Sagimet Biosciences (SGMT) 10-K 25 Mar 24 2023 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2023	Mar. 14, 2024	Jun. 30, 2023
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	001-41742
Entity Registrant Name	Sagimet Biosciences Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-5991472
Entity Address, Address Line One	155 Bovet Road, Suite 303
Entity Address, City or Town	San Mateo
Entity Address State Or Province	CA
Entity Address, Postal Zip Code	94402
City Area Code	650
Local Phone Number	561-8600
Title of 12(b) Security	Series A Common Stock,$0.0001 par value per share
Trading Symbol	SGMT
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			$ 0
Entity Central Index Key	0001400118
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false
Auditor Name	Deloitte & Touche LLP
Auditor Location	San Francisco, California
Auditor Firm ID	34
Series A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		30,393,397
Series B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,520,490

BALANCE SHEETS

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 75,139	$ 158
Marketable securities	19,758	32,187
Prepaid expenses and other current assets	1,749	447
Total current assets	96,646	32,792
Operating lease right-of-use assets	73	212
Deposits		27
Total assets	96,719	33,031
Current liabilities:
Accounts payable	186	1,125
Accrued expenses and other current liabilities (includes $31 and $0 payable to related parties as of December 31, 2023 and 2022, respectively)	5,403	4,021
Operating lease liabilities	65	133
Total current liabilities	5,654	5,279
Long-term liabilities:
Operating lease liabilities, less current portion		78
Warrant liability		4
Total liabilities	5,654	5,361
Commitments and contingencies (Note 8)
Redeemable convertible preferred stock: $0.0001 par value; no shares authorized, issued, or outstanding at December 31, 2023; 1,373,810,170 shares authorized and 1,373,730,625 shares issued and outstanding at December 31, 2022; liquidation value of $232,963 at December 31, 2022		214,620
Stockholders' equity (deficit):
Undesignated preferred stock: $0.0001 par value; 10,000,000 and no shares authorized at December 31, 2023 and 2022, respectively. No shares issued and outstanding at December 31, 2023 and 2022, respectively
Common stock		1
Additional paid-in capital	340,777	35,001
Accumulated other comprehensive income (loss)	30	(84)
Accumulated deficit	(249,744)	(221,868)
Total stockholders' equity (deficit)	91,065	(186,950)
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)	96,719	33,031
Series A Common Stock
Stockholders' equity (deficit):
Common stock	2
Series B Common Stock
Stockholders' equity (deficit):
Common stock

BALANCE SHEETS (Parenthetical)

BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accrued expenses and other current liabilities	$ 5,403	$ 4,021
Redeemable convertible preferred stock, par value	$ 0.0001	$ 0.0001
Redeemable convertible preferred stock, shares authorized	0	1,373,810,170
Redeemable convertible preferred stock, issued	0	1,373,730,625
Redeemable convertible preferred stock, outstanding	0	1,373,730,625
Redeemable convertible preferred stock, liquidation preference		$ 232,963
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	0	1,608,370,000
Common stock, shares issued	0	185,084
Common stock, shares outstanding	0	185,084
Related party
Accrued expenses and other current liabilities	$ 31	$ 0
Series A Common Stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	500,000,000	0
Common stock, shares issued	21,375,402	0
Common stock, shares outstanding	21,375,402	0
Series B Common Stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	15,000,000	0
Common stock, shares issued	1,520,490	0
Common stock, shares outstanding	1,520,490	0

STATEMENTS OF OPERATIONS AND CO

STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue:
Revenue	$ 2,000
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	us-gaap:LicenseMember	us-gaap:LicenseMember
Operating expenses:
Research and development	$ 19,777	$ 24,919
General and administrative	12,963	6,136
Total operating expenses	32,740	31,055
Loss from operations	(30,740)	(31,055)
Other income, net:
Change in fair value of stock warrant liability	4	3
Interest income and other	2,860	553
Total other income, net	2,864	556
Net loss	(27,876)	(30,499)
Other comprehensive gain (loss):
Net unrealized gain (loss) on marketable securities	114	(84)
Total other comprehensive gain (loss)	114	(84)
Comprehensive loss	$ (27,762)	$ (30,583)
Net loss per share attributable to common stockholders, basic	$ (2.66)	$ (165.20)
Net loss per share attributable to common stockholders, diluted	$ (2.66)	$ (165.20)
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic	10,460,335	184,619
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted	10,460,335	184,619

STATEMENTS OF REDEEMABLE CONVER

STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Common stock Series A Common Stock	Common stock Series B Common Stock	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated Other Comprehensive (Loss) Income	Series A Common Stock	Series B Common Stock	Total
Beginning balance at Dec. 31, 2021			$ 1	$ 33,109	$ (191,369)				$ (158,259)
Beginning balance (in shares) at Dec. 31, 2021			183,457
Increase (Decrease) In Stockholders' Deficit
Net Income (Loss)					(30,499)				(30,499)
Exercise of stock options	$ 0	$ 0	$ 0	12	0	$ 0			12
Exercise of stock options (in shares)	0	0	1,627
Unrealized gain (loss) on marketable securities						(84)			(84)
Stock-based compensation expense				1,880					1,880
Ending balance at Dec. 31, 2022			$ 1	35,001	(221,868)	(84)			$ (186,950)
Ending balance (in shares) at Dec. 31, 2022			185,084				0	0	185,084
Increase (Decrease) In Stockholders' Deficit
Net Income (Loss)					(27,876)				$ (27,876)
Conversion of Redeemable Convertible Preferred Stock to Series A and Series B Common Stock	$ 1			214,619					214,620
Conversion of Redeemable Convertible Preferred Stock to Series A and Series B Common Stock (in shares)	15,117,912	1,520,490
Reclassification of Common Stock to Series A Common Stock	$ 1		$ (1)
Reclassification of Common Stock to Series A Common Stock (in shares)	210,315		(210,315)
Sale of Series A Common Stock in public offering, net of issuance costs of $10,267				86,161					86,161
Sale of Series A Common Stock in public offering, net of issuance costs of $10,267 (in shares)	6,026,772
Exercise of stock options				6					$ 6
Exercise of stock options (in shares)	7,614								7,614
Exercise of common stock warrants (in shares)	12,789		25,231
Unrealized gain (loss) on marketable securities						114			$ 114
Stock-based compensation expense				4,990					4,990
Ending balance at Dec. 31, 2023	$ 2			$ 340,777	$ (249,744)	$ 30			$ 91,065
Ending balance (in shares) at Dec. 31, 2023	21,375,402	1,520,490					21,375,402	1,520,490	0

STATEMENTS OF REDEEMABLE CONV_2

STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - Temporary Equity - USD ($) $ in Thousands	Redeemable convertible preferred stock	Total
Beginning balance, Temporary equity at Dec. 31, 2021	$ 214,620
Beginning balance, Temporary equity (in shares) at Dec. 31, 2021	1,373,730,625
Increase (Decrease) in Temporary Equity
Exercise of stock options	$ 0	$ 12
Exercise of stock options (in shares)	0
Ending balance, Temporary equity at Dec. 31, 2022	$ 214,620	$ 214,620
Ending balance, Temporary equity (in shares) at Dec. 31, 2022	1,373,730,625	1,373,730,625
Increase (Decrease) in Temporary Equity
Exercise of stock options		$ 6
Exercise of stock options (in shares)		7,614
Conversion of Redeemable Convertible Preferred Stock to Series A and Series B Common Stock	$ (214,620)	$ 214,620
Conversion of Redeemable Convertible Preferred Stock to Series A and Series B Common Stock (in shares)	(1,373,730,625)
Ending balance, Temporary equity (in shares) at Dec. 31, 2023		0

STATEMENTS OF REDEEMABLE CONV_3

STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT)
Issuance costs	$ 10,267

STATEMENTS OF CASH FLOWS

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net Income (Loss)	$ (27,876)	$ (30,499)
Adjustments to reconcile net loss to net cash used in operating activities:
Accretion of discount on marketable securities, net	(37)	(212)
Non-cash lease expense	139	130
Stock-based compensation expense	4,990	1,880
Change in fair value of stock warrant liability	(4)	(3)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(952)	1,436
Accounts payable and accrued liabilities	120	2,915
Operating lease liabilities	(146)	(137)
Net cash used in operating activities	(23,766)	(24,490)
Cash flows from investing activities:
Purchases of marketable securities	(19,620)	(41,446)
Sales of marketable securities	32,200	9,436
Net cash provided by (used in) investing activities	12,580	(32,010)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriters' commissions and discounts	89,679
Payment of deferred financing costs	(3,518)	(85)
Proceeds from exercise of stock options	6	12
Net cash provided by (used in) financing activities	86,167	(73)
Net increase (decrease) in cash and cash equivalents	74,981	(56,573)
Cash and cash equivalents at beginning of period	158	56,731
Cash and cash equivalents at end of period	75,139	$ 158
Supplemental non-cash investing and financing activities:
Conversion of Redeemable Convertible Preferred Stock to Series A and Series B Common Stock	214,620
Reclassification of common stock to Series A common stock	1
Deferred financing costs in accrued expenses	$ 323

Organization and description of

Organization and description of business	12 Months Ended
	Dec. 31, 2023
Organization and description of business
Organization and description of business	1. Organization and description of business Overview Sagimet Biosciences Inc. (the Company) was incorporated in Delaware on December 19, 2006, as 3-V Biosciences, Inc. and is headquartered in San Mateo, California. The Company changed its name from 3-V Biosciences, Inc. to Sagimet Biosciences Inc. in August 2019. The Company is a clinical-stage biopharmaceutical company developing novel therapeutics called fatty acid synthase (FASN) inhibitors that target dysfunctional metabolic pathways in diseases resulting from the overproduction of the fatty acid, palmitate. Reverse stock split A one-for- 79.4784 Initial public offering On July 18, 2023, the Company completed its initial public offering (IPO), in which it issued and sold 5,312,500 shares of Series A common stock at a price to the public of $16.00 per share. The aggregate gross proceeds of the IPO were $96.4 million, inclusive of an additional 714,272 shares of Series A common stock sold upon the partial exercise of the underwriters’ purchase option. The Company received approximately $86.2 million in net proceeds after deducting underwriting discounts, commissions, and offering expenses. In connection with the IPO, the Company’s outstanding redeemable convertible preferred stock automatically converted into 15,117,912 shares of Series A common stock and 1,520,490 shares of Series B common stock. The rights of the holders of Series A common stock and Series B common stock are substantially identical, except with respect to voting and conversion. Each share of Series A common stock is entitled to one vote and shares of Series B common stock are non-voting, except as may be required by law. Each share of Series B common stock may be converted at any time into one share of Series A common stock at the option of its holder, subject to the ownership limitations provided for in the Company’s eleventh amended and restated certificate of incorporation (the Charter). See Note 10. Reclassification of common stock On July 18, 2023, each share of the Company’s common stock issued and outstanding became reclassified as one share of Series A common stock. Any stock certificate that immediately prior to July 18, 2023 represented shares of the Company’s common stock was deemed to represent shares of Series A common stock, without the need for surrender or exchange thereof. Risks, uncertainties and going concern The Company is subject to certain risks and uncertainties, including, but not limited to changes in any of the following areas that the Company believes could have a material adverse effect on future financial position or results of operations: the availability of future financing; the ability to obtain regulatory approval and market acceptance of, and reimbursement for, the Company’s drug candidates if approved; the performance of third-party clinical research organizations and manufacturers; protection of the intellectual property; litigation or claims against the Company based on intellectual property, patent, product, regulatory or other factors; and the Company’s ability to attract and retain employees necessary to support commercial success. In addition, significant changes in the biotechnology industry or the approval of competitive products or therapies could adversely affect the Company’s development and operating results. The Company will require substantial additional capital to fund its research and development and ongoing operating expenses. As of December 31, 2023, the Company has relied on public and private equity and debt financings, including its July 2023 IPO, to fund its operations. The Company has incurred net losses and negative cash flows from operations since inception and as of December 31, 2023, had an accumulated deficit of $249.7 million and cash, cash equivalents and marketable securities of $94.9 million. The Company expects to incur additional losses and negative cash flows from operations for at least the next 12 months. The Company expects that its cash, cash equivalents and marketable securities as of December 31, 2023, in addition to the $104.7 million in net proceeds from the sale of Series A common stock in January 2024 (see Note 13), will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance of these financial statements. In the future, the Company may need to raise additional funds until it is able to generate sufficient revenues to fund its development activities. The Company’s future operating activities, coupled with its plans to raise capital or issue debt financing, may provide additional liquidity in the future, however these actions are not solely within the control of the Company and the Company is unable to predict the outcome of these actions to generate the liquidity ultimately required. ​

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2023
Summary of significant accounting policies
Summary of significant accounting policies	2. Summary of significant accounting policies Basis of presentation The financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Updates (ASU) of the Financial Accounting Standards Board (FASB). Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Such estimates include variable consideration related to our collaboration agreement, accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock and common stock valuations prior to the IPO and stock option valuations and stock-based compensation. On an ongoing basis, the Company evaluates its estimates and judgments, which are based on historical and anticipated results and trends and on various other assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates. Segment information The Company operates and manages its business as a single operating segment for the purposes of assessing performance and making operating decisions. The Company’s current focus is on developing and commercializing therapeutics for the treatment of metabolic dysfunction-associated steatohepatitis (MASH) and other diseases where FASN plays a pathogenic role. The Company has one operating segment and therefore one reportable segment. The determination of reportable segments is based on the chief operating decision maker's (CODM) use of financial information provided for the purpose of assessing performance and making operating decisions. The Company's CODM is its chief executive officer. Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash, cash equivalents, and marketable securities. Cash and cash equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. As of December 31, 2023 and 2022, cash and cash equivalents which are denominated in U.S. dollars, consisted of bank deposits including deposits in a money market fund. All cash and cash equivalents were unrestricted as to withdrawal or use. Marketable securities The Company classifies its marketable debt securities as available-for-sale and records such assets at estimated fair value in the balance sheets. The Company adopted Accounting Standards Update (ASU) No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s public offerings are capitalized and recorded on the balance sheets. Upon closing of the IPO in July 2023, all deferred offering costs were reclassified to additional paid-in-capital in the balance sheet, representing a reduction in IPO proceeds. As of December 31, 2023, the Company had $0.3 million of deferred financing costs capitalized within prepaid expenses and other current assets on the balance sheet related to its upcoming public offering. Upon closing of the public offering in January 2024, all deferred financing costs were reclassified to additional paid-in-capital, representing a reduction in the proceeds from the public offering. See Note 13. On March 21, 2022, the Company withdrew its Registration Statement on Form S-1 initially filed with the Securities and Exchange Commission (SEC) on April 6, 2021. Concurrently, all of the deferred financing costs of $1.4 million capitalized as of December 31, 2021 were expensed within operating expenses in the statement of operations and comprehensive loss for the year ended December 31, 2022. Impairment of long-lived assets The Company evaluates the carrying amount of its long-lived assets whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss is recognized when estimated future cash flows expected to result from the use of the asset and its eventual disposition are less than the carrying amount of the asset. To date, there have been no such impairment losses. Leases The Company determines if an arrangement is or contains a lease and the classification of that lease at inception of a contract. Specifically, the Company considers whether it controls the underlying asset and has the right to obtain substantially all the economic benefits or outputs from the asset. The Company enters into lease agreements for its office facility and accounts for its lease obligations under ASU No. 2016-02, Leases Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the lease commencement date. Operating lease ROU assets are based on the corresponding lease liability adjusted for (i) payments made at or before the commencement date, (ii) initial direct costs incurred, and (iii) tenant incentives under the lease. The Company does not account for renewals or early terminations unless it is reasonably certain to exercise these options at commencement. Operating lease expense is recognized on a straight-line basis over the lease term. The Company accounts for lease and non-lease components as a single lease component for operating leases. The Company does not record leases with terms of 12 months or less on the balance sheets. As the implicit rate for the operating lease was not determinable, the Company used an incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future payments. The Company’s incremental borrowing rate was estimated to approximate the interest rate on a collateralized basis with similar terms and payments, in an economic environment where the leased asset is located. The Company determined the incremental borrowing rate by considering various factors, such as its credit rating, interest rates of similar debt instruments of entities with comparable credit rating, the lease term and the currency in which the lease was denominated. Accrued research and development expense Research and development costs are charged to expense as incurred. Research and development expenses include certain payroll and personnel expenses, consulting costs, external contract research and development expenses, and allocated overhead, including rent, equipment depreciation and utilities. Advance payments for goods or services for future research and development activities are deferred and expensed as the goods are delivered or the related services are performed. The Company estimates preclinical study and clinical trial expenses based on the services performed pursuant to contracts with research institutions and clinical research organizations that conduct and manage preclinical studies and clinical trials on the Company’s behalf. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. These estimates are based on communications with the third-party service providers and the Company’s estimates of accrued expenses and on information available at each balance sheet date. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Redeemable convertible preferred stock The Company recorded its redeemable convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The redeemable convertible preferred stock was recorded outside of stockholders’ deficit because the shares contained liquidation features that were not solely within the Company’s control. The Company did not adjust the carrying values of the redeemable convertible preferred stock to the liquidation preferences of such shares because it was uncertain whether or when an event would occur that would obligate the Company to pay the liquidation preferences to holders of shares of redeemable convertible preferred stock. Upon the closing of the IPO, the redeemable convertible preferred stock automatically converted to shares of Series A and Series B common stock. Common stock warrants From time to time, the Company has issued warrants to investors and creditors together with the Company’s debt and equity financings. The Company accounts for warrants in accordance with the guidance contained in ASC 815, Derivatives and Hedging Revenue recognition The Company enters into collaboration and licensing arrangements that generally contain multiple elements or deliverables, which may include (i) licenses to the Company’s technology, (ii) research and development activities performed for the collaboration partner, (iii) participation on joint steering committees (JSCs), and (iv) the manufacturing of clinical or preclinical material. Payments pursuant to these arrangements include milestone payments upon achieving significant development events, research and development reimbursements, sales milestones, and royalties on future drug sales. Variable consideration is constrained until it is probable that the revenue is not at a significant risk of reversal in a future period. In determining the appropriate amount of revenue to be recognized for the components of the arrangements that are within the scope of ASC 606, Revenue from Contracts with Customers above. The Company uses judgment to determine whether milestones or other variable consideration, except for royalties, should be included in the transaction price as described further below. At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being achieved and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. At the end of each subsequent reporting period, the Company reevaluates the probability of achievement of all milestones subject to constraint and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. For arrangements that include sales-based royalties or milestone payments, for which the license is deemed to be the predominant item, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). Stock-based compensation expense The Company provides share-based payments in the form of stock options and restricted stock awards. For awards only subject to service conditions, the Company uses the straight-line attribution method for recognizing compensation expense over the requisite service period, which is generally the vesting period of the award. Compensation expense is recognized on awards ultimately expected to vest. Forfeitures are recorded when they occur. For awards with performance vesting conditions, the Company evaluates the probability of achieving the performance condition at each reporting date. No compensation expense is recognized for awards subject to performance conditions until it is probable that the performance condition will be met. If the performance condition is probable of being achieved, the Company recognizes expense for such performance awards over the requisite service period using the accelerated attribution method. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company has historically been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends on common stock and does not expect to pay any cash dividends in the foreseeable future. Prior to the Company’s IPO, there was no public market for the Company’s common stock, and consequently, the estimated fair value of the common stock was determined by the board of directors as of the date of each option grant, with input from management, considering third-party valuations of our common stock as well as the board of directors’ assessment of additional objective and subjective factors that it believed were relevant and which may have changed from the date of the most recent third-party valuation through the date of the grant. Following the Company’s IPO, in connection with the accounting for granted stock options and other awards the Company may grant, the fair value of the common stock is determined based on the quoted market price of the common stock. Income taxes The Company accounts for income taxes using the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates. In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. In the event the Company determines that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, it would make an adjustment to the valuation allowance that would reduce the provision for income taxes. Conversely, in the event that all or part of the net deferred tax assets are determined not to be realizable in the future, an adjustment to the valuation allowance would be charged to earnings in the period when such determination is made. As of December 31, 2023 and 2022, the Company has recorded a full valuation allowance on its deferred tax assets. Tax benefits related to uncertain tax positions are recognized when it is more likely than not that a tax position will be sustained during an audit. Interest and penalties related to unrecognized tax benefits are included within the provision for income tax. Comprehensive loss Comprehensive loss includes all changes in stockholders’ equity (deficit) during a period from non-owner sources. The cumulative amount of these changes is reported on the balance sheets. Net loss per share attributable to common stockholders Basic and diluted net loss per share is computed using the two-class method required for multiple classes of common stock and participating securities. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders for all periods presented. Basic net loss per common share attributable to common stockholders is calculated by dividing the net loss by the weighted-average number of common shares outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted-average number of common shares and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share attributable to common stockholders calculation, the redeemable convertible preferred stock, common stock options, restricted stock units and common and redeemable convertible preferred stock warrants are considered to be potentially dilutive securities. As the Company has reported a net loss for the periods presented, basic and diluted net loss per share attributable to common stockholders is the same. On July 18, 2023, each share of the Company’s common stock issued and outstanding became reclassified as one share of Series A common stock. The rights of the holders of Series A and Series B common stock are identical except with respect to voting and conversion. Each share of Series A common stock is entitled to one vote per share and shares of Series B common stock are non-voting. Each share of Series B common stock may be converted at any time into one share of Series A common stock at the option of the holder, subject to certain ownership limitations. As such, basic and diluted net loss per share attributable to common stockholders is presented on a combined basis as undistributed earnings, when allocated to each series of common stock, result in the same net loss per share for all periods presented. The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common, Series A and Series B common stockholders for the periods presented because including them would have been antidilutive. ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2023 2022 Options to purchase Series A common stock 3,753,507 — Warrant to purchase Series A common stock ​ 1,000 ​ — Redeemable convertible preferred stock on an as converted basis — 16,638,476 Options to purchase common stock ​ — ​ 3,190,450 Warrants to purchase common stock — 40,268 Warrant to purchase redeemable convertible preferred stock — 79,545 Restricted stock units ​ 1,132,410 ​ — Total 4,886,917 19,948,739 ​ Emerging growth company status The Company is an emerging growth company (EGC) as defined in the Jumpstart Our Business Startups Acts of 2012, as amended (the JOBS Act), and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not EGCs. The Company may take advantage of these exemptions until it is no longer an EGC under Section 107 of the JOBS Act and has elected to use the extended transition period for complying with new or revised accounting standards. As a result of this election, the Company’s financial statements may not be comparable to companies that comply with public company FASB standards’ effective dates. Recently adopted accounting pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments New accounting pronouncements not yet adopted In August 2020, the FASB issued ASU No. 2020-06 , Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40); Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280)—Improvements to Reportable Segment Disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740 )— Improvements to Income Tax Disclosures ​

Fair value measurements and fai

Fair value measurements and fair value of financial instruments	12 Months Ended
	Dec. 31, 2023
Fair value measurements and fair value of financial instruments
Fair value measurements and fair value of financial instruments	3. Fair value measurements and fair value of financial instruments The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1— Level 2— Level 3— As of December 31, 2023 and 2022, financial assets measured at fair value on a recurring basis consist of cash, cash equivalents, and marketable securities. The carrying amount of cash and cash equivalents was $75.1 million and $0.2 million as of December 31, 2023 and, 2022, respectively, which approximates the fair value and was determined based upon Level 1 and Level 2 inputs. The fair value of marketable securities, which are Level 2 financial instruments, is based upon market prices quoted on the last day of the fiscal period or other observable market inputs. The Company obtains pricing information from its investment manager and generally determines the fair value of investment securities using standard observable inputs, including reported trades, broker/dealer quotes, bids and/or offers. The carrying values of the Company’s accounts payable and accrued expenses and other current liabilities approximate their fair values due to the short-term nature of these liabilities. 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 Level 3 liabilities that are measured at fair value on a recurring basis consists of the Series A common stock warrant liability and the redeemable convertible preferred stock warrant liability. The following tables set forth the Company’s financial assets that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ ​ Valuation Amortized Unrealized Unrealized Estimated ​ ​ ​ Hierarchy ​ cost ​ Gains ​ Losses ​ Fair Value Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ ​ Level 1 ​ $ 69,516 ​ $ — ​ $ — ​ $ 69,516 Corporate debt securities ​ ​ Level 2 ​ ​ 4,622 ​ ​ — ​ ​ — ​ ​ 4,622 Total cash equivalents ​ ​ ​ ​ $ 74,138 ​ $ — ​ $ — ​ $ 74,138 Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial paper ​ Level 2 ​ ​ 9,879 ​ 19 ​ — ​ 9,898 Corporate debt securities ​ ​ Level 2 ​ 2,945 ​ 4 ​ — ​ 2,949 U.S. Treasury securities ​ ​ Level 2 ​ 6,904 ​ 7 ​ — ​ 6,911 Total marketable securities ​ ​ ​ ​ $ 19,728 ​ $ 30 ​ $ — ​ $ 19,758 Total assets ​ ​ ​ ​ $ 93,866 ​ $ 30 ​ $ — ​ $ 93,896 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Valuation Amortized Unrealized Unrealized Estimated ​ ​ ​ Hierarchy ​ cost ​ Gains ​ Losses ​ Fair Value Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ ​ Level 1 ​ $ 38 ​ $ — ​ $ — ​ $ 38 Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial paper ​ ​ Level 2 ​ ​ 15,950 ​ ​ — ​ ​ — ​ ​ 15,950 Corporate debt securities ​ ​ Level 2 ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ ​ Level 2 ​ 4,035 ​ — ​ (19) ​ 4,016 Total marketable securities ​ ​ ​ ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187 Total assets ​ ​ ​ ​ $ 32,309 ​ $ — ​ $ (84) ​ $ 32,225 ​ The following tables provide a summary of changes in the estimated fair value of the financial instruments using significant Level 3 inputs (in thousands): ​ ​ ​ ​ Balance - January 1, 2022 ​ $ 7 Change in fair value of redeemable convertible preferred stock warrant liability ​ (3) Balance - December 31, 2022 ​ $ 4 Change in fair value of redeemable convertible preferred stock warrant liability ​ 1 Change in fair value of Series A common stock warrant liability ​ ​ (5) Balance - December 31, 2023 ​ $ — ​ During the periods presented, the Company has not changed the manner in which it values liabilities that are measured at estimated fair value using Level 3 inputs. There were no transfers within the hierarchy during the periods presented. Redeemable convertible preferred stock warrant liability and Series A common stock warrant liability In connection with a note payable entered into on April 10, 2015, which was repaid in full in May 2019, the Company issued a warrant to purchase 79,545 shares of Series D redeemable convertible preferred stock. The Company completed its IPO on July 18, 2023. Subsequently, pursuant to the terms of the warrant, the warrant was converted into a warrant to purchase 1,000 shares of Series A common stock and the expiration date was automatically extended until July 18, 2026, the third anniversary date of the closing of the Company’s IPO. See Note 10. The Company estimates the fair value of the Series A common stock warrant liability and the redeemable convertible preferred stock warrant liability using an option pricing model and assumptions that are based on the individual characteristics of the warrants on the valuation date, Series A common stock market price, as well as assumptions for fair value of the underlying redeemable convertible preferred stock, expected volatility, expected life, dividends and risk-free interest rate. As of December 31, 2023, the fair value of the Series A common stock warrant liability was determined to be $0.3 thousand assuming a volatility rate of 85.2%, an expected term of 2.55 years, no dividends, and a risk-free interest rate of 4.11%. As of December 31, 2022, the fair value of the redeemable convertible preferred stock warrant liability was determined to be $4 thousand assuming a volatility rate of 97.3%, an expected term of 2.28 years, no dividends, and a risk-free interest rate of 4.36%.

Prepaid expenses and other curr

Prepaid expenses and other current assets	12 Months Ended
	Dec. 31, 2023
Prepaid expenses and other current assets
Prepaid expenses and other current assets	4. Prepaid expenses and other current assets Prepaid expenses and other current assets consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 ​ 2022 Prepaid insurance ​ $ 585 ​ $ 61 Prepaid clinical expenses ​ ​ 767 ​ ​ 352 Deferred financing costs ​ ​ 323 ​ ​ — Other ​ 74 ​ 34 Total ​ $ 1,749 ​ $ 447 ​

Accrued expenses and other curr

Accrued expenses and other current liabilities	12 Months Ended
	Dec. 31, 2023
Accrued expenses and other current liabilities
Accrued expenses and other current liabilities	​ 5. Accrued expenses and other current liabilities Accrued expenses and other current liabilities consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 ​ 2022 Accrued clinical costs ​ $ 2,668 ​ $ 3,162 Employees’ compensation ​ 1,105 ​ 636 Accrued research ​ ​ 632 ​ ​ 166 Accrued outside services ​ ​ 442 ​ ​ — Deferred offering costs ​ ​ 323 ​ ​ — Other ​ 233 ​ 57 Total ​ $ 5,403 ​ $ 4,021 ​

Related parties

Related parties	12 Months Ended
	Dec. 31, 2023
Related parties
Related parties	6. Related parties Ascletis BioScience Co. Ltd In January 2019, the Company entered into a license agreement that became effective in February 2019 with Ascletis BioScience Co. Ltd. (Ascletis), a subsidiary of Ascletis Pharma Inc. (Ascletis Pharma), biotechnology company incorporated in the Cayman Islands and headquartered in Hangzhou, China. Ascletis Pharma, through a subsidiary, was the lead investor in the Company’s Series E redeemable convertible preferred stock financing in February 2019. The parties entered into this agreement with the intention to develop, manufacture, and commercialize the Company’s proprietary FASN inhibitor, denifanstat. Under the terms of the license agreement, the Company granted Ascletis and its affiliates an exclusive, royalty-bearing sublicensable right and license under the Company’s intellectual property to develop, manufacture, commercialize and otherwise exploit denifanstat and other products containing denifanstat-related compounds in Greater China, consisting of the People’s Republic of China, Hong Kong, Macau and Taiwan. The Company will bear all expenses related to development activities in Greater China as part of a global Phase 2 trial, except for clinical operations and regulatory staff provided by Ascletis. The Company conducted all development activities in connection with the FASCINATE-1 Phase 2 clinical trial in the United States and Greater China at its sole expense, except for certain in-kind contributions by Ascletis in Greater China. Ascletis is solely responsible for all development activities in connection with obtaining and maintaining regulatory approvals for denifanstat in Greater China. The Company received $60 thousand as reimbursement pursuant to the license agreement for Greater China patent prosecution costs during the year ended December 31, 2022. The Company did not receive any such reimbursements during the year ended December 31, 2023. The Company is eligible to receive development and commercial milestone payments from Ascletis in aggregate of up to $122.0 million as well as tiered royalties ranging from percentages in the high single digits to mid-teens on future net sales of denifanstat, which is referred to as ASC40 in Greater China. This license and Phase 2 research and development services components of this agreement are representative of a relationship with a customer and therefore are subject to ASC 606. In January 2022, Ascletis initiated dosing of a Phase 3 trial for recurrent glioblastoma multiforme (GBM), potentially triggering a $2.0 million development milestone payment, net of applicable taxes, under the license agreement. The parties were in discussions regarding the form and amount of consideration related to this milestone until July 2023, at which time the Company concluded that the risk of reversal was no longer present, resulting in revenue recognition of $2.0 million. In August 2023, the Company received a $1.7 million milestone payment (representing the $2.0 million development milestone payment, net of applicable taxes which are recorded in general and administrative in the statement of operations and comprehensive loss) from Ascletis. As of December 31, 2023, the Company accrued $31 thousand of expenses incurred during the year related to its portion of expenses owed under a sponsored research agreement that is co-sponsored by Ascletis. There were no payments made to Ascletis during the year ended December 31, 2023. The Company paid Ascletis under their manufacturing arrangement $4 thousand during the year ended December 31, 2022. Assignment and Assumption Agreement In July 2023, the Company entered into an Assignment and Assumption Agreement with Ascletis and Ascletis’ affiliate Gannex Pharma Co., Ltd. (Gannex) under which Ascletis, while remaining responsible for performance under the license agreement, assigned all of its rights and obligations under the license agreement to Gannex and Gannex assumed such rights and obligations, effective as of October 2019.

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases
Leases	7. Leases Facility lease agreement On March 12, 2019, the Company executed a 38-month non-cancelable operating lease agreement for 3,030 square feet of office space for its headquarters facility which commenced April 1, 2019. The lease provides for monthly lease payments of approximately $12 thousand with annual increases. On December 20, 2021, the lease agreement was amended to extend the term of the lease through June 2024. The Company has accounted for the lease as an operating lease. Operating lease cost was $0.2 million for both the years ended December 31, 2023 and 2022. The following is a schedule by year of future maturities of the Company’s operating lease liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 2024 $ 66 Total lease payments ​ 66 Less: interest ​ (1) Total ​ $ 65 ​ Supplemental cash flow information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 158 ​ $ 157 ​ Weighted-average remaining lease term and discount rate were as follows as of December 31, 2023: ​ ​ ​ ​ ​ Weighted-average remaining lease term ​ 0.5 years Weighted-average discount rate ​ 7 % ​

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and contingencies
Commitments and contingencies	8. Commitments and contingencies Guarantees and indemnifications In the normal course of business, the Company enters into agreements that contain a variety of representations and provide for general indemnification. The Company’s exposure under these agreements is unknown because it involves claims that may be made against the Company in the future. In addition, the Company has entered into indemnification agreements with members of its board of directors and its executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. To date, the Company has not paid any claims or been required to defend any action related to its indemnification obligations. As of December 31, 2023, the Company does not have any material indemnification claims that were probable or reasonably possible and consequently has not recorded related liabilities. Legal The Company is not party to any material legal proceedings at this time. From time to time, the Company may become involved in various legal proceedings that arise in the ordinary course of its business. Defined Contribution Plan The Company has a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code of 1986, as amended. The 401(k) Plan covers all employees who meet defined minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pretax basis. The Company has not made any employer contributions to the 401(k) Plan as of December 31, 2023 and 2022.

Redeemable convertible preferre

Redeemable convertible preferred stock	12 Months Ended
	Dec. 31, 2023
Redeemable convertible preferred stock
Redeemable convertible preferred stock	9. Redeemable convertible preferred stock Prior to the IPO, the authorized, issued and outstanding shares of the redeemable convertible preferred stock, liquidation preferences and carrying values were as follows as of December 31, 2022 (in thousands, except share numbers): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Issued and ​ ​ ​ ​ ​ ​ Authorized ​ Outstanding ​ Liquidation ​ Carrying ​ ​ Shares ​ Shares ​ Preference ​ Value Series A 23,301 23,301 ​ $ 233 ​ $ 232 Series B 3,217 3,217 ​ 37 ​ 37 Series B‑1 8,827,439 8,827,439 ​ 7,768 ​ 7,258 Series C 22,732,250 22,732,250 ​ 20,004 ​ 17,909 Series D 24,509,954 24,430,409 ​ 21,499 ​ 19,833 Series A’ 720,199 720,199 ​ — ​ — Series B’ 1,953,304 1,953,304 ​ — ​ — Series B‑1’ 14,001,243 14,001,243 ​ — ​ 2,780 Series C’ 1,037 1,037 ​ — ​ — Series D’ 3,475,426 3,475,426 ​ — ​ 739 Series D‑1 51,331,148 51,331,148 ​ 45,171 ​ 26,894 Series E 631,638,725 631,638,725 ​ 58,231 ​ 58,496 Series F 614,592,927 614,592,927 ​ 80,020 ​ 80,442 Total 1,373,810,170 1,373,730,625 ​ $ 232,963 ​ $ 214,620 ​ In connection with the IPO, all of the Company’s outstanding redeemable convertible preferred stock automatically converted into 15,117,912 shares of Series A common stock and 1,520,490 shares of Series B common stock.

Stockholders' equity (deficit)

Stockholders' equity (deficit)	12 Months Ended
	Dec. 31, 2023
Stockholders' equity (deficit)
Stockholders' equity (deficit)	10. Stockholders’ equity (deficit) Common stock Per the Charter, the total number of shares of capital stock authorized for issuance is 500,000,000 shares of Series A common stock, 15,000,000 shares of Series B common stock and 10,000,000 shares of undesignated preferred stock. Holders of Series A common stock are entitled to one vote and Series B common stock are not entitled to vote. Upon the voluntary or involuntary liquidation, dissolution or winding up of the Company, the net assets of the Company will be distributed pro rata to the holders of Series A common stock and Series B common stock. Each share of Series B common stock is convertible, at any time at the option of the holder, into one share of Series A common stock, unless that holder would beneficially own a number of Series A common stock in excess of 4.99% of the total number of shares of Series A common stock then issued and outstanding. On July 18, 2023, upon the Company’s IPO, each share of the Company’s common stock issued and outstanding became reclassified as one share of Series A common stock (see Note 1). The Company’s reserved shares of common stock are as follows: ​ ​ ​ ​ ​ ​ December 31, ​ 2023 Options to purchase Series A common stock 3,753,507 Awards authorized and available for issuance 1,453,558 Warrant to purchase Series A Common Stock ​ 1,000 Redeemable convertible preferred stock on an as converted basis — Series D redeemable convertible preferred stock warrant — Warrants to purchase common stock — Restricted stock units ​ 1,132,410 Shares reserved under Employee Stock Purchase Plan ​ 215,497 Total 6,555,972 ​ Warrants ​ The following tables summarize the Company’s outstanding Series A common stock warrant, common stock warrants and redeemable convertible preferred stock warrants: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ Fair Value on ​ ​ ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ Issuance ​ Fair Value Issuance Date Shares Share Date for (in thousands) Recorded Against April 2015 1,000 ​ $ 69.94 July 2026 Series A Common ​ $ 68 Debt ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ Fair Value on ​ ​ ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ Issuance ​ Fair Value Issuance Date Shares Share Date for (in thousands) Recorded Against June 2013 26,846 ​ $ 0.79 June 2023 Common ​ $ 339 Redeemable convertible preferred stock January 2014 13,422 ​ $ 0.79 January 2024 Common ​ 223 Redeemable convertible preferred stock April 2015 79,545 ​ $ 0.88 April 2025 Series D ​ 68 Debt ​

Stock-based compensation

Stock-based compensation	12 Months Ended
	Dec. 31, 2023
Stock-based compensation
Stock-based compensation	11. Stock-based compensation In 2023, the 2023 Stock Option and Incentive Plan (2023 Plan), was adopted by the board of directors, approved by the Company’s stockholders on July 4, 2023, and became effective on July 13, 2023. The 2023 Plan replaced the 2017 Equity Incentive Plan (2017 Plan), which itself took the place of the expired 2007 plan. The 2023 Plan permits the granting of both incentive stock options to purchase Series A common stock under Section 422 of the Code and non-qualified stock options. On July 18, 2023, each share of the Company’s common stock issued and outstanding became reclassified as one share of Series A common stock, therefore, outstanding options prior to the IPO were to purchase common stock, and after the IPO are to purchase Series A common stock. The number of shares initially reserved for issuance under the 2023 Plan was 2,585,968. The number of shares of Series A common stock reserved under the 2023 Plan will automatically increase each year on January 1, by (i) 4% of the outstanding number of shares of our Series A common stock on the immediately preceding December 31 or (ii) a lesser number of shares as determined by the compensation committee of the board of directors. As of December 31, 2023, 1,453,558 shares are available for future grant under the 2023 Plan. Options under the 2023 Plan can be granted for periods of up to ten years and generally vest over four years. The exercise price of an option shall not be less than 100% of the estimated fair value of the shares on the date of grant as determined by the Company’s board of directors, provided, however, that an ISO granted to a 10% stockholder does not have an exercise price that is less than 110% of the estimated fair value of the shares on the date of grant and shall not have a contractual term longer than five years. The following table summarizes stock option transactions (in thousands, except share and per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Number of ​ ​ ​ ​ Average ​ ​ ​ ​ ​ Shares ​ Weighted- ​ Remaining ​ ​ ​ ​ ​ Underlying ​ Average ​ Contractual ​ Aggregate ​ ​ Outstanding ​ Exercise ​ Term ​ Intrinsic ​ ​ Options ​ Price ​ (in Years) ​ Value Outstanding, January 1, 2023 3,190,450 ​ $ 7.10 8.1 ​ $ 3,998 Options granted 585,919 ​ ​ 13.51 ​ Options exercised ​ (7,614) ​ ​ 0.79 ​ ​ ​ ​ ​ Options cancelled (523) ​ ​ 4.77 ​ Options expired (14,725) ​ ​ 10.10 ​ Outstanding, December 31, 2023 3,753,507 ​ $ 7.99 7.1 ​ $ 8 Shares vested and exercisable as of December 31, 2023 2,141,323 ​ $ 6.99 5.9 ​ $ 8 ​ The aggregate intrinsic value is calculated as the difference between the option exercise price and the estimated fair value of the underlying common stock. The total intrinsic value of options exercised during the years ended December 31, 2023 and 2022 was $88 thousand and $2 thousand, respectively. The weighted average grant date fair value of options granted during the years ended December 31, 2023 and 2022 was $10.28 and $6.04 per share, respectively. As of December 31, 2023, there was $10.9 million of total unrecognized compensation cost related to the Company’s stock options which the Company expects to recognize over an estimated weighted-average period of 2.79 years. Performance-based options The Company may award grants of performance-based options to eligible individuals. Performance-based options vest based on performance measures against predetermined objectives that could include successful completion of qualified equity offerings or announced topline results for clinical trials and positive clinical results over a specified performance period. The total number of Series A common stock shares underlying outstanding options, as presented in the table above, includes 619,742 performance-based options with a weighted-average exercise price of $6.38 as of December 31, 2023 and 2022. There were 598,513 performance-based shares vested and exercisable as of December 31, 2023. The total fair value of the performance-based shares vested during the year ended December 31, 2023 was $11 thousand. As of the year ended December 31, 2023, there was $6 thousand of unrecognized compensation cost related to the awards which the Company expects to recognize over an estimated weighted-average period of 0.1 years. Restricted stock units Restricted stock units (RSUs) are share awards that entitle the holder to receive freely tradeable shares of the Company’s common stock upon vesting. The RSUs cannot be transferred and the awards are subject to forfeiture if the holder’s employment terminates prior to the release of the vesting restrictions. The RSUs generally vest over a four-year period in equal amounts on an annual basis, provided the employee remains continuously employed with the Company. The fair value of the RSUs is equal to the closing price of the Company’s Series A common stock on the grant date. During the year ended December 31, 2023, the Company granted 1,132,410 RSUs with a weighted-average grant date fair value of $2.96 per share. All of the RSUs granted were outstanding as of December 31, 2023. No RSUs vested during the year ended December 31, 2023. As of December 31, 2023 there was $3.2 million of unrecognized stock-based compensation expense related to RSUs, which is expected to be recognized over a weighted-average period of 3.6 years. Stock-based compensation The Company has recorded aggregate stock-based compensation expense in the statements of operations and comprehensive loss as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 ​ 2022 General and administrative expense ​ $ 4,171 ​ $ 1,204 Research and development expense ​ 819 ​ 676 Total stock-based compensation expense ​ $ 4,990 ​ $ 1,880 ​ The fair value of each award granted was estimated on the date of grant using the Black-Scholes option pricing model using the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 ​ ​ 2022 ​ Expected volatility 89 - 91 % ​ 88 - 90 % Risk-free interest rate 3.6 % ​ 3.0 - 4.2 % Dividend yield — ​ — Expected term 5.0 - 7.0 years ​ 5.4 - 7.0 years ​ Employee stock purchase plan The 2023 Employee Stock Purchase Plan (the ESPP), was adopted by the board of directors on June 22, 2023, approved by the Company’s stockholders on July 4, 2023 and became effective on July 13, 2023. A total of 215,497 shares of Series A common stock were initially reserved for issuance under this plan. The number of shares of Series A common stock reserved under the ESPP will automatically increase each year on January 1 through January 1, 2033, by the least of (i) 215,497 shares of Series A common stock, (ii) 1% of the outstanding number of shares of the Company’s Series A common stock on the immediately preceding December 31 or (iii) such lesser number of shares of Series A common stock as determined by the administrator of the ESPP. During the year ended December 31, 2023, no shares of Series A common stock were issued under the 2023 ESPP. ESPP shares will not be made available to employees until May 2024.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2023
Income taxes
Income taxes	12. Income taxes A reconciliation of the provision for income taxes to the amount computed by applying the statutory income tax rate of 21% to the net loss is summarized for the years ended December 31, 2023 and 2022 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2023 ​ 2022 Federal income taxes at statutory rates 21.00 % ​ 21.00 % State income tax, net of federal benefit 0.54 ​ ​ 0.43 ​ Research and development credits 2.92 ​ ​ 3.48 ​ Stock-based compensation ​ 1.49 ​ ​ (0.81) ​ Change in valuation allowance ​ (25.95) ​ ​ (24.10) ​ Effective income tax rate ​ — % ​ — % ​ For the years ended December 31, 2023 and 2022, the Company did not record a deferred income tax expense or benefit. Income tax expense has been nominal for the years ended December 31, 2023 and 2022. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents significant components of the Company’s net deferred tax assets as of December 31, 2023 and 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 ​ 2022 Deferred tax assets: ​ ​ ​ ​ ​ Net operating loss carryforwards $ 31,097 ​ $ 28,707 Capitalized start-up costs and research expenses ​ 15,409 ​ ​ 13,004 Research and development credits ​ ​ 5,943 ​ ​ 4,977 Accruals, reserves and other ​ ​ 312 ​ ​ 221 Stock compensation ​ ​ 2,382 ​ ​ 923 Lease liabilities ​ ​ 14 ​ ​ 47 Total gross deferred assets ​ ​ 55,157 ​ ​ 47,879 Valuation allowance ​ ​ (55,114) ​ ​ (47,834) Total deferred tax assets ​ ​ 43 ​ ​ 45 Deferred tax liabilities: ​ ​ ​ ​ ​ ​ Right-of-use assets ​ ​ (15) ​ ​ (45) Other ​ ​ (28) ​ ​ — Total deferred liabilities ​ ​ (43) ​ ​ (45) Net deferred tax assets ​ $ — ​ $ — ​ The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets. Based on the Company’s history of operating losses, the Company has concluded that it is more likely than not that the benefit of its deferred tax assets will not be realized. Accordingly, the Company has provided a full valuation allowance for deferred tax assets as of December 31, 2023 and 2022. The valuation allowance increased $7.3 million and $7.4 million during the years ended December 31, 2023 and 2022, respectively. As of December 31, 2023, the Company had U.S. federal net operating loss (NOL) carryforwards of approximately $139.6 million which may be available to offset future federal income. Federal NOLs incurred prior to January 1, 2018 of approximately $91.0 million expire beginning in 2029 while federal NOLs incurred after December 31, 2017 of approximately $48.6 million will have an indefinite carryforward period, subject to annual limitations. As of December 31, 2023, the Company also had state NOL carryforwards of approximately $25.5 million which may be available to offset future state income and expire at various years beginning with 2028. As of December 31, 2023, the Company had federal research and development tax credit carryforwards of approximately $5.5 million available to reduce future tax liabilities which expire at various years beginning with 2028. As of December 31, 2023, the Company had state credit carryforwards of approximately $2.6 million available to reduce future tax liabilities which do not expire. Under Section 382 of the Internal Revenue Code of 1986, as amended (IRC), the ability to utilize NOL carryforwards or other tax attributes, such as research tax credits, in any taxable year may be limited if the Company has experienced an “ownership change.” Generally, a Section 382 ownership change occurs if there is a cumulative increase of more than 50 percentage points in the stock ownership of one or more stockholders or groups of stockholders who owns at least 5% of a corporation’s stock within a specified testing period. Similar rules may apply under state tax laws. As a result, the amount of NOL and research and credit carryforwards presented in our financial statements could be limited and may expire unutilized. The Company has not performed a Section 382 analysis through December 31, 2023, and as such, the Company is not able to determine the impact on the NOLs and tax credit carryforwards. 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 applies the two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be substantiated on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount, which is more than 50% likely of being realized upon ultimate settlement. Income tax positions must meet a more likely than not recognition threshold at the effective date to be recognized upon the adoption of ASC 740 and in subsequent periods. This interpretation also provides guidance on measurement, de-recognition, classification, interest and penalties, accounting in interim periods and transition. A reconciliation of the unrecognized tax benefits is as follows for the years ended December 31, 2023 and 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 ​ 2022 Unrecognized tax benefits as of the beginning of the year $ 1,534 ​ $ 1,035 Increase related to current year tax positions ​ 250 ​ ​ 499 Unrecognized tax benefits as of the end of the year $ 1,784 ​ $ 1,534 ​ No amount of the unrecognized tax benefits, if recognized, would reduce the Company’s annual effective tax rate because the benefits are in the form of deferred tax assets for which a full valuation allowance has been recorded. The Company does not anticipate a significant change to its unrecognized tax benefits over the next twelve months. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2023, the Company had no accrued interest or penalties related to uncertain tax positions and no amounts have been recognized in the Company’s statements of operations and comprehensive loss. There are no ongoing examinations by taxing authorities at this time. The Company files United States and state income tax returns with varying statutes of limitations. The Company’s tax years from inception in 2006 will remain open to examination due to the carryover of the unused NOLs and tax credits. The Company does not have any tax audits or other proceedings pending.

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2023
Subsequent events
Subsequent events	13. Subsequent events On January 30, 2024, the Company closed an underwritten public offering of its Series A common stock and issued 9,000,000 shares of Series A common stock at $12.50 per share for proceeds of $104.7 million, net of underwriting discounts, commissions and offering expenses. ​

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2023
Summary of significant accounting policies
Basis of presentation	Basis of presentation The financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Updates (ASU) of the Financial Accounting Standards Board (FASB).
Use of Estimates	Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Such estimates include variable consideration related to our collaboration agreement, accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock and common stock valuations prior to the IPO and stock option valuations and stock-based compensation. On an ongoing basis, the Company evaluates its estimates and judgments, which are based on historical and anticipated results and trends and on various other assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Segment information	Segment information The Company operates and manages its business as a single operating segment for the purposes of assessing performance and making operating decisions. The Company’s current focus is on developing and commercializing therapeutics for the treatment of metabolic dysfunction-associated steatohepatitis (MASH) and other diseases where FASN plays a pathogenic role. The Company has one operating segment and therefore one reportable segment. The determination of reportable segments is based on the chief operating decision maker's (CODM) use of financial information provided for the purpose of assessing performance and making operating decisions. The Company's CODM is its chief executive officer.
Concentration of credit risk	Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash, cash equivalents, and marketable securities.
Cash and cash equivalents	Cash and cash equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. As of December 31, 2023 and 2022, cash and cash equivalents which are denominated in U.S. dollars, consisted of bank deposits including deposits in a money market fund. All cash and cash equivalents were unrestricted as to withdrawal or use.
Marketable securities	Marketable securities The Company classifies its marketable debt securities as available-for-sale and records such assets at estimated fair value in the balance sheets. The Company adopted Accounting Standards Update (ASU) No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments
Deferred financing costs	Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s public offerings are capitalized and recorded on the balance sheets. Upon closing of the IPO in July 2023, all deferred offering costs were reclassified to additional paid-in-capital in the balance sheet, representing a reduction in IPO proceeds. As of December 31, 2023, the Company had $0.3 million of deferred financing costs capitalized within prepaid expenses and other current assets on the balance sheet related to its upcoming public offering. Upon closing of the public offering in January 2024, all deferred financing costs were reclassified to additional paid-in-capital, representing a reduction in the proceeds from the public offering. See Note 13. On March 21, 2022, the Company withdrew its Registration Statement on Form S-1 initially filed with the Securities and Exchange Commission (SEC) on April 6, 2021. Concurrently, all of the deferred financing costs of $1.4 million capitalized as of December 31, 2021 were expensed within operating expenses in the statement of operations and comprehensive loss for the year ended December 31, 2022.
Impairment of long-lived assets	Impairment of long-lived assets The Company evaluates the carrying amount of its long-lived assets whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss is recognized when estimated future cash flows expected to result from the use of the asset and its eventual disposition are less than the carrying amount of the asset. To date, there have been no such impairment losses.
Leases	Leases The Company determines if an arrangement is or contains a lease and the classification of that lease at inception of a contract. Specifically, the Company considers whether it controls the underlying asset and has the right to obtain substantially all the economic benefits or outputs from the asset. The Company enters into lease agreements for its office facility and accounts for its lease obligations under ASU No. 2016-02, Leases Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the lease commencement date. Operating lease ROU assets are based on the corresponding lease liability adjusted for (i) payments made at or before the commencement date, (ii) initial direct costs incurred, and (iii) tenant incentives under the lease. The Company does not account for renewals or early terminations unless it is reasonably certain to exercise these options at commencement. Operating lease expense is recognized on a straight-line basis over the lease term. The Company accounts for lease and non-lease components as a single lease component for operating leases. The Company does not record leases with terms of 12 months or less on the balance sheets. As the implicit rate for the operating lease was not determinable, the Company used an incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future payments. The Company’s incremental borrowing rate was estimated to approximate the interest rate on a collateralized basis with similar terms and payments, in an economic environment where the leased asset is located. The Company determined the incremental borrowing rate by considering various factors, such as its credit rating, interest rates of similar debt instruments of entities with comparable credit rating, the lease term and the currency in which the lease was denominated.
Accrued research and development expense	Accrued research and development expense Research and development costs are charged to expense as incurred. Research and development expenses include certain payroll and personnel expenses, consulting costs, external contract research and development expenses, and allocated overhead, including rent, equipment depreciation and utilities. Advance payments for goods or services for future research and development activities are deferred and expensed as the goods are delivered or the related services are performed. The Company estimates preclinical study and clinical trial expenses based on the services performed pursuant to contracts with research institutions and clinical research organizations that conduct and manage preclinical studies and clinical trials on the Company’s behalf. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. These estimates are based on communications with the third-party service providers and the Company’s estimates of accrued expenses and on information available at each balance sheet date. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly.
Redeemable convertible preferred stock	Redeemable convertible preferred stock The Company recorded its redeemable convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The redeemable convertible preferred stock was recorded outside of stockholders’ deficit because the shares contained liquidation features that were not solely within the Company’s control. The Company did not adjust the carrying values of the redeemable convertible preferred stock to the liquidation preferences of such shares because it was uncertain whether or when an event would occur that would obligate the Company to pay the liquidation preferences to holders of shares of redeemable convertible preferred stock. Upon the closing of the IPO, the redeemable convertible preferred stock automatically converted to shares of Series A and Series B common stock.
Common stock warrants	Common stock warrants From time to time, the Company has issued warrants to investors and creditors together with the Company’s debt and equity financings. The Company accounts for warrants in accordance with the guidance contained in ASC 815, Derivatives and Hedging
Revenue recognition	Revenue recognition The Company enters into collaboration and licensing arrangements that generally contain multiple elements or deliverables, which may include (i) licenses to the Company’s technology, (ii) research and development activities performed for the collaboration partner, (iii) participation on joint steering committees (JSCs), and (iv) the manufacturing of clinical or preclinical material. Payments pursuant to these arrangements include milestone payments upon achieving significant development events, research and development reimbursements, sales milestones, and royalties on future drug sales. Variable consideration is constrained until it is probable that the revenue is not at a significant risk of reversal in a future period. In determining the appropriate amount of revenue to be recognized for the components of the arrangements that are within the scope of ASC 606, Revenue from Contracts with Customers above. The Company uses judgment to determine whether milestones or other variable consideration, except for royalties, should be included in the transaction price as described further below. At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being achieved and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. At the end of each subsequent reporting period, the Company reevaluates the probability of achievement of all milestones subject to constraint and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. For arrangements that include sales-based royalties or milestone payments, for which the license is deemed to be the predominant item, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).
Stock-based compensation expense	Stock-based compensation expense The Company provides share-based payments in the form of stock options and restricted stock awards. For awards only subject to service conditions, the Company uses the straight-line attribution method for recognizing compensation expense over the requisite service period, which is generally the vesting period of the award. Compensation expense is recognized on awards ultimately expected to vest. Forfeitures are recorded when they occur. For awards with performance vesting conditions, the Company evaluates the probability of achieving the performance condition at each reporting date. No compensation expense is recognized for awards subject to performance conditions until it is probable that the performance condition will be met. If the performance condition is probable of being achieved, the Company recognizes expense for such performance awards over the requisite service period using the accelerated attribution method. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company has historically been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends on common stock and does not expect to pay any cash dividends in the foreseeable future. Prior to the Company’s IPO, there was no public market for the Company’s common stock, and consequently, the estimated fair value of the common stock was determined by the board of directors as of the date of each option grant, with input from management, considering third-party valuations of our common stock as well as the board of directors’ assessment of additional objective and subjective factors that it believed were relevant and which may have changed from the date of the most recent third-party valuation through the date of the grant. Following the Company’s IPO, in connection with the accounting for granted stock options and other awards the Company may grant, the fair value of the common stock is determined based on the quoted market price of the common stock.
Income taxes	Income taxes The Company accounts for income taxes using the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates. In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. In the event the Company determines that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, it would make an adjustment to the valuation allowance that would reduce the provision for income taxes. Conversely, in the event that all or part of the net deferred tax assets are determined not to be realizable in the future, an adjustment to the valuation allowance would be charged to earnings in the period when such determination is made. As of December 31, 2023 and 2022, the Company has recorded a full valuation allowance on its deferred tax assets. Tax benefits related to uncertain tax positions are recognized when it is more likely than not that a tax position will be sustained during an audit. Interest and penalties related to unrecognized tax benefits are included within the provision for income tax.
Comprehensive loss	Comprehensive loss Comprehensive loss includes all changes in stockholders’ equity (deficit) during a period from non-owner sources. The cumulative amount of these changes is reported on the balance sheets.
Net loss per share attributable to common stockholders	Net loss per share attributable to common stockholders Basic and diluted net loss per share is computed using the two-class method required for multiple classes of common stock and participating securities. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders for all periods presented. Basic net loss per common share attributable to common stockholders is calculated by dividing the net loss by the weighted-average number of common shares outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted-average number of common shares and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share attributable to common stockholders calculation, the redeemable convertible preferred stock, common stock options, restricted stock units and common and redeemable convertible preferred stock warrants are considered to be potentially dilutive securities. As the Company has reported a net loss for the periods presented, basic and diluted net loss per share attributable to common stockholders is the same. On July 18, 2023, each share of the Company’s common stock issued and outstanding became reclassified as one share of Series A common stock. The rights of the holders of Series A and Series B common stock are identical except with respect to voting and conversion. Each share of Series A common stock is entitled to one vote per share and shares of Series B common stock are non-voting. Each share of Series B common stock may be converted at any time into one share of Series A common stock at the option of the holder, subject to certain ownership limitations. As such, basic and diluted net loss per share attributable to common stockholders is presented on a combined basis as undistributed earnings, when allocated to each series of common stock, result in the same net loss per share for all periods presented. The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common, Series A and Series B common stockholders for the periods presented because including them would have been antidilutive. ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2023 2022 Options to purchase Series A common stock 3,753,507 — Warrant to purchase Series A common stock ​ 1,000 ​ — Redeemable convertible preferred stock on an as converted basis — 16,638,476 Options to purchase common stock ​ — ​ 3,190,450 Warrants to purchase common stock — 40,268 Warrant to purchase redeemable convertible preferred stock — 79,545 Restricted stock units ​ 1,132,410 ​ — Total 4,886,917 19,948,739
Emerging growth company status	Emerging growth company status The Company is an emerging growth company (EGC) as defined in the Jumpstart Our Business Startups Acts of 2012, as amended (the JOBS Act), and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not EGCs. The Company may take advantage of these exemptions until it is no longer an EGC under Section 107 of the JOBS Act and has elected to use the extended transition period for complying with new or revised accounting standards. As a result of this election, the Company’s financial statements may not be comparable to companies that comply with public company FASB standards’ effective dates.
New accounting pronouncements not yet adopted	Recently adopted accounting pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments New accounting pronouncements not yet adopted In August 2020, the FASB issued ASU No. 2020-06 , Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40); Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280)—Improvements to Reportable Segment Disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740 )— Improvements to Income Tax Disclosures ​

Summary of significant accoun_3

Summary of significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2023
Summary of significant accounting policies
Schedule of potentially dilutive securities	​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2023 2022 Options to purchase Series A common stock 3,753,507 — Warrant to purchase Series A common stock ​ 1,000 ​ — Redeemable convertible preferred stock on an as converted basis — 16,638,476 Options to purchase common stock ​ — ​ 3,190,450 Warrants to purchase common stock — 40,268 Warrant to purchase redeemable convertible preferred stock — 79,545 Restricted stock units ​ 1,132,410 ​ — Total 4,886,917 19,948,739

Fair value measurements and f_2

Fair value measurements and fair value of financial instruments (Tables)	12 Months Ended
	Dec. 31, 2023
Fair value measurements and fair value of financial instruments
Schedule of marketable securities, available-for-sale	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ ​ Valuation Amortized Unrealized Unrealized Estimated ​ ​ ​ Hierarchy ​ cost ​ Gains ​ Losses ​ Fair Value Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ ​ Level 1 ​ $ 69,516 ​ $ — ​ $ — ​ $ 69,516 Corporate debt securities ​ ​ Level 2 ​ ​ 4,622 ​ ​ — ​ ​ — ​ ​ 4,622 Total cash equivalents ​ ​ ​ ​ $ 74,138 ​ $ — ​ $ — ​ $ 74,138 Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial paper ​ Level 2 ​ ​ 9,879 ​ 19 ​ — ​ 9,898 Corporate debt securities ​ ​ Level 2 ​ 2,945 ​ 4 ​ — ​ 2,949 U.S. Treasury securities ​ ​ Level 2 ​ 6,904 ​ 7 ​ — ​ 6,911 Total marketable securities ​ ​ ​ ​ $ 19,728 ​ $ 30 ​ $ — ​ $ 19,758 Total assets ​ ​ ​ ​ $ 93,866 ​ $ 30 ​ $ — ​ $ 93,896 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Valuation Amortized Unrealized Unrealized Estimated ​ ​ ​ Hierarchy ​ cost ​ Gains ​ Losses ​ Fair Value Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ ​ Level 1 ​ $ 38 ​ $ — ​ $ — ​ $ 38 Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial paper ​ ​ Level 2 ​ ​ 15,950 ​ ​ — ​ ​ — ​ ​ 15,950 Corporate debt securities ​ ​ Level 2 ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ ​ Level 2 ​ 4,035 ​ — ​ (19) ​ 4,016 Total marketable securities ​ ​ ​ ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187 Total assets ​ ​ ​ ​ $ 32,309 ​ $ — ​ $ (84) ​ $ 32,225
Summary of changes in the estimated fair value of the financial instruments	The following tables provide a summary of changes in the estimated fair value of the financial instruments using significant Level 3 inputs (in thousands): ​ ​ ​ ​ Balance - January 1, 2022 ​ $ 7 Change in fair value of redeemable convertible preferred stock warrant liability ​ (3) Balance - December 31, 2022 ​ $ 4 Change in fair value of redeemable convertible preferred stock warrant liability ​ 1 Change in fair value of Series A common stock warrant liability ​ ​ (5) Balance - December 31, 2023 ​ $ —

Prepaid expenses and other cu_2

Prepaid expenses and other current assets (Tables)	12 Months Ended
	Dec. 31, 2023
Prepaid expenses and other current assets
Schedule of prepaid expenses and other current assets	Prepaid expenses and other current assets consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 ​ 2022 Prepaid insurance ​ $ 585 ​ $ 61 Prepaid clinical expenses ​ ​ 767 ​ ​ 352 Deferred financing costs ​ ​ 323 ​ ​ — Other ​ 74 ​ 34 Total ​ $ 1,749 ​ $ 447 ​

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Accrued expenses and other current liabilities
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 ​ 2022 Accrued clinical costs ​ $ 2,668 ​ $ 3,162 Employees’ compensation ​ 1,105 ​ 636 Accrued research ​ ​ 632 ​ ​ 166 Accrued outside services ​ ​ 442 ​ ​ — Deferred offering costs ​ ​ 323 ​ ​ — Other ​ 233 ​ 57 Total ​ $ 5,403 ​ $ 4,021 ​

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases
Schedule of future maturities of operating lease liabilities	The following is a schedule by year of future maturities of the Company’s operating lease liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 2024 $ 66 Total lease payments ​ 66 Less: interest ​ (1) Total ​ $ 65 ​
Schedule of supplemental lease information	Supplemental cash flow information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 158 ​ $ 157 ​ Weighted-average remaining lease term and discount rate were as follows as of December 31, 2023: ​ ​ ​ ​ ​ Weighted-average remaining lease term ​ 0.5 years Weighted-average discount rate ​ 7 % ​

Redeemable convertible prefer_2

Redeemable convertible preferred stock (Tables)	12 Months Ended
	Dec. 31, 2023
Redeemable convertible preferred stock
Schedule of redeemable convertible preferred stock	Prior to the IPO, the authorized, issued and outstanding shares of the redeemable convertible preferred stock, liquidation preferences and carrying values were as follows as of December 31, 2022 (in thousands, except share numbers): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Issued and ​ ​ ​ ​ ​ ​ Authorized ​ Outstanding ​ Liquidation ​ Carrying ​ ​ Shares ​ Shares ​ Preference ​ Value Series A 23,301 23,301 ​ $ 233 ​ $ 232 Series B 3,217 3,217 ​ 37 ​ 37 Series B‑1 8,827,439 8,827,439 ​ 7,768 ​ 7,258 Series C 22,732,250 22,732,250 ​ 20,004 ​ 17,909 Series D 24,509,954 24,430,409 ​ 21,499 ​ 19,833 Series A’ 720,199 720,199 ​ — ​ — Series B’ 1,953,304 1,953,304 ​ — ​ — Series B‑1’ 14,001,243 14,001,243 ​ — ​ 2,780 Series C’ 1,037 1,037 ​ — ​ — Series D’ 3,475,426 3,475,426 ​ — ​ 739 Series D‑1 51,331,148 51,331,148 ​ 45,171 ​ 26,894 Series E 631,638,725 631,638,725 ​ 58,231 ​ 58,496 Series F 614,592,927 614,592,927 ​ 80,020 ​ 80,442 Total 1,373,810,170 1,373,730,625 ​ $ 232,963 ​ $ 214,620

Stockholders' equity (deficit)

Stockholders' equity (deficit) (Tables)	12 Months Ended
	Dec. 31, 2023
Stockholders' equity (deficit)
Schedule of shares of common stock reserved for future issuance	​ ​ ​ ​ ​ ​ December 31, ​ 2023 Options to purchase Series A common stock 3,753,507 Awards authorized and available for issuance 1,453,558 Warrant to purchase Series A Common Stock ​ 1,000 Redeemable convertible preferred stock on an as converted basis — Series D redeemable convertible preferred stock warrant — Warrants to purchase common stock — Restricted stock units ​ 1,132,410 Shares reserved under Employee Stock Purchase Plan ​ 215,497 Total 6,555,972
Schedule of outstanding warrants	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ Fair Value on ​ ​ ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ Issuance ​ Fair Value Issuance Date Shares Share Date for (in thousands) Recorded Against April 2015 1,000 ​ $ 69.94 July 2026 Series A Common ​ $ 68 Debt ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ Fair Value on ​ ​ ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ Issuance ​ Fair Value Issuance Date Shares Share Date for (in thousands) Recorded Against June 2013 26,846 ​ $ 0.79 June 2023 Common ​ $ 339 Redeemable convertible preferred stock January 2014 13,422 ​ $ 0.79 January 2024 Common ​ 223 Redeemable convertible preferred stock April 2015 79,545 ​ $ 0.88 April 2025 Series D ​ 68 Debt ​

Stock-based compensation (Table

Stock-based compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Stock-based compensation
Schedule of option activity transactions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Number of ​ ​ ​ ​ Average ​ ​ ​ ​ ​ Shares ​ Weighted- ​ Remaining ​ ​ ​ ​ ​ Underlying ​ Average ​ Contractual ​ Aggregate ​ ​ Outstanding ​ Exercise ​ Term ​ Intrinsic ​ ​ Options ​ Price ​ (in Years) ​ Value Outstanding, January 1, 2023 3,190,450 ​ $ 7.10 8.1 ​ $ 3,998 Options granted 585,919 ​ ​ 13.51 ​ Options exercised ​ (7,614) ​ ​ 0.79 ​ ​ ​ ​ ​ Options cancelled (523) ​ ​ 4.77 ​ Options expired (14,725) ​ ​ 10.10 ​ Outstanding, December 31, 2023 3,753,507 ​ $ 7.99 7.1 ​ $ 8 Shares vested and exercisable as of December 31, 2023 2,141,323 ​ $ 6.99 5.9 ​ $ 8
Schedule of stock-based compensation expense	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 ​ 2022 General and administrative expense ​ $ 4,171 ​ $ 1,204 Research and development expense ​ 819 ​ 676 Total stock-based compensation expense ​ $ 4,990 ​ $ 1,880
Schedule of fair value assumptions	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 ​ ​ 2022 ​ Expected volatility 89 - 91 % ​ 88 - 90 % Risk-free interest rate 3.6 % ​ 3.0 - 4.2 % Dividend yield — ​ — Expected term 5.0 - 7.0 years ​ 5.4 - 7.0 years

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income taxes
Schedule of tax rate reconciliation	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2023 ​ 2022 Federal income taxes at statutory rates 21.00 % ​ 21.00 % State income tax, net of federal benefit 0.54 ​ ​ 0.43 ​ Research and development credits 2.92 ​ ​ 3.48 ​ Stock-based compensation ​ 1.49 ​ ​ (0.81) ​ Change in valuation allowance ​ (25.95) ​ ​ (24.10) ​ Effective income tax rate ​ — % ​ — %
Summary of deferred taxes	​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 ​ 2022 Deferred tax assets: ​ ​ ​ ​ ​ Net operating loss carryforwards $ 31,097 ​ $ 28,707 Capitalized start-up costs and research expenses ​ 15,409 ​ ​ 13,004 Research and development credits ​ ​ 5,943 ​ ​ 4,977 Accruals, reserves and other ​ ​ 312 ​ ​ 221 Stock compensation ​ ​ 2,382 ​ ​ 923 Lease liabilities ​ ​ 14 ​ ​ 47 Total gross deferred assets ​ ​ 55,157 ​ ​ 47,879 Valuation allowance ​ ​ (55,114) ​ ​ (47,834) Total deferred tax assets ​ ​ 43 ​ ​ 45 Deferred tax liabilities: ​ ​ ​ ​ ​ ​ Right-of-use assets ​ ​ (15) ​ ​ (45) Other ​ ​ (28) ​ ​ — Total deferred liabilities ​ ​ (43) ​ ​ (45) Net deferred tax assets ​ $ — ​ $ —
Schedule of unrecognized tax benefits	A reconciliation of the unrecognized tax benefits is as follows for the years ended December 31, 2023 and 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 ​ 2022 Unrecognized tax benefits as of the beginning of the year $ 1,534 ​ $ 1,035 Increase related to current year tax positions ​ 250 ​ ​ 499 Unrecognized tax benefits as of the end of the year $ 1,784 ​ $ 1,534

Organization and description _2

Organization and description of business (Details) $ / shares in Units, $ in Thousands			12 Months Ended
	Jul. 18, 2023 USD ($) $ / shares shares	Jul. 07, 2023	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Organization and description of business
Reverse stock split ratio		0.012582
Net proceeds			$ 89,679
Net loss			27,876	$ 30,499
Cash flows from operations			23,766	24,490
Accumulated deficit			(249,744)	(221,868)
Cash and cash equivalents			75,139	158
Short-term investments			19,758	$ 32,187
Cash and cash equivalents and marketable securities			94,900
Series A Common Stock
Organization and description of business
Proceeds from stock issuance			$ 104,700
Shares issued upon conversion (in number of shares) | shares	15,117,912
Series B Common Stock
Organization and description of business
Shares issued upon conversion (in number of shares) | shares	1,520,490
IPO | Series A Common Stock
Organization and description of business
Shares issued (in shares) | shares	5,312,500
Share price (in dollars per share) | $ / shares	$ 16
Proceeds from stock issuance	$ 96,400
Net proceeds	$ 86,200
Underwriter | Series A Common Stock
Organization and description of business
Shares issued (in shares) | shares	714,272

Summary of significant accoun_4

Summary of significant accounting policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)
Summary of significant accounting policies
Number of operating segment | segment	1
Number of reportable segment | segment	1
Deferred financing costs in accrued expenses	$ 323
Deferred financing costs writeoff		$ 1,400
Impairment losses	$ 0

Summary of significant accoun_5

Summary of significant accounting policies - Dilutive shares (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive securities
Potentially dilutive securities	4,886,917	19,948,739
Options to purchase common stock | Series A Common Stock
Antidilutive securities
Potentially dilutive securities	3,753,507
Options to purchase common stock | Common stock
Antidilutive securities
Potentially dilutive securities		3,190,450
Warrants | Series A Common Stock
Antidilutive securities
Potentially dilutive securities	1,000
Warrants | Redeemable convertible preferred stock
Antidilutive securities
Potentially dilutive securities		79,545
Warrants | Common stock
Antidilutive securities
Potentially dilutive securities		40,268
Redeemable convertible preferred stock
Antidilutive securities
Potentially dilutive securities		16,638,476
Restricted stock units
Antidilutive securities
Potentially dilutive securities	1,132,410

Fair value measurements and f_3

Fair value measurements and fair value of financial instruments - Fair value (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair value on a recurring basis
Cash and cash equivalents	$ 75,139	$ 158
Recurring
Fair value on a recurring basis
Amortized Cost	93,866	32,309
Unrealized Gains	30
Unrealized Losses		(84)
Estimated Fair Value	93,896	32,225
Recurring | Cash Equivalents
Fair value on a recurring basis
Amortized Cost	74,138
Estimated Fair Value	74,138
Recurring | Short-Term Investments
Fair value on a recurring basis
Amortized Cost	19,728	32,271
Unrealized Gains	30
Unrealized Losses		(84)
Estimated Fair Value	19,758	32,187
Recurring | Level 1 | Cash Equivalents | Money market funds
Fair value on a recurring basis
Amortized Cost	69,516	38
Estimated Fair Value	69,516	38
Recurring | Level 2 | Cash Equivalents | Corporate debt securities
Fair value on a recurring basis
Amortized Cost	4,622
Estimated Fair Value	4,622
Recurring | Level 2 | Short-Term Investments | Commercial paper
Fair value on a recurring basis
Amortized Cost	9,879	15,950
Unrealized Gains	19
Estimated Fair Value	9,898	15,950
Recurring | Level 2 | Short-Term Investments | Corporate debt securities
Fair value on a recurring basis
Amortized Cost	2,945	12,286
Unrealized Gains	4
Unrealized Losses		(65)
Estimated Fair Value	2,949	12,221
Recurring | Level 2 | Short-Term Investments | U.S. Treasury securities
Fair value on a recurring basis
Amortized Cost	6,904	4,035
Unrealized Gains	7
Unrealized Losses		(19)
Estimated Fair Value	$ 6,911	$ 4,016

Fair value measurements and f_4

Fair value measurements and fair value of financial instruments - Level 3 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Summary of changes
Beginning balance	$ 4	$ 7
Ending balance		4
Redeemable Convertible Preferred Stock Warrant
Summary of changes
Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability	1	$ (3)
Redeemable convertible preferred stock
Summary of changes
Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability	$ (5)

Fair value measurements and f_5

Fair value measurements and fair value of financial instruments - Warrants (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) Y dividend $ / shares shares	Dec. 31, 2022 USD ($) dividend Y $ / shares shares	Jul. 18, 2023 shares	Apr. 10, 2015 shares
Redeemable Convertible Preferred Stock Warrant Liability
Change in fair value of stock warrant liability	$ (4,000)	$ (3,000)
Series D redeemable convertible preferred stock warrants
Redeemable Convertible Preferred Stock Warrant Liability
Number of warrants issued | shares	1,000	79,545		79,545
Fair value of warrant liability	$ 68,000	$ 68,000
Exercise price of warrant | $ / shares	$ 69.94	$ 0.88
Redeemable convertible preferred stock
Redeemable Convertible Preferred Stock Warrant Liability
Fair value of warrant liability	$ 300
Number of securities called by warrants | shares			1,000
Redeemable convertible preferred stock | Volatility rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input	0.852
Redeemable convertible preferred stock | Expected term
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input | Y	2.55
Redeemable convertible preferred stock | Dividends
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input | dividend	0
Redeemable convertible preferred stock | Risk-free interest rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input	0.0411
Redeemable Convertible Preferred Stock Warrant
Redeemable Convertible Preferred Stock Warrant Liability
Fair value of warrant liability		$ 4,000
Redeemable Convertible Preferred Stock Warrant | Volatility rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input		0.973
Redeemable Convertible Preferred Stock Warrant | Expected term
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input | Y		2.28
Redeemable Convertible Preferred Stock Warrant | Dividends
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input | dividend		0
Redeemable Convertible Preferred Stock Warrant | Risk-free interest rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input		0.0436

Prepaid expenses and other cu_3

Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Prepaid expenses and other current assets
Prepaid Insurance	$ 585	$ 61
Prepaid clinical expenses	767	352
Deferred financing costs	323
Other	74	34
Total	$ 1,749	$ 447

Accrued expenses and other cu_3

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accrued expenses and other current liabilities
Accrued clinical costs	$ 2,668	$ 3,162
Employees' compensation	1,105	636
Accrued research	632	166
Accrued outside services	442
Deferred offering costs	323
Other	233	57
Total	$ 5,403	$ 4,021

Related parties (Details)

Related parties (Details) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Aug. 31, 2023	Jul. 31, 2023	Jan. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Related parties
Accrued expenses and other current liabilities				$ 5,403	$ 4,021
Revenue				2,000
Related party
Related parties
Accrued expenses and other current liabilities				31	0
Investor | Ascletis
Related parties
Amount received as reimbursement				0	60
Maximum eligible development and commercial milestone payments				122,000
Amount paid				0	$ 4
Development milestone payment trigger	$ 1,700		$ 2,000
Development milestone triggered, net	$ 2,000
Revenue		$ 2,000
Investor | Research agreement | Ascletis
Related parties
Accrued expenses and other current liabilities				$ 31

Leases (Details)

Leases (Details) $ in Thousands		12 Months Ended
	Mar. 12, 2019 USD ($) ft²	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Leases
Operating lease term	38 months
Rented area (in square feet) | ft²	3,030
Monthly lease payments	$ 12
Operating lease cost		$ 200	$ 200

Leases - Maturities (Details)

Leases - Maturities (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Leases
2024	$ 66
Total lease payments	66
Less: interest	(1)
Total	$ 65

Leases - Supplemental (Details)

Leases - Supplemental (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flow information
Operating cash flows from operating leases	$ 158	$ 157
Weighted-average remaining lease term	6 months
Discount rate	7%

Redeemable convertible prefer_3

Redeemable convertible preferred stock (Details) - USD ($) $ in Thousands	Jul. 18, 2023	Dec. 31, 2023	Dec. 31, 2022
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized		0	1,373,810,170
Redeemable convertible preferred stock, issued		0	1,373,730,625
Redeemable convertible preferred stock, outstanding		0	1,373,730,625
Redeemable convertible preferred stock, liquidation preference			$ 232,963
Redeemable convertible preferred stock, carrying value			$ 214,620
Series A
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			23,301
Redeemable convertible preferred stock, issued			23,301
Redeemable convertible preferred stock, outstanding			23,301
Redeemable convertible preferred stock, liquidation preference			$ 233
Redeemable convertible preferred stock, carrying value			$ 232
Series B
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			3,217
Redeemable convertible preferred stock, issued			3,217
Redeemable convertible preferred stock, outstanding			3,217
Redeemable convertible preferred stock, liquidation preference			$ 37
Redeemable convertible preferred stock, carrying value			$ 37
Series B-1
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			8,827,439
Redeemable convertible preferred stock, issued			8,827,439
Redeemable convertible preferred stock, outstanding			8,827,439
Redeemable convertible preferred stock, liquidation preference			$ 7,768
Redeemable convertible preferred stock, carrying value			$ 7,258
Series C
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			22,732,250
Redeemable convertible preferred stock, issued			22,732,250
Redeemable convertible preferred stock, outstanding			22,732,250
Redeemable convertible preferred stock, liquidation preference			$ 20,004
Redeemable convertible preferred stock, carrying value			$ 17,909
Series D
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			24,509,954
Redeemable convertible preferred stock, issued			24,430,409
Redeemable convertible preferred stock, outstanding			24,430,409
Redeemable convertible preferred stock, liquidation preference			$ 21,499
Redeemable convertible preferred stock, carrying value			$ 19,833
Series A'
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			720,199
Redeemable convertible preferred stock, issued			720,199
Redeemable convertible preferred stock, outstanding			720,199
Series B'
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			1,953,304
Redeemable convertible preferred stock, issued			1,953,304
Redeemable convertible preferred stock, outstanding			1,953,304
Series B-1'
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			14,001,243
Redeemable convertible preferred stock, issued			14,001,243
Redeemable convertible preferred stock, outstanding			14,001,243
Redeemable convertible preferred stock, carrying value			$ 2,780
Series C'
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			1,037
Redeemable convertible preferred stock, issued			1,037
Redeemable convertible preferred stock, outstanding			1,037
Series D'
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			3,475,426
Redeemable convertible preferred stock, issued			3,475,426
Redeemable convertible preferred stock, outstanding			3,475,426
Redeemable convertible preferred stock, carrying value			$ 739
Series D-1
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			51,331,148
Redeemable convertible preferred stock, issued			51,331,148
Redeemable convertible preferred stock, outstanding			51,331,148
Redeemable convertible preferred stock, liquidation preference			$ 45,171
Redeemable convertible preferred stock, carrying value			$ 26,894
Series E
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			631,638,725
Redeemable convertible preferred stock, issued			631,638,725
Redeemable convertible preferred stock, outstanding			631,638,725
Redeemable convertible preferred stock, liquidation preference			$ 58,231
Redeemable convertible preferred stock, carrying value			$ 58,496
Series F
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized			614,592,927
Redeemable convertible preferred stock, issued			614,592,927
Redeemable convertible preferred stock, outstanding			614,592,927
Redeemable convertible preferred stock, liquidation preference			$ 80,020
Redeemable convertible preferred stock, carrying value			$ 80,442
Series A Common Stock
Redeemable convertible preferred stock
Shares issued upon conversion (in number of shares)	15,117,912
Series B Common Stock
Redeemable convertible preferred stock
Shares issued upon conversion (in number of shares)	1,520,490

Stockholders' equity (deficit_2

Stockholders' equity (deficit) - Stock (Details) - shares	Dec. 31, 2023	Jul. 13, 2023	Dec. 31, 2022
Stockholders' deficit
Common stock, shares authorized	0		1,608,370,000
Preferred stock, shares authorized	10,000,000		0
Common stock shares reserved for future issuance	6,555,972
Redeemable convertible preferred stock
Stockholders' deficit
Common stock shares reserved for future issuance	1,000
Employee Stock Purchase Plan
Stockholders' deficit
Common stock shares reserved for future issuance	215,497
Series A Common Stock
Stockholders' deficit
Common stock, shares authorized	500,000,000		0
Beneficial ownership stock held (as a percent)	4.99%
Series A Common Stock | Employee Stock Purchase Plan
Stockholders' deficit
Common stock shares reserved for future issuance		215,497
Awards authorized and available for issuance
Stockholders' deficit
Common stock shares reserved for future issuance	1,453,558
Options to purchase common stock
Stockholders' deficit
Common stock shares reserved for future issuance	3,753,507
Restricted stock units
Stockholders' deficit
Common stock shares reserved for future issuance	1,132,410

Stockholders' equity (deficit_3

Stockholders' equity (deficit) - Warrants (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022	Apr. 10, 2015
Common warrants issued on June 2013
Stock warrants
Number of warrants issued		26,846
Exercise price of warrant		$ 0.79
Fair value of warrant liability		$ 339,000
Common warrants issued on January 2014
Stock warrants
Number of warrants issued		13,422
Exercise price of warrant		$ 0.79
Fair value of warrant liability		$ 223,000
Common warrants issued on April 2015
Stock warrants
Number of warrants issued	1,000	79,545	79,545
Exercise price of warrant	$ 69.94	$ 0.88
Fair value of warrant liability	$ 68,000	$ 68,000
Redeemable convertible preferred stock
Stock warrants
Fair value of warrant liability	$ 300

Stock-based compensation (Detai

Stock-based compensation (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jul. 13, 2023	Dec. 31, 2023	Dec. 31, 2022
Stock-based compensation
Common stock shares reserved for future issuance		6,555,972
Intrinsic Value		$ 88	$ 2
Weighted average grant date fair value		$ 10.28	$ 6.04
Restricted Stock Units
Stock-based compensation
Number of shares Issued under 2023 ESPP		1,132,410
Vesting period		4 years
Number of RSUs vested		0
Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period		$ 2.96
Total unrecognized compensation cost		$ 3,200
Weighted average period of years		3 years 7 months 6 days
2023 Equity incentive plan
Stock-based compensation
Common stock shares reserved for future issuance	2,585,968	1,453,558
Annual increase in reserved shares of common stock (as a percent)	4%
Contractual term	10 years
Percentage of price on estimated fair value	100%
2023 Equity incentive plan | Shareholder having 10% holding
Stock-based compensation
Contractual term	5 years
Percentage of price on estimated fair value	110%
Percentage of shareholder not having exercise price not less than 100% of fair value	10%
Employee Stock Purchase Plan
Stock-based compensation
Common stock shares reserved for future issuance		215,497
Employee Stock Purchase Plan | Series A Common Stock
Stock-based compensation
Common stock shares reserved for future issuance	215,497
Annual increase in reserved shares of common stock (as a percent)	1%
Number of shares Issued under 2023 ESPP		0

Stock-based compensation - Stoc

Stock-based compensation - Stock options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Number of Shares
Balance at the beginning	3,190,450
Options granted	585,919
Options exercised	(7,614)
Options cancelled	(523)
Options expired	(14,725)
Balance at the end	3,753,507	3,190,450
Shares vested and exercisable at the end	2,141,323
Weighted-Average Exercise Price
Balance at the beginning (in dollars per share)	$ 7.10
Options granted (in dollars per share)	13.51
Options exercised (in dollars per share)	0.79
Options cancelled (in dollars per share)	4.77
Options expired (in dollars per share)	10.10
Balance at the end (in dollars per share)	7.99	$ 7.10
Vested and Exercisable at the end (in dollars per share)	$ 6.99
Term and Intrinsic Value
Weighted- Average Remaining Contractual Term, Outstanding	7 years 1 month 6 days	8 years 1 month 6 days
Weighted- Average Remaining Contractual Term, Exercisable	5 years 10 months 24 days
Aggregate Intrinsic Value, Outstanding	$ 8	$ 3,998
Aggregate Intrinsic Value, Exercisable	8
Time-based options
Term and Intrinsic Value
Total unrecognized compensation cost	$ 10,900
Remaining weighted-average period for unrecognized compensation cost	2 years 9 months 14 days
Performance-based options
Number of Shares
Balance at the beginning	619,742
Balance at the end	619,742	619,742
Shares vested and exercisable at the end	598,513
Weighted-Average Exercise Price
Balance at the end (in dollars per share)	$ 6.38
Term and Intrinsic Value
Fair value of options vested	$ 11
Total unrecognized compensation cost	$ 6
Remaining weighted-average period for unrecognized compensation cost	1 month 6 days

Stock-based compensation - Expe

Stock-based compensation - Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Stock-based compensation
Total stock-based compensation	$ 4,990	$ 1,880
General and administrative
Stock-based compensation
Total stock-based compensation	4,171	1,204
Research and development
Stock-based compensation
Total stock-based compensation	$ 819	$ 676

Stock-based compensation - Fair

Stock-based compensation - Fair value input (Details) - Employee Stock Option	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Stock-based compensation
Expected volatility, minimum	89%	88%
Expected volatility, maximum	91%	90%
Risk-free interest rate	3.60%
Risk-free interest rate, Minimum		3%
Risk-free interest rate, Maximum		4.20%
Minimum
Stock-based compensation
Expected term	5 years	5 years 4 months 24 days
Maximum
Stock-based compensation
Expected term	7 years	7 years

Income taxes - Rate reconciliat

Income taxes - Rate reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Reconciliation of the provision for income taxes, in percent
Federal income taxes at statutory rates	21%	21%
State income tax, net of federal benefit	0.54%	0.43%
Research and development credits	2.92%	3.48%
Stock-based compensation	1.49%	(0.81%)
Change in valuation allowance	(25.95%)	(24.10%)

Income taxes - Deferred (Detail

Income taxes - Deferred (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Net operating loss carryforwards	$ 31,097	$ 28,707
Capitalized start-up costs and research expenses	15,409	13,004
Research and development credits	5,943	4,977
Accruals, reserves and other	312	221
Stock compensation	2,382	923
Lease liabilities	14	47
Total gross deferred assets	55,157	47,879
Valuation allowance	(55,114)	(47,834)
Total deferred tax assets	43	45
Deferred tax liabilities:
Right-of-use assets	(15)	(45)
Other	(28)
Total deferred liabilities	$ (43)	$ (45)

Income taxes - Carryforwards (D

Income taxes - Carryforwards (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income taxes
Change in valuation allowance	$ 7.3	$ 7.4
Federal
Income taxes
Operating loss carryforwards	139.6
Operating loss carryforward subject to expiration	91
Operating loss carryforward not subject to expiration	48.6
Research and development tax credit carryforward	5.5
State
Income taxes
Operating loss carryforwards	25.5
Research and development tax credit carryforward	$ 2.6

Income taxes - Unrecognized (De

Income taxes - Unrecognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Schedule of reconciliation of the unrecognized tax benefits
Unrecognized tax benefits as of the beginning of the year	$ 1,534	$ 1,035
Increase related to current year tax positions	250	499
Unrecognized tax benefits as of the end of the year	1,784	$ 1,534
Unrecognized tax benefit impacting effective tax rate	0
Accrued interest related to uncertain tax positions	$ 0

Subsequent events (Details)

Subsequent events (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jan. 30, 2024	Dec. 31, 2023
Subsequent events
Proceeds from initial public offering, net of underwriters' commissions and discounts		$ 89,679
Subsequent Event
Subsequent events
Shares issued (in shares)	9,000,000
Share price (in dollars per share)	$ 12.50
Proceeds from initial public offering, net of underwriters' commissions and discounts	$ 104,700

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ (27,876)	$ (30,499)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false