Cymabay Therapeutics (CBAY) 10-K 28 Feb 24 2023 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2023	Jan. 31, 2024	Jun. 30, 2023
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
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	Yes
Entity Filer Category	Large 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		114,724,381
Entity Shell Company	false
Entity File Number	001-36500
Entity Tax Identification Number	94-3103561
Entity Address, Address Line One	7601 Dumbarton Circle
Entity Address, City or Town	Fremont
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94555
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			$ 954,563,272
ICFR Auditor Attestation Flag	true
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	San Mateo, California
Document Financial Statement Error Correction [Flag]	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 206,535	$ 20,291
Marketable securities	187,720	115,194
Prepaid expenses and other current assets	9,547	2,588
Total current assets	403,802	138,073
Non-current marketable securities	21,932	0
Property and equipment, net	465	701
Right-of-use assets	5,260	169
Other assets	3,227	2,909
Total assets	434,686	141,852
Current liabilities:
Accounts payable	3,828	1,096
Accrued research and development expenses	5,633	6,530
Development financing liability - current portion	10,000	0
Deferred collaboration revenue - current portion	1,689	0
Other accrued liabilities	15,693	7,815
Total current liabilities	36,843	15,441
Development financing liability - non-current portion	99,172	90,227
Deferred collaboration revenue - non-current portion	1,100	0
Lease liabilities - non-current portion	5,315	30
Total liabilities	142,430	105,698
Commitments and contingencies
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; 113,864,976 and 84,681,063 shares issued and outstanding as of December 31, 2023 and December 31, 2022, respectively	11	8
Additional paid-in capital	1,270,328	909,329
Accumulated other comprehensive income (loss)	144	(326)
Accumulated deficit	(978,227)	(872,857)
Total stockholders' equity	292,256	36,154
Total liabilities and stockholders' equity	$ 434,686	$ 141,852

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
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	113,864,976	84,681,063
Common stock, shares outstanding	113,864,976	84,681,063

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Collaboration revenue	$ 31,073	$ 0	$ 0
Operating expenses:
Research and development	80,799	67,995	64,542
General and administrative	51,953	25,116	23,040
Total operating expenses	132,752	93,111	87,582
Loss from operations	(101,679)	(93,111)	(87,582)
Other income (expense), net:
Interest income	13,490	2,017	167
Interest expense	(18,945)	(14,907)	(2,583)
Other income	1,764	0	0
Total other income (expense), net	(3,691)	(12,890)	(2,416)
Net loss	(105,370)	(106,001)	(89,998)
Other comprehensive (loss) income:
Unrealized gain (loss) on marketable securities, net of tax	470	(313)	(21)
Total other comprehensive income (loss)	470	(313)	(21)
Comprehensive loss	$ (104,900)	$ (106,314)	$ (90,019)
Basic net loss per common share	$ (0.99)	$ (1.21)	$ (1.27)
Diluted net loss per common share	$ (0.99)	$ (1.21)	$ (1.27)
Weighted average common shares outstanding used to calculate basic net loss per common share	106,204,273	87,804,063	71,055,331
Weighted average common shares outstanding used to calculate diluted net loss per common share	106,204,273	87,804,063	71,055,331

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Balance at beginning of period at Dec. 31, 2020	$ 142,706	$ 7	$ 819,549	$ 8	$ (676,858)
Balance at beginning 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
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
Stock-based compensation expense	9,996		9,996
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
Issuance of common stock upon exercise of stock options	9		9
Issuance of common stock upon exercise of stock options (Shares)		3,124
Issuance costs related to issuance of common stock and pre-funded warrants	5		5
Stock-based compensation expense	9,517		9,517
Net loss	(106,001)				(106,001)
Net unrealized gain (loss) on marketable securities	(313)			(313)
Balance at end of period at Dec. 31, 2022	36,154	$ 8	909,329	(326)	(872,857)
Balance at end of period (in shares) at Dec. 31, 2022		84,681,063
Issuance of common stock upon exercise of stock options	10,632		10,632
Issuance of common stock upon exercise of stock options (Shares)		2,216,186
Issuance of common stock upon exercise of pre-funded warrants (Shares)		624,992
Issuance of common stock and pre-funded warrants, net of issuance costs	335,140	$ 3	335,137
Issuance of common stock and pre-funded warrants, net of issuance costs (Shares)		26,342,735
Stock-based compensation expense	15,230		15,230
Net loss	(105,370)				(105,370)
Net unrealized gain (loss) on marketable securities	470			470
Balance at end of period at Dec. 31, 2023	$ 292,256	$ 11	$ 1,270,328	$ 144	$ (978,227)
Balance at end of period (in shares) at Dec. 31, 2023		113,864,976

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2021
Statement of Stockholders' Equity [Abstract]
Stock issuance cost	$ 21,359	$ 4,965

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net loss	$ (105,370)	$ (106,001)	$ (89,998)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	681	625	669
Non-cash lease expense	215	85	19
Stock-based compensation expense	15,230	9,517	9,996
Accretion of development financing liability	18,945	14,907	2,583
Write-off of deferred financing costs	0	0	312
Net (accretion) amortization of investments in marketable securities	(7,864)	(874)	637
Changes in assets and liabilities:
Prepaid expenses and other current assets	(6,959)	1,976	386
Other assets	110	(1,189)	(1,513)
Accounts payable	2,732	(1,444)	2,309
Deferred collaboration revenue	2,789	0	0
Accrued research and development expenses	(897)	(3,222)	5,054
Other accrued liabilities	7,857	1,540	115
Net cash used in operating activities	(72,531)	(84,080)	(69,431)
Investing activities
Purchases of property and equipment	(445)	(148)	(87)
Purchases of marketable securities	(305,674)	(174,977)	(78,084)
Proceeds from maturities of marketable securities	219,550	129,140	126,760
Net cash (used in) provided by investing activities	(86,569)	(45,985)	48,589
Financing activities
Proceeds from issuance of common stock pursuant to equity award plans	10,632	9	219
Proceeds from issuance of common stock and pre-funded warrants, net of issuance costs	335,140	(459)	70,499
Proceeds from development financing, net of transaction costs	0	25,000	47,737
Net cash provided by financing activities	345,772	24,550	118,455
Net increase (decrease) in cash, cash equivalents and restricted cash	186,672	(105,515)	97,613
Cash, cash equivalents, and restricted cash at beginning of period	20,291	125,806	28,193
Cash, cash equivalents, and restricted cash at end of period	206,963	20,291	125,806
Supplemental operating activities
Cash paid for amounts included in the measurement of lease liabilities	762	686	666
Supplemental non-cash investing and financing activities
Right-of-use assets acquired in exchange for operating lease liabilities	4,833	0	0
Right-of-use assets acquired in exchange for finance lease liabilities	466	0	0
Accrued financing costs	$ 0	$ 0	$ 464

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net Income (Loss)	$ (105,370)	$ (106,001)	$ (89,998)

Insider Trading Arrangements

Insider Trading Arrangements	12 Months Ended
	Dec. 31, 2023 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	The adoption or termination of contracts, instructions or written plans for the purchase or sale of our securities by our Section 16 officers and directors for the three months ended December 31, 2023, each of which is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) Aggregate number of Expiration Date or securities to be Name Title Trading Arrangement Action Date Adopted Termination Date purchased or sold Paul Quinlan General Rule 10b5-1 Adopted December 21, 2023 August 30, 2024 95,000 Lewis Stuart Chief Commercial Rule 10b5-1 Termination August 30, 2024 December 7, 2023 300,000
Paul Quinlan [Member]
Trading Arrangements, by Individual
Name	Paul Quinlan
Title	GeneralCounsel
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	December 21, 2023
Termination Date	August 30, 2024
Aggregate Available	95,000
Lewis Stuart [Member]
Trading Arrangements, by Individual
Name	Lewis Stuart
Title	Chief CommercialOfficer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	August 30, 2024
Termination Date	December 7, 2023
Aggregate Available	300,000

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2023
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 innovative therapies for patients with liver and other chronic diseases with high unmet medical need. The Company’s lead 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 Fremont, California and it operates in segment. Liquidity The Company has incurred net operating losses and negative cash flows from operations since its inception. During the year ended December 31, 2023, the Company incurred a net loss of $105.4 million and used $72.5 million of cash in operations. As of December 31, 2023, the Company had an accumulated deficit of 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, 2023, the Company completed certain transactions as follows: • On January 6, 2023, the Company entered into a Collaboration and License Agreement with Kaken Pharmaceutical Co., Ltd (Kaken). Pursuant to the agreement, the Company granted Kaken an exclusive license to commercialize seladelpar for the treatment of PBC in Japan and received an upfront cash payment of $34.2 million. For further details, refer to Note 5—Collaboration and License Agreement • On January 23, 2023, the Company sold 11,821,428 shares of common stock at $7.00 per share and a pre-funded Note 10—Stockholders’ Equity • On September 11, 2023, the Company sold 14,521,307 shares of common stock at $17.13 per share and a pre-funded Note 10—Stockholders’ Equity As of December 31, 2023, the Company had cash, cash equivalents and marketable securities totaling $416.2 million. As the Company continues to advance its clinical studies of seladelpar, the Company believes its existing funds are sufficient to fund the Company’s current operating expenses 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: future 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

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
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. Revenue Recognition At the inception of an arrangement, the Company evaluates if a counterparty to a contract is a customer, if the arrangement is within the scope of ASC 606—Revenue from Contracts with Customers each Collaboration Revenues The Company periodically enters into collaboration arrangements with third party collaborators, under which the Company may license certain rights to its intellectual property to permit collaborators to further develop, manufacture and/or commercialize its drug candidates. The terms of these agreements typically include, but are not limited to, payments to the Company for one or more of the following: nonrefundable, upfront license fees; development and commercial milestones whose payment is typically contingent upon milestone achievement; funding of research and/or development activities; product supply; and royalties on net sales of licensed products. For each collaboration agreement that results in revenues, the Company identifies all material promised goods and services, which may include, but are not limited to, one or more of the following: a license to intellectual property and know-how, re-assessed Once the estimated transaction price is established, amounts are allocated to identified performance obligations. The transaction price is generally allocated to each separate performance obligation based on its estimated standalone selling price (SSP). To determine SSPs, the Company uses various estimation methods, including the adjusted market assessment approach, which utilizes prices observable in the market for similar goods and services, the expected cost plus a margin approach, as well as applies valuation techniques involving projected discounted cash flows. These approaches may include the use of assumptions and estimates requiring significant judgement. The Company recognizes the amount of the transaction price allocated to each respective performance obligation as revenue when the performance obligation is satisfied or as it is satisfied. If a performance obligation is satisfied over time, the Company applies an appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. The Company receives payments from its customers based on payment terms established in each contract. Upfront payments and fees are recorded as deferred revenue upon receipt or when due until the Company performs its obligations under these arrangements. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. If the arrangement includes optional goods and services, the Company assesses whether delivery of such goods and services requires the customer to pay fees consistent with their standalone selling prices, or if customer may be entitled to incremental discounts that it would not have received without entering into the agreement and committing to purchase the initial goods and services. The presence of such discounts indicates the customer has received material rights which also represent performance obligations. Upfront License Fees: Development and Regulatory Milestone Payments re-evaluates Sales-based Milestone and Royalty Payments: 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 equivalents approximate their related fair value due to the short-term nature of these instruments. Cash equivalents are classified as level 1 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 categ o es As of December 31, 2023 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 127,231 $ —  $ —  $ 127,231 U.S. treasury securities —  15,181 —  15,181 U.S and foreign commercial paper —  19,916 —  19,916 U.S. agency securities —  33,207 —  33,207 Total cash equivalents 127,231 68,304 —  195,535 Marketable securities: U.S. and foreign commercial paper —  66,317 —  66,317 U.S. and foreign corporate debt securities —  5,536 —  5,536 U.S. agency securities —  40,914 —  40,914 U.S. treasury securities —  96,885 —  96,885 Total marketable securities —  209,652 —  209,652 Total assets measured at fair value $ 127,231 $ 277,956 $ —  $ 405,187 As of December 31, 2022 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 9,770 $ — $ — $ 9,770 Total cash equivalents 9,770 — — 9,770 Marketable securities: U.S. and foreign commercial paper — 46,121 — 46,121 U.S. and foreign corporate debt securities — 24,807 — 24,807 Supranational debt securities — 12,890 — 12,890 U.S. agency securities — 7,759 — 7,759 U.S. treasury securities — 23,617 — 23,617 Total marketable securities — 115,194 — 115,194 Total assets measured at fair value $ 9,770 $ 115,194 $ — $ 124,964 The Company estimates the fair value of its money market funds, corporate debt, 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 $98.9 million. 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, attainment of certain sales milestones and the discount rate. 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, money market funds, and marketable debt securities which are subject to minimal credit and market risk. The Company invests excess cash in marketable securities with high credit ratings. These securities consist primarily of corporate debt, commercial paper, U.S. treasury, U.S. agency securities and supranational debt securities and are classified as “available-for-sale.” from the balance sheet date. The Company considers marketable securities as non-current investments if the maturity date is in excess of from the balance sheet date. Realized gains and losses from the sale of marketable securities, if any, are calculated using the specific-identification method. Expected losses judged to be related partially or in whole to declines in credit risk-related factors of the security issuer are included in interest expense in the consolidated statements of operations and comprehensive loss at the time the factors contributing to the expected losses are identified. 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 expected losses on its marketable securities related to credit risk-related declines in market value. In determining whether a decline in market value is related to expected credit losses, various factors are considered, including the cause, duration of time and severity of the expected loss, 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. Accrued interest receivable is included as part of Prepaid expenses and other current assets in the consolidated balance sheets. 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. The Company maintains deposits in excess of FDIC insured deposit limits with its financial institutions. 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. Property and Equipment, Net Property and equipment are recorded at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method, and the costs are amortized over the estimated useful lives of the respective assets, which are generally three non-cancelable Long-Lived Assets The Company reviews the carrying value long-lived assets, including right-of-use Leases As of December 31, 2023, the Company had two operating leases pertaining to its corporate office space, including the new subleased office space in Fremont, California, and a The Company recognizes a lease asset for its right to use the underlying asset and a lease liability for the corresponding lease obligation. The Company determines whether an arrangement is or contains a lease at contract inception. Operating and finance leases are included in lease right-of-use right-of-use At lease inception, the Company analyzes the terms of the contract to determine whether its leases should be classified as an operating lease or a finance lease. The right-of-use non-lease non-lease right-of-use Refer to Note 8—Leases 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 assets, and facilities and information technology that support research and development activities. Research and development costs are expensed as incurred. 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 non-current 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, and provided such prepayments are nonrefundable, they 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 and 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 Development Financing Agreement (the Financing Agreement) (See Note 7—Development Financing Agreement 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, at each reporting date, the Company 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, 2023. 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 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 and common stock equivalents outstanding during the period. The weighted-average common shares outstanding for the years ended December 31, 2023, 2022, and 2021 include pre-funded Note 10—Stockholders’ Equity were 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, 2023 2022 2021 Numerator: Net loss $ (105,370 ) $ (106,001 ) $ (89,998 ) Denominator: Weighted average number of: Common stock shares outstanding 101,479,061 84,679,063 70,712,865 Pre-funded 4,725,212 3,125,000 342,466 Total 106,204,273 87,804,063 71,055,331 Net loss per share $ (0.99 ) $ (1.21 ) $ (1.27 ) The following table shows the total outstanding securities considered anti-dilutive and therefore excluded from the computation of diluted net loss per share: Year Ended December 31, 2023 2022 2021 Common stock options 16,539,905 13,930,195 10,791,431 Incentive awards — 101,182 101,182 Total 16,539,905 14,031,377 10,892,613 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)

Cash Equivalents and Marketable

Cash Equivalents and Marketable Securities	12 Months Ended
	Dec. 31, 2023
Cash and Cash Equivalents [Abstract]
Cash Equivalents and Marketable Securities	3. Cash Equivalents and Marketable Securities Cash equivalents and marketable available-for-sale Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value As of December 31, 2023: Cash equivalents: Money market funds $ 127,231 $ — $ — $ 127,231 U.S. treasury securities 15,179 2 — 15,181 U.S and foreign commercial paper 19,924 — (8 ) 19,916 U.S. agency securities 33,219 — (12 ) 33,207 Total cash equivalents 195,553 2 (20 ) 195,535 Current marketable securities: U.S. and foreign commercial paper 66,354 3 (40 ) 66,317 U.S. and foreign corporate debt securities 5,538 — (2 ) 5,536 U.S. agency securities 30,595 23 (12 ) 30,606 U.S. treasury securities 85,210 54 (3 ) 85,261 Total current marketable securities 187,697 80 (57 ) 187,720 Non-current U.S. agency securities 10,241 67 — 10,308 U.S. treasury securities 11,552 72 — 11,624 Total non-current 21,793 139 — 21,932 Total marketable securities $ 405,043 $ 221 $ (77 ) $ 405,187 As of December 31, 2022: Cash equivalents: Money market funds $ 9,770 $ — $ — $ 9,770 Total cash equivalents 9,770 — — 9,770 Current marketable securities: U.S. and foreign commercial paper 46,121 — — 46,121 U.S. and foreign corporate debt securities 24,964 — (157 ) 24,807 Supranational debt securities 12,946 — (56 ) 12,890 U.S. agency securities 7,782 16 (39 ) 7,759 U.S. treasury securities 23,707 2 (92 ) 23,617 Total current marketable securities 115,520 18 (344 ) 115,194 Total marketable securities $ 125,290 $ 18 $ (344 ) $ 124,964 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 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. There were no realized gains and losses for the years ended December 31, 2023, 2022 some The following table shows the fair value of the Company’s marketable securities, by contractual maturity, as of December 31, 2023 (in thousands): Due less than 1 year $ 187,720 Due between 1 and 2 years 21,932 Total fair value $ 209,652 As of December 31, 2023, we had $0.4 million of restricted cash to collateralize letters of credit related to certain lease commitments. This balance is included in Other assets and was classified as non-current A reconciliation of cash, cash equivalents and restricted cash reported in the accompanying consolidated balance sheets to the amount reported within the accompanying consolidated statements of cash flows is as follows (in thousands): December 31, 2023 2022 Cash and cash equivalents $ 206,535 $ 20,291 Restricted cash (included in Other assets) 428 — Total cash, cash equivalents, and restricted cash $ 206,963 $ 20,291

Certain Balance Sheet Items

Certain Balance Sheet Items	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Certain Balance Sheet Items	4. Certain Balance Sheet Items Property and equipment, net are recorded at cost and consist of the following (in thousands): December 31, 2023 2022 Leasehold improvements $ 2,429 $ 2,429 Office and computer equipment 958 290 Purchased software 44 44 Furniture and fixtures 464 687 Total 3,895 3,450 Less: Accumulated depreciation and amortization (3,430 ) (2,749 ) Property and equipment, net $ 465 $ 701 Depreciation and amortization expense for the years ended December 31, 2023, 2022 and 2021 was approximately $0.7 million, $0.6 million and $0.7 million, respectively, and was recorded straight-line in both research and development expense and general and administrative expense in the consolidated statements of operations and comprehensive loss. All of the Company’s property and equipment is located in the U.S. Other accrued liabilities consist of the following (in thousands): December 31, 2023 2022 Accrued compensation $ 8,980 $ 5,779 Accrued professional fees and other 6,706 1,372 Current portion of operating lease liabilities 7 664 Total other accrued liabilities $ 15,693 $ 7,815

Collaboration and License Agree

Collaboration and License Agreement	12 Months Ended
	Dec. 31, 2023
Disclosure Of Collaboration And License Agreement [Abstract]
Collaboration and License Agreement	5. Collaboration and License Agreement On January 6, 2023, the Company entered into a Collaboration and License Agreement (the License Agreement) with Kaken Pharmaceuticals Co., Ltd (Kaken). The Company granted Kaken an exclusive license to develop and commercialize seladelpar (the Licensed Product) for the treatment of primary biliary cholangitis (PBC) in Japan. Pursuant to the terms of the License Agreement, Kaken will bear the cost of, and be responsible for, among other things, conducting the clinical studies and other developmental activities for the Licensed Product in PBC in Japan as well as preparing and filing applications for regulatory approval and commercializing the Licensed Product in Japan. Kaken is obligated to use commercially reasonable efforts to develop, obtain regulatory approval for, and commercialize, the Licensed Product in Japan, including obtaining pricing approval for the Licensed Product in Japan. The License Agreement also obligates the Company to transfer the licensed technology and know-how pre-clinical The Company agreed to supply to Kaken its requirements of Licensed Product for clinical and commercial use, which may be terminated upon specified circumstances, and with appropriate technology transfer. The supply of the Licensed Products to Kaken for clinical use will be provided based on the Clinical Manufacturing and Supply Agreement (the Clinical Supply Agreement) which was entered into in October 2023. Per the Clinical Supply Agreement, the Company will supply clinical materials to Kaken as specified in separate written purchase orders, to be used for Kaken’s development of the Licensed Product in accordance with the License Agreement. The Company concluded that the Clinical Supply Agreement combined with each purchase order represents a contract with a customer under the scope of ASC 606. The Company identified key performance obligations that primarily include the supply of clinical materials and CMC activities and other assistance. The Company will recognize the amounts allocated to the supply of clinical materials upon delivery of the materials and will recognize any CMC activities and other assistance as revenue over time as these activities are conducted. The Company is also responsible for the completion of global CMC development activities to enable future commercial supply of the Licensed Product to Kaken. The Company may also be requested by Kaken to conduct CMC activities specific to commercialization in Japan and to provide other assistance. Pursuant to the License Agreement, the Company and Kaken also agreed to establish a joint steering committee to provide strategic oversight of both parties’ activities under the License Agreement. The License Agreement may be terminated early by either party for material breach, upon a party’s insolvency or bankruptcy or upon a challenge by one party of any patents of the other party, and Kaken may terminate in specified situations, including for a safety concern, clinical failure, or termination of an underlying in-license to the In consideration of the license and other rights granted by the Company, Kaken made an upfront cash payment to the Company of ¥4.5 billion in January 2023 (or $34.2 million, comprised of $33.7 million of contract consideration and a $0.5 million foreign exchange gain recorded in the three months ended March 31, 2023) and is obligated to pay potential milestone payments to the Company totaling up to ¥17.0 billion (approximately $128.0 million at contract inception date) upon the achievement of certain regulatory and sales milestones. The Company concluded that Kaken is a customer and that the arrangement represents a contract with a customer under the scope of ASC 606. The Company identified the following key promised goods and services that represent performance obligations under the arrangement: (1) the exclusive license to develop and commercialize seladelpar in Japan, including the initial transfer of the underlying technology and know-how, (2) delivery of data gathered through the execution of the Company’s ongoing development activities for PBC to support Kaken’s regulatory filings in Japan which will occur at specific points in time when such information is available, and (3) completing the Company’s global CMC development activities and the reporting of such activities for the manufacture and supply of the Licensed Product to Kaken. To determine the standalone selling price of each performance obligation above, estimation approaches involving significant estimates and assumptions were used that include but are not limited to, expected market opportunity and pricing, future clinical trial and CMC development costs, timelines, and likelihood of success of clinical and regulatory activities. To determine the standalone selling price of the license, the Company used a discounted cash flow analysis of projected cash flows and potential revenues from the commercial sale of seladelpar in Japan. To determine the standalone selling prices of the Company’s obligation to deliver data from ongoing development activities and its obligation to complete global CMC development activities, the expected cost plus margin approach was used. The Company recognized $ million of collaboration revenue for the year ended December 31, 2023 related to the $ million upfront fee. $ million of the collaboration revenue recognized during the year ended December 31, 2023 relates to the completion of the initial technology transfer associated with the license to develop and commercialize seladelpar in Japan. The remaining $ million portion of the upfront fee is deferred and will be recognized on completion of the Company’s ongoing clinical data delivery and CMC development performance obligations. This deferred collaboration revenue is expected to be recognized as the remaining performance obligations are satisfied at different points in time in the future. Of the $ million balance of deferred collaboration revenue, $ million is classified as non-current on the Company’s consolidated balance sheet, as this portion of the deferred collaboration revenue balance is expected to be recognized beyond twelve months from the balance sheet date. All future potential milestone amounts were not included in the transaction price, as they were all determined to be fully constrained as they are contingent on the achievement of development activities, regulatory approvals and sales-based milestones as defined in the License Agreement. Additionally, the

In-License Agreement

In-License Agreement	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
In-License Agreement	6. In-License Janssen Pharmaceutica NV In June 2006, the Company entered into an exclusive worldwide, royalty-bearing license to seladelpar and certain other PPAR d d d d d d

Development Financing Agreement

Development Financing Agreement	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Development Financing Agreement	7. 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 provided the Company up to $75.0 million in base funding, of which $25.0 million was provided in August 2021, $25.0 million was provided in November 2021, and $25.0 million was provided in January 2022. 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 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 upon first reaching certain cumulative U.S. product sales thresholds, and (y) $37.5 million upon first reaching a specified U.S. product sales run rate. Promptly following receipt of Regulatory Approval, the Company is required to execute a note agreement and deliver a promissory note to Abingworth within two business days to convert the fixed and variable success payments into a note payable. At the time that Abingworth receives, collectively, an aggregate of 3.1x of the funding provided (approximately $232.5 million), 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 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 x of the funding provided or upon termination 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, 2023, 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 is being 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 are also being 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, 2023, 2022, and 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 Cash received 25,000 Accretion of development financing liability 14,907 Balance at December 31, 2022 $ 90,227 Accretion of development financing liability 18,945 Balance at December 31, 2023 $ 109,172 As of December 31, 2023, $10.0 million of the development financing liability was classified as a current liability based on the Company’s expectation of achieving the regulatory approval milestone within twelve months. The remaining balance of $99.2 million is classified as a non-current

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	8. Leases The Company had one non-cancelable operating lease agreement for its corporate office in Newark, California, pertaining to square feet of corporate office space, that commenced was amended on April 16, 2018, and was extended to March 15, 2024 in February 2024. The Company also signed a non-cancellable sublease agreement with a new lessor on December 1, 2023 for its new corporate office, which is located in Fremont, California. This sublease encompasses a total of square feet of building space. The sublease has a rent abatement period for the first 13 full months from the date the premises were made available to the Company, which began in December 2023. In addition to fixed monthly rent payments, the Company must also pay variable operating expenses, which consist of (i) Parcel Operating Expenses, (ii) Parking Operating Expenses and (iii) Campus Operating Expenses (all as defined in the Sublease). The sublease also includes furniture, fixtures, and equipment (“FF&E”) transferred to the Company in December 2023. In assessing the lease classification of the Fremont sublease, the office component (building and land) met the criteria for classification as an operating lease and the FF&E component of the sublease met the criteria for classification as a finance lease. As of December 31, 2023, the Company’s operating and finance lease portfolio each had a weighted average remaining term of 8.4 years. As of December 31, 2022, the Company’s operating lease portfolio had a weighted average remaining term of years. The Company cannot determine the implicit rate in its leases for the Newark, California lease and 10.7% for the new sublease in Fremont, California as the discount rate when measuring operating lease liabilities. 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 lease commencement date. For the years ended December 31, 2023, 2022, and 2021, the Company incurred $0.7 million, $0.7 million and $0.6 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 The balance sheet classification of our operating lease assets and liabilities were as follows (in thousands): Operating leases Finance lease Total leases Assets: Right-of-use $ 4,802 $ 458 $ 5,260 Liabilities: Current portion included in other accrued liabilities 7 — 7 Non-current portion lease 4,848 467 5,315 Total lease liabilities $ 4,855 $ 467 $ 5,322 As of December 31, 2023, the maturities of the Company’s operating and finance lease liabilities were as follows (in thousands): Operating leases Finance lease Total leases Lease commitments: Year ending December 31, 2024 $ 30 $ — $ 30 2025 527 51 578 2026 867 84 951 2027 894 86 980 2028 961 93 1,054 Thereafter 5,085 491 5,576 Total undiscounted future minimum lease payments 8,364 805 9,169 Less imputed interest (3,509 ) (338 ) (3,847 ) Total lease liabilities 4,855 467 5,322 Less: current portion of lease liabilities (7 ) — (7 ) Non-current portion $ 4,848 $ 467 $ 5,315

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. 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 t recognized any liabilities relating to these obligations as of December 31, 2023 and 2022. No assurances can be given that the covering insurers will not attempt to dispute the validity, applicability, or amount of coverage without obligations. Legal Proceedings From time to time, we may become involved in legal proceedings relating to claims arising from the ordinary course of business. Our management believes that there are currently no claims or actions pending against us, the ultimate disposition of which could reasonably be expected to have a material adverse effect on our results of operations, financial condition or cash flows. Apart from such incidental matters, been submitted to the Company. Between February 26 and 27, 2024, the Company received three demand letters from purported holders of Shares, one of which enclosed a draft complaint. The Company also separately received a draft complaint from a purported holder of Shares that was unaccompanied by a demand letter. Each demand letter alleges disclosure deficiencies in the Schedule 14D-9 and demands an issuance of corrective disclosures. Both of the draft complaints identify as prospective defendants the Company and members of the Company Board. The draft complaints allege that the defendants caused to be filed with the SEC a materially incomplete and misleading Schedule 14D-9 in violation of Sections 14(d)(4), 14(e) and 20(a) of the Exchange Act and Rule 14D 9 promulgated thereunder. Among other remedies, the draft complaints threaten to seek an order enjoining the defendants from proceeding with or consummating the Offer, unless and until the defendants disclose certain allegedly material information that was allegedly omitted from the Schedule 14D-9; granting rescissory damages; awarding the plaintiff costs and disbursements of its action, including reasonable attorneys’ and expert fees and expenses; and granting such other and further relief as the court may deem just and proper. The Company believes that the allegations contained in the demand letters and draft complaints are without merit. On February 26, 2024, the Company received a demand letter from a purported holder of Shares that requests access to certain books and records of the Company to investigate purported breaches of fiduciary duty, director independence and disinterestedness, corporate wrongdoing and/or inadequate disclosures in connection with the Transactions and related to the transaction documents. The Company is preparing a response.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Stockholders' Equity	10. Stockholders’ Equity Preferred and Common Stock Authorized The Company is authorized to issue 10,000,000 shares of preferred stock as of December 31, 2023 and 2022, and 200,000,000 shares of common stock as of December 31, 2023 and 2022. Common Stock Reserved for Future Issuance As of December 31, 2023 and 2022, the Company had reserved shares of common stock for future issuances as follows: December 31, 2023 2022 Pre-funded 5,226,628 3,125,000 Equity award plans: Options and incentive awards outstanding, all equity plans 16,539,905 14,031,377 Equity awards available for future grant - 2023 Plan 8,637,460 — Equity awards available for future grant - 2013 Plan — 2,680,621 Equity awards available for future grant - 2020 Plan 552,500 — Total shares of common stock reserved for future issuance 30,956,493 19,836,998 Sale of Common Stock and Pre-funded On September 11, 2023, pursuant to a shelf registration statement on Form S-3, pre-funded pre-funded per share, was fully exercisable upon issuance and has no expiration date. The aggregate net proceeds to the Company from this offering was approximately $ The pre-funded paid-in pre-funded pre-funded On January 23, 2023, pursuant to a shelf registration statement on Form S-3, pre-funded pre-funded The pre-funded paid-in pre-funded Pursuant to the Company’s public equity offering completed in November 2021, the Company issued pre-funded pre-funded pre-funded paid-in pre-funded pre-funded In total, pre-funded warrants from the above November 2021, January 2023, and September 2023 public offerings to purchase up to an aggregate of shares of common stock remain outstanding as of December 31, 2023. At-the-Market (ATM) Facility In March 2023, we filed a registration statement on Form S-3 with the SEC and entered into an at-the-market facility (ATM) to sell up to $100.0 million of common stock under the registration statement pursuant to the Controlled Equity Offering SM

Stock Plans and Stock-Based Com

Stock Plans and Stock-Based Compensation	12 Months Ended
	Dec. 31, 2023
Share-based Payment Arrangement [Abstract]
Stock Plans and Stock-Based Compensation	11. Stock Plans and Stock-Based Compensation Stock Plans 2023 Equity Incentive Plan In June 2023, the Company’s stockholders approved the Company’s 2023 Equity Incentive Plan (the 2023 Plan), pursuant to which the Company may grant incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, and other stock awards to its directors, employees and consultants (each, a Participant), with certain limitations. The 2023 Plan is the successor to and continuation of the Company’s 2013 Equity Incentive Plan and returning and remaining shares under the 2013 Plan will become available for issuance pursuant to awards granted under the 2023 Plan. The 2023 Plan permits the Company to grant options and stock appreciation rights at an exercise price not less than 100% of the Fair Market Value (as defined in the 2023 Plan) on the grant date of the underlying award. With certain exceptions, (i) no option or stock appreciation right may be exercised after the expiration of ten years from the grant date of such award and (ii) the vesting of options and stock appreciation rights will cease upon termination of the Participant’s Continuous Service (as defined in the 2023 Plan). Restricted stock awards and restricted stock unit awards will be subject to terms and conditions as determined by the Company’s Board. Except as otherwise provided pursuant to agreement or by the determination of the Board, the vesting of restricted stock awards and restricted stock unit awards will cease upon termination of the Participant’s Continuous Service. A restricted stock unit award may be settled by the issuance of shares of common stock or cash (or any combination thereof) or in any form of payment as determined by the Board and specified in the restricted stock unit award agreement. The Board will determine factors related to the achievement of performance and other terms and conditions when granting performance awards pursuant to the 2023 Plan. The aggregate number of shares of common stock that may be issued under the 2023 Plan will not exceed 25,883,628 shares; provided, that, the aggregate maximum number of shares of common stock that may be issued pursuant to the exercise of incentive stock options is 9,500,000 shares. The share reserve under the 2023 Plan may be increased upon approval by the Company’s stockholders. 2020 New Hire Plan In October 2020, the Company’s board of directors approved the 2020 New Hire Plan, as amended in July 2023 (the 2020 New Hire 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 New Hire Plan has a term of ten years. The 2020 New Hire 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 New Hire Plan may be increased at the discretion of and approval by the board of directors. Stock Plan Summary As of December 31, 2023, there were 8,637,460 552,500 years 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 % 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 % of fair value; (iii) award stock bonuses; and (iv) grant rights to acquire restricted stock at not less than % of fair value. Options generally vest over a 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 31, 2023, there were 8,637,460, 552,500, and no shares available for grant under the 2023, 2020, and 2013 Plans, respectively. The following table summarizes activity in the Company’s stock option grants: Shares Weighted Weighted Aggregate Outstanding as of December 31, 2022 13,930,195 $ 5.26 Options granted 5,685,135 9.46 Options exercised (2,115,004 ) 4.79 Options forfeited (930,421 ) 5.91 Options expired (30,000 ) 12.72 Outstanding as of December 31, 2023 16,539,905 $ 6.71 6.87 $ 279,610 Vested and expected to vest as of December 31, 2023 16,539,905 $ 6.71 6.87 $ 279,610 Exercisable as of December 31, 2023 10,096,612 $ 5.97 5.64 $ 178,177 The total intrinsic value of options exercised was $19.7 million, immaterial and $0.2 million for the years ended December 31, 2023, 2022, and 2021, respectively. The total fair value of options vested was $ million, $ million and $ million for the years ended December 31, 2023, 2022, and 2021, respectively. As of December 31, 2023, unamortized stock-based compensation expense of $37.8 million is expected to be recognized over a weighted average period of 2.7 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. The incentive awards were fully vested as of December 31, 2023 and 2022 and have a term of 10 years. Incentive awards outstanding totaled 0 and 101,182 as of December 31, 2023 and 2022, 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 December 31, 2023 2022 2021 Research and development $ 5,758 $ 4,274 $ 4,470 General and administrative 9,472 5,243 5,526 Total stock-based compensation expense $ 15,230 $ 9,517 $ 9,996 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 December 31, 2023 2022 2021 Expected term (years) 6.1 6.0 6.1 Expected volatility 96 % 101 % 104 % Risk-free interest rate 3.8 % 1.8 % 0.9 % Expected dividend yield — — — Weighted-average grant date fair value per share $ 7.50 $ 2.33 $ 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 due to the lack of sufficient prior exercise data available. Therefore, for stock option grants made during the years ended December 31, 2023, 2022, and 2021, 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 Company will reevaluate this methodology at a point in time when sufficient exercise data becomes available. 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, 2023
Postemployment Benefits [Abstract]
401(k) Plan	12. 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 $2,500, $750 and $750, for the years ended December 31, 2023, 2022, and 2021, and accordingly matching contributions totaling an insignificant amount were made in the years ended December 31, 2023, 2022, and 2021.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	13. 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, 2023 2022 Deferred tax assets: Federal and state net operating loss carryforwards $ 91,783 $ 87,681 Federal and state research and development tax credit carryforwards 41,714 32,016 Intangibles 4,365 5,040 Capitalized research and development 26,101 11,872 Stock-based compensation 3,358 6,624 Other 3,329 1,574 Total deferred tax assets 170,650 144,807 Deferred tax liabilities: Depreciation and amortization — (79 ) Other (1,135 ) (36 ) Total deferred tax liabilities (1,135 ) (115 ) Valuation allowance $ (169,515 ) $ (144,692 ) 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 valuation allowance increased by $24.8 million primarily due primarily to the Company’s capitalized research and development expenditures, federal and state tax credit carryforwards, and the taxable loss incurred during the year ended December 31, 2023. These valuation allowance increases were offset by the reduction of stock-based compensation deferred tax assets as of December 31, 2023. For the year ended December 31, 2022, the valuation allowance decreased by $ 29.2 million due primarily to a $38.4 million write-off The following is a reconciliation of the expected statutory federal income tax provision to the actual income tax provision (in thousands): Year Ended December 31, 2023 2022 2021 Income tax benefit at federal statutory tax rate $ (22,128 ) $ (22,260 ) $ (18,900 ) Change in valuation allowance 24,852 (29,165 ) 14,739 Impairment of tax attributes 4,905 38,398 —  Research credits (8,622 ) (2,640 ) (2,802 ) Development financing liability 3,978 12,301 6,654 Permanent differences (2,230 ) 511 429 State income taxes, net of federal benefit (1,132 ) 2,806 (267 ) Other, net 377 49 147 Income tax (benefit) expense $ —  $ —  $ —  Pursuant to Internal Revenue Code (IRC) Sections 382 and 383 and similar state laws, 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% within a three-year period. In 2022, the Company completed an ownership change analysis and determined that its net operating losses and research and development credits were subject to limitations due to historical changes in ownership that occurred through December 31, 2022. Accordingly, the net operating loss carryforwards reflected in the deferred tax assets as of December 31, 2022 have been reduced to reflect Section 382 limitations resulting from these changes. The Section 382 analysis was updated through December 31, 2023 with no further restrictions on use of net operating loss or credit carryforwards. As the Company is expected to incur additional losses in the future, any future ownership changes that might occur could further restrict the Company’s ability to utilize its net operating loss and research and development carryforwards. As of December 31, 2023, the Company had federal net operating loss carryforwards of $ million and state net operating loss carryforwards of $ million to offset future taxable income, if any. In addition, the Company had federal research and development tax credit carryforwards of $ million, federal orphan drug tax credit carryforwards of $ million, and state research and development tax credit carryforwards of $ million. If not utilized, the federal net operating losses for the years beginning before January 1, 2018 of $ million will expire beginning in through , and the federal net operating losses for the tax years beginning after January 1, 2018 of $ million will be carried forward indefinitely (subject to certain utilization limitations). The following table summarizes activity related to the Company’s gross unrecognized tax benefits (in thousands): Balances as of December 31, 2020 $ 7,205 Increases related to prior year tax positions 9 Increases related to 2021 tax positions 783 Balances as of December 31, 2021 7,997 Decreases related to prior year tax positions (1,223 ) Increases related to 2022 tax positions 730 Balances as of December 31, 2022 7,504 Decreases related to prior year tax positions (14 ) Increases related to 2023 tax positions 2,514 Balances as of December 31, 2023 $ 10,004 The unrecognized tax benefits, if recognized, would not have an impact on the Company’s effective tax rate assuming the Company continues to maintain a full valuation allowance position. Based on prior year’s operations and experience, the Company does not business. The Company’s major income tax filing jurisdictions are the U.S. federal and California state 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 2004 to 2022 remain open for income tax examination by tax authorities in the U.S. and states in which the Company files tax returns. Interest and penalties for the years ended December 31, 2023 and 202 2 In August 2022, the Inflation Reduction Act of 2022 (IRA) was signed into law. The IRA provides several tax incentives, including the expanded Internal Revenue Code (IRC) Section 179D deduction, increased ability to leverage the R&D credit to offset payroll taxes for eligible start-up

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Event	14. Subsequent Event Pending Acquisition by Gilead On February 11, 2024, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Gilead Sciences, Inc. (“Gilead”) and Pacific Merger Sub, Inc., a wholly owned subsidiary of Gilead (“Purchaser”). The Merger Agreement provides for the acquisition of the Company by Gilead in a two-step all cash transaction, consisting of a tender offer (the “Offer”), followed by a subsequent merger of Purchaser with and into the Company (the “Merger” and, together with the Offer and the other transactions contemplated by the Merger Agreement, the “Transactions”), with the Company continuing as the surviving corporation. On February 23, 2024, Purchaser commenced the Offer for all of the Company’s issued and outstanding shares of common stock, par value $ 0.0001 per share (“Shares”), other than any Shares owned by the Company (including those held in the Company’s treasury), Gilead or Purchaser (“Excluded Shares”), at a purchase price of $32.50 per Share (the “Offer Price”), net to the seller in cash, without interest and subject to any required withholding of taxes. The Offer will initially remain open until March 21, 2024 (unless otherwise agreed to in writing by Gilead and us), which period may be extended for additional periods of up to 10 business days per extension (or such other duration as may be agreed to in writing by the Company and Gilead) to permit the conditions to the Offer to be satisfied. The obligation of Purchaser to accept for payment Shares validly tendered pursuant to the Offer is subject to customary closing conditions, including: (i) Shares having been validly tendered and not validly withdrawn that, considered together with all other Shares (if any) beneficially owned by Gilead and its affiliates, represent one more Share than 50% of the total number of Shares outstanding at the time of the expiration of the Offer (including, for the avoidance of doubt, all Shares that become outstanding as a result of the “cashless exercise” of the outstanding pre-funded warrants of the Company, as described below); (ii) the accuracy of the Company’s representations and warranties contained in the Merger Agreement (subject to any applicable Material Adverse Effect (as defined in the Merger Agreement) and materiality qualifiers); (iii) the absence of a willful and material breach by the Company of the “no-shop” restrictions described in the Merger Agreement and the Company’s performance of its other obligations, covenants and agreements under the Merger Agreement in all material respects; (iv) the absence, since the date of the Merger Agreement, of any Material Adverse Effect; (v) the expiration or early termination of the waiting period applicable to the Offer under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and if Gilead and the Company have entered into an agreement with any governmental body regarding the timing of the consummation of the Offer, such consummation being permitted under such agreement and (vi) the absence of any judgment, temporary restraining order, preliminary or permanent injunction or other order, decree or ruling restraining, enjoining or otherwise preventing the acquisition of or payment for Shares pursuant to the Offer or the consummation of the Offer or the Merger or subsequent integration. As soon as practicable following the acceptance of the Shares validly tendered and not validly withdrawn pursuant to the Offer and the consummation of the Offer, subject to the satisfaction or waiver of certain customary conditions set forth in the Merger Agreement, the Merger will be effected under Section 251(h) of the Delaware General Corporation Law, as amended, without a meeting or vote of the Company’s stockholders. At the effective time of the Merger (the “Effective Time”), each issued and outstanding Share, other than any Excluded Shares, any Shares irrevocably accepted for purchase pursuant to the Offer (“Tendered Shares”) or any Dissenting Shares (as defined in the Merger Agreement), will be converted into the right to receive the Offer Price (the “Merger Consideration”), in cash, without interest and subject to any required withholding of taxes. At the Effective Time, each stock option to purchase Shares that is then outstanding and unexercised, whether or not vested and which has a per-share exercise price that is less than the Merger Consideration, will be automatically canceled and converted into the right to receive a lump-sum cash payment equal to (i) the excess of (a) the Merger Consideration over (b) the exercise price payable per Share under such stock option, multiplied by (ii) the total number of Shares subject to such stock option immediately prior to the Effective Time. At the Effective Time, each restricted stock unit award with respect to Shares that is then outstanding will be automatically canceled and converted into the right to receive a lump-sum cash payment equal to the product, rounded to the nearest cent, of (i) the number of Shares subject to such restricted stock unit award as of the Effective Time and (ii) the Merger Consideration. At the Offer Acceptance Time, each pre-funded warrant of the Company to purchase Shares that is outstanding immediately prior to the Effective Time will automatically be deemed to be exercised in full in a “cashless exercise” pursuant to the warrant agreement to which such warrant is subject. At the Effective Time, holders of Shares issued pursuant to such “cashless exercise” of the pre-funded warrants of the Company in accordance with the applicable warrant agreements and the Merger Agreement shall become entitled to the Merger Consideration as described above in respect of Shares other than the Excluded Shares, the Tendered Shares and any Dissenting Shares. The Merger Agreement contains certain termination rights for the Company and Gilead. Upon termination of the Merger Agreement under specified circumstances, the Company will be required to pay Gilead a termination fee in the amount of $151.6 million.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
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.
Revenue Recognition	Revenue Recognition At the inception of an arrangement, the Company evaluates if a counterparty to a contract is a customer, if the arrangement is within the scope of ASC 606—Revenue from Contracts with Customers each Collaboration Revenues The Company periodically enters into collaboration arrangements with third party collaborators, under which the Company may license certain rights to its intellectual property to permit collaborators to further develop, manufacture and/or commercialize its drug candidates. The terms of these agreements typically include, but are not limited to, payments to the Company for one or more of the following: nonrefundable, upfront license fees; development and commercial milestones whose payment is typically contingent upon milestone achievement; funding of research and/or development activities; product supply; and royalties on net sales of licensed products. For each collaboration agreement that results in revenues, the Company identifies all material promised goods and services, which may include, but are not limited to, one or more of the following: a license to intellectual property and know-how, re-assessed Once the estimated transaction price is established, amounts are allocated to identified performance obligations. The transaction price is generally allocated to each separate performance obligation based on its estimated standalone selling price (SSP). To determine SSPs, the Company uses various estimation methods, including the adjusted market assessment approach, which utilizes prices observable in the market for similar goods and services, the expected cost plus a margin approach, as well as applies valuation techniques involving projected discounted cash flows. These approaches may include the use of assumptions and estimates requiring significant judgement. The Company recognizes the amount of the transaction price allocated to each respective performance obligation as revenue when the performance obligation is satisfied or as it is satisfied. If a performance obligation is satisfied over time, the Company applies an appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. The Company receives payments from its customers based on payment terms established in each contract. Upfront payments and fees are recorded as deferred revenue upon receipt or when due until the Company performs its obligations under these arrangements. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. If the arrangement includes optional goods and services, the Company assesses whether delivery of such goods and services requires the customer to pay fees consistent with their standalone selling prices, or if customer may be entitled to incremental discounts that it would not have received without entering into the agreement and committing to purchase the initial goods and services. The presence of such discounts indicates the customer has received material rights which also represent performance obligations. Upfront License Fees: Development and Regulatory Milestone Payments re-evaluates Sales-based Milestone and Royalty Payments:
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 equivalents approximate their related fair value due to the short-term nature of these instruments. Cash equivalents are classified as level 1 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 categ o es As of December 31, 2023 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 127,231 $ —  $ —  $ 127,231 U.S. treasury securities —  15,181 —  15,181 U.S and foreign commercial paper —  19,916 —  19,916 U.S. agency securities —  33,207 —  33,207 Total cash equivalents 127,231 68,304 —  195,535 Marketable securities: U.S. and foreign commercial paper —  66,317 —  66,317 U.S. and foreign corporate debt securities —  5,536 —  5,536 U.S. agency securities —  40,914 —  40,914 U.S. treasury securities —  96,885 —  96,885 Total marketable securities —  209,652 —  209,652 Total assets measured at fair value $ 127,231 $ 277,956 $ —  $ 405,187 As of December 31, 2022 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 9,770 $ — $ — $ 9,770 Total cash equivalents 9,770 — — 9,770 Marketable securities: U.S. and foreign commercial paper — 46,121 — 46,121 U.S. and foreign corporate debt securities — 24,807 — 24,807 Supranational debt securities — 12,890 — 12,890 U.S. agency securities — 7,759 — 7,759 U.S. treasury securities — 23,617 — 23,617 Total marketable securities — 115,194 — 115,194 Total assets measured at fair value $ 9,770 $ 115,194 $ — $ 124,964 The Company estimates the fair value of its money market funds, corporate debt, 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 $98.9 million. 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, attainment of certain sales milestones and the discount rate.
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, money market funds, and marketable debt securities which are subject to minimal credit and market risk. The Company invests excess cash in marketable securities with high credit ratings. These securities consist primarily of corporate debt, commercial paper, U.S. treasury, U.S. agency securities and supranational debt securities and are classified as “available-for-sale.” from the balance sheet date. The Company considers marketable securities as non-current investments if the maturity date is in excess of from the balance sheet date. Realized gains and losses from the sale of marketable securities, if any, are calculated using the specific-identification method. Expected losses judged to be related partially or in whole to declines in credit risk-related factors of the security issuer are included in interest expense in the consolidated statements of operations and comprehensive loss at the time the factors contributing to the expected losses are identified. 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 expected losses on its marketable securities related to credit risk-related declines in market value. In determining whether a decline in market value is related to expected credit losses, various factors are considered, including the cause, duration of time and severity of the expected loss, 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. Accrued interest receivable is included as part of Prepaid expenses and other current assets in the consolidated balance sheets.
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. The Company maintains deposits in excess of FDIC insured deposit limits with its financial institutions. 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.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are recorded at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method, and the costs are amortized over the estimated useful lives of the respective assets, which are generally three non-cancelable
Long-Lived Assets	Long-Lived Assets The Company reviews the carrying value long-lived assets, including right-of-use
Leases	Leases As of December 31, 2023, the Company had two operating leases pertaining to its corporate office space, including the new subleased office space in Fremont, California, and a The Company recognizes a lease asset for its right to use the underlying asset and a lease liability for the corresponding lease obligation. The Company determines whether an arrangement is or contains a lease at contract inception. Operating and finance leases are included in lease right-of-use right-of-use At lease inception, the Company analyzes the terms of the contract to determine whether its leases should be classified as an operating lease or a finance lease. The right-of-use non-lease non-lease right-of-use Refer to Note 8—Leases
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 assets, and facilities and information technology that support research and development activities. Research and development costs are expensed as incurred. 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 non-current 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, and provided such prepayments are nonrefundable, they 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 and 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 Development Financing Agreement (the Financing Agreement) (See Note 7—Development Financing Agreement 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, at each reporting date, the Company 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, 2023. 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
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 and common stock equivalents outstanding during the period. The weighted-average common shares outstanding for the years ended December 31, 2023, 2022, and 2021 include pre-funded Note 10—Stockholders’ Equity were 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, 2023 2022 2021 Numerator: Net loss $ (105,370 ) $ (106,001 ) $ (89,998 ) Denominator: Weighted average number of: Common stock shares outstanding 101,479,061 84,679,063 70,712,865 Pre-funded 4,725,212 3,125,000 342,466 Total 106,204,273 87,804,063 71,055,331 Net loss per share $ (0.99 ) $ (1.21 ) $ (1.27 ) The following table shows the total outstanding securities considered anti-dilutive and therefore excluded from the computation of diluted net loss per share: Year Ended December 31, 2023 2022 2021 Common stock options 16,539,905 13,930,195 10,791,431 Incentive awards — 101,182 101,182 Total 16,539,905 14,031,377 10,892,613
Recently Issued Accounting Pronouncements	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, 2023
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 categ o es As of December 31, 2023 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 127,231 $ —  $ —  $ 127,231 U.S. treasury securities —  15,181 —  15,181 U.S and foreign commercial paper —  19,916 —  19,916 U.S. agency securities —  33,207 —  33,207 Total cash equivalents 127,231 68,304 —  195,535 Marketable securities: U.S. and foreign commercial paper —  66,317 —  66,317 U.S. and foreign corporate debt securities —  5,536 —  5,536 U.S. agency securities —  40,914 —  40,914 U.S. treasury securities —  96,885 —  96,885 Total marketable securities —  209,652 —  209,652 Total assets measured at fair value $ 127,231 $ 277,956 $ —  $ 405,187 As of December 31, 2022 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 9,770 $ — $ — $ 9,770 Total cash equivalents 9,770 — — 9,770 Marketable securities: U.S. and foreign commercial paper — 46,121 — 46,121 U.S. and foreign corporate debt securities — 24,807 — 24,807 Supranational debt securities — 12,890 — 12,890 U.S. agency securities — 7,759 — 7,759 U.S. treasury securities — 23,617 — 23,617 Total marketable securities — 115,194 — 115,194 Total assets measured at fair value $ 9,770 $ 115,194 $ — $ 124,964
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, 2023 2022 2021 Numerator: Net loss $ (105,370 ) $ (106,001 ) $ (89,998 ) Denominator: Weighted average number of: Common stock shares outstanding 101,479,061 84,679,063 70,712,865 Pre-funded 4,725,212 3,125,000 342,466 Total 106,204,273 87,804,063 71,055,331 Net loss per share $ (0.99 ) $ (1.21 ) $ (1.27 )
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: Year Ended December 31, 2023 2022 2021 Common stock options 16,539,905 13,930,195 10,791,431 Incentive awards — 101,182 101,182 Total 16,539,905 14,031,377 10,892,613

Cash Equivalents and Marketab_2

Cash Equivalents and Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2023
Cash and Cash Equivalents [Abstract]
Cash Equivalents and Marketable Available-for-Sale Securities	Cash equivalents and marketable available-for-sale Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value As of December 31, 2023: Cash equivalents: Money market funds $ 127,231 $ — $ — $ 127,231 U.S. treasury securities 15,179 2 — 15,181 U.S and foreign commercial paper 19,924 — (8 ) 19,916 U.S. agency securities 33,219 — (12 ) 33,207 Total cash equivalents 195,553 2 (20 ) 195,535 Current marketable securities: U.S. and foreign commercial paper 66,354 3 (40 ) 66,317 U.S. and foreign corporate debt securities 5,538 — (2 ) 5,536 U.S. agency securities 30,595 23 (12 ) 30,606 U.S. treasury securities 85,210 54 (3 ) 85,261 Total current marketable securities 187,697 80 (57 ) 187,720 Non-current U.S. agency securities 10,241 67 — 10,308 U.S. treasury securities 11,552 72 — 11,624 Total non-current 21,793 139 — 21,932 Total marketable securities $ 405,043 $ 221 $ (77 ) $ 405,187 As of December 31, 2022: Cash equivalents: Money market funds $ 9,770 $ — $ — $ 9,770 Total cash equivalents 9,770 — — 9,770 Current marketable securities: U.S. and foreign commercial paper 46,121 — — 46,121 U.S. and foreign corporate debt securities 24,964 — (157 ) 24,807 Supranational debt securities 12,946 — (56 ) 12,890 U.S. agency securities 7,782 16 (39 ) 7,759 U.S. treasury securities 23,707 2 (92 ) 23,617 Total current marketable securities 115,520 18 (344 ) 115,194 Total marketable securities $ 125,290 $ 18 $ (344 ) $ 124,964
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, 2023 (in thousands): Due less than 1 year $ 187,720 Due between 1 and 2 years 21,932 Total fair value $ 209,652
Schedule of restricted cash and cash equivalents	A reconciliation of cash, cash equivalents and restricted cash reported in the accompanying consolidated balance sheets to the amount reported within the accompanying consolidated statements of cash flows is as follows (in thousands): December 31, 2023 2022 Cash and cash equivalents $ 206,535 $ 20,291 Restricted cash (included in Other assets) 428 — Total cash, cash equivalents, and restricted cash $ 206,963 $ 20,291

Certain Balance Sheet Items (Ta

Certain Balance Sheet Items (Tables)	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Property and Equipment	Property and equipment, net are recorded at cost and consist of the following (in thousands): December 31, 2023 2022 Leasehold improvements $ 2,429 $ 2,429 Office and computer equipment 958 290 Purchased software 44 44 Furniture and fixtures 464 687 Total 3,895 3,450 Less: Accumulated depreciation and amortization (3,430 ) (2,749 ) Property and equipment, net $ 465 $ 701
Other Accrued Liabilities	Other accrued liabilities consist of the following (in thousands): December 31, 2023 2022 Accrued compensation $ 8,980 $ 5,779 Accrued professional fees and other 6,706 1,372 Current portion of operating lease liabilities 7 664 Total other accrued liabilities $ 15,693 $ 7,815

Development Financing Agreeme_2

Development Financing Agreement (Tables)	12 Months Ended
	Dec. 31, 2023
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 Cash received 25,000 Accretion of development financing liability 14,907 Balance at December 31, 2022 $ 90,227 Accretion of development financing liability 18,945 Balance at December 31, 2023 $ 109,172

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Summary Of Our Operating Lease Assets And Liabilities	The balance sheet classification of our operating lease assets and liabilities were as follows (in thousands): Operating leases Finance lease Total leases Assets: Right-of-use $ 4,802 $ 458 $ 5,260 Liabilities: Current portion included in other accrued liabilities 7 — 7 Non-current portion lease 4,848 467 5,315 Total lease liabilities $ 4,855 $ 467 $ 5,322
Summary Of Maturities Of The Company's Operating And Finance Lease Liabilities	As of December 31, 2023, the maturities of the Company’s operating and finance lease liabilities were as follows (in thousands): Operating leases Finance lease Total leases Lease commitments: Year ending December 31, 2024 $ 30 $ — $ 30 2025 527 51 578 2026 867 84 951 2027 894 86 980 2028 961 93 1,054 Thereafter 5,085 491 5,576 Total undiscounted future minimum lease payments 8,364 805 9,169 Less imputed interest (3,509 ) (338 ) (3,847 ) Total lease liabilities 4,855 467 5,322 Less: current portion of lease liabilities (7 ) — (7 ) Non-current portion $ 4,848 $ 467 $ 5,315

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Summary of Reserved Shares of Common Stock for Future Issuances	As of December 31, 2023 and 2022, the Company had reserved shares of common stock for future issuances as follows: December 31, 2023 2022 Pre-funded 5,226,628 3,125,000 Equity award plans: Options and incentive awards outstanding, all equity plans 16,539,905 14,031,377 Equity awards available for future grant - 2023 Plan 8,637,460 — Equity awards available for future grant - 2013 Plan — 2,680,621 Equity awards available for future grant - 2020 Plan 552,500 — Total shares of common stock reserved for future issuance 30,956,493 19,836,998

Stock Plans and Stock-Based C_2

Stock Plans and Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
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 Outstanding as of December 31, 2022 13,930,195 $ 5.26 Options granted 5,685,135 9.46 Options exercised (2,115,004 ) 4.79 Options forfeited (930,421 ) 5.91 Options expired (30,000 ) 12.72 Outstanding as of December 31, 2023 16,539,905 $ 6.71 6.87 $ 279,610 Vested and expected to vest as of December 31, 2023 16,539,905 $ 6.71 6.87 $ 279,610 Exercisable as of December 31, 2023 10,096,612 $ 5.97 5.64 $ 178,177
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 December 31, 2023 2022 2021 Research and development $ 5,758 $ 4,274 $ 4,470 General and administrative 9,472 5,243 5,526 Total stock-based compensation expense $ 15,230 $ 9,517 $ 9,996
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 December 31, 2023 2022 2021 Expected term (years) 6.1 6.0 6.1 Expected volatility 96 % 101 % 104 % Risk-free interest rate 3.8 % 1.8 % 0.9 % Expected dividend yield — — — Weighted-average grant date fair value per share $ 7.50 $ 2.33 $ 3.91

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023 2022 Deferred tax assets: Federal and state net operating loss carryforwards $ 91,783 $ 87,681 Federal and state research and development tax credit carryforwards 41,714 32,016 Intangibles 4,365 5,040 Capitalized research and development 26,101 11,872 Stock-based compensation 3,358 6,624 Other 3,329 1,574 Total deferred tax assets 170,650 144,807 Deferred tax liabilities: Depreciation and amortization — (79 ) Other (1,135 ) (36 ) Total deferred tax liabilities (1,135 ) (115 ) Valuation allowance $ (169,515 ) $ (144,692 ) 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): Year Ended December 31, 2023 2022 2021 Income tax benefit at federal statutory tax rate $ (22,128 ) $ (22,260 ) $ (18,900 ) Change in valuation allowance 24,852 (29,165 ) 14,739 Impairment of tax attributes 4,905 38,398 —  Research credits (8,622 ) (2,640 ) (2,802 ) Development financing liability 3,978 12,301 6,654 Permanent differences (2,230 ) 511 429 State income taxes, net of federal benefit (1,132 ) 2,806 (267 ) Other, net 377 49 147 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): Balances as of December 31, 2020 $ 7,205 Increases related to prior year tax positions 9 Increases related to 2021 tax positions 783 Balances as of December 31, 2021 7,997 Decreases related to prior year tax positions (1,223 ) Increases related to 2022 tax positions 730 Balances as of December 31, 2022 7,504 Decreases related to prior year tax positions (14 ) Increases related to 2023 tax positions 2,514 Balances as of December 31, 2023 $ 10,004

Organization and Description _2

Organization and Description of Business - Additional Information (Detail) $ / shares in Units, $ in Thousands, ¥ in Billions			12 Months Ended
	Sep. 11, 2023 USD ($) $ / shares shares	Jan. 23, 2023 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) segment shares	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jan. 06, 2023 USD ($)	Jan. 06, 2023 JPY (¥)	Nov. 30, 2021 $ / shares shares
Class of Stock [Line Items]
Number of operating segments | segment			1
Net loss			$ (105,370)	$ (106,001)	$ (89,998)
Cash flows from operating activities			(72,531)	(84,080)	$ (69,431)
Accumulated deficit			(978,227)	$ (872,857)
Cash and cash equivalents and marketable securities			$ 416,200
Number of new stock issued during the period. | shares	14,521,307	11,821,428
Sale of Stock, Price Per Share | $ / shares	$ 17.13	$ 7
Total gross offering proceeds	$ 242,800	$ 92,400
Collaboration and License Agreement [Member]
Class of Stock [Line Items]
Upfront cash payment						$ 34,200	¥ 4.5
Prefunded warrants [Member]
Class of Stock [Line Items]
Sale of Stock, Price Per Share | $ / shares	$ 17.1299	$ 6.9999						$ 3.9999
Number of common stock into which the class of warrant or right may be converted | shares	583,771	2,142,857	5,226,628					3,125,000

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, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 405,187	$ 124,964
Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	195,535	9,770
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	127,231	9,770
Cash Equivalents [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	15,181
Cash Equivalents [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	19,916
Cash Equivalents [Member] | US Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	33,207
Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	209,652	115,194
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	96,885	23,617
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	66,317	46,121
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	40,914	7,759
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	5,536	24,807
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		12,890
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	127,231	9,770
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	127,231	9,770
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	127,231	9,770
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	277,956	115,194
Level 2 [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	68,304
Level 2 [Member] | Cash Equivalents [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	15,181
Level 2 [Member] | Cash Equivalents [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	19,916
Level 2 [Member] | Cash Equivalents [Member] | US Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	33,207
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	209,652	115,194
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	96,885	23,617
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	66,317	46,121
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	40,914	7,759
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	$ 5,536	24,807
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		$ 12,890

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) Facility Leased_Facilities
Product Information [Line Items]
Cash and cash equivalents, maturity description	90 days or less
Fair value of development financing liability | $	$ 98.9
Number of leased facilities operating leases | Facility	2
Furnitures Fixtures And Equipment [Member]
Product Information [Line Items]
Number of leased facilities finance leases | Leased_Facilities	1
Maximum [Member]
Product Information [Line Items]
Short-term contractual maturities	1 year
Property and equipment, estimated useful lives	3 years
Minimum [Member]
Product Information [Line Items]
Short-term contractual maturities	1 year
Property and equipment, estimated useful lives	7 years

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Computation of Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net loss	$ (105,370)	$ (106,001)	$ (89,998)
Denominator:
Weighted average, Basic	106,204,273	87,804,063	71,055,331
Weighted average, Diluted	106,204,273	87,804,063	71,055,331
Net loss per share—basic	$ (0.99)	$ (1.21)	$ (1.27)
Net loss per share—diluted	$ (0.99)	$ (1.21)	$ (1.27)
Prefunded warrants [Member]
Denominator:
Weighted average, Basic	4,725,212	3,125,000	342,466
Weighted average, Diluted	4,725,212	3,125,000	342,466
Common Stock [Member]
Denominator:
Weighted average, Basic	101,479,061	84,679,063	70,712,865
Weighted average, Diluted	101,479,061	84,679,063	70,712,865

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted loss per share	16,539,905	14,031,377	10,892,613
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	16,539,905	13,930,195	10,791,431
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	0	101,182	101,182

Cash Equivalents and Marketab_3

Cash Equivalents and Marketable Securities - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Restricted Cash	$ 428	$ 0
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Realized gains and losses	0	0	$ 0
Marketable investments continuous unrealized loss position	$ 0	$ 0

Cash Equivalents and Marketab_4

Cash Equivalents and Marketable Securities - Cash Equivalents and Marketable Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	$ 187,720	$ 115,194
Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	195,553	9,770
Gross Unrealized Gains	2
Gross Unrealized Losses	(20)
Estimated Fair Value	195,535	9,770
Cash and Cash Equivalents [Member] | Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	127,231	9,770
Estimated Fair Value	127,231	9,770
Cash and Cash Equivalents [Member] | U.S. and Foreign Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	19,924
Gross Unrealized Losses	(8)
Estimated Fair Value	19,916
Cash and Cash Equivalents [Member] | U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	15,179
Gross Unrealized Gains	2
Estimated Fair Value	15,181
Cash and Cash Equivalents [Member] | U.S. agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	33,219
Gross Unrealized Losses	(12)
Estimated Fair Value	33,207
Current marketable securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	187,697	115,520
Gross Unrealized Gains	80	18
Gross Unrealized Losses	(57)	(344)
Estimated Fair Value	187,720	115,194
Current marketable securities [Member] | U.S. and Foreign Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	66,354	46,121
Gross Unrealized Gains	3
Gross Unrealized Losses	(40)
Estimated Fair Value	66,317	46,121
Current marketable securities [Member] | U.S. and Foreign Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,538	24,964
Gross Unrealized Losses	(2)	(157)
Estimated Fair Value	5,536	24,807
Current marketable securities [Member] | U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	85,210	23,707
Gross Unrealized Gains	54	2
Gross Unrealized Losses	(3)	(92)
Estimated Fair Value	85,261	23,617
Current marketable securities [Member] | U.S. agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	30,595	7,782
Gross Unrealized Gains	23	16
Gross Unrealized Losses	(12)	(39)
Estimated Fair Value	30,606	7,759
Current marketable securities [Member] | Supranational Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		12,946
Gross Unrealized Losses		(56)
Estimated Fair Value		12,890
Maketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	405,043	125,290
Gross Unrealized Gains	221	18
Gross Unrealized Losses	(77)	(344)
Estimated Fair Value	405,187	$ 124,964
Non-current marketable securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	21,793
Gross Unrealized Gains	139
Estimated Fair Value	21,932
Non-current marketable securities [Member] | U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,552
Gross Unrealized Gains	72
Estimated Fair Value	11,624
Non-current marketable securities [Member] | U.S. agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,241
Gross Unrealized Gains	67
Estimated Fair Value	$ 10,308

Cash Equivalents and Marketab_5

Cash Equivalents and Marketable Securities - Schedule Of Fair Value Of The Company Marketable Securities By Contractual Maturity (Detail) $ in Thousands	Dec. 31, 2023 USD ($)
Contractual Obligation Fiscal Year Maturity Schedule [Line Items]
Due less than 1 year	$ 187,720
Due between 1 and 2 years	21,932
Total fair value	$ 209,652

Cash Equivalents and Marketab_6

Cash Equivalents and Marketable Securities - Schedule Of Restricted Cash And Cash Equivalents (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 206,535	$ 20,291
Restricted cash (included in Other assets)	428	0
Total cash, cash equivalents, and restricted cash	$ 206,963	$ 20,291

Certain Balance Sheet Items - P

Certain Balance Sheet Items - Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,895	$ 3,450
Less: Accumulated depreciation and amortization	(3,430)	(2,749)
Property and equipment, net	465	701
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,429	2,429
Office and Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	958	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	$ 464	$ 687

Certain Balance Sheet Items - A

Certain Balance Sheet Items - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 0.7	$ 0.6	$ 0.7

Certain Balance Sheet Items - O

Certain Balance Sheet Items - Other Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accrued compensation	$ 8,980	$ 5,779
Accrued professional fees and other	6,706	1,372
Current portion of operating lease liabilities	7	664
Total other accrued liabilities	$ 15,693	$ 7,815

Collaboration and License Agr_2

Collaboration and License Agreement - Additional Information (Detail) $ in Thousands, ¥ in Billions			3 Months Ended	12 Months Ended
	Jan. 06, 2023 USD ($)	Jan. 06, 2023 JPY (¥)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Jan. 06, 2023 JPY (¥)	Dec. 31, 2022 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deferred collaboration revenue, noncurrent				$ 1,100		$ 0
Collaboration and License Agreement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront cash payment	$ 34,200				¥ 4.5
Potential milestone payments	128,000	¥ 17
Collaborative arrangement contract consideration	$ 33,700
Collaboration revenue				31,100
Deferred collaboration revenue				2,700
Deferred collaboration revenue, noncurrent				1,100
Upfront Payment Contract Consideration Fee Income Received				33,700
Collaboration revenue from contract with customers excluding assessed tax				$ 31,000
Realized gain loss, foreign currency transaction, after tax			$ 500

In-License Agreement - Addition

In-License Agreement - Additional Information (Detail) - Janssen Pharmaceutical NV [Member] - USD ($)	1 Months Ended
	Jun. 30, 2006	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Accrued royalties		$ 0	$ 0	$ 0
Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of royalty on net sales	8%

Development Financing Agreeme_3

Development Financing Agreement - Additional Information (Detail) - USD ($) $ in Thousands				12 Months Ended
	Jan. 31, 2022	Nov. 30, 2021	Aug. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jul. 30, 2021
Debt Instrument [Line Items]
Description Of Percentage Fixed Success Payments			2.0
Repayments of Lines of Credit			$ 10,000
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			$ 232,500
Percentage of Accelerate Payment Payable On Funds provided			1.35
Description Repayments On Funds Provided Upon Termination Of Financing Agreement			2.0
Imputed Interest Rate of Development Financing Liability				19.20%
Development Financing Liability Current				$ 10,000	$ 0
Repayments of Long-Term Debt				$ 99,200
Fixed Success Payments [Member]
Debt Instrument [Line Items]
Anniversary Payments Due Year One			$ 15,000
Anniversary Payments Due Year Two			22,500
Anniversary Payments Due Year Three			22,500
Anniversary Payments Due Year Four			25,000
Anniversary Payments Due Year Five			27,500
Anniversary Payments Due Year Six			27,500
Variable Success Payments [Member]
Debt Instrument [Line Items]
Payments Upon Reaching Cumulative US Product Sales Thresholds Year One			17,500
Payments Upon Reaching Cumulative US Product Sales Thresholds Year Two			27,500
Payments upon reaching product sales run rate			37,500
Installment Funding Number Three [Member]
Debt Instrument [Line Items]
Proceeds from Lines of Credit	$ 25,000
ABW Cyclops SPV LP [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							$ 75,000
ABW Cyclops SPV LP [Member] | Installment Funding Number One [Member]
Debt Instrument [Line Items]
Proceeds from Lines of Credit			$ 25,000
ABW Cyclops SPV LP [Member] | Installment Funding Number Two [Member]
Debt Instrument [Line Items]
Proceeds from Lines of Credit		$ 25,000
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%
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%
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%

Development Financing Agreeme_4

Development Financing Agreement - Schedule of Changes in Fair Value of Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Balance, beginning of period	$ 90,227	$ 50,320	$ 0
Cash received		25,000	50,000
Debt discount			(2,263)
Accretion of development financing liability	18,945	14,907	2,583
Balance, end of period	$ 109,172	$ 90,227	$ 50,320

Leases - Summary Of Our Operati

Leases - Summary Of Our Operating Lease Assets And Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease right-of-use assets	$ 4,802
Current portion of operating lease liabilities included in other accrued liabilities	7	$ 664
Non-current portion of operating lease liabilities	4,848
Total operating lease liability	4,855
Finance lease right-of-use assets	458
Current portion of finance lease liabilities included in other accrued liabilities	0
Non-current portion of finance lease liabilities	467
Total finance lease liability	467
Right-of-use assets	5,260
Current portion included in other accrued liabilities	7
Non-current portion of lease liabilities	5,315
Total operating lease liability	$ 5,322
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Right Of Use Assets
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Lease Liabilities Noncurrent
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Right Of Use Assets
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Lease Liabilities Noncurrent

Leases - Summary Of Maturities

Leases - Summary Of Maturities Of The Company's Operating And Finance Lease Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
2024	$ 30
2025	527
2026	867
2027	894
2028	961
Thereafter	5,085
Total undiscounted future minimum lease payments	8,364
Less imputed interest	(3,509)
Total operating lease liability	4,855
Less: current portion of operating lease liability	(7)	$ (664)
Non-current portion of lease liabilities	4,848
2024	0
2025	51
2026	84
2027	86
2028	93
Thereafter	491
Total undiscounted future minimum lease payments	805
Less imputed interest	(338)
Total finance lease liability	467
Less: current portion of operating lease liability	0
Non-current portion of lease liabilities	467
2024	30
2025	578
2026	951
2027	980
2028	1,054
Thereafter	5,576
Total undiscounted future minimum lease payments	9,169
Less imputed interest	(3,847)
Total operating lease liability	5,322
Less: current portion of operating lease liability	(7)
Non-current portion of lease liabilities	$ 5,315
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Lease Liabilities Noncurrent

Leases - Additional Information

Leases - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) ft² Facility	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease portfolio, weighted average remaining lease term	8 years 4 months 24 days	1 year 1 month 6 days
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Accrued Liabilities, Current	Other Accrued Liabilities, Current
Number of leased facilities | Facility	2
Area of office space | ft²	52,416
Finance lease portfolio , weighted average remaining lease term	8 years 4 months 24 days
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
Newark California Lease [Member] | CALIFORNIA
Lessee, Lease, Description [Line Items]
Weighted average lease discount rate	12.60%
New Sublease In Fremont California [Member] | CALIFORNIA
Lessee, Lease, Description [Line Items]
Weighted average lease discount rate		10.70%
Operating Expense [Member]
Lessee, Lease, Description [Line Items]
Lease costs | $	$ 0.7	$ 0.7	$ 0.6

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Indemnification liabilities	$ 0	$ 0

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions				1 Months Ended
	Sep. 11, 2023	Feb. 28, 2023	Jan. 23, 2023	Feb. 28, 2023	Dec. 31, 2023	Dec. 31, 2022	Nov. 30, 2021
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
Number of new stock issued during the period.	14,521,307		11,821,428
Sale of Stock, Price Per Share	$ 17.13		$ 7
Collaboration and License Agreement [Member]
Class of Stock [Line Items]
Sale of stock, consideration received on transaction	$ 242.8		$ 92.4
Prefunded warrants [Member]
Class of Stock [Line Items]
Number of common stock into which the class of warrant or right may be converted	583,771		2,142,857		5,226,628		3,125,000
Sale of Stock, Price Per Share	$ 17.1299		$ 6.9999				$ 3.9999
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.0001		$ 0.0001				$ 0.0001
Class Of warrant Or right number of common stock issuable on exercise of warrants				625,000
Stock issued on exercise of warrants		624,992
ATM Offering [Member]
Class of Stock [Line Items]
Common stock value subscribed					$ 100

Stockholder's Equity - Summary

Stockholder's Equity - Summary of Reserved Shares of Common Stock for Future Issuances (Detail) - shares	Dec. 31, 2023	Jun. 01, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	30,956,493		19,836,998
Equity awards available for future grant - 2023 Plan [Member]
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	8,637,460	9,500,000	0
CBAYEquity incentive plan two thousand and thirteen [Member]
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	0		2,680,621
CBAYEquity incentive plan two thousand and twenty plan [Member]
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	552,500		0
Options and Incentive awards [Member]
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	16,539,905		14,031,377
Prefunded warrants [Member]
Class of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	5,226,628		3,125,000

Stock Plans and Stock-Based C_3

Stock Plans and Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended		12 Months Ended
	Jun. 01, 2023	Jul. 31, 2023	Sep. 30, 2013	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2017	Apr. 30, 2014	Jan. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised				$ 19.7	$ 0.2	$ 0.2
Fair value of options vested				3.1	$ 0.6	$ 0.7
Unamortized employee and non-employee stock-based compensation expense				$ 37.8
Unamortized employee and non-employee stock-based compensation expense recognized period				2 years 8 months 12 days
Options exercised				5,685,135
Share reserved for issue				30,956,493	19,836,998
Stock options outstanding				16,539,905	13,930,195
2020 Equity Incentive 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%
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%
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%
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%
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%
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%
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 reserved for issue									252,752
Exercisable weighted average price per share										$ 5.21
Stock options outstanding				0	101,182
2023 Equity Incentive 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	100%
Shares available for grant				8,637,460
Share reserved for issue	9,500,000			8,637,460	0
Number of shares authorized for issuance under share-based payment arrangement	25,883,628
2020 New Hire Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant				552,500
Share reserved for issue				552,500
Stock Plan Summary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercised				5,685,135	3,692,868
Amended In July 2023 [Member] | 2020 Equity Incentive 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%
Share based compensation arrangement by share based payment award, award vesting period		4 years

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, 2023 USD ($) $ / shares shares
Shares Subject to Outstanding Options
Outstanding at the beginning of period | shares	13,930,195
Options granted | shares	5,685,135
Options exercised | shares	(2,115,004)
Options forfeited | shares	(930,421)
Options expired | shares	(30,000)
Outstanding as end of period | shares	16,539,905
Vested and expected to vest | shares	16,539,905
Exercisable | shares	10,096,612
Weighted-Average Exercise Price of Options
Outstanding at the beginning of period | $ / shares	$ 5.26
Options granted | $ / shares	9.46
Options exercised | $ / shares	4.79
Options forfeited | $ / shares	5.91
Options expired | $ / shares	12.72
Outstanding as end of period | $ / shares	6.71
Vested and expected to vest | $ / shares	6.71
Exercisable | $ / shares	$ 5.97
Weighted-Average Remaining Contractual Term (Years)
Outstanding	6 years 10 months 13 days
Vested and expected to vest	6 years 10 months 13 days
Exercisable	5 years 7 months 20 days
Aggregate Intrinsic Value (In Thousands)
Outstanding | $	$ 279,610
Vested and expected to vest | $	279,610
Exercisable | $	$ 178,177

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 15,230	$ 9,517	$ 9,996
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	5,758	4,274	4,470
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 9,472	$ 5,243	$ 5,526

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years 1 month 6 days	6 years	6 years 1 month 6 days
Expected volatility	96%	101%	104%
Risk-free interest rate	3.80%	1.80%	0.90%
Expected dividend yield	0%	0%	0%
Weighted-average grant date fair value per share	$ 7.5	$ 2.33	$ 3.91

401(k) Plan - Additional Inform

401(k) Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Employees contribution to qualified savings plan	$ 2,500	$ 750	$ 750

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 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 2043. The federal research and development and federal orphan drug tax credit carryforwards expire 2033 through 2043, and the state tax credit will carry forward indefinitely.
Provision for income taxes		$ 0	$ 0
Net valuation allowance increase (decrease)		24,800	(29,200)
Significant change to its unrecognized tax benefits over the next twelve months		$ 0
Income tax examination years		the tax years 2004 to 2022 remain open for income tax examination by tax authorities
Alternate Minimum Tax Rate	15%
Revenues	$ 1,000,000	$ 31,073	0	$ 0
Write off of tax attribute due to limitation			$ 38,400
Minimum [Member]
Income Tax [Line Items]
Open tax year		2004
Maximum [Member]
Income Tax [Line Items]
Open tax year		2022
Domestic Tax Authority [Member]
Income Tax [Line Items]
Federal net operating loss		$ 365,600
Description of net operating loss carryforwards, expire period		federal research and development and federal orphan drug tax credit carryforwards expire 2033 through 2043
Net operating loss carryforward		$ 365,600
Research and development tax credit carry forwards		38,400
Domestic Tax Authority [Member] | Orphan Drug [Member]
Income Tax [Line Items]
Research and development tax credit carry forwards		$ 4,500
Domestic Tax Authority [Member] | Minimum [Member]
Income Tax [Line Items]
NOL carry forward expiry date		2034
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		$ 214,900
Net operating loss carryforward		214,900
Research and development tax credit carry forwards		$ 11,000
State and Local Jurisdiction [Member] | Federal [member]
Income Tax [Line Items]
Federal net operating loss					$ 287,200	$ 78,400
Net operating loss carryforward					$ 287,200	$ 78,400
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		2043
Federal And State Tax Authority [Member]
Income Tax [Line Items]
Cumulative percentage change in ownership percentage permissible		50%
Period for considering the cumulative percentage change in ownership percentage		3 years

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Federal and state net operating loss carryforwards	$ 91,783	$ 87,681
Federal and state research and development tax credit carryforwards	41,714	32,016
Intangibles	4,365	5,040
Capitalized research and development	26,101	11,872
Stock-based compensation	3,358	6,624
Other	3,329	1,574
Total deferred tax assets	170,650	144,807
Deferred tax liabilities:
Depreciation and amortization	0	(79)
Other	(1,135)	(36)
Total deferred tax liabilities	(1,135)	(115)
Valuation allowance	(169,515)	(144,692)
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, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income tax benefit at federal statutory tax rate	$ (22,128)	$ (22,260)	$ (18,900)
Change in valuation allowance	24,852	(29,165)	14,739
Impairment of tax attributes	4,905	38,398	0
Research credits	(8,622)	(2,640)	(2,802)
Development financing liability	3,978	12,301	6,654
Permanent differences	(2,230)	511	429
State income taxes, net of federal benefit	(1,132)	2,806	(267)
Other, net	377	49	147
Income tax (benefit) expense	$ 0	$ 0	$ 0

Income Taxes - Summary of Gross

Income Taxes - Summary of Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Balance at beginning of period	$ 7,504	$ 7,997	$ 7,205
Increases related to prior year tax positions			9
Decreases related to prior year tax positions	(14)	(1,223)
Increases related to tax positions	2,514	730	783
Balance at end of period	$ 10,004	$ 7,504	$ 7,997

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Feb. 23, 2024	Feb. 11, 2024	Dec. 31, 2023	Sep. 11, 2023	Jan. 23, 2023	Dec. 31, 2022
Subsequent Event [Line Items]
Common stock, par value			$ 0.0001			$ 0.0001
Sale of stock, price per share				$ 17.13	$ 7
Subsequent Event [Member]
Subsequent Event [Line Items]
Termination fee payable contingently		$ 151.6
Tender Offer [Member] | Merger Agreement with Gilead Sciences and Pacific Merger Hub [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Common stock, par value	$ 0.0001
Sale of stock, price per share	$ 32.5
Additional offer period business days	10 days
Percentage of shares outstanding	50%