OnKure Therapeutics (OKUR) 10-K 28 Mar 24 2023 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Mar. 26, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2023
Entity File Number	001-40315
Entity Registrant Name	RENEO PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-2309515
Entity Address, Address Line One	18575 Jamboree Road, Suite 275-S
Entity Address, City or Town	Irvine
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92612
City Area Code	858
Local Phone Number	283-0280
Title of 12(b) Security	Common Stock, $0.0001 Par Value per Share
Trading Symbol	RPHM
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 151.4
Entity Common Stock, Shares Outstanding		33,420,808
Entity Central Index Key	0001637715
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	San Diego, California, United States
Documents Incorporated by Reference	Part III of this Annual Report on Form 10-K (the Annual Report) incorporates by reference certain information from the registrant’s definitive proxy statement for its 2024 annual meeting of stockholders (the Proxy Statement), which the registrant intends to file pursuant to Regulation 14A with the Securities and Exchange Commission not later than 120 days after the registrant’s fiscal year end of December 31, 2023 . Except with respect to information specifically incorporated by reference into this Annual Report, the Proxy Statement is not deemed to be filed as part of this Annual Report.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 27,632	$ 19,927
Short-term investments	75,331	81,246
Prepaid expenses and other current assets	3,659	5,180
Total current assets	106,622	106,353
Property and equipment, net	134	453
Right-of-use assets	599	1,292
Other non-current assets	81	84
Total assets	107,436	108,182
Current liabilities:
Accounts payable	8,717	1,893
Accrued expenses	9,129	4,827
Operating lease liabilities, current portion	331	404
Total current liabilities	18,177	7,124
Operating lease liabilities, less current portion	642	1,059
Performance award	7	29
Total liabilities	18,826	8,212
Stockholders' equity (deficit):
Common stock, $0.0001 par value; 200,000,000 shares authorized at December 31, 2022 and December 31, 2021; 24,699,553 shares issued and outstanding at December 31, 2022; and 24,457,838 and 24,455,390 shares issued and outstanding at December 31, 2021, respectively	3	3
Additional paid-in capital	307,073	236,693
Accumulated deficit	(218,474)	(136,683)
Accumulated other comprehensive (loss) income	8	(43)
Total stockholders' equity	88,610	99,970
Total liabilities and stockholders' equity	$ 107,436	$ 108,182

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common stock, Par value	$ 0.0001	$ 0.0001
Common stock, authorized	200,000,000	200,000,000
Common stock, issued	33,420,808	24,699,553
Common stock, outstanding	33,420,808	24,699,553

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating expenses:
Research and development	$ 56,613	$ 37,705
General and administrative	26,440	16,143
Total operating expenses	83,053	53,848
Loss from operations	(83,053)	(53,848)
Other income:
Other income	5,665	1,893
Net loss	(77,388)	(51,955)
Unrealized gain (loss) on short-term investments	51	(77)
Comprehensive loss	$ (77,337)	$ (52,032)
Net loss per share attributable to common stockholders, basic	$ (2.52)	$ (2.12)
Net loss per share attributable to common stockholders, diluted	$ (2.52)	$ (2.12)
Weighted-average shares used in computing net loss per share, basic	30,676,455	24,496,425
Weighted-average shares used in computing net loss per share, diluted	30,676,455	24,496,425

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	At The Market Facility [Member]	Public Offering [Member]	Private Placement [Member]	Common Stock [Member]	Common Stock [Member] At The Market Facility [Member]	Common Stock [Member] Public Offering [Member]	Common Stock [Member] Private Placement [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] At The Market Facility [Member]	Additional Paid-in Capital [Member] Public Offering [Member]	Additional Paid-in Capital [Member] Private Placement [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]
Beginning Balance at Dec. 31, 2021	$ 147,211				$ 3				$ 231,902				$ 34	$ (84,728)
Beginning Balance (in shares) at Dec. 31, 2021					24,455,390
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock		$ 193								$ 193
Issuance of common stock (in shares)						92,085
Stock based compensation	4,320								4,320
Issuance of common stock in connection with equity plans	278								278
Issuance of common stock in connection with equity plans (in shares)					152,078
Other comprehensive income (loss)	(77)												(77)
Net loss	(51,955)													(51,955)
Ending Balance at Dec. 31, 2022	99,970				$ 3				236,693				(43)	(136,683)
Ending Balance (in shares) at Dec. 31, 2022					24,699,553
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock		$ 1,009	$ 58,862	$ 4,667						$ 1,009	$ 58,862	$ 4,667
Issuance of common stock (in shares)						407,877	7,906,250	625,000
Stock based compensation	5,112								5,112
Issuance of common stock in connection with equity plans	730								730
Issuance of common stock in connection with equity plans (in shares)					358,571
Repurchase and retirement of common stock in connection with common stock repurchase agreement (in shares)					(576,443)
Repurchase and retirement of common stock in connection with common stock repurchase agreement	(4,403)													(4,403)
Other comprehensive income (loss)	51												51
Net loss	(77,388)													(77,388)
Ending Balance at Dec. 31, 2023	$ 88,610				$ 3				$ 307,073				$ 8	$ (218,474)
Ending Balance (in shares) at Dec. 31, 2023					33,420,808

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (77,388)	$ (51,955)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	5,112	4,320
Depreciation and amortization	170	88
Amortization/accretion on short-term investments	(4,777)	(817)
Changes in the fair value of performance award	(22)	(415)
Non-cash lease expense	355	441
Right-of-use and leasehold improvement impairment expenses	650	17
Changes in operating assets and liabilities:
Prepaid and other assets	1,524	878
Accounts payable and accrued expenses	11,118	518
Operating lease liabilities	(424)	(437)
Net cash used in operating activities	(63,682)	(47,362)
Cash flows from investing activities
Purchases of property and equipment	(221)	(346)
Purchase of available-for-sale short-term investments	(231,257)	(101,596)
Proceeds from maturities of available-for-sale short-term investments	242,000	44,100
Net cash provided by (used in) investing activities	10,522	(57,842)
Cash flows from financing activities
Proceeds from private placement of common stock, net of offering costs	4,667	193
Repurchase of common stock in connection with common stock repurchase agreement	(4,403)
Proceeds from issuance of common stock in connection with equity plans	730	278
Net cash provided by financing activities	60,865	471
Net increase (decrease) in cash and cash equivalents	7,705	(104,733)
Cash and cash equivalents, beginning of period	19,927	124,660
Cash and cash equivalents, end of period	27,632	19,927
Supplemental cash flow information:
Right-of-use assets obtained in exchange for lease obligations		$ 1,733
Public Offering [Member]
Cash flows from financing activities
Proceeds from issuance of common stock, net of offering costs	58,862
At-The-Market Facility [Member]
Cash flows from financing activities
Proceeds from issuance of common stock, net of offering costs	$ 1,009

Organization and Business

Organization and Business	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Business	1. Organization and Business Organization Reneo Pharmaceuticals, Inc. (Reneo or the Company) commenced operations on September 22, 2014 as a pharmaceutical company and has historically focused on the development of therapies for patients with rare genetic mitochondrial diseases. In December 2017, the Company in-licensed mavodelpar (REN001), a novel oral peroxisome proliferator-activated receptor delta (PPARδ) agonist. Risks and Uncertainties On December 14, 2023, the Company announced that its pivotal STRIDE study, a global, randomized, double-blind, placebo-controlled Phase 2b trial of mavodelpar in adult patients with primary mitochondria myopathy due to mitochondrial DNA defects, did not meet its primary or secondary efficacy endpoints. As a result, the Company suspended the development activities of its only product candidate, mavodelpar, and implemented cash preservation activities, including substantial workforce reduction. In December 2023, the Company implemented a workforce reduction and recognized approximately $ 2.5 million in severance and continuation of benefit expenses for the year ended December 31, 2023. The Company is subject to a number of risks similar to other pharmaceutical companies including, but not limited to, dependency on the clinical and commercial success of the Company’s potential product candidates, ability to obtain regulatory approval of any such potential product candidates, the need for substantial additional financing to achieve its goals, uncertainty of broad adoption of its approved products, if any, by physicians, consumers and third-party payors, significant competition and untested manufacturing capabilities, and dependence on key individuals and sole source suppliers. Liquidity From its inception in 2014, the Company has incurred significant losses and negative cash flows from operations and expects to continue to incur net losses into the foreseeable future and may never become profitable. As of December 31, 2023, the Company had cash, cash equivalents and short-term investments of $ 103.0 million to fund future operations. Since inception through December 31, 2023, the Company has funded its operations primarily through the issuance and sale of equity securities. Management has prepared cash flow forecasts which indicate that, based on the Company’s current cash resources available and working capital, the Company will have sufficient resources to fund its operations for at least one year after the date the consolidated financial statements are issued. Future capital requirements will depend on many factors, including the timing and extent of spending on its operations and there can be no assurance that the Company will be successful in obtaining additional funding, that the Company’s projections of its future working capital needs will prove accurate, or that any additional funding would be sufficient to continue operations in future years. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible, and/or suspend or curtail planned programs. Any of these actions could negatively impact the Company’s business, results of operations, and future prospects. Public Offerings In May 2022, the Company entered into an at-the-market equity offering sales agreement with Leerink Partners LLC (Leerink), previously SVB Securities LLC (2022 ATM Facility), under which it could offer and sell from time to time at its sole discretion, up to $ 20.0 million in shares of its common stock. On November 13, 2023, concurrent with entering into the 2023 ATM Facility (defined below), the Company and Leerink terminated the 2022 ATM Facility. The Company had sold an aggregate of $ 1.2 million under the 2022 ATM Facility as of the termination date. In May 2023, the Company completed a public offering in which it sold an aggregate of 7,906,250 shares of common stock, which included the full exercise of the underwriters’ option to purchase an additional 1,031,250 shares of common stock, at a price of $ 8.00 per share. The Company received total net proceeds from the offering of approximately $ 58.9 million, after deducting underwriting discounts and commissions and offering expenses. Also, in May 2023, the Company completed a concurrent private placement in which it sold an aggregate of 625,000 shares of common stock to Abingworth Bioventures 8 L.P., a holder of more than 5 % of the Company’s common stock, at a price of $ 8.00 per share. The Company received total net proceeds of approximately $ 4.7 million, after deducting advisor fees and other estimated fees and expenses. On November 13, 2023, the Company entered into an at-the-market equity offering sales agreement (Sales Agreement) with Leerink under which it may offer and sell, from time to time, at its sole discretion, up to $ 100.0 million in shares of its common stock (2023 ATM Facility). As of December 31, 2023 , the Company had no t sold any shares of its common stock under the 2023 ATM Facility and on March 25, 2024, the Company provided notice to Leerink of its election to terminate the Sales Agreement, effective as of April 8, 2024 .

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 Consolidation The Company’s consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States (GAAP) and reflect the operation of the Company and its wholly owned subsidiary. All intercompany balances and transactions among the consolidated entities have been eliminated in consolidation. Use of Estimates The preparation of the Company’s consolidated financial statements requires management to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure in the Company’s consolidated financial statements and accompanying notes. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. By their nature, estimates are subject to an inherent degree of uncertainty and, as such, actual results may differ from management’s estimates. Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less, when purchased, to be cash equivalents. As of December 31, 2023 and 2022 , the Company had cash balances deposited at major financial institutions. Cash balances are subject to minimal credit risk as the balances are with high credit quality financial institutions. Cash and cash equivalents include cash in readily available checking, money market accounts and repurchase agreements. Short-term Investments The Company accounts for short-term investments in accordance with Accounting Standard Codification (ASC) Topic 320, Investments – Debt and Equity Securities . Management determines the appropriate classification of its investments at the time of purchase and reevaluates such determinations at each reporting period. At December 31, 2023, the Company’s investments comprised of U.S. treasury securities and commercial paper classified as available-for-sale securities. Available-for-sale securities are carried at fair value, with the unrealized gains and losses reported in accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses on sales of investments are included in interest income and are derived using the specific identification method for determining the cost of securities. When the fair value of an available-for-sale debt security falls below the amortized cost basis it is evaluated to determine if any of the decline in value is attributable to credit loss. Decreases in fair value attributable to credit loss are recorded directly to earnings with a corresponding allowance for credit losses, limited to the amount that the fair value is less than the amortized cost basis. If the credit quality subsequently improves the allowance is reversed up to a maximum of the previously recorded credit losses. When the Company intends to sell an impaired available-for-sale debt security, or if it is more likely than not that the Company will be required to sell the security prior to recovering the amortized cost basis, the entire fair value adjustment will immediately be recognized in earnings with no corresponding allowance for credit losses. The Company did not recognize any credit losses on its short-term investments during the years ended December 31, 2023 and 2022. Money market account balances are included as cash and cash equivalents on the consolidated balance sheets, which are also disclosed in Note 4, Fair Value Measurements . Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash, cash equivalents and short-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. Property and Equipment, Net Property and equipment are stated at cost, less accumulated depreciation and amortization. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. Maintenance and repairs are expensed as incurred. The following estimated useful lives were used to depreciate or amortize the Company’s assets: Estimated Useful Life Furniture and fixtures 5 years Computers and software 3 years Leasehold improvements Shorter of useful life or remaining lease term Impairment of Long-Lived Assets Long-lived assets consist primarily of property and equipment. Long-lived assets are evaluated for impairment when events and circumstances indicate the assets might be impaired by first comparing the estimated future undiscounted cash flows of the asset or asset group to the carrying value. If the carrying value exceeds the estimated future undiscounted cash flows, an impairment loss is recognized based on the amount that the carrying value exceeds the fair value of the asset or asset group. As a result of suspending development activities of the Company’s only product candidate, mavodelpar, the Company recognized $ 0.3 million and $ 0.4 million in impairment losses of right-of-use assets and leasehold improvements, respectively, for the year ended December 31, 2023. The Company recognized an immaterial amount in impairment related to its leases for the year ended December 31, 2022. Leases The Company determines if an arrangement includes a lease at inception. Leases with an initial term of 12 months or less are not recorded on the balance sheet. The Company’s lease terms may include options to extend or terminate a lease when it is reasonably certain that it will exercise that option. The Company combines lease and non-lease components when determining lease payments. Right-of-use (ROU) assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term, unless there is a transfer of title or purchase option the Company is reasonably certain to exercise. For leases where an implicit rate is not readily determinable, the Company uses its incremental borrowing rate based on information available at the lease commencement date to determine the present value of future lease payments. Lease expense for operating leases is recognized on a straight-line basis over the expected lease term. Research and Development Costs and Accruals All research and development costs are expensed as incurred. Research and development costs consist primarily of costs associated with manufacturing drug substance and drug product, costs associated with preclinical studies, clinical trials managed through contract research organizations (CROs) and other third parties, license fees, salaries and employee benefits. The Company bases its expense accruals related to clinical trials on its estimates of the services received and efforts expended pursuant to contracts with multiple research institutions and CROs that conduct and manage clinical trials on its behalf. The financial terms of these agreements vary from contract to contract and may result in uneven payment flows. Payments under certain contracts depend on factors such as the successful enrollment of patients and the completion of clinical trial milestones. In accruing costs, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. To date, the Company has not experienced significant changes in its estimates of accrued research and development expenses after a reporting period. License Fees The Company expenses amounts paid to acquire licenses associated with products under development when the ultimate recoverability of the amounts paid is uncertain and the technology has no alternative future use when acquired. Acquisitions of technology licenses are charged to expense or capitalized based upon management’s assessment regarding the ultimate recoverability of the amounts paid and the potential for alternative future use. The Company has determined that technological feasibility for its product candidate would be reached when the requisite regulatory approvals are obtained to make the product available for sale. Contingent milestone payments are recognized when the related contingency is resolved, and the amounts are paid or become payable. These amounts are expensed to research and development if there is no alternative future use associated with the license or capitalized as an intangible asset if alternative future use of the license exists. Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which 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. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two-step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to unrecognized tax benefits. The Company is subject to taxation in the United States and the United Kingdom (UK). As of December 31, 2023 , the Company’s tax years since inception are subject to examination by taxing authorities in the United States, and the UK tax returns from 2018 forward are subject to examination. Stock-Based Compensation The Company recognizes stock-based compensation expense for grants under its 2014 and 2021 Equity Incentive Plans and employee stock purchase plan (ESPP). The Company accounts for all stock-based awards granted to employees and directors at their fair value and recognizes compensation expense over the award’s vesting period. Determining the amount of stock-based compensation to be recorded requires the Company to develop estimates of fair values of stock options as of the grant date. The Company calculates the grant date fair values of stock options using the Black-Scholes valuation model, which requires the input of subjective assumptions, including but not limited to expected stock price volatility over the term of the awards and the expected term of stock options. The fair value of restricted stock awards granted to employees is based on the quoted closing market price per share on grant date. The Company granted restricted stock awards with performance conditions that are based upon the achievement of pre-specified clinical development or regulatory performance events. As the outcome of each event has inherent risks and uncertainties, and a positive outcome may not be known until the event is achieved, the Company will begin to recognize the value of the performance-based restricted stock awards when the achievement of each performance condition is deemed probable, a determination that requires significant judgment by management. Compensation cost is recognized under the accelerated method and is adjusted in future periods for subsequent changes in the expected outcome of the performance-related conditions. The Company granted restricted stock awards with market conditions. The Company measures the fair value of stock-based awards with market-based vesting conditions on the date of grant using a Monte Carlo simulation model. In accordance with accounting guidance for awards with market conditions, the stock-based compensation expense will be recognized over the derived service period regardless of whether the award achieves the market condition and will only be adjusted to the extent the service condition is not met. Foreign Currency Transactions The functional currency of Reneo Pharma Ltd, the Company’s wholly owned subsidiary in the UK, is the U.S. dollar. All foreign exchange transactional and remeasurement gains and losses are recognized in the consolidated statements of operations and comprehensive loss. For the years ended December 31, 2023 and 2022 , total foreign currency gains and losses were immaterial. Comprehensive Income or Loss Comprehensive income or loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. New Accounting Pronouncements Recently Adopted Accounting Pronouncements In June 2016, the Financial Accounting Standard Board (FASB) issued Accounting Standard Update (ASU) 2016-13, Financial Instruments - Credit Losses (ASC 326), Measurement of Credit Losses on Financial Instruments . The standard amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. For available-for-sale debt securities, entities will be required to recognize an allowance for credit losses rather than a reduction in the carrying value of the asset. Entities will no longer be permitted to consider the length of time that fair value has been less than amortized cost when evaluating when credit losses should be recognized. This new guidance was effective for the Company as of January 1, 2023. The Company adopted the guidance as of January 1, 2023 , with no material impact on its consolidated financial statements and related disclosures. Recent Accounting Pronouncements Not Yet Adopted In December 2023, the FASB issued ASU 2023-09, Income Taxes (ASC 740), Improvements to Income Tax Disclosures. The standard will require more detailed information in the rate reconciliation table and for income taxes paid, among other enhancements. The standard is effective for years beginning after December 15, 2025 and early adoption is permitted. The Company is evaluating the impact of this standard on its consolidated financial statements.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Net Loss Per Share	3. Net Loss Per Share The Company computes basic loss per share by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share assumes the conversion, exercise or issuance of all potential common stock equivalents, unless the effect of inclusion would be anti-dilutive. For purposes of this calculation, common stock shares to be issued upon exercise of all outstanding stock options and vesting of restricted stock units were excluded from the diluted net loss per share calculation for the years ended December 31, 2023 and 2022 because such shares are anti-dilutive. Historical outstanding anti-dilutive securities not included in the diluted net loss per share calculation include the following: As of December 31, 2023 2022 Common stock options outstanding 5,301,254 5,877,745 Unvested restricted stock units 326,500 329,500 Total 5,627,754 6,207,245

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements ASC Topic 820, Fair Value Measurement , establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing an asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. ASC Topic 820 identifies fair value as the exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC Topic 820 establishes a three-tier fair value hierarchy that distinguishes between the following: • Level 1 – Observable inputs such as quoted prices in active markets for identical assets or liabilities. • Level 2 – Inputs, other than quoted prices in active markets, which are observable for the asset or liability, either directly or indirectly. • Level 3 – Unobservable inputs in which there is little or no market data, which requires the Company to develop its own assumptions. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The Company’s financial assets are subject to fair value measurements on a recurring basis. The Company categorizes its money market funds as Level 1, using the quoted prices in active markets. Commercial paper and U.S. treasury securities are categorized as Level 2, using significant other observable inputs. The fair value of the Company’s investments in certain money market funds is their face value and such instruments are classified as Level 1 and are included in cash and cash equivalents on the consolidated balance sheets. Investments are reviewed periodically to identify possible other-than-temporary impairments. As the Company has the ability and intends to hold these investments with unrealized losses for a reasonable period of time sufficient for the recovery of fair value, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired for any of the periods presented. In connection with the Company’s chief executive officer’s (CEO) employment agreement, he is entitled to receive a special performance bonus in the amount of $ 7.5 million (Performance Award), payable in cash, common stock or a combination of cash and common stock, at the election of the Company, based on achievement of certain conditions as described in more detail in Note 9. The Company estimated the fair value of the Performance Award using a Monte Carlo simulation, which incorporates the stock price at the date of the valuation and utilizes Level 3 inputs such as volatility, probabilities of success, and other inputs that are not observable in active markets. The Performance Award is required to be measured at fair value on a recurring basis each reporting period, with changes in the fair value recognized in general and administrative expense in the consolidated statements of operations and comprehensive loss over the derived service period of the award. No assets or liabilities were transferred into or out of their classifications during the years ended December 31, 2023 and 2022. The recurring fair value measurement of the Company’s assets and liabilities measured at fair value at December 31, 2023 consisted of the following (in thousands): Quoted Prices in Significant Other Significant Total Assets Cash and cash equivalents: Money market investments $ 10,983 $ — $ 10,983 U.S. treasury securities — 9,928 — $ 9,928 Short-term investments: U.S. treasury securities — 75,331 — 75,331 Total $ 10,983 $ 85,259 $ — $ 96,242 Liabilities Performance award $ — $ — $ 7 $ 7 Total $ — $ — $ 7 $ 7 The recurring fair value measurement of the Company’s assets and liabilities measured at fair value at December 31, 2022 consisted of the following (in thousands): Quoted Prices in Significant Other Significant Total Assets Cash and cash equivalents: Money market investments $ 9,365 $ — $ — $ 9,365 Commercial paper — 4,978 — 4,978 Short-term investments: U.S. treasury securities — 76,253 — 76,253 Commercial paper — 4,993 — 4,993 Total $ 9,365 $ 86,224 $ — $ 95,589 Liabilities Performance award $ — $ — $ 29 $ 29 Total $ — $ — $ 29 $ 29 The following table sets forth a summary of changes in the fair value measurements of the Performance Award liability (in thousands): Performance Balance as of January 1, 2023 $ 29 Change in fair value ( 22 ) Balance as of December 31, 2023 $ 7

Marketable Debt Securities

Marketable Debt Securities	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Debt Securities	5. Marketable Debt Securities The Company’s investments in debt securities are carried at fair value and classified as current assets available-for-sale and represent the investment of funds available for current operations. Unrealized gains and losses on available-for-sale debt securities are included in other comprehensive income or loss, and charged to income or expense in the period when realized. The following tables summarize the gross unrealized gains and losses of the Company’s available-for-sale securities (in thousands): As of December 31, 2023 Amortized Gross Gross Fair Available-for-sale securities: U.S. treasury securities $ 75,324 $ 8 $ ( 1 ) $ 75,331 Total $ 75,324 $ 8 $ ( 1 ) $ 75,331 As of December 31, 2022 Amortized Gross Gross Fair Available-for-sale securities: U.S. treasury securities $ 76,297 $ 2 $ ( 46 ) $ 76,253 Commercial paper 4,993 — — 4,993 Total $ 81,290 $ 2 $ ( 46 ) $ 81,246

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	6. Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): As of December 31,  2023 2022 Computer, software and office equipment  $ 254  $ 300 Leasehold improvements*  —  255 Total property and equipment, gross  254  555 Less: accumulated depreciation and amortization  ( 120 )  ( 102 ) Total property and equipment, net  $ 134  $ 453 *All leasehold improvements were fully impaired and written off. For further information see Note 13.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2023
Accrued Liabilities, Current [Abstract]
Accrued Expenses	7. Accrued Expenses Accrued expenses consisted of the following (in thousands): As of December 31, 2023 2022 Accrued clinical and regulatory $ 3,661 $ 1,872 Accrued contract manufacturing cost 1,100 1,583 Accrued compensation* 3,948 807 Accrued other 420 565 Total accrued expenses $ 9,129 $ 4,827 *Accrued compensation includes severance costs. For further information see Note 13.

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	8. Leases The Company’s headquarters are located in Irvine, California, where it leases office space under a lease agreement that expires in November 2026. The Company leases additional office space located in Sandwich, UK under a lease agreement that expires in October 2027 (UK lease), with an option to early terminate in October 2025 with no termination fee. In January 2024, the Company exercised its early termination option . The Company concluded that its current leases are impaired and recognized approximately $ 0.3 million of ROU assets impairment expense for the year ended December 31, 2023. For further information, see Note 13. At December 31, 2023, the weighted average incremental borrowing rate was 5 % and the weighted average remaining lease term was 3.8 years for the operating leases held by the Company. For the years ended December 31, 2023 and 2022, cash paid for amounts included for the measurement of lease liabilities was $ 0.5 million. For the years ended December 31, 2023 and 2022, operating lease expense was $ 0.4 million and $ 0.5 million, respectively. Maturities of lease liabilities by fiscal year for the Company’s operating leases are as follows: As of December 31, 2023 2024 $ 381 2025 367 2026 285 Total lease payments 1,033 Less: Imputed interest ( 60 ) Present value of lease liabilities $ 973

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation In March 2021, the Company’s Board of Directors adopted the Company’s 2021 Equity Incentive Plan (2021 Plan), which is the successor to the Company’s 2014 Equity Incentive Plan (2014 Plan). As of the effective date of the 2021 Plan, awards granted under the 2014 Plan that are forfeited or otherwise become available under the 2014 Plan will be included and available for issuance under the 2021 Plan. Under the 2021 Plan, the Company may grant stock options, stock appreciation rights, restricted stock awards, restricted stock units, and other awards to individuals who are employees, officers, directors or consultants of the Company and its affiliates. Under the 2014 Plan, certain employees were granted the ability to early exercise their options. The shares of common stock issued pursuant to the early exercise of unvested stock options are restricted and continue to vest over the requisite service period after issuance. The Company has the option to repurchase any unvested shares at the original purchase price upon any voluntary or involuntary termination. The shares purchased by the employees pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be outstanding until those shares vest. As of December 31, 2023 , there were no unvested shares of common stock outstanding that were issued pursuant to the early exercise of stock options. Shares Reserved for Future Issuance As of December 31, 2023, the Company had reserved shares of its common stock for future issuance as follows: Shares Common stock options outstanding 5,301,254 Unvested restricted stock units 326,500 Available for future grants under the 2021 Equity Incentive Plan 2,109,225 Available for future grants under the 2021 Employee Stock Purchase Plan 445,890 Total shares of common stock reserved 8,182,869 Stock Options A summary of the Company’s stock option activity and related information for the year ended December 31, 2023 is as follows: Options Weighted- Weighted- Aggregate Outstanding at December 31, 2022 5,877,745 $ 4.47 8.2 $ 907 Granted 578,915 6.85 Exercised ( 173,824 ) 2.31 Forfeited/Expired ( 981,582 ) 4.69 Outstanding at December 31, 2023 5,301,254 $ 4.76 6.9 $ — Vested at December 31, 2023 3,228,343 $ 4.91 6.1 $ — Exercisable at December 31, 2023 3,592,125 $ 4.91 6.2 $ — Options exercisable at December 31, 2023 include vested options and options eligible for early exercise. All outstanding options as of December 31, 2023 are expected to vest. Unrecognized stock-based compensation expense at December 31, 2023 was $ 5.9 million, which is expected to be recognized over a weighted-average vesting term of 2.0 years. The Company estimates stock awards fair value on the date of grant using the Black-Scholes valuation, with the vesting being subject to service requirements. The Company accounts for forfeitures when they occur. The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants were as follows: Year Ended December 31, 2023 2022 Risk-free interest rate 4.0 % 3.4 % Expected volatility 88.6 % 84.8 % Expected term (in years) 5.9 6.0 Expected dividend yield — % — % Risk-free interest rate. The Company bases the risk-free interest rate assumption on the U.S. Treasury’s rates for U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the award being valued. Expected volatility. The expected volatility assumption was based on the volatilities of a peer group of similar companies whose share prices are publicly available. The peer group was developed based on companies in the biotechnology industry. Expected term. The expected term represents the period of time that options are expected to be outstanding. Because the Company does not have historical exercise behavior, it determines the expected life assumption using the simplified method, which is an average of the contractual term of the option and its vesting period. Expected dividend yield. The Company bases the expected dividend yield assumption on the fact that it has never paid cash dividends and has no present intention to pay cash dividends. Restricted Stock Units (RSUs) RSUs consist of time-based units (TSUs), performance-based units (PSUs) and market-based units (MSUs). The following table summarizes RSU activities during the year ended December 31, 2023: Number of Weighted-Average Unvested at December 31, 2022 329,500 $ 5.67 Granted 137,000 5.82 Cancelled ( 140,000 ) 5.35 Unvested at December 31, 2023 326,500 $ 5.90 Time-Based Units TSUs typically vest over four years , with 25 % vesting on the one-year anniversary of the employee’s hire date and the remainder vesting monthly or quarterly over the following three years subject to the employee’s continued employment with the Company through the vesting dates. The fair value of the awards was based on the value of the Company’s common stock at the grant date of the award and expense is recognized on a straight-line basis. The Company had 57,000 unvested shares underlying TSUs as of December 31, 2023. The stock-based compensation expense related to such TSUs for the year ended December 31, 2023 was immaterial. Unrecognized stock-based compensation expense at December 31, 2023 was $ 0.3 million, which is expected to be recognized over a weighted-average vesting term of 1.3 years. Performance-Based Units The vesting of the PSUs is based on the Company achieving certain regulatory milestones and is subject to the employee’s continued employment with the Company through the achievement date. The fair value of the awards was based on the value of the Company’s common stock at the grant date of the award and expense recognition is based on the probability of achieving the performance conditions. Stock-based compensation expense is adjusted in future periods for subsequent changes in the expected outcome of the performance conditions. The Company had 149,500 unvested shares underlying PSUs as of December 31, 2023. The Company concluded that achievement of the performance conditions was not probable as of December 31, 2023 and 2022 , and therefore no stock-based compensation expense was recognized for the years ended December 31, 2023 and 2022 in connection with the PSUs. As of December 31, 2023 , there was $ 1.1 million of unrecognized stock-based compensation expense related to PSUs that were deemed not probable of vesting. Market-Based Units The vesting of the MSUs is based on the Company’s closing stock price trading above $ 20 per share for 30 consecutive trading days subject to the employee’s continued employment with the Company through the date of achievement. The share price of the Company’s common stock on the date of issuance of the MSUs was $ 2.78 per share. The fair value was based on Monte Carlo simulation model on the grant date. Stock-based compensation expense is recognized over the derived service period of approximately 3 years. The Company had 120,000 unvested shares underlying MSUs as of December 31, 2023. Stock-based compensation expense related to the MSUs during the years ended December 31, 2023 and 2022 was immaterial. As of December 31, 2023, unrecognized stock-based compensation expense related to the MSUs was immaterial. Performance Award In connection with the CEO’s employment agreement, he is entitled to receive a Performance Award in the amount of $ 7.5 million, payable in cash, common stock or a combination of cash and common stock, at the election of the Company, in the event that (i) the Company’s market value exceeds $ 750.0 million utilizing the volume-weighted average of the closing sale price of its common stock on the Nasdaq Stock Market or other principal exchange for each of the 30 trading days immediately prior to the measurement date, or (ii) the fair market value of the net proceeds available for distribution to the Company’s stockholders in connection with a change in control as defined in the Company’s severance benefit plan, as determined in good faith by its Board of Directors, exceeds $ 750.0 million. The Company has determined that the Performance Award is subject to ASC 718, Compensation – Stock Compensation and includes both market and performance conditions. Since the Company’s initial public offering (IPO), neither of the events have yet been satisfied. The Company estimated the fair value of the Performance Award at each reporting period using the Monte Carlo simulation (Note 4), which is recognized as stock-based compensation expense over the derived service period. For the years ended December 31, 2023 and 2022 , the Company reversed approximately $ 22,000 and $ 0.4 million in stock-based compensation expenses, respectively, as a direct result of the decreased value of the Performance Award caused by a decline in the Company’s common stock price. 2021 Employee Stock Purchase Plan In March 2021, the Company’s Board of Directors adopted the ESPP, which became effective immediately prior to the execution of the underwriting agreement in connection with the Company’s IPO. As of December 31, 2023 , 288,466 shares have been issued under the ESPP. In September 2021, the compensation committee of the Company’s Board of Directors adopted the Company’s 2021 UK Sharesave Sub-plan (SAYE). An allocation of 25,875 shares of common stock from the ESPP reserve pool was approved and reserved for issuance under the SAYE. No shares have been issued under the SAYE through December 31, 2023. The stock-based compensation expense related to the ESPP and the SAYE for the years ended December 31, 2023 and 2022 , was $ 0.4 million and $ 0.2 million, respectively. Stock-Based Compensation Expense The following table summarizes stock-based compensation expense, including expense associated with options, TSUs, MSUs and award modifications for unvested options, reflected in the consolidated statements of operations and comprehensive loss (in thousands): Year Ended December 31, 2023 2022 Research and development $ 1,815 $ 1,593 General and administrative 3,297 2,727 Total $ 5,112 $ 4,320

License Agreement

License Agreement	12 Months Ended
	Dec. 31, 2023
License Agreement
License Agreement	10. License Agreement In December 2017, the Company entered into a license agreement (the vTv License Agreement) with vTv Therapeutics LLC (vTv Therapeutics), under which the Company obtained an exclusive, worldwide, sublicensable license under certain vTv Therapeutics intellectual property to develop, manufacture and commercialize PPARδ agonists and products containing such PPARδ agonists, including mavodelpar, for any therapeutic, prophylactic or diagnostic application in humans. Since the Company has suspended all development activity related to mavodelpar, it is not currently performing any development efforts under the vTv License Agreement. To date, the Company has paid a $ 3.0 million upfront payment, $ 2.0 million in milestone payments and issued an aggregate of 576,443 shares of its common stock to vTv Therapeutics. 576,443 shares of its common stock previously issued to vTv Therapeutics under the vTv License Agreement for an aggregate purchase price of approximately $ 4.4 million in a private, non-underwritten transaction. Upon the achievement of certain pre-specified development and regulatory milestones, the Company is also required to pay vTv Therapeutics milestone payments totaling up to $ 64.5 million. The Company is also required to pay vTv Therapeutics up to $ 30.0 million in total sales-based milestones upon achievement of certain sales thresholds of the licensed product. As of December 31, 2023, the Company has paid an aggregate of $ 2.0 million in development and regulatory milestone payments. In addition, the Company is obligated to make royalty payments to vTv Therapeutics at mid-single digit to low teen percentage royalty rates, based on tiers of annual net sales of licensed products, subject to certain customary reductions. There were no milestone payments achieved or recorded for the years ended December 31, 2023 and 2022.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
IncomeTaxes	11. Income Taxes The Company’s net loss was generated in the following jurisdictions (in thousands): Year Ended December 31, 2023 2022 Domestic $ ( 78,132 ) $ ( 51,994 ) Foreign 744 39 Net loss $ ( 77,388 ) $ ( 51,955 ) The components of net deferred taxes consisted of the following (in thousands): As of December 31, 2023 2022 Deferred tax assets: NOL carryforwards $ 23,490 $ 16,381 Capitalized research and development expenses 15,274 7,465 Credit carryforwards 6,111 4,061 Intangible assets 2,902 3,202 Compensation accruals 1,885 989 Operating lease liabilities 245 316 Depreciation 89 78 Other 2 2 Gross deferred tax assets 49,998 32,494 Less valuation allowance ( 49,872 ) ( 32,214 ) Total deferred tax assets 126 280 Deferred tax liabilities: ROU assets ( 126 ) ( 280 ) Net deferred tax assets (liabilities) $ — $ — For the years ended December 31, 2023 and 2022 , the Company recorded no provision for income taxes. A reconciliation of the effective tax rate to the amount computed by applying the statutory federal income tax rate to the loss from operations is summarized for the years ended December 31, 2023 and 2022, as follows: As of December 31, 2023 2022 U.S. federal statutory income tax rate 21.0 % 21.0 % Tax credits, net 2.5 % 3.4 % Return-to-provision adjustment 0.1 % 0.5 % Other ( 0.1 )% ( 0.8 )% GILTI inclusion ( 0.4 )% ( 0.3 )% Foreign Rate Differential ( 0.1 )% — Valuation allowance ( 23.0 )% ( 23.8 )% U.S. federal effective tax rate 0.0 % 0.0 % The Company had federal net operating loss (NOL) carryforwards available of approximately $ 110.9 million as of December 31, 2023, before consideration of limitations under Section 382 of the Internal Revenue Code of 1986, as amended (Section 382), as further described below. The federal NOLs generated after 2017 of $ 109.3 million will carry forward indefinitely. NOLs generated prior to 2018 of $ 1.6 million will begin to expire in 2034 . Additionally, the Company had state NOL carryforwards available of $ 1.8 million as of December 31, 2023 . The state NOLs may be used to offset future taxable income and will begin to expire in 2034 . The Company has generated UK NOLs of $ 0.2 million which carryforward indefinitely. At December 31, 2023, the Company had federal and state tax credit carry forwards of approximately $ 16.9 million and $ 0.7 million, respectively. The Company has not performed a formal research and development credit study with respect to these credits. The federal credits will begin to expire in 2034 , if unused, and the state credits carry forward indefinitely. The future utilization of the Company’s NOL and tax credit carryforwards to offset future taxable income may be subject to a substantial annual limitation as a result of changes in ownership by stockholders that hold 5 % or more of the Company’s common stock. An assessment of such ownership changes under Section 382 was not completed through December 31, 2023. To the extent that an assessment is completed in the future, the Company’s ability to utilize tax attributes could be restricted on a year-by-year basis and certain attributes could expire before they are utilized. The Company will examine the impact of any potential ownership changes in the future. The Company has elected to record the inclusion related to the Global Intangible Low-Taxed Income (GILTI) in the period incurred. The estimated GILTI inclusion generated by the Company’s wholly-owned controlled foreign corporation in the UK for the year ended December 31, 2023 was $ 1.5 million. This amount is included in the income tax provision, however, has zero impact to the provision due to the full valuation allowance. The Company has established a full valuation allowance for its deferred tax assets due to uncertainties that preclude it from determining that it is more likely than not that the Company will be able to generate sufficient taxable income to realize such assets. Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to utilize the existing deferred tax assets. A significant piece of objective negative evidence evaluated was the cumulative loss incurred over the three-year period ended December 31, 2023. Such objective evidence limits the ability to consider other subjective evidence such as the Company’s projections for future growth. Based on this evaluation, as of December 31, 2023, a full valuation allowance of $ 49.9 million has been recorded against the Company net deferred tax assets, as the Company has determined that none of the Company’s balance of deferred tax assets is more likely than not to be realized. The amount of the deferred tax assets considered realizable, however, could be adjusted in the future if objective negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence, such as estimates of future taxable income during carryforward periods and the Company’s projections for growth. The following table summarizes the changes to unrecognized tax benefits (in thousands): Year Ended December 31, 2023 2022 Beginning balance of unrecognized tax benefits $ 7,094 $ 2,999 Additions based on tax positions related to the current year 4,331 4,095 Ending balance of unrecognized tax benefits $ 11,425 $ 7,094 The amount of the unrecognized tax benefits that would impact the effective tax rate, absent the valuation allowance, would be $ 11.0 million. Due to the full valuation allowance, the impact, however, is zero. At December 31, 2023 and 2022 , the Company has no t accrued any interest or penalties related to uncertain tax positions. The Company does not anticipate that there will be a significant change in the amount of unrecognized tax benefits over the next 12 months. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. The Company is subject to taxation in the United States and the UK. The Company’s federal and state returns since inception are subject to examination due to the carryover of net operating losses. The Company has not been, nor is it currently, under examination by any tax authorities. The UK tax returns from 2018 forward are subject to examination by the UK tax authorities.

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	12. Commitments and Contingencies Legal Proceedings The Company is currently not a party to any legal proceedings, nor is the Company aware of any threatened or pending litigation . However, from time-to-time in the future, the Company could be involved in disputes, including litigation, relating to claims arising out of operations in the normal course of business, which may have a material adverse effect on the Company’s consolidated results of operations or financial position. 401(k) Plan The Company maintains a defined contribution 401(k) plan available to eligible employees. Employee contributions are voluntary and are determined on an individual basis, limited to the maximum amount allowable under federal tax regulations. Matching contributions to the 401(k) plan are made for certain eligible employees to meet non-discrimination provisions of the plan. During the years ended December 31, 2023 and 2022 , the expense recorded by the Company was $ 0.2 million and immaterial, respectively.

Financial Impact of Suspension

Financial Impact of Suspension of Mavodelpar Development Activities	12 Months Ended
	Dec. 31, 2023
Restructuring and Related Activities [Abstract]
Financial Impact of Suspension of Mavodelpar Development Activities	13. Financial Impact of Suspension of Mavodelpar Development Activities On December 14, 2023, the Company announced that its pivotal STRIDE study did not meet its primary or secondary efficacy endpoints. As a result, the Company suspended the development activities of its only product candidate, mavodelpar, and implemented cash preservation activities, including substantial workforce reductions. In December 2023, the Company implemented a workforce reduction and recognized approximately $ 2.5 million in severance and continuation of benefit expenses for the year ended December 31, 2023. In addition, the Company assessed the impairment of its ROU and fixed assets due to the suspension of mavodelpar’s development activities and concluded that its current leases and leasehold improvements were impaired. The Company recognized approximately $ 0.3 million and $ 0.4 million of impairment expenses for ROU and leasehold improvements for the year ended December 31, 2023, respectively.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events In February 2024, the Company implemented a second workforce reduction. As a result of this workforce reduction, the Company will recognize approximately $ 1.6 million in severance and continuation of benefit expenses in first quarter of 2024.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The Company’s consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States (GAAP) and reflect the operation of the Company and its wholly owned subsidiary. All intercompany balances and transactions among the consolidated entities have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the Company’s consolidated financial statements requires management to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure in the Company’s consolidated financial statements and accompanying notes. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. By their nature, estimates are subject to an inherent degree of uncertainty and, as such, actual results may differ from management’s estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less, when purchased, to be cash equivalents. As of December 31, 2023 and 2022 , the Company had cash balances deposited at major financial institutions. Cash balances are subject to minimal credit risk as the balances are with high credit quality financial institutions. Cash and cash equivalents include cash in readily available checking, money market accounts and repurchase agreements.
Short-term Investments	Short-term Investments The Company accounts for short-term investments in accordance with Accounting Standard Codification (ASC) Topic 320, Investments – Debt and Equity Securities . Management determines the appropriate classification of its investments at the time of purchase and reevaluates such determinations at each reporting period. At December 31, 2023, the Company’s investments comprised of U.S. treasury securities and commercial paper classified as available-for-sale securities. Available-for-sale securities are carried at fair value, with the unrealized gains and losses reported in accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses on sales of investments are included in interest income and are derived using the specific identification method for determining the cost of securities. When the fair value of an available-for-sale debt security falls below the amortized cost basis it is evaluated to determine if any of the decline in value is attributable to credit loss. Decreases in fair value attributable to credit loss are recorded directly to earnings with a corresponding allowance for credit losses, limited to the amount that the fair value is less than the amortized cost basis. If the credit quality subsequently improves the allowance is reversed up to a maximum of the previously recorded credit losses. When the Company intends to sell an impaired available-for-sale debt security, or if it is more likely than not that the Company will be required to sell the security prior to recovering the amortized cost basis, the entire fair value adjustment will immediately be recognized in earnings with no corresponding allowance for credit losses. The Company did not recognize any credit losses on its short-term investments during the years ended December 31, 2023 and 2022. Money market account balances are included as cash and cash equivalents on the consolidated balance sheets, which are also disclosed in Note 4, Fair Value Measurements .
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash, cash equivalents and short-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are stated at cost, less accumulated depreciation and amortization. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. Maintenance and repairs are expensed as incurred. The following estimated useful lives were used to depreciate or amortize the Company’s assets: Estimated Useful Life Furniture and fixtures 5 years Computers and software 3 years Leasehold improvements Shorter of useful life or remaining lease term
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets consist primarily of property and equipment. Long-lived assets are evaluated for impairment when events and circumstances indicate the assets might be impaired by first comparing the estimated future undiscounted cash flows of the asset or asset group to the carrying value. If the carrying value exceeds the estimated future undiscounted cash flows, an impairment loss is recognized based on the amount that the carrying value exceeds the fair value of the asset or asset group. As a result of suspending development activities of the Company’s only product candidate, mavodelpar, the Company recognized $ 0.3 million and $ 0.4 million in impairment losses of right-of-use assets and leasehold improvements, respectively, for the year ended December 31, 2023. The Company recognized an immaterial amount in impairment related to its leases for the year ended December 31, 2022.
Leases	Leases The Company determines if an arrangement includes a lease at inception. Leases with an initial term of 12 months or less are not recorded on the balance sheet. The Company’s lease terms may include options to extend or terminate a lease when it is reasonably certain that it will exercise that option. The Company combines lease and non-lease components when determining lease payments. Right-of-use (ROU) assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term, unless there is a transfer of title or purchase option the Company is reasonably certain to exercise. For leases where an implicit rate is not readily determinable, the Company uses its incremental borrowing rate based on information available at the lease commencement date to determine the present value of future lease payments. Lease expense for operating leases is recognized on a straight-line basis over the expected lease term.
Research and Development Costs and Accruals	Research and Development Costs and Accruals All research and development costs are expensed as incurred. Research and development costs consist primarily of costs associated with manufacturing drug substance and drug product, costs associated with preclinical studies, clinical trials managed through contract research organizations (CROs) and other third parties, license fees, salaries and employee benefits. The Company bases its expense accruals related to clinical trials on its estimates of the services received and efforts expended pursuant to contracts with multiple research institutions and CROs that conduct and manage clinical trials on its behalf. The financial terms of these agreements vary from contract to contract and may result in uneven payment flows. Payments under certain contracts depend on factors such as the successful enrollment of patients and the completion of clinical trial milestones. In accruing costs, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. To date, the Company has not experienced significant changes in its estimates of accrued research and development expenses after a reporting period.
License Fees	License Fees The Company expenses amounts paid to acquire licenses associated with products under development when the ultimate recoverability of the amounts paid is uncertain and the technology has no alternative future use when acquired. Acquisitions of technology licenses are charged to expense or capitalized based upon management’s assessment regarding the ultimate recoverability of the amounts paid and the potential for alternative future use. The Company has determined that technological feasibility for its product candidate would be reached when the requisite regulatory approvals are obtained to make the product available for sale. Contingent milestone payments are recognized when the related contingency is resolved, and the amounts are paid or become payable. These amounts are expensed to research and development if there is no alternative future use associated with the license or capitalized as an intangible asset if alternative future use of the license exists.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which 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. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two-step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to unrecognized tax benefits. The Company is subject to taxation in the United States and the United Kingdom (UK). As of December 31, 2023 , the Company’s tax years since inception are subject to examination by taxing authorities in the United States, and the UK tax returns from 2018 forward are subject to examination.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes stock-based compensation expense for grants under its 2014 and 2021 Equity Incentive Plans and employee stock purchase plan (ESPP). The Company accounts for all stock-based awards granted to employees and directors at their fair value and recognizes compensation expense over the award’s vesting period. Determining the amount of stock-based compensation to be recorded requires the Company to develop estimates of fair values of stock options as of the grant date. The Company calculates the grant date fair values of stock options using the Black-Scholes valuation model, which requires the input of subjective assumptions, including but not limited to expected stock price volatility over the term of the awards and the expected term of stock options. The fair value of restricted stock awards granted to employees is based on the quoted closing market price per share on grant date. The Company granted restricted stock awards with performance conditions that are based upon the achievement of pre-specified clinical development or regulatory performance events. As the outcome of each event has inherent risks and uncertainties, and a positive outcome may not be known until the event is achieved, the Company will begin to recognize the value of the performance-based restricted stock awards when the achievement of each performance condition is deemed probable, a determination that requires significant judgment by management. Compensation cost is recognized under the accelerated method and is adjusted in future periods for subsequent changes in the expected outcome of the performance-related conditions. The Company granted restricted stock awards with market conditions. The Company measures the fair value of stock-based awards with market-based vesting conditions on the date of grant using a Monte Carlo simulation model. In accordance with accounting guidance for awards with market conditions, the stock-based compensation expense will be recognized over the derived service period regardless of whether the award achieves the market condition and will only be adjusted to the extent the service condition is not met.
Foreign Currency Transactions	Foreign Currency Transactions The functional currency of Reneo Pharma Ltd, the Company’s wholly owned subsidiary in the UK, is the U.S. dollar. All foreign exchange transactional and remeasurement gains and losses are recognized in the consolidated statements of operations and comprehensive loss. For the years ended December 31, 2023 and 2022 , total foreign currency gains and losses were immaterial.
Comprehensive Income or Loss	Comprehensive Income or Loss Comprehensive income or loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources.
New Accounting Pronouncements	New Accounting Pronouncements Recently Adopted Accounting Pronouncements In June 2016, the Financial Accounting Standard Board (FASB) issued Accounting Standard Update (ASU) 2016-13, Financial Instruments - Credit Losses (ASC 326), Measurement of Credit Losses on Financial Instruments . The standard amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. For available-for-sale debt securities, entities will be required to recognize an allowance for credit losses rather than a reduction in the carrying value of the asset. Entities will no longer be permitted to consider the length of time that fair value has been less than amortized cost when evaluating when credit losses should be recognized. This new guidance was effective for the Company as of January 1, 2023. The Company adopted the guidance as of January 1, 2023 , with no material impact on its consolidated financial statements and related disclosures. Recent Accounting Pronouncements Not Yet Adopted In December 2023, the FASB issued ASU 2023-09, Income Taxes (ASC 740), Improvements to Income Tax Disclosures. The standard will require more detailed information in the rate reconciliation table and for income taxes paid, among other enhancements. The standard is effective for years beginning after December 15, 2025 and early adoption is permitted. The Company is evaluating the impact of this standard on its consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Schedule of Property Plant and Equipment useful lives	The following estimated useful lives were used to depreciate or amortize the Company’s assets: Estimated Useful Life Furniture and fixtures 5 years Computers and software 3 years Leasehold improvements Shorter of useful life or remaining lease term

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Schedule of Anti-dilutive securities not included in diluted net loss per share calculation	Historical outstanding anti-dilutive securities not included in the diluted net loss per share calculation include the following: As of December 31, 2023 2022 Common stock options outstanding 5,301,254 5,877,745 Unvested restricted stock units 326,500 329,500 Total 5,627,754 6,207,245

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of recurring fair value measurement of the Company's assets and liabilities	The recurring fair value measurement of the Company’s assets and liabilities measured at fair value at December 31, 2023 consisted of the following (in thousands): Quoted Prices in Significant Other Significant Total Assets Cash and cash equivalents: Money market investments $ 10,983 $ — $ 10,983 U.S. treasury securities — 9,928 — $ 9,928 Short-term investments: U.S. treasury securities — 75,331 — 75,331 Total $ 10,983 $ 85,259 $ — $ 96,242 Liabilities Performance award $ — $ — $ 7 $ 7 Total $ — $ — $ 7 $ 7 The recurring fair value measurement of the Company’s assets and liabilities measured at fair value at December 31, 2022 consisted of the following (in thousands): Quoted Prices in Significant Other Significant Total Assets Cash and cash equivalents: Money market investments $ 9,365 $ — $ — $ 9,365 Commercial paper — 4,978 — 4,978 Short-term investments: U.S. treasury securities — 76,253 — 76,253 Commercial paper — 4,993 — 4,993 Total $ 9,365 $ 86,224 $ — $ 95,589 Liabilities Performance award $ — $ — $ 29 $ 29 Total $ — $ — $ 29 $ 29
Schedule Changes in fair value measurements of the Performance Award	The following table sets forth a summary of changes in the fair value measurements of the Performance Award liability (in thousands): Performance Balance as of January 1, 2023 $ 29 Change in fair value ( 22 ) Balance as of December 31, 2023 $ 7

Marketable Debt Securities (Tab

Marketable Debt Securities (Tables)	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Gross Unrealized Gains and Losses of Available-for-Sale Securities	The following tables summarize the gross unrealized gains and losses of the Company’s available-for-sale securities (in thousands): As of December 31, 2023 Amortized Gross Gross Fair Available-for-sale securities: U.S. treasury securities $ 75,324 $ 8 $ ( 1 ) $ 75,331 Total $ 75,324 $ 8 $ ( 1 ) $ 75,331 As of December 31, 2022 Amortized Gross Gross Fair Available-for-sale securities: U.S. treasury securities $ 76,297 $ 2 $ ( 46 ) $ 76,253 Commercial paper 4,993 — — 4,993 Total $ 81,290 $ 2 $ ( 46 ) $ 81,246

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property and equipment, net	Property and equipment, net, consisted of the following (in thousands): As of December 31,  2023 2022 Computer, software and office equipment  $ 254  $ 300 Leasehold improvements*  —  255 Total property and equipment, gross  254  555 Less: accumulated depreciation and amortization  ( 120 )  ( 102 ) Total property and equipment, net  $ 134  $ 453 *All leasehold improvements were fully impaired and written off. For further information see Note 13.

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Schedule of Accrued expenses	Accrued expenses consisted of the following (in thousands): As of December 31, 2023 2022 Accrued clinical and regulatory $ 3,661 $ 1,872 Accrued contract manufacturing cost 1,100 1,583 Accrued compensation* 3,948 807 Accrued other 420 565 Total accrued expenses $ 9,129 $ 4,827 *Accrued compensation includes severance costs. For further information see Note 13.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Schedule of Maturities of lease liabilities by fiscal year for operating leases	Maturities of lease liabilities by fiscal year for the Company’s operating leases are as follows: As of December 31, 2023 2024 $ 381 2025 367 2026 285 Total lease payments 1,033 Less: Imputed interest ( 60 ) Present value of lease liabilities $ 973

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Summary of common stock reserved for future issuance	As of December 31, 2023, the Company had reserved shares of its common stock for future issuance as follows: Shares Common stock options outstanding 5,301,254 Unvested restricted stock units 326,500 Available for future grants under the 2021 Equity Incentive Plan 2,109,225 Available for future grants under the 2021 Employee Stock Purchase Plan 445,890 Total shares of common stock reserved 8,182,869
Summary of the Company's stock option activity	A summary of the Company’s stock option activity and related information for the year ended December 31, 2023 is as follows: Options Weighted- Weighted- Aggregate Outstanding at December 31, 2022 5,877,745 $ 4.47 8.2 $ 907 Granted 578,915 6.85 Exercised ( 173,824 ) 2.31 Forfeited/Expired ( 981,582 ) 4.69 Outstanding at December 31, 2023 5,301,254 $ 4.76 6.9 $ — Vested at December 31, 2023 3,228,343 $ 4.91 6.1 $ — Exercisable at December 31, 2023 3,592,125 $ 4.91 6.2 $ —
Summary of weighted-average assumptions to determine the fair value of the employee stock option	The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants were as follows: Year Ended December 31, 2023 2022 Risk-free interest rate 4.0 % 3.4 % Expected volatility 88.6 % 84.8 % Expected term (in years) 5.9 6.0 Expected dividend yield — % — %
Summary of RSU activities	RSUs consist of time-based units (TSUs), performance-based units (PSUs) and market-based units (MSUs). The following table summarizes RSU activities during the year ended December 31, 2023: Number of Weighted-Average Unvested at December 31, 2022 329,500 $ 5.67 Granted 137,000 5.82 Cancelled ( 140,000 ) 5.35 Unvested at December 31, 2023 326,500 $ 5.90
Summary of Non-cash stock-based compensation expense recorded	The following table summarizes stock-based compensation expense, including expense associated with options, TSUs, MSUs and award modifications for unvested options, reflected in the consolidated statements of operations and comprehensive loss (in thousands): Year Ended December 31, 2023 2022 Research and development $ 1,815 $ 1,593 General and administrative 3,297 2,727 Total $ 5,112 $ 4,320

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Summay of company's loss before provision for income taxes	The Company’s net loss was generated in the following jurisdictions (in thousands): Year Ended December 31, 2023 2022 Domestic $ ( 78,132 ) $ ( 51,994 ) Foreign 744 39 Net loss $ ( 77,388 ) $ ( 51,955 )
Components of net deferred taxes asset and liabilities	The components of net deferred taxes consisted of the following (in thousands): As of December 31, 2023 2022 Deferred tax assets: NOL carryforwards $ 23,490 $ 16,381 Capitalized research and development expenses 15,274 7,465 Credit carryforwards 6,111 4,061 Intangible assets 2,902 3,202 Compensation accruals 1,885 989 Operating lease liabilities 245 316 Depreciation 89 78 Other 2 2 Gross deferred tax assets 49,998 32,494 Less valuation allowance ( 49,872 ) ( 32,214 ) Total deferred tax assets 126 280 Deferred tax liabilities: ROU assets ( 126 ) ( 280 ) Net deferred tax assets (liabilities) $ — $ —
Summarized reconciliation of income tax rate	A reconciliation of the effective tax rate to the amount computed by applying the statutory federal income tax rate to the loss from operations is summarized for the years ended December 31, 2023 and 2022, as follows: As of December 31, 2023 2022 U.S. federal statutory income tax rate 21.0 % 21.0 % Tax credits, net 2.5 % 3.4 % Return-to-provision adjustment 0.1 % 0.5 % Other ( 0.1 )% ( 0.8 )% GILTI inclusion ( 0.4 )% ( 0.3 )% Foreign Rate Differential ( 0.1 )% — Valuation allowance ( 23.0 )% ( 23.8 )% U.S. federal effective tax rate 0.0 % 0.0 %
Summarizes the changes to unrecognized tax benefits	The following table summarizes the changes to unrecognized tax benefits (in thousands): Year Ended December 31, 2023 2022 Beginning balance of unrecognized tax benefits $ 7,094 $ 2,999 Additions based on tax positions related to the current year 4,331 4,095 Ending balance of unrecognized tax benefits $ 11,425 $ 7,094

Organization and Business (Narr

Organization and Business (Narrative) (Details) - USD ($)			1 Months Ended		3 Months Ended	12 Months Ended
	Mar. 25, 2024	Nov. 13, 2023	May 31, 2023	May 31, 2022	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Severance and continuation of benefit expenses						$ 2,500,000
Cash, cash equivalents at carrying value and short term investments						103,000,000
Percentage of Common Stock Held by Affiliate			5%
Scenario Forecast [Member]
Severance and continuation of benefit expenses					$ 1,600,000
IPO [Member]
Common stock issued and sold, Shares			7,906,250
Option to purchase shares of common stock			1,031,250
Share price			$ 8
Proceeds from issuance of common stock under the at-the-market facility, net of offering costs			$ 58,900,000
ATM facility [Member]
Common stock issued and sold						1,009,000	$ 193,000
Proceeds from issuance of common stock under the at-the-market facility, net of offering costs						1,009,000
Private Placement [Member]
Common stock issued and sold, Shares			625,000
Common stock issued and sold						$ 4,667,000
Share price			$ 8
Proceeds from issuance of common stock under the at-the-market facility, net of offering costs			$ 4,700,000
Common Stock [Member] | ATM facility [Member]
Common stock issued and sold, Shares						407,877	92,085
Common stock issued and sold		$ 0
Common Stock [Member] | Private Placement [Member]
Common stock issued and sold, Shares						625,000
Leerink Partners LLC [Member] | Subsequent Event [Member]
Sales Agreement Termination Date	Apr. 08, 2024
Leerink Partners LLC [Member] | ATM facility [Member]
Proceeds from issuance of common stock under the at-the-market facility, net of offering costs				$ 1,200,000
Leerink Partners LLC [Member] | Common Stock [Member] | ATM facility [Member]
Common stock issued and sold		$ 100,000,000		$ 20,000,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Accounting Policies [Line Items]
Right-of-use (ROU) assets impairment expense	$ 0.3
Right-of-use and leasehold improvement impairment expenses	$ 0.4
Accounting Standards Update 2016-13 [Member]
Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2023
Change in accounting principle, accounting standards update, immaterial effect	true

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Property and equipment, Net (Details)	12 Months Ended
	Dec. 31, 2023
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Computers and software
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	Shorter of useful life or remaining lease term

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of potentially issuable common shares not included in computation of diluted net loss per share (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	5,627,754	6,207,245
Common Stock Options Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	5,301,254	5,877,745
Unvested Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	326,500	329,500

Net Loss Per Share - Anti-dilut

Net Loss Per Share - Anti-dilutive securities not included in the diluted net loss per share calculation (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	5,627,754	6,207,245
Common Stock Options Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	5,301,254	5,877,745
Unvested Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	326,500	329,500

Fair Value Measurements - Narra

Fair Value Measurements - Narratives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Assets transferred into L3	$ 0	$ 0
Assets transferred out of L3	0	0
Liabilities transferred into L3	0	0
Liabilities transferred out of L3	0	$ 0
Performance Shares [Member] | Chief Executive Officer [Member]
Special performance bonus payable	$ 7,500

Fair Value Measurements - Recur

Fair Value Measurements - Recurring fair value measurement of the Company's assets and liabilities (Detail) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 96,242	$ 95,589
Total	7	29
Quoted Prices in Active Markets For Identical Items (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	10,983	9,365
Significant Other Observable Inputs (Level 2)[Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	85,259	86,224
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	7	29
Performance Award Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	7	29
Performance Award Liability [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	7	29
Money market investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	10,983	9,365
Money market investments [Member] | Quoted Prices in Active Markets For Identical Items (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	10,983	9,365
US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	9,928
Short-term investments	75,331	76,253
US Treasury Securities [Member] | Significant Other Observable Inputs (Level 2)[Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	9,928
Short-term investments	$ 75,331	76,253
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		4,978
Short-term investments		4,993
Commercial Paper [Member] | Significant Other Observable Inputs (Level 2)[Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		4,978
Short-term investments		$ 4,993

Fair Value Measurements - Sched

Fair Value Measurements - Schedule Changes in fair value measurements of the Performance Award (Detail) - Performance Award [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 29
Change in fair value	(22)
Ending Balance	$ 7

Marketable Debt Securities - Su

Marketable Debt Securities - Summary of Gross Unrealized Gains and Losses of Available-for-Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 75,324	$ 81,290
Gross Unrealized Gains	8	2
Gross Unrealized Losses	(1)	(46)
Fair Market Value	75,331	81,246
US Treasury Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	75,324	76,297
Gross Unrealized Gains	8	2
Gross Unrealized Losses	(1)	(46)
Fair Market Value	$ 75,331	76,253
Commercial Paper [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost		4,993
Fair Market Value		$ 4,993

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 254	$ 555
Less: accumulated depreciation and amortization	(120)	(102)
Total property and equipment, net	134	453
Computer, software and office equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 254	300
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		$ 255

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued clinical and regulatory	$ 3,661	$ 1,872
Accrued contract manufacturing cost	1,100	1,583
Accrued compensation	3,948	807
Accrued other	420	565
Total accrued expenses	$ 9,129	$ 4,827

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Right-of-use (ROU) assets impairment expense	$ 0.3
Weighted average incremental borrowing rate	5%
Weighted average remaining lease term	3 years 9 months 18 days
Payments for operating leases liabilities	$ 0.5	$ 0.5
Operating lease expense	$ 0.4	$ 0.5
Lease Agreement [Member]
Lessee, Lease, Description [Line Items]
Lessee, operating lease, existence of option to terminate [true false]	true
Right-of-use (ROU) assets impairment expense	$ 0.3

Leases - Maturities of lease li

Leases - Maturities of lease liabilities (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Leases [Abstract]
2024	$ 381
2025	367
2026	285
Total lease payments	1,033
Less: Imputed interest	(60)
Present value of lease liabilities	$ 973

Stock-Based Compensation - Equi

Stock-Based Compensation - Equity Incentive Plans (Details)	12 Months Ended
	Dec. 31, 2023 shares
Equity Incentive Plan 2014 | Common Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share options exercised unvested shares outstanding	0

Stock-Based Compensation - Shar

Stock-Based Compensation - Shares Reserved for Future Issuance (Details)	Dec. 31, 2023 shares
Class of Stock [Line Items]
Total shares of common stock reserved	8,182,869
Common Stock Options Outstanding
Class of Stock [Line Items]
Total shares of common stock reserved	5,301,254
Unvested Restricted Stock Units
Class of Stock [Line Items]
Total shares of common stock reserved	326,500
Equity Incentive Plan 2021
Class of Stock [Line Items]
Total shares of common stock reserved	2,109,225
Employee Stock Purchase Plan (ESPP) 2021
Class of Stock [Line Items]
Total shares of common stock reserved	445,890

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock option activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Options Outstanding
Outstanding at beginning of period (in shares)	5,877,745
Granted (in shares)	578,915
Exercised (in shares)	(173,824)
Forfeited/Expired (in shares)	(981,582)
Outstanding at end of period (in shares)	5,301,254	5,877,745
Vested (in shares)	3,228,343
Exercisable (in shares)	3,592,125
Weighted-Average Exercise Price
Outstanding at beginning of period (in dollars per share)	$ 4.47
Granted (in dollars per share)	6.85
Exercised (in dollars per share)	2.31
Forfeited/Expired (in dollars per share)	4.69
Outstanding at end of period (in dollars per share)	4.76	$ 4.47
Vested (in dollars per share)	4.91
Exercisable (in dollars per share)	$ 4.91
Weighted-Average Remaining Contractual Term (in years) / Aggregate Intrinsic Value
Weighted Average Remaining Contractual Term (in years), Options Outstanding	6 years 10 months 24 days	8 years 2 months 12 days
Weighted Average Remaining Contractual Term (in years), Vested	6 years 1 month 6 days
Weighted Average Remaining Contractual Term (in years), Exercisable	6 years 2 months 12 days
Aggregate Intrinsic Value, Outstanding	$ 0	$ 907
Aggregate Intrinsic Value, Vested	0
Aggregate Intrinsic Value, Exercisable		$ 0
Unrecognized stock-based compensation expense	$ 5,900
Weighted-average vesting term	2 years

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Weighted-average assumptions
Risk-free interest rate	4%	3.40%
Expected volatility	88.60%	84.80%
Expected term (in years)	5 years 10 months 24 days	6 years
Expected dividend yield	0%	0%

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units (RSUs) (Details) - Equity Incentive Plan 2021 - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested at Beginning | shares	329,500
Granted | shares	137,000
Cancelled | shares	(140,000)
Unvested at End | shares	326,500
Weighted Average Grant Date Fair Value
Unvested at Beginning | $ / shares	$ 5.67
Granted | $ / shares	5.82
Cancelled | $ / shares	5.35
Unvested at End | $ / shares	$ 5.9

Stock-Based Compensation - Time

Stock-Based Compensation - Time-Based Units (Additional Information) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unrecognized compensation expense	$ 5.9
Weighted-average vesting term	2 years
Equity Incentive Plan 2021 | Time-Based Restricted Units
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period	4 years
Unvested shares | shares	57,000
Unrecognized compensation expense	$ 0.3
Weighted-average vesting term	1 year 3 months 18 days
Vesting rights, description	TSUs typically vest over four years, with 25% vesting on the one-year anniversary of the employee’s hire date and the remainder vesting monthly or quarterly over the following three years subject to the employee’s continued employment with the Company through the vesting dates.
Equity Incentive Plan 2021 | Time-Based Restricted Units | 25% Vesting on One-year Anniversary
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period	1 year
Vesting percentage	25%
Equity Incentive Plan 2021 | Time-Based Restricted Units | Remainder Vesting Monthly or Quarterly over Three Years
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period	3 years

Stock-Based Compensation - Perf

Stock-Based Compensation - Performance-Based Units (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense	$ 5,112,000	$ 4,320,000
Unrecognized compensation expense	$ 5,900,000
Equity Incentive Plan 2021 | Performance-based Restricted Units
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unvested shares	149,500
Stock-based compensation expense	$ 0	$ 0
Unrecognized compensation expense	$ 1,100,000

Stock-Based Compensation - Mark

Stock-Based Compensation - Market-Based Units (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) Days $ / shares shares
Stock-Based Compensation
Unrecognized stock-based compensation expense | $	$ 5.9
Equity Incentive Plan 2021 | Market-Based Units | Employee
Stock-Based Compensation
Threshold share price for vesting of shares	$ 20
Consecutive trading days | Days	30
Share Price	$ 2.78
Service period	3 years
Unvested shares | shares	120,000

Stock-Based Compensation - Appo

Stock-Based Compensation - Appointment of CEO (Details) - Chief executive officer	12 Months Ended
	Dec. 31, 2023 USD ($) Days	Dec. 31, 2022 USD ($)
Stock-Based Compensation
Reversal of share based compensation expense	$ 22,000	$ 400,000
Performance Shares [Member]
Stock-Based Compensation
Special performance bonus payable	7,500,000
Threshold market value	$ 750,000,000
Number of trading days | Days	30
Threshold fair market value of the net proceeds	$ 750,000,000

Stock-Based Compensation - Empl

Stock-Based Compensation - Employee Stock Purchase Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Stock-Based Compensation
Stock-based compensation expense	$ 5,112	$ 4,320
2021 Employee Stock Purchase Plan
Stock-Based Compensation
Number of shares issued	288,466
Stock-based compensation expense	$ 400	$ 200
UK Sharesave Sub-plan (SAYE)
Stock-Based Compensation
Options authorized	25,875
Number of shares issued	0

Stock-Based Compensation - Non-

Stock-Based Compensation - Non-cash stock-based compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Stock-Based Compensation
Stock-based compensation expense	$ 5,112	$ 4,320
Research and development
Stock-Based Compensation
Stock-based compensation expense	1,815	1,593
General and administrative
Stock-Based Compensation
Stock-based compensation expense	$ 3,297	$ 2,727

License Agreement (Details)

License Agreement (Details) - vTv Therapeutics - USD ($)		1 Months Ended	12 Months Ended
	Oct. 30, 2023	Dec. 31, 2017	Dec. 31, 2023	Dec. 31, 2022
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestone payments paid		$ 2,000,000
Development and regulatory milestone payments			$ 2,000,000
Milestone payments			$ 0	$ 0
Milestone payments payable on achievement of sales thresholds of the licensed product		30,000,000
Common Stock [Member] | Common Stock Repurchase Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Number of shares repurchased	576,443
Shares repurchased, aggregate purchase price	$ 4,400,000
Research and development
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Upfront license fee payment		$ 3,000,000
Common stock issued, Shares		576,443
Milestone payments payable on achievement of development and regulatory milestones		$ 64,500,000

Income Taxes - Company's loss b

Income Taxes - Company's loss before provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Domestic	$ (78,132)	$ (51,994)
Foreign	744	39
Net loss	$ (77,388)	$ (51,955)

Income Taxes - Components of ne

Income Taxes - Components of net deferred taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
NOL carryforwards	$ 23,490	$ 16,381
Capitalized research and development expenses	15,274	7,465
Credit carryforwards	6,111	4,061
Intangible assets	2,902	3,202
Compensation accruals	1,885	989
Operating lease liabilities	245	316
Depreciation	89	78
Other	2	2
Gross deferred tax assets	49,998	32,494
Less valuation allowance	(49,872)	(32,214)
Total deferred tax assets	126	280
ROU assets	(126)	(280)
Net deferred tax assets (liabilities)

Income Taxes - Schedule Of Effe

Income Taxes - Schedule Of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. federal statutory income tax rate	21%	21%
Tax credits, net	2.50%	3.40%
Return-to-provision adjustment	0.10%	0.50%
Other	(0.10%)	(0.80%)
GILTI inclusion	(0.40%)	(0.30%)
Foreign Rate Differential	(0.10%)	0%
Valuation allowance	(23.00%)	(23.80%)
U.S. federal effective tax rate	0%	0%

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating Loss Carryforwards [Line Items]
Income Tax Expense (Benefit)	$ 0	$ 0
Stockholders ownership percentage	5%
Valuation allowance of DTA	$ 49,872,000	32,214,000
Unrecognized tax benefits	11,000,000
Income Tax Examination, Penalties and Interest Accrued	0	$ 0
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	110,900,000
Net operating loss carryforwards, not subject to expiration	109,300,000
Net operating loss carryforwards, subject to expiration	$ 1,600,000
Net operating loss carryforwards, subject to expiration period	2034
Tax credit carry forwards	$ 16,900,000
Tax credit carry forwards expiration	2034
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 1,800,000
Net operating loss carryforwards period	2034
Tax credit carry forwards	$ 700,000
UK
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, not subject to expiration	200,000
GILTI	$ 1,500,000

Income Taxes - Changes to unrec

Income Taxes - Changes to unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Beginning balance of unrecognized tax benefits	$ 7,094	$ 2,999
Additions based on tax positions related to the current year	4,331	4,095
Ending balance of unrecognized tax benefits	$ 11,425	$ 7,094

Commitments and Contingencies (

Commitments and Contingencies (Additional Information) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Matching contributions expense recorded	$ 0.2

Financial Impact of Suspensio_2

Financial Impact of Suspension of Mavodelpar Development Activities - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Restructuring and Related Activities [Abstract]
Severance and continuation of benefit expenses	$ 2.5
Right-of-use (ROU) assets impairment expense	0.3
Right-of-use and leasehold improvement impairment expenses	$ 0.4

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Subsequent Event [Line Items]
Severance and continuation of benefit expenses		$ 2.5
Forecast [Member]
Subsequent Event [Line Items]
Severance and continuation of benefit expenses	$ 1.6