the Company issued certain incentive awards to directors, employees and a consultant which are subject to 252,752 shares of the Company’s common stock and are exercisable at a weighted average price of $5.21 per share when vested. The Company may determine at its option whether to settle exercised awards in shares of common stock or in cash. Each recipient’s incentive award defines the number of common shares that may be acquired upon exercise provided the Company chooses to settle in shares. For awards settled in cash, the Company must pay the recipient the excess of the fair market value of the Company’s common stock on the date of exercise over the exercise price paid by the recipient multiplied by the number of shares the recipient would be entitled to receive had the award been settled in shares of the Company’s common stock. Pursuant to their terms, the incentive awards have a term of 10 years and were initially scheduled to vest 100% on the second anniversary of their grant date. However, as a result of the approval by the Company’s stockholders of a 500,000 share increase to the 2013 Plan’s share reserve in June 2014, the incentive awards were automatically modified to vest monthly over four years effective from their grant date. The Company recognized the value of the incentive awards over the remaining four year vesting period which ended in the first quarter of 2018. The Company recorded no stock-based compensation expense in the years ended December 31, 2021 and 2020 pertaining to its incentive awards. Incentive awards outstanding totaled 101,182 and 101,441 as of December 31, 2021 and 2020, respectively. Stock-Based Compensation Expense Stock-based compensation expense is included in the consolidated statements of operations and comprehensive loss and is as follows (in thousands): Year Ended 2021 2020 Research and development $ 4,470 $ 2,739 General and administrative 5,526 4,585 Total stock-based compensation expense $ 9,996 $ 7,324 Valuation Assumptions The following table presents the weighted-average assumptions the Company used in the Black-Scholes option-pricing model to derive the grant date fair values of stock options granted in each of the years presented along with the resulting estimated weighted-average grant date fair values per share: Year Ended 2021 2020 Expected term (years) 6.1 6.1 Expected volatility 104 % 105 % Risk-free interest rate 0.9 % 0.4 % Expected dividend yield — — Weighted-average grant date fair value per share $ 3.91 $ 3.91 Expected Term The Company does not believe it can currently place reliance on its historical exercise and post-vesting termination activity to provide accurate data for estimating the expected term. Therefore, for stock option grants made during the years ended December 31, 2021 and 2020, the Company has elected to use the simplified method for estimating the expected term, which is an average of the contractual term of the options and its ordinary vesting period. The expected term represents the period of time that options are expected to be outstanding. Expected Volatility The Company estimates expected volatility by measuring the historical volatility of its common stock price over a historical period commensurate with the expected term of the related award. Risk-Free Interest Rate The risk-free interest rate assumption was based on U.S. treasury instruments with constant maturities whose term was consistent with the expected term of stock options granted by the Company. Expected Dividend Yield The Company has never declared or paid cash dividends and does not plan to pay cash dividends in the foreseeable future. Consequently, the Company uses an expected dividend yield of zero.

401(k) Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2021
Postemployment Benefits [Abstract]
401(k) Plan	11. 401(k) Plan The Company provides a qualified 401(k) savings plan for its employees. All employees are eligible to participate, provided they meet the requirements of the plan. As is permitted under the plan, the Company has elected to match employee contributions up to $750 and accordingly matching contributions totaling an insignificant amount were made in the years ended December 31, 2021 and 2020.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes No provision for U.S. income taxes exists due to tax losses incurred in all periods presented. All losses incurred were U.S. based. Significant components of the Company’s deferred tax assets are as follows (in thousands): December 31, 2021 2020 Deferred tax assets: Federal and state net operating loss carryforwards $ 129,898 $ 123,144 State and federal research and development tax credit carryforwards 31,951 28,861 Capitalized research and development 5,670 2,363 Stock-based compensation 5,329 3,822 Other 1,222 1,256 Total deferred tax assets 174,070 159,446 Deferred tax liabilities: Depreciation and amortization (158 ) (269 ) Other (53 ) (57 ) Total deferred tax liabilities (211 ) (326 ) Valuation allowance (173,859 ) (159,120 ) Net deferred tax assets $ — $ — Realization of the net deferred tax assets is dependent upon future taxable income, if any, the amount and timing of which is uncertain. Based on the weight of available positive and negative objective evidence, management believes it more likely than not that the Company’s deferred tax assets are not realizable. Accordingly, the net deferred tax assets have been fully offset by a valuation allowance. The net valuation allowance increased by $14.7 million and $17.2 million due to the increase in the Company’s taxable losses during the years ended December 31, 2021 and 2020, respectively. The following is a reconciliation of the expected statutory federal income tax provision to the actual income tax provision (in thousands): December 31, 2021 2020 Income tax benefit at federal statutory tax rate $ (18,900 ) $ (10,707 ) Change in valuation allowance 14,739 17,181 State income taxes, net of federal benefit (267 ) (4,768 ) Research credits (2,802 ) (2,911 ) Cancelled options 141 982 Development financing liability 6,654 — Permanent differences 429 152 Other, net 6 71 Income tax (benefit) expense $ — $ — Pursuant to Internal Revenue Code (IRC), Section 382 and 383, use of the Company’s U.S. federal and state net operating loss and research and credit carryforwards may be limited in the event of a cumulative change in ownership of more than 50.0% within a three-year period. The Company completed an analysis under IRC Sections 382 and 383 through December 21, 2007 and determined that the Company’s net operating losses and research and development credits were subject to limitations due to changes in ownership through December 31, 2007. The net operating loss carryforwards reflected in the deferred tax assets at December 31, 2021 have been adjusted to reflect Section 382 limitations resulting from that change. The Company has been in a net operating loss position since 2008. The Company has not performed any additional analysis for IRC Sections 382 and 383 and there is a risk that additional changes in ownership could have occurred since December 31, 2007. If a change in ownership were to have occurred, additional net operating loss and tax credit carryforwards could be eliminated or restricted. If eliminated, the related asset would be removed from the deferred tax asset schedule with a corresponding reduction in the valuation allowance. As of December 31, 2021, the Company had federal net operating loss carryforwards of $522.7 million and state net operating loss carryforwards of $288.3 million to offset future taxable income, if any. In addition, the Company had federal research and development tax credit carryforwards of $10.2 million, federal orphan drug tax credit carryforwards of $24.8 million, and state research and development tax credit carryforwards of $6.2 million. If not utilized, the federal net operating losses for the years beginning before January 1, 2018 of $255.7 million will expire beginning in 2024 through 2037, and the federal net operating losses for the tax years beginning after January 1, 2018 of $267.0 million will be carried forward indefinitely (subject to certain utilization limitations). The state net operating loss carryforwards will expire beginning in 2028 through 2041. The federal research and development and federal orphan drug tax credit carryforwards expire 2021 through 2041, and the state tax credit will carry forward indefinitely. Interest and penalties for the years ended December 31, 2021 and 2020 were not material. The following table summarizes activity related to the Company’s gross unrecognized tax benefits (in thousands): Total Balances as of December 31, 2019 6,386 Decreases related to prior year tax positions (58 ) Increases related to 2020 tax positions 877 Balances as of December 31, 2020 $ 7,205 In 9 Increases related to 2021 tax positions 783 Balances as of December 31, 2021 $ 7,997 The Company files income tax returns in the U.S. federal and California jurisdictions and is not currently under examination by federal, state, or local taxing authorities for any open tax years. Due to net operating loss carryforwards, the tax years 2001 to 2021 remain open for income tax examination by tax authorities in the U.S. and states in which the Company files tax returns. In March 2020, the Families First Coronavirus Response Act (FFCR Act) and the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) were each enacted in response to the COVID-19 pandemic. The FFCR Act and the CARES Act contain numerous income tax provisions relating to refundable payroll tax credits, deferment of employer side social security payments, net operating loss carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. In June 2020, Assembly Bill 85 (A.B. 85) was signed into California law. A.B. 85 provides for a three-year suspension of the use of net operating losses for medium and large businesses and a three-year cap on the use of business incentive tax credits to offset no more than $5.0 million of tax per year. A.B. 85 suspends the use of net operating losses for taxable years 2020, 2021 and 2022 for certain taxpayers with taxable income of $1.0 million or more. The carryover period for any net operating losses that are suspended under this provision will be extended. A.B. 85 also requires that business incentive tax credits including carryovers may not reduce the applicable tax by more than $5.0 million for taxable years 2020, 2021 and 2022. In December 2020, the Consolidated Appropriations Act, 2021 (CAA) was signed into law. The CAA included additional funding through tax credits as part of its economic package for 2021. The FFCR Act, CARES Act, A.B. 85 and CAA did not have a material impact on the Company’s consolidated financial statements; however, the Company continues to examine the impacts the FFCR Act, CARES Act, A.B. 85 and CAA may have on its business, results of operations, financial condition and liquidity.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates The accompanying consolidated financial statements are comprised of the accounts of CymaBay and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The Company has no unconsolidated subsidiaries or investments accounted for under the equity method. These consolidated statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP), which requires management to make informed estimates and assumptions that impact the amounts and disclosures reported in the consolidated financial statements and accompanying notes. Accounting estimates and assumptions are inherently uncertain. Management bases its estimates on historical experience and on assumptions believed to be reasonable under the circumstances. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes, and management must select an amount that falls within that range of reasonable estimates. Actual results could differ materially from those estimates and assumptions. These estimates form the basis for making judgments about the carrying values of assets and liabilities when these values are not readily apparent from other sources. Estimates are assessed each reporting period and updated to reflect current information and any changes in estimates will generally be reflected in the period first identified.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company’s financial instruments during the periods reported consist of cash, cash equivalents, marketable securities, accounts payable, certain accrued liabilities, and the development financing liability. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Assets and liabilities that are measured at fair value are reported using a three-level fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs and is as follows: Level 1—Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Inputs other than quoted prices in active markets that are observable for the asset or liability, either directly or indirectly. Level 3—Inputs that are significant to the fair value measurement and are unobservable (i.e. supported by little market activity), which requires the reporting entity to develop its own valuation techniques and assumptions. The carrying amounts of cash, accounts payable, and certain accrued liabilities approximate their related fair values due to the short-term nature of these instruments. Cash is classified as level 1 and accounts payable and accrued liabilities as level 2 under the fair value hierarchy. The following tables present the Company’s financial assets that are measured at fair value on a recurring basis using the above input categories (in thousands): As of December 31, 2021 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 85,638 $ — $ — $ 85,638 Total cash equivalents 85,638 — — 85,638 Marketable securities: U.S. and foreign commercial paper — 28,760 — 28,760 U.S. and foreign corporate debt securities — 23,535 — 23,535 Asset-backed securities — 8,522 — 8,522 U.S. treasury securities — 7,979 — 7,979 Total marketable securities — 68,796 — 68,796 Total assets measured at fair value $ 85,638 $ 68,796 $ — $ 154,434 As of December 31, 2020 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 22,415 $ — $ — $ 22,415 Total cash equivalents 22,415 — — 22,415 Marketable securities: U.S. treasury securities — 15,499 — 15,499 U.S. and foreign commercial paper — 38,561 — 38,561 U.S. and foreign corporate debt securities — 29,189 — 29,189 U.S. agency securities — 23,994 — 23,994 Asset-backed securities — 7,885 — 7,885 Supranational debt securities — 3,002 — 3,002 Total marketable securities — 118,130 — 118,130 Total assets measured at fair value $ 22,415 $ 118,130 $ — $ 140,545 The Company estimates the fair value of its money market funds, corporate debt, asset backed securities, commercial paper U.S. treasury and agency securities and supranational debt securities by taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs. The fair value of the Company’s development financing liability is consistent with its carrying value, which is recorded at amortized cost. The development financing liability is classified as level 3 under the fair value hierarchy as its valuation is based on a discounted cash flow model that uses unobservable inputs such as the estimated timing of regulatory approval and attainment of certain sales milestones.
Cash, Cash Equivalents, and Marketable Securities	Cash, Cash Equivalents, and Marketable Securities The Company considers all highly liquid investments with an original maturity of 90 days or less at the time of purchase to be cash equivalents. Cash and cash equivalents consist of deposits with commercial banks in checking, interest-bearing, and money market funds. The Company invests excess cash in marketable securities with high credit ratings . “available-for-sale.” Realized gains and losses from the sale of marketable securities, if any, are calculated using the specific-identification method. Realized gains and losses and declines in value judged to be other-than-temporary are included in interest income or expense in the consolidated statements of operations and comprehensive loss. Unrealized holding gains and losses are reported in accumulated other comprehensive loss in the consolidated balance sheets. To date, the Company has not recorded any impairment charges on its marketable securities related to other-than-temporary declines in market value. In determining whether a decline in market value is other-than-temporary, various factors are considered, including the cause, duration of time and severity of the impairment, any adverse changes in the investees’ financial condition, and the Company’s intent and ability to hold the security for a period of time sufficient to allow for an anticipated recovery in market value.
Concentration of Risk	Concentration of Risk Cash, cash equivalents, and marketable securities consist of financial instruments that potentially subject the Company to a concentration of credit risk to the extent of the fair value recorded on the balance sheet. The Company invests cash that is not required for immediate operating needs primarily in highly liquid instruments that bear minimal risk. The Company has established guidelines relating to the quality, diversification, and maturities of securities to enable the Company to manage its credit risk. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash, cash equivalents and investments and issuers of investments to the extent recorded on the consolidated balance sheets. Certain materials and key components that the Company utilizes in its operations are obtained through single suppliers. Since the suppliers of key components and materials must be named in an NDA filed with the FDA for a product, significant delays can occur if the qualification of a new supplier is required. If delivery of material from the Company’s suppliers were interrupted for any reason, the Company may be unable to supply any of its product candidates for clinical trials.
Other Risks and Uncertainties	Other Risks and Uncertainties In March 2020, the World Health Organization declared the global novel coronavirus disease (COVID-19) COVID-19 COVID-19 COVID-19 COVID-19
Property and Equipment	Property and Equipment Property and equipment are recorded at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated non-cancelable
Long-Lived Assets	Long-Lived Assets The Company reviews the carrying value long-lived assets, including right-of-use
Leases	Leases The Company has one lease, a non-cancelable right-of-use right-of-use The operating lease right-of-use non-lease non-lease
Research and Development Expenses	Research and Development Expenses Research and development expenses consist of costs incurred in identifying, developing, and testing product candidates. These expenses consist primarily of costs for research and development personnel, including related stock-based compensation; contract research organizations (CRO) and other third parties that assist in managing, monitoring, and analyzing clinical trials; investigator and site fees; laboratory services; consultants; contract manufacturing services; non-clinical development costs are expensed as incurred, including expenses that may or may not be reimbursed under research and development funding arrangements. Payments made prior to the receipt of goods or services to be used in research and development are recorded as prepaid assets until the goods are received or services are rendered. Such payments are evaluated for current or long-term classification based on when they will be realized. Additionally, if expectations change such that the Company does not expect goods to be delivered or services to be rendered, such prepayments are charged to expense . The Company records expenses related to clinical studies and manufacturing development activities based on its estimates of the services received and efforts expended pursuant to contracts with multiple CROs and manufacturing vendors that conduct and manage these activities on its behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract, and may result in uneven payment flows. There may be instances in which payments made to the Company’s vendors will exceed the level of services provided and result in a prepayment. Payments under some of these contracts depend on factors such as the successful enrollment of subjects and the completion of clinical trial milestones. In amortizing or accruing service fees, the Company estimates the time period over which services will be performed, enrollment of subjects, number of sites activated and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the Company’s estimate, the Company will adjust the accrued or prepaid expense balance accordingly. To date, there have been no material differences from the Company’s estimates to the amounts actually incurred.
Development Financing Agreement	Development Financing Agreement The Company accounts for the Financing Agreement (see Note 6) as a debt instrument. Accordingly, the Company has recorded payments received under the Financing Agreement as part of a development financing liability in the Company’s consolidated balance sheet. The liability is recorded at amortized cost and accreted to the contractual success fee amounts based on the estimated timing of regulatory approval and attainment of certain sales milestones using an imputed interest rate. Certain transaction fees incurred specifically to complete the Financing Agreement were capitalized and recorded as a reduction to the carrying amount of the development financing liability and are being amortized to interest expense using the effective interest rate method. There are several factors that could affect the estimated timing of regulatory approval and attainment of sales milestones, some of which are not entirely within the Company’s control. Therefore, the Company periodically reassesses the estimated timing of regulatory approval and attainment of sales milestones, and the expected contractual success fee payments due therefrom. If the timing and/or amount of such expected payments is materially different than original estimates, the Company will prospectively adjust the accretion of the development financing liability and the imputed interest rate. The Company identified certain contingent repayment features in the Financing Agreement that are required to be bifurcated from the debt host instrument as embedded derivative liabilities; however, the Company determined the fair value of these features, both individually and in the aggregate, was immaterial at inception and as of December 31, 2021. The fair value of these features will be assessed at each reporting date and will be marked to market, if material. To determine the amount to record for the embedded derivative liabilities, the Company must assess the probability of occurrence of various potential future events that could affect the timing and/or amount of future cash flows related to the Financing Agreement.
Pre-funded Warrants	Pre-funded Warrants Pursuant to the Company’s public equity offering completed in November 2021 , the Company issued pre-funded warrants to purchase 3,125,000 shares of common stock at a price of $3.9999 per share. These pre-funded warrants have an exercise price of $0.0001 per share, were fully exercisable upon issuance, and have no expiration date. The Company determined that the pre-funded warrants should be equity classified because they are freestanding financial instruments, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, permit the holders to receive a fixed number of shares of common stock upon exercise, are indexed to the Company’s common stock and meet the equity classification criteria. In addition, such pre-funded paid-in Note 9—Stockholders’ Equity .
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation is measured at fair value on the grant date of the award. Compensation cost is recognized as expense on a straight-line basis over the vesting period for options with service conditions and forfeitures are accounted for as they occur. The Company uses the Black-Scholes option-pricing model to determine the fair value of stock option awards. The determination of fair value for stock-based awards using an option-pricing model requires management to make certain assumptions regarding subjective input variables such as expected term, dividends, volatility and risk-free rate. If actual results are not consistent with the Company’s assumptions used in making these estimates, the Company may be required to increase or decrease compensation expense, which could be material to the Company’s results of operations.
Income Taxes	Income Taxes The Company utilizes the liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on differences between the financial reporting and the tax bases of assets and liabilities and are measured using enacted tax rates and laws that will be in effect when the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. A valuation allowance is recorded when it is more likely than not that all or part of a deferred tax asset will not be realized. When the Company establishes or reduces the valuation allowance related to the deferred tax assets, the provision for income taxes will increase or decrease, respectively, in the period such determination is made. The accounting guidance for uncertainty in income taxes prescribes a recognition threshold and measurement attribute criteria for the financial recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination based on the technical merits of the position. The Company is required to file federal and state income tax returns in the United States. The preparation of these income tax returns requires the Company to interpret the applicable tax laws and regulations in effect that could affect the amount of tax paid to these jurisdictions. The Company records interest related to income tax reserves, if any, as interest expense, and any penalties would be recorded as other expense in the consolidated statements of operations and comprehensive loss.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss and net unrealized gains and losses on marketable securities, which are presented in a single continuous statement. Other comprehensive (loss) gain is also disclosed in the consolidated balance sheets and statements of stockholders’ equity in accumulated other comprehensive income (loss), and is stated net of related tax effects, if any.
Net Loss Per Common Share	Net Loss Per Common Share Basic net loss per share of common stock is based on the weighted average number of shares of common stock outstanding equivalents during the period. The weighted-average common shares outstanding as of December 31, 2021 includes pre-funded 3,125,000 shares of common stock that were issued in connection with the November 2021 public offering, as discussed in Note 9— Stockholders’ Equity The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share amounts): Year Ended December 31, 2021 2020 Numerator: Net loss $ (89,998 ) $ (50,986 ) Denominator: Weighted average number of common stock shares outstanding 71,055,331 68,893,127 Net loss per share $ (1.27 ) $ (0.74 ) The following table shows the total outstanding securities considered anti-dilutive and therefore excluded from the computation of diluted net loss per share (in thousands): Year Ended 2021 2020 Common stock options 10,791 8,812 Incentive awards 101 101 Total 10,892 8,913
Recently Adopted and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements ASU 2019-12 In December 2019, the FASB issued ASU 2019-12, step-up Recently Issued Accounting Pronouncements ASU 2016-13 In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments available-for-sale No. 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842)

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Schedule of Fair Value Assets Measured on Recurring Basis	The following tables present the Company’s financial assets that are measured at fair value on a recurring basis using the above input categories (in thousands): As of December 31, 2021 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 85,638 $ — $ — $ 85,638 Total cash equivalents 85,638 — — 85,638 Marketable securities: U.S. and foreign commercial paper — 28,760 — 28,760 U.S. and foreign corporate debt securities — 23,535 — 23,535 Asset-backed securities — 8,522 — 8,522 U.S. treasury securities — 7,979 — 7,979 Total marketable securities — 68,796 — 68,796 Total assets measured at fair value $ 85,638 $ 68,796 $ — $ 154,434 As of December 31, 2020 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 22,415 $ — $ — $ 22,415 Total cash equivalents 22,415 — — 22,415 Marketable securities: U.S. treasury securities — 15,499 — 15,499 U.S. and foreign commercial paper — 38,561 — 38,561 U.S. and foreign corporate debt securities — 29,189 — 29,189 U.S. agency securities — 23,994 — 23,994 Asset-backed securities — 7,885 — 7,885 Supranational debt securities — 3,002 — 3,002 Total marketable securities — 118,130 — 118,130 Total assets measured at fair value $ 22,415 $ 118,130 $ — $ 140,545
Computation of Basic and Diluted Net Loss per Share	The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share amounts): Year Ended December 31, 2021 2020 Numerator: Net loss $ (89,998 ) $ (50,986 ) Denominator: Weighted average number of common stock shares outstanding 71,055,331 68,893,127 Net loss per share $ (1.27 ) $ (0.74 )
Anti-Dilutive Securities Excluded from the Computation of Diluted Net Loss per Share	The following table shows the total outstanding securities considered anti-dilutive and therefore excluded from the computation of diluted net loss per share (in thousands): Year Ended 2021 2020 Common stock options 10,791 8,812 Incentive awards 101 101 Total 10,892 8,913

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Marketable Available-for-Sale Securities	Marketable available-for-sale Amortized Gross Gross Estimated As of December 31, 2021: Cash equivalents: Money market funds $ 85,638 $ — $ — $ 85,638 Total cash equivalents 85,638 — — 85,638 Current marketable securities: U.S. and foreign commercial paper 28,760 — — 28,760 U.S. and foreign corporate debt securities 15,476 — (8 ) 15,468 Asset-backed securities 8,524 1 (3 ) 8,522 U.S. treasury securities 7,982 — (3 ) 7,979 Total current marketable securities 60,742 1 (14 ) 60,729 Non-current U.S. corporate debt securities 8,067 2 (2 ) 8,067 Total marketable securities $ 154,447 $ 3 $ (16 ) $ 154,434 Amortized Gross Gross Estimated As of December 31, 2020: Cash equivalents: Money market funds $ 22,415 $ — $ — $ 22,415 Total cash equivalents 22,415 — — 22,415 Current marketable securities: U.S. and foreign commercial paper 38,561 — — 38,561 U.S. and foreign corporate debt securities 29,186 7 (4 ) 29,189 Asset-backed securities 7,883 2 — 7,885 U.S. treasury securities 23,991 3 — 23,994 U.S. agency securities 15,498 1 — 15,499 Supranational debt securities 3,003 — (1 ) 3,002 Total current marketable securities 118,122 13 (5 ) 118,130 Total marketable securities $ 140,537 $ 13 $ (5 ) $ 140,545
Schedule of fair value of the Company marketable securities by contractual maturity	The following table shows the fair value of the Company’s marketable securities, by contractual maturity, as of December 31, 2021 (in thousands): Due less than 1 year $ 146,367 Due between 1 and 2 years 8,067 Total fair value $ 154,434

Certain Balance Sheet Items (Ta

Certain Balance Sheet Items (Tables)	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Property and Equipment	Property and equipment consist of the following (in thousands): December 31, 2021 2020 Leasehold improvements $ 2,429 $ 2,430 Office and computer equipment 290 290 Purchased software 44 44 Furniture and fixtures 539 451 Total 3,302 3,215 Less: Accumulated depreciation and amortization (2,124 ) (1,454 ) Property and equipment, net $ 1,178 $ 1,761
Other Accrued Liabilities	Other accrued liabilities consist of the following (in thousands): December 31, 2021 2020 Accrued compensation $ 3,986 $ 3,769 Accrued professional fees and other 1,333 677 Current portion of operating lease liability 567 482 Total other accrued liabilities $ 5,886 $ 4,928

Development Financing Agreeme_2

Development Financing Agreement (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of Changes in Fair Value of Liabilities	The following table sets forth a summary of the changes in the carrying value of the Company’s development financing liability (in thousands): Balance at December 31, 2020 $ — Cash received 50,000 Debt discount (2,263 ) Accretion of development financing liability 2,583 Balance at December 31, 2021 $ 50,320

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Summary of Maturities of Operating Lease Liabilities	As of December 31, 2021, the maturities of the Company’s operating lease liabilities were as follows (in thousands): Year ending December 31, 2022 $ 686 2023 707 2024 30 Total undiscounted future minimum lease payments 1,423 Less imputed interest 161 Total operating lease liability 1,262 Less: current portion of operating lease liability 567 Long-term portion of lease liability $ 695

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Summary of Reserved Shares of Common Stock for Future Issuances	As of December 31, 2021 and 2020, the Company had reserved shares of common stock for future issuances as follows: December 31, 2021 2020 Prefunded warrants to purchase common stock 3,125,000 — Equity award plans: Options and incentive awards outstanding, all equity plans 10,892,613 8,913,071 Equity awards available for future grant—2013 Plan 1,588,613 167,159 Equity awards available for future grant—2020 Plan — 750,000 Total shares of common stock reserved for future issuance 15,606,226 9,830,230

Stock Plans and Stock-Based C_2

Stock Plans and Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Grants, Including Performance Options	The following table summarizes activity in the Company’s stock option grants: Shares Weighted- Weighted- Aggregate Intrinsic Outstanding as of December 31, 2020 8,811,630 $ 6.35 Options granted 2,660,965 4.84 Options exercised (106,847 ) 2.05 Options forfeited (307,018 ) 5.89 Options expired (267,299 ) 7.60 Outstanding as of December 31, 2021 10,791,431 $ 6.01 7.28 $ 1,514 Vested and expected to vest as of December 31, 2021 10,791,431 $ 6.01 7.28 $ 1,514 Exercisable as of December 31, 2021 6,327,680 $ 6.62 6.22 $ 1,510
Summary of Stock-Based Compensation Expense	Stock-based compensation expense is included in the consolidated statements of operations and comprehensive loss and is as follows (in thousands): Year Ended 2021 2020 Research and development $ 4,470 $ 2,739 General and administrative 5,526 4,585 Total stock-based compensation expense $ 9,996 $ 7,324
Estimated Weighted-Average Grant Date Fair Value	The following table presents the weighted-average assumptions the Company used in the Black-Scholes option-pricing model to derive the grant date fair values of stock options granted in each of the years presented along with the resulting estimated weighted-average grant date fair values per share: Year Ended 2021 2020 Expected term (years) 6.1 6.1 Expected volatility 104 % 105 % Risk-free interest rate 0.9 % 0.4 % Expected dividend yield — — Weighted-average grant date fair value per share $ 3.91 $ 3.91

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Components of Deferred Tax Assets	Significant components of the Company’s deferred tax assets are as follows (in thousands): December 31, 2021 2020 Deferred tax assets: Federal and state net operating loss carryforwards $ 129,898 $ 123,144 State and federal research and development tax credit carryforwards 31,951 28,861 Capitalized research and development 5,670 2,363 Stock-based compensation 5,329 3,822 Other 1,222 1,256 Total deferred tax assets 174,070 159,446 Deferred tax liabilities: Depreciation and amortization (158 ) (269 ) Other (53 ) (57 ) Total deferred tax liabilities (211 ) (326 ) Valuation allowance (173,859 ) (159,120 ) Net deferred tax assets $ — $ —
Summary of Reconciliation of Expected Statutory Federal Income Tax Provision to Actual Income Tax Provision	The following is a reconciliation of the expected statutory federal income tax provision to the actual income tax provision (in thousands): December 31, 2021 2020 Income tax benefit at federal statutory tax rate $ (18,900 ) $ (10,707 ) Change in valuation allowance 14,739 17,181 State income taxes, net of federal benefit (267 ) (4,768 ) Research credits (2,802 ) (2,911 ) Cancelled options 141 982 Development financing liability 6,654 — Permanent differences 429 152 Other, net 6 71 Income tax (benefit) expense $ — $ —
Summary of Gross Unrecognized Tax Benefits	The following table summarizes activity related to the Company’s gross unrecognized tax benefits (in thousands): Total Balances as of December 31, 2019 6,386 Decreases related to prior year tax positions (58 ) Increases related to 2020 tax positions 877 Balances as of December 31, 2020 $ 7,205 In 9 Increases related to 2021 tax positions 783 Balances as of December 31, 2021 $ 7,997

Organization and Description _2

Organization and Description of Business - Additional Information (Detail) $ / shares in Units, $ in Thousands	Nov. 30, 2021USD ($)	Nov. 22, 2021USD ($)$ / sharesshares	Aug. 31, 2021USD ($)	Jul. 30, 2021USD ($)INSTALLMENTS	Dec. 31, 2021USD ($)Agreement	Dec. 31, 2020USD ($)
Class of Stock [Line Items]
Number of operating segments | Agreement					1
Net loss					$ (89,998)	$ (50,986)
Cash flows from operating activities					(69,431)	(44,725)
Accumulated deficit					(766,856)	$ (676,858)
Cash and cash equivalents and marketable securities					194,600
Line Of Credit Optional Amount Of Borrowing Capacity				$ 25,000
Number of new stock issued during the period. | shares		15,625,000
Sale of Stock, Price Per Share | $ / shares		$ 4
Total gross offering proceeds		$ 75,000
Payments of Stock underwriting discount and other offering expenses		$ 5,000
Prefunded warrants [Member]
Class of Stock [Line Items]
Sale of Stock, Price Per Share | $ / shares		$ 3.9999
Number of common stock into which the class of warrant or right may be converted | shares		3,125,000
Abw Cyclops Spv Lp [Member]
Class of Stock [Line Items]
Proceeds from Lines of Credit				$ 75,000
Number of funding installments | INSTALLMENTS				3
Line Of Credit Optional Amount Of Borrowing Capacity				$ 25,000
Costs Incurred, Development Costs				$ 100,000
Abw Cyclops Spv Lp [Member] | Financing agreement funding installments two [Member]
Class of Stock [Line Items]
Proceeds from Lines of Credit	$ 25,000		$ 25,000		$ 25,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Schedule of Fair Value Assets Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 154,434	$ 140,545
Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	85,638	22,415
Cash Equivalents [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	85,638	22,415
Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	68,796	118,130
Short-term Investments [Member] | U.S. and Foreign Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	28,760	38,561
Short-term Investments [Member] | U.S. and Foreign Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	23,535	29,189
Short-term Investments [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	8,522	7,885
Short-term Investments [Member] | US Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		23,994
Short-term Investments [Member] | U.S. Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	7,979	15,499
Short-term Investments [Member] | Supranational Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		3,002
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	85,638	22,415
Level 1 [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	85,638	22,415
Level 1 [Member] | Cash Equivalents [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	85,638	22,415
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	68,796	118,130
Level 2 [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	68,796	118,130
Level 2 [Member] | Short-term Investments [Member] | U.S. and Foreign Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	28,760	38,561
Level 2 [Member] | Short-term Investments [Member] | U.S. and Foreign Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	23,535	29,189
Level 2 [Member] | Short-term Investments [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	8,522	7,885
Level 2 [Member] | Short-term Investments [Member] | US Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		23,994
Level 2 [Member] | Short-term Investments [Member] | U.S. Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 7,979	15,499
Level 2 [Member] | Short-term Investments [Member] | Supranational Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		$ 3,002

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Additional Information (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2021	Nov. 22, 2021
Product Information [Line Items]
Cash and cash equivalents, maturity description	90 days or less
Sale of Stock, Price Per Share		$ 4
Prefunded warrants [Member]
Product Information [Line Items]
Number of common stock into which the class of warrant or right may be converted		3,125,000
Sale of Stock, Price Per Share		$ 3.9999
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.0001
Maximum [Member]
Product Information [Line Items]
Short-term contractual maturities	1 year
Property and equipment, estimated useful lives	7 years
Minimum [Member]
Product Information [Line Items]
Short-term contractual maturities	1 year

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Computation of Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss	$ (89,998)	$ (50,986)
Denominator:
Weighted average number of common stock shares outstanding	71,055,331	68,893,127
Net loss per share	$ (1.27)	$ (0.74)

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Anti-Dilutive Securities Excluded from the Computation of Diluted Net Loss per Share (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted loss per share	10,892	8,913
Common Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted loss per share	10,791	8,812
Incentive Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted loss per share	101	101

Marketable Securities - Additio

Marketable Securities - Additional Information (Detail) - Debt Securities [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Realized gains and losses	$ 0	$ 0
Marketable investments continuous unrealized loss position	$ 0	$ 0

Marketable Securities - Marketa

Marketable Securities - Marketable Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 8,067
Estimated Fair Value	60,729	$ 118,130
Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	85,638	22,415
Estimated Fair Value	85,638	22,415
Cash and Cash Equivalents [Member] | Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	85,638	22,415
Estimated Fair Value	85,638	22,415
Current marketable securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	60,742	118,122
Gross Unrealized Gains	1	13
Gross Unrealized Losses	(14)	(5)
Estimated Fair Value	60,729	118,130
Current marketable securities [Member] | U.S. and Foreign Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	28,760	38,561
Estimated Fair Value	28,760	38,561
Current marketable securities [Member] | U.S. and Foreign Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	15,476	29,186
Gross Unrealized Gains		7
Gross Unrealized Losses	(8)	(4)
Estimated Fair Value	15,468	29,189
Current marketable securities [Member] | Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,524	7,883
Gross Unrealized Gains	1	2
Gross Unrealized Losses	(3)
Estimated Fair Value	8,522	7,885
Current marketable securities [Member] | U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,982	23,991
Gross Unrealized Gains		3
Gross Unrealized Losses	(3)
Estimated Fair Value	7,979	23,994
Current marketable securities [Member] | US Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		15,498
Gross Unrealized Gains		1
Estimated Fair Value		15,499
Current marketable securities [Member] | Supranational Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		3,003
Gross Unrealized Losses		(1)
Estimated Fair Value		3,002
Maketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	154,447	140,537
Gross Unrealized Gains	3	13
Gross Unrealized Losses	(16)	(5)
Estimated Fair Value	154,434	$ 140,545
Non-current marketable securities [Member] | U.S. and Foreign Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Gains	2
Gross Unrealized Losses	(2)
Estimated Fair Value	$ 8,067

Marketable Securities - Schedul

Marketable Securities - Schedule Of Fair Value Of The Company Marketable Securities By Contractual Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Contractual Obligation Fiscal Year Maturity Schedule [Line Items]
Due less than 1 year	$ 146,367
Due between 1 and 2 years	8,067
Total fair value	$ 154,434	$ 140,545

Certain Balance Sheet Items - P

Certain Balance Sheet Items - Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,302	$ 3,215
Less: Accumulated depreciation and amortization	(2,124)	(1,454)
Property and equipment, net	1,178	1,761
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,429	2,430
Office and Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	290	290
Purchased Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	44	44
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 539	$ 451

Certain Balance Sheet Items - A

Certain Balance Sheet Items - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 0.7	$ 0.6

Certain Balance Sheet Items - O

Certain Balance Sheet Items - Other Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accrued compensation	$ 3,986	$ 3,769
Accrued professional fees and other	1,333	677
Current portion of operating lease liability	567	482
Total other accrued liabilities	$ 5,886	$ 4,928

License Agreement - Additional

License Agreement - Additional Information (Detail) - Janssen Pharmaceutical NV [Member] - USD ($)	1 Months Ended
	Jun. 30, 2006	Dec. 31, 2021	Dec. 31, 2020
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Accrued royalties		$ 0	$ 0
Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of royalty on net sales	8.00%

Development Financing Agreeme_3

Development Financing Agreement - Additional Information (Detail) - USD ($) $ in Millions	Jan. 31, 2022	Nov. 30, 2021	Aug. 31, 2021	Jul. 30, 2021	Dec. 31, 2021
Debt Instrument [Line Items]
Line Of Credit Optional Amount Of Borrowing Capacity				$ 25
Description Of Percentage Fixed Success Payments			2.0
Repayments of Lines of Credit			$ 10
Percentage Optional Funding			133.00%
Description Of Percentage Variable Success Payments			1.1
Description Of Aggregate Return From The Funds Provided			3.1
Aggregate Return Percentage From The Funds Provided			$ 232.5
Percentage of Accelerate Payment Payable On Funds provided			1.35
Description Repayments On Funds Provided Upon Termination Of Financing Agreement			2.0
Aggregate Return From The Optional Funds Provided			$ 310
Percentage of Unamortized Portion of The Development Financing Liability					20.00%
Fixed Success Payments [Member]
Debt Instrument [Line Items]
Anniversary Payments Due Year One			15
Anniversary Payments Due Year Two			22.5
Anniversary Payments Due Year Three			22.5
Anniversary Payments Due Year Four			25
Anniversary Payments Due Year Five			27.5
Anniversary Payments Due Year Six			27.5
Variable Success Payments [Member]
Debt Instrument [Line Items]
Payments Upon Reaching Cumulative US Product Sales Thresholds Year One			17.5
Payments Upon Reaching Cumulative US Product Sales Thresholds Year Two			27.5
Payments upon reaching product sales run rate			37.5
Installment Funding Number Three [Member]
Debt Instrument [Line Items]
Proceeds from Lines of Credit	$ 25
ABW Cyclops SPV LP [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				100
Proceeds from Lines of Credit				75
Line Of Credit Optional Amount Of Borrowing Capacity				$ 25
ABW Cyclops SPV LP [Member] | Installment Funding Number One [Member]
Debt Instrument [Line Items]
Proceeds from Lines of Credit			$ 25
ABW Cyclops SPV LP [Member] | Installment Funding Number Two [Member]
Debt Instrument [Line Items]
Proceeds from Lines of Credit		$ 25
Financing Agreement Termination Event Condition One [Member] | ABW Cyclops SPV LP [Member]
Debt Instrument [Line Items]
Percentage of amount to be paid by entity upon the termination of the agreement					310.00%
Financing Agreement Termination Event Condition Two [Member] | ABW Cyclops SPV LP [Member]
Debt Instrument [Line Items]
Percentage of amount to be paid by entity upon the termination of the agreement					200.00%
Financing Agreement Termination Event Condition Three [Member] | ABW Cyclops SPV LP [Member]
Debt Instrument [Line Items]
Percentage of amount to be paid by entity upon the termination of the agreement					100.00%

Development Financing Agreeme_4

Development Financing Agreement - Schedule of Changes in Fair Value of Liabilities (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Debt Disclosure [Abstract]
Balance, beginning of period	$ 0
Cash received	50,000
Debt discount	(2,263)
Accretion of development financing liability	2,583
Balance, end of period	$ 50,320

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	Mar. 12, 2021	Jan. 15, 2021	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Loss Contingency, Lawsuit Filing Date		January 15, 2021
Loss Contingency, Name of Plaintiff		Genfit S.A.
Loss Contingency, Allegations		alleging misappropriation of trade secrets and related causes of action based on the Company’s receipt of a Genfit protocol synopsis for Genfit’s Phase 3 clinical trial of its drug candidate elafibranor in patients with primary biliary cholangitis.
Loss Contingency, Actions Taken by Defendant		The Company intends to defend itself vigorously. While the outcome of any litigation is inherently uncertain, based on currently available information, management does not currently believe a loss associated with this matter is probable, nor is any amount reasonably estimable
Indemnification liabilities				$ 0	$ 0
Loss Contingency, Actions Taken by Court, Arbitrator or Mediator	On March 12, 2021, the Court granted a Temporary Restraining Order (later converted to a Preliminary Injunction), prohibiting the Company from accessing or disseminating the protocol synopsis, using any Genfit trade secrets contained therein or destroying any evidence related thereto.
Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Lawsuit Filing Date			April 16, 2021

Leases - Summary of Maturities

Leases - Summary of Maturities of Operating Lease Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
2022	$ 686
2023	707
2024	30
Total undiscounted future minimum lease payments	1,423
Less imputed interest	161
Total operating lease liability	1,262	$ 1,700
Less: current portion of operating lease liability	567	482
Long-term portion of lease liability	$ 695	$ 1,262

Leases - Additional Information

Leases - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)ft²Facility	Dec. 31, 2020USD ($)
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term	2 years 1 month 6 days	3 years 1 month 6 days
Lease, option to extend	option to extend for an additional 5 years
Operating lease right-of-use asset	$ 254	$ 272
Operating lease liability	1,262	1,700
Short term portion of operating lease liability	$ 567	$ 482
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Accrued Liabilities, Current	Other Accrued Liabilities, Current
Long-term portion of operating lease liability	$ 695	$ 1,262
Lease Facility [Member]
Lessee, Lease, Description [Line Items]
Number of leased facilities | Facility	1
Area of office space | ft²	17,698
Lease start date	Jan. 16, 2014
Operating Expense [Member]
Lessee, Lease, Description [Line Items]
Lease costs	$ 600	$ 500

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	Nov. 22, 2021	Dec. 31, 2021	Dec. 31, 2020	Jul. 31, 2020
Class of Stock [Line Items]
Preferred stock, shares authorized		10,000,000	10,000,000
Common stock, shares authorized		200,000,000	200,000,000
Common stock offering price	$ 4
Number of new stock issued during the period.	15,625,000
Sale of Stock, Price Per Share	$ 4
Gross Proceeds from offering	$ 70,500,000
Prefunded warrants [Member]
Class of Stock [Line Items]
Sale of Stock, Price Per Share	$ 3.9999
Number of common stock into which the class of warrant or right may be converted	3,125,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.0001
Prefunded warrants [Member] | Maximum [Member]
Class of Stock [Line Items]
Percentage Ownership By Shareholders Percentage	14.99%
Prefunded warrants [Member] | Minimum [Member]
Class of Stock [Line Items]
Percentage Ownership By Shareholders Percentage	4.99%
ATM Offering [Member]
Class of Stock [Line Items]
Common Stock, Value, Registered For Issuance				$ 200,000
Common stock value subscribed				$ 75,000
Over-Allotment Option [Member]
Class of Stock [Line Items]
Underwriter option period	$ 30,000
Common Stock, Shares Subscribed but Unissued	2,812,500

Stockholder's Equity - Summary

Stockholder's Equity - Summary of Reserved Shares of Common Stock for Future Issuances (Detail) - shares	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	15,606,226	9,830,230
CBAYEquity incentive plan two thousand and thirteen [Member]
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	1,588,613	167,159
CBAYEquity incentive plan two thousand and twenty plan [Member]
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	0	750,000
Options and Incentive awards [Member]
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	10,892,613	8,913,071
Prefunded warrants [Member]
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	3,125,000	0

Stock Plans and Stock-Based C_3

Stock Plans and Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2013	Jan. 01, 2022	Jun. 30, 2014	Apr. 30, 2014	Jan. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised		$ 200	$ 400
Fair value of options vested		700	$ 3,300
Unamortized employee and non-employee stock-based compensation expense		$ 16,900
Unamortized employee and non-employee stock-based compensation expense recognized period		2 years 7 months 6 days
Share reserved for issue		15,606,226	9,830,230
Stock-based compensation expense		$ 9,996	$ 7,324
Stock options outstanding		10,791,431	8,811,630
Equity Incentive Plan Two Thousand and Twenty Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, expiration period	10 years
Share based compensation arrangement by share based payment award, exercise price percentage			85.00%
Shares available for grant		0
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement percentage increase in share reserved	5.00%
Shares available for grant		1,588,613
2013 Equity Incentive Plan [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share reserved for issue							4,233,896
2013 Equity Incentive Plan [Member] | Incentive Stock Options for Employees and Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, exercise price percentage	100.00%
2013 Equity Incentive Plan [Member] | Nonqualified Options to Employees, Directors and Consultants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, exercise price percentage	85.00%
2013 Equity Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, exercise price percentage	85.00%
Share based compensation arrangement by share based payment award, award vesting period	4 years
2013 Equity Incentive Plan [Member] | Stock Options to 10% Stockholders [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, exercise price percentage					110.00%
Share based compensation arrangement by share based payment award, award vesting period					5 years
Incentive Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, expiration period				10 years
Share based compensation arrangement by share based payment award, award vesting period						4 years
Share reserved for issue								500,000	252,752
Exercisable weighted average price per share										$ 5.21
Stock option plan, Description		vest monthly over four years effective from their grant date
Stock-based compensation expense		$ 0	$ 0
Stock options outstanding		101,182	101,441
Incentive Awards [Member] | First Tranche [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vesting of shares						100.00%

Stock Plans and Stock-Based C_4

Stock Plans and Stock-Based Compensation - Summary of Stock Option Grants, Including Performance Options (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares
Shares Subject to Outstanding Options
Outstanding at the beginning of period | shares	8,811,630
Options granted | shares	2,660,965
Options exercised | shares	(106,847)
Options forfeited | shares	(307,018)
Options expired | shares	(267,299)
Outstanding as end of period | shares	10,791,431
Vested and expected to vest | shares	10,791,431
Exercisable | shares	6,327,680
Weighted-Average Exercise Price of Options
Outstanding at the beginning of period | $ / shares	$ 6.35
Options granted | $ / shares	4.84
Options exercised | $ / shares	2.05
Options forfeited | $ / shares	5.89
Options expired | $ / shares	7.60
Outstanding as end of period | $ / shares	6.01
Vested and expected to vest | $ / shares	6.01
Exercisable | $ / shares	$ 6.62
Weighted-Average Remaining Contractual Term (Years)
Outstanding	7 years 3 months 10 days
Vested and expected to vest	7 years 3 months 10 days
Exercisable	6 years 2 months 19 days
Aggregate Intrinsic Value (In Thousands)
Outstanding | $	$ 1,514
Vested and expected to vest | $	1,514
Exercisable | $	$ 1,510

Stock Plans and Stock-Based C_5

Stock Plans and Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 9,996	$ 7,324
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	4,470	2,739
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 5,526	$ 4,585

Stock Plans and Stock-Based C_6

Stock Plans and Stock-Based Compensation - Estimated Weighted-Average Grant Date Fair Value (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years 1 month 6 days	6 years 1 month 6 days
Expected volatility	104.00%	105.00%
Risk-free interest rate	0.90%	0.40%
Expected dividend yield	0.00%	0.00%
Weighted-average grant date fair value per share	$ 3.91	$ 3.91

401(k) Plan - Additional Inform

401(k) Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Employees contribution to qualified savings plan	$ 750,000	$ 750,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jun. 30, 2021	Dec. 31, 2018	Dec. 31, 2017
Income Tax [Line Items]
Description of net operating loss carryforwards, expire period	The state net operating loss carryforwards will expire beginning in 2028 through 2041. The federal research and development and federal orphan drug tax credit carryforwards expire 2021 through 2041, and the state tax credit will carry forward indefinitely.
Provision for income taxes	$ 0	$ 0
Net valuation allowance increase (decrease)	$ 14,700	$ 17,200
Cumulative change in ownership	50.00%
Cumulative change in ownership period	3 years
Significant change to its unrecognized tax benefits over the next twelve months	$ 0
Income tax examination years	the tax years 2001 to 2021 remain open for income tax examination by tax authorities
Maximum Threshold On Tax Credit Offset			$ 5,000
Average Taxable Income Fixed For Suspension Of Use Of Net Operating Losses			1,000
Minimum Taxable Income Fixed For Suspension Of Tax Credit Offset			$ 5,000
Minimum [Member]
Income Tax [Line Items]
Open tax year	2001
Maximum [Member]
Income Tax [Line Items]
Open tax year	2021
Domestic Tax Authority [Member]
Income Tax [Line Items]
Federal net operating loss	$ 522,700
Net operating loss carryforward	522,700
Research and development tax credit carry forwards	24,800
Domestic Tax Authority [Member] | Orphan Drug [Member]
Income Tax [Line Items]
Research and development tax credit carry forwards	$ 10,200
Domestic Tax Authority [Member] | Minimum [Member]
Income Tax [Line Items]
NOL carry forward expiry date	2024
Domestic Tax Authority [Member] | Maximum [Member]
Income Tax [Line Items]
NOL carry forward expiry date		2037
State and Local Jurisdiction [Member]
Income Tax [Line Items]
Federal net operating loss	$ 288,300
Net operating loss carryforward	288,300
Research and development tax credit carry forwards	$ 6,200
State and Local Jurisdiction [Member] | Federal [member]
Income Tax [Line Items]
Federal net operating loss				$ 267,000	$ 255,700
Net operating loss carryforward				$ 267,000	$ 255,700
State and Local Jurisdiction [Member] | Minimum [Member] | Federal [member]
Income Tax [Line Items]
NOL carry forward expiry date	2028
State and Local Jurisdiction [Member] | Maximum [Member] | Federal [member]
Income Tax [Line Items]
NOL carry forward expiry date	2041

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Federal and state net operating loss carryforwards	$ 129,898	$ 123,144
State and federal research and development tax credit carryforwards	31,951	28,861
Capitalized research and development	5,670	2,363
Stock based compensation	5,329	3,822
Other	1,222	1,256
Total deferred tax assets	174,070	159,446
Deferred tax liabilities:
Depreciation and amortization	(158)	(269)
Other	(53)	(57)
Total deferred tax liabilities	(211)	(326)
Valuation allowance	(173,859)	(159,120)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Expected Statutory Federal Income Tax Provision to Actual Income Tax Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income tax benefit at federal statutory tax rate	$ (18,900)	$ (10,707)
Change in valuation allowance	14,739	17,181
State income taxes, net of federal benefit	(267)	(4,768)
Research credits	(2,802)	(2,911)
Cancelled options	141	982
Development financing liability	6,654	0
Permanent differences	429	152
Other, net	6	71
Income tax (benefit) expense	$ 0	$ 0

Income Taxes - Summary of Gross

Income Taxes - Summary of Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Balance at beginning of period	$ 7,205	$ 6,386
Increases related to prior year tax positions	9
Decreases related to prior year tax positions		58
Increases related to tax positions	783	877
Balance at end of period	$ 7,997	$ 7,205