Sagimet Biosciences (SGMT) S-1 23 Jan 24 IPO registration Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2023
Document and Entity Information
Document Type	S-1
Entity Registrant Name	Sagimet Biosciences Inc.
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Central Index Key	0001400118
Amendment Flag	false

CONDENSED BALANCE SHEETS

CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 101,842			$ 158				$ 56,731
Short-term investments in marketable securities	0			32,187
Prepaid expenses and other current assets	974			447				1,932
Total current assets	102,816			32,792				58,663
Operating lease right-of-use assets	109			212				342
Deposits				27				27
Total assets	102,925			33,031				59,032
Current liabilities:
Accounts payable	1,702			1,125				761
Accrued expenses and other current liabilities	3,244			4,021				1,555
Operating lease liabilities	103			133				124
Total current liabilities	5,049			5,279				2,440
Long-term liabilities
Operating lease liabilities, less current portion				78				224
Redeemable convertible preferred stock warrant liability				4				7
Total liabilities	5,050			5,361				2,671
Commitments and contingencies (Note 7)
Redeemable convertible preferred stock: $0.0001 par value; no shares and 1,373,810,170 shares authorized at September 30, 2023 and December 31, 2022, respectively; no shares and 1,373,730,625 shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively; liquidation value of $232,963 at December 31, 2022				214,620				214,620
Stockholders' equity (deficit):
Undesignated preferred stock, $0.0001 par value; 10,000,000 shares and no shares authorized at September 30, 2023 and December 31, 2022, respectively; no shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively
Common stock, $0.0001 par value; 1,608,370,000 and 1,590,550,754 shares authorized at December 31, 2022 and 2021, respectively; 185,084 and 183,457 shares issued and outstanding at December 31, 2022 and 2021, respectively				1				1
Additional paid-in capital	339,466			35,001				33,109
Accumulated other comprehensive loss				(84)
Accumulated deficit	(241,593)			(221,868)				(191,369)
Total stockholders' equity (deficit)	97,875	$ (198,414)	$ (192,699)	(186,950)	$ (180,554)	$ (173,420)	$ (166,595)	(158,259)	$ (135,910)
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)	102,925			33,031				$ 59,032
Series A Common Stock
Stockholders' equity (deficit):
Common stock, $0.0001 par value; 1,608,370,000 and 1,590,550,754 shares authorized at December 31, 2022 and 2021, respectively; 185,084 and 183,457 shares issued and outstanding at December 31, 2022 and 2021, respectively	2
Series A Common Stock Warrants
Long-term liabilities
Redeemable convertible preferred stock warrant liability	$ 1
Redeemable Convertible Preferred Stock Warrant
Long-term liabilities
Redeemable convertible preferred stock warrant liability				$ 4

CONDENSED BALANCE SHEETS (Paren

CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Redeemable convertible preferred stock, par value	$ 0.0001	$ 0.0001	$ 0.0001
Redeemable convertible preferred stock, shares authorized	0	1,373,810,170	1,373,810,170
Redeemable convertible preferred stock, issued	0	1,373,730,625	1,373,730,625
Redeemable convertible preferred stock, outstanding	0	1,373,730,625	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	1,590,550,754
Common stock, shares issued	0	185,084	183,457
Common stock, shares outstanding		185,084
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		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

CONDENSED STATEMENTS OF OPERATI

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($)	1 Months Ended		3 Months Ended						9 Months Ended		12 Months Ended
	Jul. 31, 2023	Jan. 31, 2022	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Revenue:
Revenue	$ 2,000,000	$ 0	$ 2,000,000						$ 2,000,000		$ 0
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]			us-gaap:LicenseMember						us-gaap:LicenseMember
Other income (expense), net:
Research and development			$ 4,958,000			$ 6,838,000			$ 14,121,000	$ 19,072,000	24,919,000	$ 19,340,000
General and administrative			4,494,000			848,000			9,153,000	4,595,000	6,136,000	4,379,000
Total operating expenses			9,452,000			7,686,000			23,274,000	23,667,000	31,055,000	23,719,000
Loss from operations			(7,452,000)			(7,686,000)			(21,274,000)	(23,667,000)	(31,055,000)	(23,719,000)
Other income, net:
Change in fair value of redeemable convertible preferred stock tranche liability												(751,000)
Change in fair value of redeemable convertible preferred stock warrants											3,000	2,000
Interest income and other			1,095,000			218,000			1,546,000	360,000	553,000	26,000
Total other income, net			1,099,000			219,000			1,549,000	363,000	556,000	(723,000)
Net loss			(6,353,000)	$ (6,785,000)	$ (6,587,000)	(7,467,000)	$ (7,102,000)	$ (8,735,000)	(19,725,000)	(23,304,000)	(30,499,000)	(24,442,000)
Other comprehensive loss:
Net unrealized (loss) gain on investments in marketable securities				$ 13,000	$ 71,000	(56,000)	$ (106,000)		84,000	(162,000)	(84,000)
Total other comprehensive (loss) gain						(56,000)			84,000	(162,000)	(84,000)
Comprehensive loss			$ (6,353,000)			$ (7,523,000)			$ (19,641,000)	$ (23,466,000)	$ (30,583,000)	$ (24,442,000)
Net loss per share attributable to common stockholders, basic						$ (40.34)				$ (126.13)	$ (165.20)	$ (199.40)
Net loss per share attributable to common stockholders, diluted			$ (0.35)			$ (40.34)			$ (3.22)	$ (126.13)	$ (165.20)	$ (199.40)
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic						185,084				184,756	184,619	122,579
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted			18,194,682			185,084			6,131,541	184,756	184,619	122,579
Series A and Series B
Other comprehensive loss:
Net loss per share attributable to common stockholders, basic			$ (0.35)						$ (3.22)
Net loss per share attributable to common stockholders, diluted			$ (0.35)						$ (3.22)
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic			18,194,682						6,131,541
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted			18,194,682						6,131,541
Redeemable Convertible Preferred Stock Warrant
Other income, net:
Change in fair value of redeemable convertible preferred stock warrants						$ 1,000			$ (1,000)	$ 3,000	$ (3,000)	$ (2,000)
Series A Common Stock Warrants
Other income, net:
Change in fair value of redeemable convertible preferred stock warrants			$ 4,000						$ 4,000

CONDENSED STATEMENT OF REDEEMAB

CONDENSED STATEMENT 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, 2020			$ 1	$ 31,016	$ (166,927)				$ (135,910)
Beginning balance (in shares) at Dec. 31, 2020			96,507
Increase (Decrease) In Stockholders' Deficit
Net loss					(24,442)				(24,442)
Exercise of stock options				149					149
Exercise of stock options (in shares)			23,266
Exercise of common stock warrants				40					40
Exercise of common stock warrants (in shares)			63,684
Stock-based compensation expense				1,904					1,904
Ending balance at Dec. 31, 2021			$ 1	33,109	(191,369)				(158,259)
Ending balance (in shares) at Dec. 31, 2021			183,457
Increase (Decrease) In Stockholders' Deficit
Net loss					(8,735)				(8,735)
Exercise of stock options				12					12
Exercise of stock options (in shares)			1,627
Stock-based compensation expense				387					387
Ending balance at Mar. 31, 2022			$ 1	33,508	(200,104)				(166,595)
Ending balance (in shares) at Mar. 31, 2022			185,084
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 loss									(23,304)
Unrealized gain (loss) on investments in marketable securities									(162)
Ending balance at Sep. 30, 2022			$ 1	34,280	(214,673)	$ (162)			(180,554)
Ending balance (in shares) at Sep. 30, 2022			185,084
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 loss					(30,499)				(30,499)
Exercise of stock options				12					$ 12
Exercise of stock options (in shares)			1,627						1,627
Unrealized gain (loss) on investments in 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
Beginning balance at Mar. 31, 2022			$ 1	33,508	(200,104)				$ (166,595)
Beginning balance (in shares) at Mar. 31, 2022			185,084
Increase (Decrease) In Stockholders' Deficit
Net loss					(7,102)				(7,102)
Unrealized gain (loss) on investments in marketable securities						(106)			(106)
Stock-based compensation expense				383					383
Ending balance at Jun. 30, 2022			$ 1	33,891	(207,206)	(106)			(173,420)
Ending balance (in shares) at Jun. 30, 2022			185,084
Increase (Decrease) In Stockholders' Deficit
Net loss					(7,467)				(7,467)
Unrealized gain (loss) on investments in marketable securities						(56)			(56)
Stock-based compensation expense				389					389
Ending balance at Sep. 30, 2022			$ 1	34,280	(214,673)	(162)			(180,554)
Ending balance (in shares) at Sep. 30, 2022			185,084
Beginning balance at Dec. 31, 2022			$ 1	35,001	(221,868)	(84)			$ (186,950)
Beginning balance (in shares) at Dec. 31, 2022			185,084				0	0	185,084
Increase (Decrease) In Stockholders' Deficit
Net loss					(6,587)				$ (6,587)
Unrealized gain (loss) on investments in marketable securities						71			71
Stock-based compensation expense				767					767
Ending balance at Mar. 31, 2023			$ 1	35,768	(228,455)	(13)			(192,699)
Ending balance (in shares) at Mar. 31, 2023			185,084
Beginning balance at Dec. 31, 2022			$ 1	35,001	(221,868)	(84)			$ (186,950)
Beginning balance (in shares) at Dec. 31, 2022			185,084				0	0	185,084
Increase (Decrease) In Stockholders' Deficit
Net loss									$ (19,725)
Exercise of stock options (in shares)									7,614
Unrealized gain (loss) on investments in marketable securities									$ 84
Ending balance at Sep. 30, 2023	$ 2			339,466	(241,593)				97,875
Ending balance (in shares) at Sep. 30, 2023	21,375,402	1,520,490						1,520,490
Beginning balance at Mar. 31, 2023			$ 1	35,768	(228,455)	(13)			(192,699)
Beginning balance (in shares) at Mar. 31, 2023			185,084
Increase (Decrease) In Stockholders' Deficit
Net loss					(6,785)				(6,785)
Exercise of common stock warrants (in shares)			25,231
Unrealized gain (loss) on investments in marketable securities						$ 13			13
Stock-based compensation expense				1,057					1,057
Ending balance at Jun. 30, 2023			$ 1	36,825	(235,240)				(198,414)
Ending balance (in shares) at Jun. 30, 2023			210,315
Increase (Decrease) In Stockholders' Deficit
Net loss					(6,353)				(6,353)
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
Reclass of Common Stock to Series A Common Stock	$ 1		$ (1)
Reclass 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				86,161					86,161
Sale of Series A Common Stock in public offering, net of issuance costs (in shares)	6,026,772
Exercise of stock options				6					6
Exercise of stock options (in shares)	7,614
Exercise of common stock warrants (in shares)	12,789
Stock-based compensation expense				1,855					1,855
Ending balance at Sep. 30, 2023	$ 2			$ 339,466	$ (241,593)				$ 97,875
Ending balance (in shares) at Sep. 30, 2023	21,375,402	1,520,490						1,520,490

CONDENSED STATEMENT OF REDEEM_2

CONDENSED STATEMENT OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - Temporary Equity - USD ($)	Redeemable convertible preferred stock	Total
Beginning balance, Temporary equity at Dec. 31, 2020	$ 202,885,000
Beginning balance, Temporary equity (in shares) at Dec. 31, 2020	1,289,245,218
Increase (Decrease) in Temporary Equity
Exercise of stock options		$ 149,000
Issuance of Series F redeemable convertible preferred stock, net of issuance costs of $16	$ 11,735,000
Issuance of Series F redeemable convertible preferred stock, net of issuance costs of $16 (in shares)	84,485,407
Ending balance, Temporary equity at Dec. 31, 2021	$ 214,620,000	$ 214,620,000
Ending balance, Temporary equity (in shares) at Dec. 31, 2021	1,373,730,625	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Exercise of stock options		$ 12,000
Ending balance, Temporary equity at Mar. 31, 2022	$ 214,620,000
Ending balance, Temporary equity (in shares) at Mar. 31, 2022	1,373,730,625
Beginning balance, Temporary equity at Dec. 31, 2021	$ 214,620,000	$ 214,620,000
Beginning balance, Temporary equity (in shares) at Dec. 31, 2021	1,373,730,625	1,373,730,625
Increase (Decrease) in Temporary Equity
Unrealized gain (loss) on investments in marketable securities		$ (162,000)
Ending balance, Temporary equity at Sep. 30, 2022	$ 214,620,000
Ending balance, Temporary equity (in shares) at Sep. 30, 2022	1,373,730,625
Beginning balance, Temporary equity at Dec. 31, 2021	$ 214,620,000	$ 214,620,000
Beginning balance, Temporary equity (in shares) at Dec. 31, 2021	1,373,730,625	1,373,730,625
Increase (Decrease) in Temporary Equity
Exercise of stock options		$ 12,000
Unrealized gain (loss) on investments in marketable securities		(84,000)
Ending balance, Temporary equity at Dec. 31, 2022	$ 214,620,000	$ 214,620,000
Ending balance, Temporary equity (in shares) at Dec. 31, 2022	1,373,730,625	1,373,730,625
Beginning balance, Temporary equity at Mar. 31, 2022	$ 214,620,000
Beginning balance, Temporary equity (in shares) at Mar. 31, 2022	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Unrealized gain (loss) on investments in marketable securities		$ (106,000)
Ending balance, Temporary equity at Jun. 30, 2022	$ 214,620,000
Ending balance, Temporary equity (in shares) at Jun. 30, 2022	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Unrealized gain (loss) on investments in marketable securities		(56,000)
Ending balance, Temporary equity at Sep. 30, 2022	$ 214,620,000
Ending balance, Temporary equity (in shares) at Sep. 30, 2022	1,373,730,625
Beginning balance, Temporary equity at Dec. 31, 2022	$ 214,620,000	$ 214,620,000
Beginning balance, Temporary equity (in shares) at Dec. 31, 2022	1,373,730,625	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Unrealized gain (loss) on investments in marketable securities		$ 71,000
Ending balance, Temporary equity at Mar. 31, 2023	$ 214,620,000
Ending balance, Temporary equity (in shares) at Mar. 31, 2023	1,373,730,625
Beginning balance, Temporary equity at Dec. 31, 2022	$ 214,620,000	$ 214,620,000
Beginning balance, Temporary equity (in shares) at Dec. 31, 2022	1,373,730,625	1,373,730,625
Increase (Decrease) in Temporary Equity
Unrealized gain (loss) on investments in marketable securities		$ 84,000
Ending balance, Temporary equity (in shares) at Sep. 30, 2023		0
Beginning balance, Temporary equity at Mar. 31, 2023	$ 214,620,000
Beginning balance, Temporary equity (in shares) at Mar. 31, 2023	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Unrealized gain (loss) on investments in marketable securities		$ 13,000
Ending balance, Temporary equity at Jun. 30, 2023	$ 214,620,000
Ending balance, Temporary equity (in shares) at Jun. 30, 2023	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Exercise of stock options		6,000
Conversion of Redeemable Convertible Preferred Stock to Series A and Series B Common Stock	$ 1,373,730,625	$ 214,620,000
Conversion of Redeemable Convertible Preferred Stock to Series A and Series B Common Stock (in shares)	214,620,000
Ending balance, Temporary equity (in shares) at Sep. 30, 2023		0

CONDENSED STATEMENT OF REDEEM_3

CONDENSED STATEMENT OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) ( Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2021
CONDENSED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT)
Issuance costs	$ 10,267	$ 16

CONDENSED STATEMENTS OF CASH FL

CONDENSED STATEMENTS OF CASH FLOWS	12 Months Ended
	Dec. 31, 2021 USD ($)
Cash flows from operating activities
Net loss	$ (24,442,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash lease expense	134,000
Stock-based compensation expense	1,904,000
Change in fair value of redeemable convertible preferred stock warrants	(2,000)
Change in fair value of redeemable convertible preferred stock tranche liability	751,000
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(471,000)
Accounts payable and accrued expenses	560,000
Operating lease liabilities	(144,000)
Net cash used in operating activities	(21,710,000)
Cash flows from financing activities
Proceeds from issuance of redeemable convertible preferred stock, net	10,804,000
Proceeds from exercise of stock options and warrants	189,000
Payment of deferred financing costs	(1,254,000)
Net cash provided by (used in) financing activities	9,739,000
Net increase (decrease) in cash and cash equivalents	(11,971,000)
Cash and cash equivalents, beginning	68,702,000
Cash and cash equivalents, ending	56,731,000
Supplemental cash flow information
Unpaid deferred financing costs included in accounts payable and accrued expenses	171,000
Right-of-use assets obtained in exchange for operating lease obligations	282,000
Redeemable Convertible Preferred Stock Warrant
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value of redeemable convertible preferred stock warrants	$ 2,000

Organization and description of

Organization and description of business	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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 9. 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 September 30, 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, including net losses of $19.7 million for the nine months ended September 30, 2023 and $23.3 million for the nine months ended September 30, 2022. For the nine months ended September 30, 2023, and 2022, the Company had negative cash flows from operations of $16.7 million and $17.0 million, respectively. As of September 30, 2023, the Company had cash and cash equivalents of $101.8 million. The Company expects to incur additional losses and negative cash flows from operations for the next twelve months. As of November 13, 2023, the issuance date of these unaudited condensed financial statements, the Company expects that its cash and cash equivalents as of September 30, 2023 will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance of these condensed 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. Impact of COVID-19 pandemic on financial statements We experienced modest delays in our development activities as a result of the COVID-19 pandemic, primarily due to temporary closures of certain clinical sites that delayed patient enrollment in our FASCINATE-2 trial. Although the public health emergency declarations related to COVID-19 in the United States ended on May 11, 2023, the extent to which the COVID-19 pandemic will continue to impact our operations or those of our consultants and collaborators, will depend on future developments, including the global macroeconomic effects of the virus. Economic recessions, increased inflation and/or interest rates, and any disruptions to our operations or workforce availability, including those brought on by the continued effects of the COVID-19 pandemic or a similar health epidemic may have a negative effect on our operating results. Unaudited interim financial information The accompanying condensed balance sheet as of September 30, 2023, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 and 2022, the condensed statements of redeemable convertible preferred stock and stockholders’ equity (deficit) for the three and nine months ended September 30, 2023 and 2022, the condensed statements of cash flows for the nine months ended September 30, 2023 and 2022, and the related disclosures are unaudited. These unaudited condensed financial statements include all adjustments necessary, consisting of only normal recurring adjustments, to fairly state the financial position and the results of the Company’s operations and cash flows for interim periods in accordance with accounting principles generally accepted in the United States of America (GAAP). Interim period results are not necessarily indicative of results of operations or cash flows for a full year or any subsequent interim period. The condensed balance sheet as of December 31, 2022 has been derived from the audited financial statements of the Company. The accompanying unaudited condensed financial statements should be read in conjunction with the Company’s audited financial statements included elsewhere in this prospectus.	SAGIMET BIOSCIENCES INC. NOTES TO THE FINANCIAL STATEMENTS 1. 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 focused on developing a portfolio of in-house discovered, selective fatty acid synthase (FASN) inhibitors for the treatment of diseases that result from dysfunctional lipid metabolism pathways. 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. To date, the Company has relied on private equity and debt financings to fund its operations. The Company has incurred net losses and negative cash flows from operations since inception, including net losses of $30.5 million and $24.4 million for the years ended December 31, 2022 and 2021, respectively. For the years ended December 31, 2022 and 2021, the Company had negative cash flows from operations of $24.5 million and $21.7 million, respectively. As of December 31, 2022, the Company had cash, cash equivalents and short-term investments in marketable securities of $32.3 million. The Company expects to incur additional losses and negative cash flows from operations for the next twelve months. Based on its recurring losses from operations incurred since inception, expectation of continuing operating losses for the foreseeable future, and need to raise additional capital to finance its future operations, the Company has concluded that there is substantial doubt regarding the Company’s ability to continue as a going concern within one year after the date that these financial statements are issued. The Company will require substantial additional capital to fund its research and development and ongoing operating expenses. The Company is seeking to complete an initial public offering (IPO) of its Series A common stock. In the event the Company does not complete an IPO, the Company expects to seek additional funding through private equity financings, debt financings or other sources. The Company may not be able to obtain funding on acceptable terms, or at all. The terms of any future financing may adversely affect the holdings or the rights of the Company’s existing stockholders. If the Company is unable to raise additional funds when needed, it may be required to delay, reduce or eliminate its research and development. The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. These financial statements do not include any adjustments that might result from the outcome of this uncertainty. Impact of COVID-19 pandemic on financial statements The outbreak of the 2019 novel coronavirus disease (COVID-19), which was declared a global pandemic by the World Health Organization on March 11, 2020, and the related responses by public health and governmental authorities to contain and combat its outbreak and spread has severely impacted the U.S. and world economies during the end of the first quarter of 2020 and continuing through the end of 2022. COVID-19 and the U.S. response to the pandemic are significantly affecting the economy. There are no comparable events that provide guidance as to the effect the COVID-19 pandemic may have, and, as a result, the ultimate effect of the pandemic is highly uncertain and subject to change. The Company does not yet know the full extent of the effects on the economy, the markets it serves, its business, or its operations. Moving forward, economic recessions, increased inflation and/or interest rates, including those brought on by the continued COVID-19 outbreak may have a negative effect on the Company’s operating results. Any prolonged disruption to our operations or workforce availability is likely to have a significant adverse effect on the Company’s results of operations and cash flows. All of the above may be exacerbated in the future as the COVID-19 outbreak and the governmental responses thereto continue.

Summary of significant accounti

Summary of significant accounting policies	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Summary of significant accounting policies
Summary of significant accounting policies	2. Summary of significant accounting policies Basis of presentation The condensed financial statements and accompanying notes have been prepared in accordance with GAAP and the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. These condensed financial statements have been prepared on the same basis as the annual financial statements included elsewhere in this prospectus. In the Company’s opinion, the information furnished in these condensed financial statements reflects all adjustments, all of which are of a normal and recurring nature necessary for a fair presentation of the financial position and results of operations for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period. 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 expenses during the reporting period. Such estimates include accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock, common stock 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. Significant accounting policies The Company’s significant accounting policies are disclosed in the audited financial statements for the year ended December 31, 2022, included elsewhere in this prospectus, and the unaudited financial statements as of March 31, 2023 filed with the SEC. Since the date of those financial statements, there have been no changes to the Company’s significant accounting policies except as disclosed below in recently adopted accounting pronouncements. 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 The Company had no short-term investments in marketable securities as of September 30, 2023. Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s IPO are capitalized and recorded in the accrued expenses and other current liabilities in the condensed balance sheets. Upon closing of the IPO in July 2023, all deferred offering costs were reclassified to additional paid-in-capital in the condensed statements of operations and comprehensive loss, representing a reduction in IPO proceeds. On March 21, 2022, the Company withdrew its prior Registration Statement on Form S-1 initially filed with the SEC on April 16, 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 unaudited condensed statement of operations and comprehensive loss for the nine months ended September 30, 2022. 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 Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers 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). In January 2022, Ascletis BioScience Co. Ltd. (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 recorded as license revenue in the condensed statements of operations and comprehensive loss (representing the $2.0 million development milestone payment, net of applicable taxes) from Ascletis. Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash, cash equivalents and marketable securities. 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 Financial Accounting Standards Board (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	2. 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). 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 expenses during the reporting period. Such estimates include accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock, common stock 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. 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, 2022 and 2021, 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 securities as available-for-sale and records such assets at estimated fair value in the balance sheets, with unrealized gains and losses that are determined to be temporary, if any, reported as a component of other comprehensive income (loss) within the statements of operations and comprehensive loss and as a separate component of stockholders’ deficit. The Company classifies marketable securities with remaining maturities greater than three months but less than one year as short-term investments, and those with remaining maturities greater than one year are classified as long-term investments. Investments are regularly reviewed for other-than-temporary declines in fair value. The review includes the consideration of the cause of the impairment, including the creditworthiness of the security issuers, the number of investments in an unrealized loss position, the severity and duration of the unrealized losses and whether it is more likely than not that the Company will be required to sell the investments before the recovery of their amortized cost basis. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the establishment of a new cost basis for the security. The Company invests its excess cash balances primarily in corporate debt securities with strong credit ratings. Realized gains and losses are calculated on the specific identification method and recorded as interest income and were immaterial for all periods presented. As of December 31, 2022, the Company’s short-term marketable securities were invested with Silicon Valley Bank (SVB), and custodied at U.S. bank. Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash, cash equivalents and marketable securities. Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s planned IPO are capitalized and recorded on the balance sheets. The deferred financing costs will be offset against the proceeds received upon the closing of the planned IPO. In the event that the Company’s plans for an IPO are terminated, all of the deferred financing costs will be written off within operating expenses in the Company’s statements of operations and comprehensive loss. As of December 31, 2021, there were $1.4 million of deferred financing costs capitalized related to the Company’s previous IPO plans in 2021. On March 21, 2022, the Company withdrew its Registration Statement on Form S-1 initially filed with the 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. As of December 31, 2022, there were no deferred financing costs capitalized. 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 Accounting Standards Update (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 twelve 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. Revenue recognition The Company enters into collaboration and licensing arrangements that generally contain multiple elements or deliverables, which may include (1) licenses to the Company’s technology, (2) research and development activities performed for the collaboration partner, (3) participation on joint steering committees (JSCs), and (4) 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 Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers 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). In January 2022, Ascletis initiated dosing of a Phase 3 trial for recurrent GBM, potentially triggering a $2.0 million development milestone payment under the license agreement. Due to the uncertainty around the achievement of the milestone and ongoing discussions with Ascletis around the consideration for the milestone, the Company concluded it was probable that a significant reversal of the revenue related to the milestone would occur, and therefore, no revenue was recognized. 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 non-alcoholic steatohepatitis (NASH) 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. The CODM evaluates the Company’s financial information and assesses the performance of the Company based on the single operating segment. The Company assesses its determination of operating segments at least annually and continues to evaluate the internal reporting structure and potential impacts of any changes to its segment reporting. Common stock valuation Due to the absence of an active market for the Company’s common stock, the Company utilized methodologies in accordance with the framework of the American Institute of Certified Public Accountants Technical Practice Aid (Valuation of Privately Held Company Equity Securities Issued as Compensation) to estimate the fair value of its common stock. In determining the exercise prices for options granted, the Company has considered the estimated fair value of the common stock as of the measurement date. The estimated fair value of the common stock has been determined at each grant date based upon a variety of factors, including the illiquid nature of the common stock, arm’s-length sales of the Company’s capital stock (including redeemable convertible preferred stock), the effect of the rights and preferences of the redeemable convertible preferred stockholders, and the prospects of a liquidity event. Among other factors are the Company’s financial position and historical financial performance, the status of technological developments within the Company’s research, the composition and ability of the current research and management team, an evaluation or benchmark of the Company’s competition, and the current business climate in the marketplace. Significant changes to the key assumptions underlying the factors used could result in different fair values of common stock at each valuation date. Redeemable convertible preferred stock The Company records redeemable convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The redeemable convertible preferred stock is recorded outside of stockholders’ deficit because the shares contain liquidation features that are not solely within the Company’s control. The Company has not adjusted the carrying values of the redeemable convertible preferred stock to the liquidation preferences of such shares because it is 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. Subsequent adjustments to the carrying values to the liquidation preferences will be made only when it becomes probable that such a liquidation event will occur. Redeemable convertible preferred stock tranche liability The Company determined the right of the investors to purchase shares of Series F redeemable convertible preferred stock at a future date met the definition of a freestanding instrument and was recognized as a liability at fair value upon the December 2020 issuance of Series F redeemable convertible preferred stock (Redeemable Convertible Preferred Stock Tranche Liability). The liability was subject to remeasurement at each balance sheet date, with changes in fair value recognized in other income (expense) in the statements of operations and comprehensive loss. Upon closing of the Series F redeemable convertible preferred stock financing in February 2021, the Redeemable Convertible Preferred Stock Tranche Liability was extinguished, and the marked-to-market fair value of the liability was included in the carrying value of redeemable convertible preferred stock issued. 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 Financial Accounting Standards Board (FASB) ASC 815, Derivatives and Hedging Under ASC 815-40, warrants that meet the criteria for equity treatment are recorded in stockholders’ deficit. The warrants are subject to re-evaluation of the proper classification and accounting treatment at each reporting period. If the warrants no longer meet the criteria for equity treatment, they will be recorded as a liability and remeasured each period with changes recorded in the statement of operations and comprehensive loss. When issued in connection with debt, the allocated value related to the warrants is generally recorded as additional interest cost on the related debt. When issued with redeemable convertible preferred stock, the allocated value related to the warrants is recorded as additional issuance costs of the redeemable convertible preferred stock. The Company values warrants using an option pricing model. Stock-based compensation expense The Company accounts for all stock-based payment awards granted to employees and non-employees as stock-based compensation expense at fair value. The Company’s stock-based payments include stock options and grants of common stock, including common stock subject to vesting. The measurement date for employee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight- line basis. Stock-based compensation costs for non-employees are recognized as expense over the vesting period on a straight-line basis. Stock-based compensation expense is classified in the accompanying statements of operations and comprehensive loss based on the function to which the related services are provided. The Company recognizes stock-based compensation expense for the portion of awards that have vested. Forfeitures are recorded as they occur. 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. For awards with service-based vesting conditions only, the Company recognizes share-based compensation expense on a straight-line basis over the requisite service or vesting period. For awards with service- and performance-based vesting conditions, the Company recognizes stock-based compensation expense using the graded vesting method over the requisite service period beginning in the period in which the awards are deemed probable to vest, to the extent such awards are probable to vest. The Company recognizes the cumulative effect of changes in the probability outcomes in the period in which the changes occur. 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, 2022 and 2021, 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’ 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 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 and common and redeemable convertible preferred stock warrants are considered to be potentially dilutive securities. Basic and diluted net loss per share attributable to common stockholders is presented inconformity with the two-class method required for participating securities as the redeemable convertible preferred stock is considered a participating security. 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. As the Company has reported a net loss for the period presented, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders for this period. 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 In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments 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

Fair value measurements and fai

Fair value measurements and fair value of financial instruments	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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 September 30, 2023 and December 31, 2022, financial assets measured at fair value on a recurring basis consist of cash and cash equivalents. The carrying amount of cash and cash equivalents was $101.8 million and $0.2 million as of September 30, 2023 and December 31, 2022, respectively, which approximates the fair value and was determined based upon Level 1 inputs. The fair value of short-term investments 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. Marketable securities, all of which are classified as available-for-sale securities, consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ Amortized Unrealized Unrealized Estimated ​ ​ cost ​ Gains ​ Losses ​ Fair Value Commercial paper ​ $ 15,950 ​ $ — ​ $ — ​ $ 15,950 Corporate debt securities ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ 4,035 ​ — ​ (19) ​ 4,016 Total ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187 ​ There were no investments in marketable securities as of September 30, 2023. The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ fair value Level 1 Level 2 Level 3 Liabilities: ​ ​ ​ ​ Series A Common Stock Warrant Liability ​ $ 1 ​ $ — ​ $ — ​ $ 1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ value ​ Level 1 ​ Level 2 ​ Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents - money market funds ​ $ 38 ​ $ 38 ​ $ — ​ $ — Commercial paper ​ 15,950 ​ — ​ 15,950 ​ — Corporate debt securities ​ 12,221 ​ — ​ 12,221 ​ — U.S. Treasury securities ​ 4,016 ​ — ​ 4,016 ​ — Total ​ $ 32,225 ​ $ 38 ​ $ 32,187 ​ $ — Liabilities: ​ ​ ​ ​ Redeemable Convertible Preferred Stock Warrant Liability ​ $ 4 ​ $ — ​ $ — ​ $ 4 ​ 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, 2023 $ 4 Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ 1 Change in fair value of Series A Common Stock Warrant Liability ​ ​ (4) Balance - September 30, 2023 ​ $ 1 Balance - January 1, 2022 ​ $ 7 Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ (3) Balance - December 31, 2022 ​ $ 4 ​ 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. See Note 9. 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. The exercise was deemed a cashless exercise. 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 September 30, 2023, the fair value of the Series A Common Stock Warrant Liability was determined to be $1.4 thousand assuming a volatility rate of 91.5%, an expected term of 2.80 years, no dividends, and a risk-free interest rate of 4.87%. As of December 31, 2022, the fair value of the Redeemable Convertible Preferred Stock Warrant Liability was determined to be $4.0 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%. For the change in fair value of the Series A Common Stock Warrant Liability, the Company recorded other income of $4.0 thousand for both the three and nine months ended September 30, 2023, respectively, in its unaudited condensed statement of operations and comprehensive loss. For the change in fair value of the Redeemable Convertible Preferred Stock Warrant Liability, the Company recorded other expense of $1.0 thousand for the nine months ended September 30, 2023, and other income of $1.0 thousand and $3.0 thousand for the three and nine months ended September 30, 2022, respectively, in its unaudited condensed statement of operations and comprehensive loss.	3. 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— During the years ended December 31, 2022 and 2021, financial assets measured at fair value on a recurring basis consist of cash and cash equivalents which include deposits in a money market fund and short-term investments including commercial paper, corporate debt and U.S. Treasury securities. The carrying amount of cash and cash equivalents was $0.2 million and $56.7 million as of December 31, 2022 and 2021, respectively, which approximates the fair value and was determined based upon Level 1 inputs. The fair value of short-term investments 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 consist of the redeemable convertible preferred stock warrant liability and Redeemable Convertible Preferred Stock Tranche Liability. Marketable securities, all of which are classified as available-for-sale securities, consisted of the following at December 31, 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ ​ Cost ​ Gains ​ Losses ​ Fair Value Commercial paper $ 15,950 $ — $ — $ 15,950 Corporate debt securities ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ 4,035 ​ — ​ (19) ​ 4,016 Total ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187 ​ There were no marketable securities at December 31, 2021. The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ value ​ Level 1 ​ Level 2 ​ Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents – money market funds ​ $ 38 ​ $ 38 ​ $ — ​ $ — Commercial paper ​ 15,950 ​ — ​ 15,950 ​ — Corporate debt securities ​ 12,221 ​ — ​ 12,221 ​ — U.S. Treasury securities ​ 4,016 ​ — ​ 4,016 ​ — Total ​ $ 32,225 ​ $ 38 ​ $ 32,187 ​ $ — Liabilities: ​ ​ ​ ​ Redeemable convertible preferred stock warrant liability ​ $ 4 ​ $ — ​ $ — ​ $ 4 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ value Level 1 Level 2 Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents – money market funds ​ $ 56,631 ​ $ 56,631 ​ $    — ​ $ — Liabilities: ​ ​ ​ ​ Redeemable convertible preferred stock warrant liability ​ $ 7 ​ $ — ​ $ — ​ $ 7 ​ The following table provides a summary of changes in the estimated fair value of the financial instruments using significant Level 3 inputs (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Redeemable Redeemable ​ ​ convertible ​ convertible ​ ​ preferred ​ preferred ​ ​ stock ​ stock ​ ​ warrant ​ tranche ​ ​ liability ​ liability Balance – January 1, 2021 ​ $ 9 ​ $ — Change in fair value of redeemable convertible preferred stock warrant liability and establishment of Redeemable Convertible Preferred Stock Tranche Liability ​ (2) ​ 751 Extinguishment of Redeemable Convertible Stock Tranche Liability upon subsequent issuance of Series F redeemable convertible preferred stock ​ — ​ (751) Balance – December 31, 2021 ​ $ 7 ​ $ — Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ (3) ​ — Balance – December 31, 2022 ​ $ 4 ​ $ — ​ 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 In April 2015, the Company entered into a debt agreement with a financial institution which was repaid in full on May 15, 2019. In connection with the debt agreement, the Company issued to the lender 79,545 warrants to purchase Series D redeemable convertible preferred stock with an exercise price of $0.88 per share exercisable immediately with a contractual term of 10 years. The Company estimates the fair value of 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, as well as assumptions for fair value of the underlying redeemable convertible preferred stock, expected volatility, expected life, dividends and risk-free interest rate. The Company will continue to adjust the liability for changes in fair value of these warrants until the earlier of: (i) exercise of warrants; (ii) expiration of warrants; (iii) a change of control of the Company; or (iv) the consummation of an IPO. 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%. As of December 31, 2021, the fair value of the Redeemable Convertible Preferred Stock Warrant Liability was determined to be $7 thousand assuming a volatility rate of 87.2%, an expected term of 3.27 years, no dividends, and a risk-free interest rate of 1.01%. The Company recorded other income of $3 thousand and $2 thousand for the change in fair value of the Redeemable Convertible Preferred Stock Warrant Liability in its statement of operations and comprehensive loss for the years ended December 31, 2022 and 2021, respectively. Redeemable Convertible Preferred Stock Tranche Liability The Company determined the right of an investor to purchase shares of Series F redeemable convertible preferred stock in December 2020 met the definition of a freestanding instrument and was classified as a liability. The fair value in December 2020 was determined to be negligible. Immediately prior to the issuance and sale of Series F redeemable convertible preferred stock in February 2021, the fair value of the Redeemable Convertible Preferred Stock Tranche Liability was calculated to be $0.8 million. The fair value of the Redeemable Convertible Preferred Stock Tranche Liability was estimated using the intrinsic value of the Series F redeemable convertible preferred stock of $0.1391 per share. In February 2021, upon the issuance and sale of shares of Series F redeemable convertible preferred stock, the Redeemable Convertible Preferred Stock Tranche Liability was extinguished. The Company recorded other expense of $0.8 million for the change in fair value of the Series F Redeemable Convertible Preferred Stock Tranche Liability in its statement of operations and comprehensive loss for the year ended December 31, 2021.

Prepaid expenses and other curr

Prepaid expenses and other current assets	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 Prepaid insurance ​ $ 865 ​ $ 61 Prepaid clinical expenses ​ ​ 32 ​ ​ 352 Other ​ 77 ​ 34 Total ​ $ 974 ​ $ 447 ​	4. Prepaid expenses and other current assets as of December 31, 2022 and 2021 consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Prepaid clinical expenses ​ $ 352 ​ $ 423 Deferred financing costs ​ — ​ 1,425 Other ​ 95 ​ 84 Total ​ $ 447 ​ $ 1,932 ​

Accrued expenses and other curr

Accrued expenses and other current liabilities	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 Accrued clinical costs ​ $ 2,239 ​ $ 3,162 Employees’ compensation ​ 689 ​ 636 Accrued research ​ ​ 221 ​ ​ — Accrued preclinical costs ​ — ​ 166 Other ​ 95 ​ 57 Total ​ $ 3,244 ​ $ 4,021 ​	5. Accrued expenses and other current liabilities as of December 31, 2022 and 2021 consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Accrued clinical costs ​ $ 3,162 ​ $ 852 Employees’ compensation ​ 636 ​ 463 Accrued pre-clinical costs ​ 166 ​ — Accrued deferred financing costs ​ — ​ 55 Other ​ 57 ​ 185 Total ​ $ 4,021 ​ $ 1,555 ​

Related parties

Related parties	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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, a subsidiary of Ascletis Pharma Inc. (Ascletis Pharma), biotechnology company incorporated in the Cayman Islands and headquartered in Hangzhou, China and a Company investor. 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 $28.1 thousand as reimbursement pursuant to the license agreement for Greater China patent prosecution costs during the nine months ended September 30, 2022. The Company did not receive any reimbursements pursuant to the license agreement for Greater China patent prosecution costs during the nine months ended September 30, 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. Ascletis Pharma, through a subsidiary, also led the Series E preferred stock financing in February 2019. As noted below, the Company received $2.0 million related to a development milestone in August, 2023. 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 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 condensed statement of operations and comprehensive loss) from Ascletis. There were no payments made to Ascletis during the nine months ended September 30, 2023. The Company paid Ascletis under their manufacturing arrangement $4.0 thousand during the nine months ended September 30, 2022. Assignment and Assumption Agreement In July 2023, the Company entered into an Assignment and Assumption Agreement with Ascletis and Ascletis’ affiliate 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.	6. University of Zurich and ETH Zurich In April 2007, the Company entered into a license agreement with the University of Zurich and ETH Zurich, both Company investors, for exclusive rights in the United States to certain know-how and patents related to antiviral drug testing. The license agreement remains in force until the last patent expires or the agreement is canceled by either party. Upon execution of the agreement, the Company issued 192 shares of common stock to ETH Zurich and issued 96 shares of common stock to the University of Zurich. Ascletis BioScience Co. Ltd In January 2019, the Company entered into a license agreement that became effective in February 2019 with Ascletis, a subsidiary of Ascletis Pharma Inc. (Ascletis Pharma), biotechnology company incorporated in the Cayman Islands and headquartered in Hangzhou, China and a Company investor. 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 and $0.1 million as reimbursement pursuant to the license agreement for Greater China patent prosecution costs during the years ended December 31, 2022 and 2021, respectively. 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. Ascletis Pharma, through a subsidiary, also led the Series E preferred stock financing in February 2019. Under a separate manufacturing agreement with Ascletis, during the years ended December 31, 2022 and 2021, the Company paid $4 thousand and $0.9 million, respectively for the manufacture of denifanstat drug supply. The Company recorded these payments as research and development expense in the statement of operations and comprehensive loss for the respective year. 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 GBM, potentially triggering a $2.0 million development milestone payment under the license agreement. Due to the uncertainty around the achievement of the milestone and ongoing discussions with Ascletis around the consideration for the milestone, the Company concluded it was probable that a significant reversal of the revenue related to the milestone would occur, and therefore, no revenue was recognized.

Commitments and contingencies

Commitments and contingencies	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Commitments and contingencies
Commitments and contingencies	7. Commitments and contingencies 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 for the three months ended September 30, 2023, and 2022 was $37.0 thousand and $38.0 thousand, respectively, and for the nine months ended September 30, 2023 and 2022 was $111.0 thousand and $113.0 thousand, respectively. The following are schedules by year of future maturities of the Company’s operating lease liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ 2023 Remainder of 2023 $ 27 2024 ​ 79 Total lease payments ​ 106 Less: interest ​ (3) Total ​ $ 103 ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2023 $ 157 2024 ​ 80 Total lease payments ​ 237 Less: interest ​ (26) Total ​ $ 211 ​ Supplemental cash flow information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ Nine Months Ended September 30, ​ 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 118 ​ $ 118 ​ The weighted-average remaining lease term and discount rate related to the Company’s lease liabilities as of September 30, 2023 and December 31, 2022 were 0.75 years and 7% and 1.2 years and 7%, respectively. The Company’s lease discount rate is based on estimates of its incremental borrowing rate, as the discount rate implicit in the Company’s lease cannot be readily determined. As the Company does not have any outstanding debt, the Company estimates the incremental borrowing rate based on its estimated credit rating and available market information. 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 September 30, 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.	7. Facility lease agreement On March 12, 2019, the Company executed a 38 Operating lease cost for the years ended December 31, 2022 and 2021 was $0.2 million and $0.1 million, respectively. The following is a schedule by year of future maturities of the Company’s operating lease liabilities as of December 31, 2022 (in thousands): ​ ​ ​ ​ 2023 $ 157 2024 ​ ​ 80 Total lease payments ​ ​ 237 Less: interest ​ ​ (26) Total ​ $ 211 ​ Supplemental cash flow information related to leases was as follows for the years ended December 31, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year ended Year ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 157 ​ $ 157 Right-of-use assets obtained in exchange for lease obligations (non-cash): ​ ​ Operating leases ​ $ — ​ $ 282 ​ The weighted-average remaining lease term and discount rate related to the Company’s lease liabilities as of December 31, 2022 and 2021 were 1.2 years and 7% and 2.5 years and 7%, respectively. The Company’s lease discount rate is based on estimates of its incremental borrowing rate, as the discount rate implicit in the Company’s lease cannot be readily determined. As the Company does not have any outstanding debt, the Company estimates the incremental borrowing rate based on its estimated credit rating and available market information. 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. 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, 2022, and 2021, 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.

Redeemable convertible preferre

Redeemable convertible preferred stock	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Redeemable convertible preferred stock
Redeemable convertible preferred stock	8. 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.	8. The authorized, issued and outstanding shares of the redeemable convertible preferred stock, liquidation preferences and carrying values as of December 31, 2022 and 2021 were as follows (in thousands, except share numbers): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 and 2021 ​ ​ ​ ​ Issued and ​ ​ ​ ​ ​ ​ ​ ​ Authorized ​ Outstanding ​ Liquidation ​ Carrying Series 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 ​ Issuance of Series F redeemable convertible preferred stock On February 10, 2021, the Company received $11.0 million net of issuance costs from a closing of its Series F financing from new and existing investors, resulting in the issuance of 84,485,407 shares of Series F redeemable convertible preferred stock at $0.13020 per share (the Series F Original Issue Price). Rights, preferences and privileges of the redeemable convertible preferred stock The rights, preferences and privileges of the redeemable convertible preferred stock were as follows: Dividends. Company’s board of directors. Dividends on redeemable convertible preferred stock shall be payable in preference to and prior to any payments of any dividends on common stock. No dividends have been declared to date. Conversion. All of the redeemable convertible preferred stock will automatically convert into common stock, at the then-applicable conversion rate, in the event of either (i) the affirmative vote of the holders of a majority of the then-outstanding shares of series preferred, voting together as a single class on an as-converted to common stock basis, and the affirmative vote of the holders of a majority of the then-outstanding shares of Series F redeemable convertible preferred stock, or (ii) the closing of an underwritten IPO of the Company’s common stock pursuant to a registration statement on Form S-1 under the Securities Act of 1933, as amended, at a price of at least 1.25 times the Series F Original Issue Price, with aggregate gross proceeds of not less than $50.0 million. The Series D-1 is convertible into that number of fully-paid and nonassessable shares of common stock that is equal to $69.94 (as adjusted for stock splits, business combinations and reorganizations), divided by $18.0 million, subject to adjustments. Voting rights Liquidation. pari passu Deemed liquidation. The holders of Series A, B, B-1, C, D, D-1, E and F redeemable convertible preferred stock have certain liquidation rights in the event of a deemed liquidation that, in certain situations, are not solely within the control of the Company and would call for the redemption of the then outstanding Series A, B, B-1, C, D, D-1, E and F redeemable convertible preferred stock. Therefore, the Series A, B, B-1, C, D, D-1, E and F redeemable convertible preferred stock are classified outside of stockholders’ deficit on the balance sheets. The carrying value of the redeemable convertible preferred stock is not subsequently remeasured to the redemption value until the contingent redemption events are considered to be probable of occurring.

Stockholders' deficit

Stockholders' deficit	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Stockholders' equity (deficit)
Stockholders' deficit	9. 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: ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ 2023 2022 Options to purchase Series A common stock 3,766,505 3,190,450 Options authorized and available for issuance 2,585,968 181,191 Warrant to purchase Series A Common Stock ​ 1,000 ​ — Redeemable convertible preferred stock — 1,322,399,477 Series D redeemable convertible preferred stock warrant — 79,545 Warrants to purchase common stock — 40,268 Total 6,353,473 1,325,890,931 ​ 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 with an exercise price of $0.88 per share. The warrant has a term of 10 years and are exercisable in whole or in part, at any time on or before the expiration date of April 10, 2025. At the time of issuance, the fair value of the Redeemable Convertible Preferred Stock Warrant Liability was determined using an option pricing model and assumptions that are based on the individual characteristics of the warrant on the valuation date, as well as assumptions for fair value of the underlying redeemable convertible preferred stock, expected volatility, expected life, dividends and risk-free interest rate. The Company completed its IPO on July 18, 2023. Subsequently, the Redeemable Convertible Preferred Stock Warrant was converted to a warrant to purchase 1,000 shares of Series A common stock at an exercise price of $69.94 per share and the expiration date was automatically extended until July 18, 2026, the third anniversary date of the closing of the Company’s IPO. If the warrant has not been exercised prior to the expiration date, the warrant will be deemed to have been automatically exercised on the expiration date by cashless conversion. The holder of the warrant has no voting rights, or other rights as a stockholder of the Company. The warrant is subject to adjustment in the event of any diluting dividends or distributions of the common stock, or any stock split, reverse stock split, recapitalization, reorganization or similar transaction. Upon any reclassification, exchange, substitution or other event, the number and or class of the securities and property that the holder would have received for the shares if this warrant had been issued immediately before such event will be adjusted. Stock warrants The following tables summarize the Company’s outstanding Series A Common Stock Warrant, Common Stock warrants and redeemable convertible preferred stock warrants: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, 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 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ Fair Value on ​ 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 ​	9. Common stock In connection with the adoption of an amendment to the Company’s tenth amended and restated certificate of incorporation filed September 27, 2022, the number of shares of common stock that the Company is authorized to issue increased from 1,590,550,754 to 1,608,370,000. The Company’s reserved shares of common stock for future issuance related to potential conversion of the redeemable convertible preferred stock, exercise of warrants and exercise of stock options as of December 31, 2022 and 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Redeemable convertible preferred stock 1,322,399,477 1,322,399,477 Series D redeemable convertible preferred stock warrants 79,545 79,545 Options authorized and available for issuance 181,191 810,604 Options to purchase common stock 3,190,450 2,138,110 Warrants to purchase common stock 40,268 40,268 Total 1,325,890,931 1,325,468,004 ​ Redeemable Convertible Preferred 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 79,545 Series D redeemable convertible preferred stock warrants with an exercise price of $0.88 per share. The warrants have a term of 10 years and are exercisable in whole or in part, at any time on or before the expiration date of April 10, 2025. At the time of issuance, the fair value of the Redeemable Convertible Preferred Stock Warrant Liability was determined using an option pricing model and assumptions that are based on the individual characteristics of the warrant on the valuation date, as well as assumptions for fair value of the underlying redeemable convertible preferred stock, expected volatility, expected life, dividends and risk-free interest rate (see Note 2). The Series D redeemable convertible preferred stock warrant has no voting rights, or other rights as a stockholder of the Company. The warrant is subject to adjustment in the event of any diluting dividends or distributions of the common stock, or any stock split, reverse stock split, recapitalization, reorganization or similar transaction. Upon any reclassification, exchange, substitution or other event, the number and or class of the securities and property that the holder would have received for the shares if this warrant had been issued immediately before such event will be adjusted. If the Company completes an IPO within the three-year period immediately prior to the expiration date, the expiration date will automatically be extended until the third anniversary of the effective date of the Company’s IPO. If the warrant has not been exercised prior to the expiration date, the warrant will be deemed to have been automatically exercised on the expiration date by cashless conversion. Stock warrants As of December 31, 2022 and 2021, the following tables summarize the Company’s outstanding common and redeemable convertible preferred stock warrants: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 and 2021 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ Fair Value ​ Fair Value ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ on Issuance ​ Recorded Issuance Date Shares Share Date for (in thousands) Against June 2013 26,846 ​ $ 0.79 June 2023 Common ​ $ 339 Redeemable January 2014 13,422 ​ $ 0.79 January 2024 Common ​ 223 Redeemable April 2015 79,545 ​ $ 0.88 April 2025 Series D ​ 68 Debt ​

Stock-based compensation

Stock-based compensation	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Stock-based compensation
Stock-based compensation	10. Stock-based compensation In 2007, the Company adopted the 2007 Equity Incentive Plan (2007 Plan), as amended, which allowed for the granting of incentive stock options (ISOs) and non-statutory stock options (NSOs) to the employees, members of the Company’s board of directors, and consultants of the Company. In 2017, the 2007 Plan expired pursuant to its terms and the Company adopted the 2017 Equity Incentive Plan (2017 Plan) which allowed for the granting of ISOs and NSOs as well as stock appreciation rights, restricted stock awards, restricted stock units and other stock awards to employees, members of the Company’s board of directors and consultants. ISOs could be granted only to Company’s employees, including officers and directors who are also employees. NSOs could be granted to employees, directors and consultants. 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 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, 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, which will automatically increase on January 1, 2024 and each January 1 thereafter, 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 September 30, 2023, 2,585,968 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 at prices no 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 (498) ​ ​ 4.77 ​ Options expired (1,752) ​ ​ 0.79 ​ Outstanding, September 30, 2023 3,766,505 ​ $ 8.11 7.69 ​ $ 17,737 Shares vested and exercisable as of September 30, 2023 1,784,725 ​ $ 6.98 6.34 ​ $ 10,206 ​ The aggregate intrinsic value is calculated as the difference between the option exercise price and the estimated fair value of the underlying common stock. Time-based options The Company may award time-based options which vest and become exercisable, subject to the participant’s continued employment or service through the applicable vesting date. Options granted have various vesting schedules including some that vest immediately and some that vest over four years. The following table summarizes time-based stock option activity: ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ ​ ​ Shares ​ ​ ​ ​ ​ Underlying ​ Weighted- ​ ​ Outstanding ​ Average ​ ​ Options ​ Exercise Price Outstanding, January 1, 2023 2,570,708 ​ $ 7.56 Options granted 585,919 ​ 13.51 Options exercised ​ (7,614) ​ ​ 0.79 Options cancelled (498) ​ 4.77 Options expired (1,752) ​ 0.79 Outstanding, September 30, 2023 3,146,763 ​ $ 8.69 Shares vested and exercisable as of September 30, 2023 1,186,212 ​ $ 14.42 ​ The total fair value of the time-based shares vested during the nine months ended September 30, 2023 was $1.8 million. As of September 30, 2023, there was $12.0 million of total unrecognized compensation cost related to the awards. The cost is being recognized over a remaining weighted-average period of 2.4 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 was 619,742 with a weighted-average exercise price of $6.38 as of December 31, 2022 and September 30, 2023, respectively. There were 598,513 shares vested and exercisable as of September 30, 2023. The total fair value of the performance-based shares vested during the nine months ended September 30, 2023 was $11.1 thousand. As of the nine months ended September 30, 2023, there was $28.2 thousand of unrecognized compensation cost related to the awards. The cost is being recognized over a remaining weighted-average period of less than one year. The Company has recorded aggregate stock-based compensation expense related to the issuance of stock option awards to employees and non-employees in the unaudited condensed statements of operations and comprehensive loss as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, Nine Months Ended September 30, ​ ​ 2023 2022 ​ 2023 ​ 2022 General and administrative expense ​ $ 1,649 ​ $ 220 ​ $ 3,103 ​ $ 663 Research and development expense ​ 206 ​ 169 ​ 576 ​ 496 Total stock-based compensation expense ​ $ 1,855 ​ $ 389 ​ $ 3,679 ​ $ 1,159 ​ The expected term of the stock options represents the average of the contractual term of the options and the weighted-average expected vesting period. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The expected volatility rate was based on the historical volatilities of comparable companies in the Company’s industry. The Company has never declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. Consequently, the Company used an expected dividend yield of zero. 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: ​ ​ ​ ​ Nine Months Ended Nine Months Ended ​ ​ ​ September 30, 2023 ​ September 30, 2022 ​ Expected volatility ​ 89 - 91 % 88 - 90 % Risk-free interest rate ​ 3.6 % 2.3 – 3.0 % 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, which will automatically increase on January 1, 2024 and each January 1 thereafter 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 nine months ended September 30, 2023, no shares of Series A common stock were issued under the 2023 ESPP.	10. In 2007, the Company adopted the 2007 Equity Incentive Plan, as amended, which allowed for the granting of incentive stock options (ISOs) and non-statutory stock options (NSOs) to the employees, members of the Company’s board of directors, and consultants of the Company. In 2017, the 2007 Equity Incentive Plan expired pursuant to its terms and the Company adopted the 2017 Equity Incentive Plan (2017 Plan) which allows for the granting of ISOs and NSOs as well as stock appreciation rights, restricted stock awards, restricted stock units and other stock awards to employees, members of the Company’s board of directors and consultants. ISOs may be granted only to Company’s employees, including officers and directors who are also employees. NSOs may be granted to employees, directors and consultants. As of December 31, 2022 and 2021, 181,191 and 810,604 shares are available for future grant under the 2017 Plan, respectively. Options under the 2017 Plan may be granted for periods of up to ten years and at prices no 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 shall 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 for the year ended December 31, 2022 (in thousands, except share and per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ Number of Shares ​ Weighted- ​ Remaining ​ ​ ​ ​ ​ Underlying ​ Average ​ Contractual ​ Aggregate ​ ​ Outstanding ​ Exercise ​ Term ​ Intrinsic ​ ​ Options ​ Price ​ (in Years) ​ Value Outstanding, January 1, 2022 2,138,110 ​ $ 7.15 8.1 ​ $ 4,670 Options granted 1,080,304 ​ $ 7.15 ​ Options exercised (1,627) ​ $ 7.24 ​ Options cancelled (887) ​ $ 31.46 ​ Options expired (25,450) ​ $ 12.75 ​ Outstanding, December 31, 2022 3,190,450 ​ $ 7.10 8.1 ​ 3,998 Shares vested and exercisable as of December 31, 2022 1,510,555 ​ $ 7.15 6.8 ​ 2,303 ​ The aggregate intrinsic value is calculated as the difference between the option exercise price and the estimated fair value of the underlying common stock. Time-based options The Company may award time-based options which vest and become exercisable, subject to the participant’s continued employment or service through the applicable vesting date. Options granted have various vesting schedules including some that vest immediately and some that vest over four years. The following table summarizes time-based stock option activity for the year ended December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Weighted- ​ ​ Shares Underlying ​ Average ​ ​ Outstanding ​ Exercise ​ ​ Options ​ Price Outstanding, January 1, 2022 1,537,241 $ 7.95 Options granted 1,061,431 ​ $ 7.15 Options exercised (1,627) ​ $ 7.24 Options cancelled (887) ​ $ 31.46 Options expired (25,450) ​ $ 12.75 Outstanding, December 31, 2022 2,570,708 ​ $ 7.56 Vested, December 31, 2022 1,459,480 ​ ​ Subsequent to the issuance of the financial statements for the year ended December 31, 2021, the Company identified and corrected an immaterial error related to the total number of shares of outstanding time-based option awards disclosed. Management evaluated the correction on a quantitative and qualitative basis and has determined that it is immaterial to the financial statements as of and for the year ended December 31, 2021. The weighted-average grant date fair value of time-based options granted during the year ended December 31, 2022 was $6.36 per share. The total fair value of the time-based shares vested during the year ended December 31, 2022 was $1.8 million. As of December 31, 2022, there was $9.1 million of total unrecognized compensation cost related to the awards. The cost is being recognized over a remaining weighted-average period of 3.2 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 following table summarizes performance-based stock option activity for the year ended December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ Number of Weighted- ​ ​ Shares Underlying ​ Average ​ ​ Outstanding ​ Exercise ​ ​ Options ​ Price Outstanding, January 1, 2022 600,869 ​ $ 6.36 Options Granted 18,873 ​ $ 7.15 Options Exercised — ​ — Outstanding, December 31, 2022 619,742 ​ $ 6.38 Vested, December 31, 2022 51,075 ​ ​ The weighted-average grant date fair value of performance-based options granted during the year ended December 31, 2022 was $7.15 per share. The total fair value of the performance-based shares vested during the year ended December 31, 2022 was $82 thousand. As of the year ended December 31, 2022, there was no unrecognized compensation cost related to the awards because it was improbable that the performance conditions would be met. The cost is being recognized over a remaining weighted-average period of less than one year. The Company has recorded aggregate stock-based compensation expense related to the issuance of stock option awards to employees and non-employees in the statements of operations and comprehensive loss as follows for the years ended December 31, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 General and administrative ​ $ 1,204 ​ $ 1,325 Research and development ​ 676 ​ 579 Total stock-based compensation ​ $ 1,880 ​ $ 1,904 ​ The fair value of each award granted was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions for the years ended December 31, 2022 and 2021. ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2022 Expected volatility 88 – 90 % Risk-free interest rate 3.0 – 4.2 ​ Dividend yield — ​ Expected term 5.4 7.0 ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 Expected volatility 89 – 94 % Risk-free interest rate 0.4 – 1.3 ​ Dividend yield — ​ Expected term 5.0 ​ ​ The expected term of the stock options represents the average of the contractual term of the options and the weighted-average expected vesting period. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The expected volatility rate was based on the historical volatilities of comparable companies in the Company’s industry. The Company has never declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. Consequently, the Company used an expected dividend yield of zero.

Net loss per share attributable

Net loss per share attributable to common stockholders	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Net loss per share attributable to common stockholders
Net loss per share attributable to common stockholders	11. Net loss per share attributable to common stockholders The table below is the calculation of basic and diluted loss per share attributable to common, Series A common and Series B common stockholders (in thousands, except share and per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Three Months Nine Months Nine Months ​ ​ Ended ​ Ended ​ Ended ​ Ended ​ ​ September 30, ​ September 30, ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to common stockholders ​ $ — ​ $ (7,467) ​ $ — ​ $ (23,304) Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted ​ — ​ 185,084 ​ — ​ 184,756 Net loss per share attributable to common stockholders, basic and diluted ​ $ — ​ $ (40.34) ​ $ — ​ $ (126.13) Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to Series A and Series B common stockholders ​ $ (6,353) ​ $ — ​ $ (19,725) ​ $ — Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to Series A and Series B common stockholders, basic and diluted ​ 18,194,682 ​ — ​ 6,131,541 ​ — Net loss per share attributable to Series A and Series B common stockholders, basic and diluted ​ $ (0.35) ​ $ — ​ $ (3.22) ​ $ — ​ The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common, Series A common and Series B common stockholders for the periods presented because including them would have been antidilutive. 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, options prior to the IPO were to purchase common stock, and after the IPO are to purchase Series A common stock. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months ​ Three Months ​ Nine Months ​ Nine Months ​ ​ Ended ​ Ended ​ Ended ​ Ended ​ ​ September 30, ​ September 30, ​ September 30, ​ September 30, ​ 2023 2022 2023 2022 Options to purchase Series A common stock 3,766,505 2,198,675 3,766,505 2,198,675 Warrant to purchase Series A Common Stock ​ 1,000 ​ — ​ 1,000 ​ — Redeemable convertible preferred stock — 16,638,476 — 16,638,476 Warrants to purchase common stock — 40,268 — 40,268 Warrant to purchase redeemable convertible preferred stock — 79,545 — 79,545 Total 3,767,505 18,956,964 3,767,505 18,956,964 ​	11. The table below is the calculation of basic and diluted loss per share attributable to common stockholders for the years ended December 31, 2022 and 2021 (in thousands, except share and per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Numerator: ​ ​ Net loss attributable to common stockholders ​ $ (30,499) ​ $ (24,442) Denominator: ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted ​ 184,619 ​ 122,579 Net loss per share attributable to common stockholders, basic and diluted ​ $ (165.20) ​ $ (199.40) ​ The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been antidilutive: ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Redeemable convertible preferred stock 16,638,476 16,638,476 Options to purchase common stock 3,190,450 2,138,110 Warrants to purchase common stock 40,268 40,268 Warrants to purchase redeemable convertible preferred stock 79,545 79,545 Total 19,948,739 18,896,399 ​

Income taxes

Income taxes	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Income taxes
Income taxes	12. Income taxes The provision for income taxes primarily relates to projected federal and state income taxes calculated on the projected taxable income for the period. To determine the quarterly provision for income taxes, the Company uses an estimated annual effective tax rate, which is generally based on expected annual income as well as statutory tax rates in the various jurisdictions in which the Company operates. In addition, the tax effects of certain significant or unusual items are recognized discretely in the quarter during which they occur and can be a source of variability in the effective tax rates from quarter to quarter. As per ASC 740-270, the Company’s interim tax provision is computed based on the estimated annual effective tax rate approach. The estimated annual effective tax rate approach is used to determine the tax related to ordinary income unless certain exceptions apply. The Company records a valuation allowance to reduce its deferred taxes to the amount it believes is more likely than not to be realized. In making such determination, the Company considers all available positive and negative evidence quarterly, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies, and recent financial performance. Forming a conclusion that a valuation allowance is not required is difficult when there is negative evidence such as cumulative losses in recent years. Based upon the Company’s review of all positive and negative evidence, the Company continues to have a full valuation allowance on its deferred tax assets as of September 30, 2023. The Company accounts for the uncertainty in income taxes by utilizing a comprehensive model for the recognition, measurement, presentation and disclosure in financial statements of any uncertain tax positions that have been taken or are expected to be taken on an income tax return. There have been no changes in the estimated uncertain positions or tax benefits recorded as of December 31, 2022.	12. 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, 2022 and 2021 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Federal income taxes at statutory rates 21.00 % 21.00 % State income tax, net of federal benefit 0.43 0.40 ​ Research and development credits 3.48 3.08 ​ Stock-based compensation (0.81) (1.19) ​ Change in valuation allowance (24.10) (22.64) ​ Other permanent items — (0.65) ​ Effective income tax rate — % — % ​ For the years ended December 31, 2022 and 2021, the Company did not record a deferred income tax expense or benefit. Income tax expense has been nominal for the years ended December 31, 2022 and 2021. 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, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2022 ​ 2021 Deferred tax assets: ​ ​ Net operating loss carryforwards ​ $ 28,707 ​ $ 28,350 Capitalized start-up costs and research expenses ​ 13,004 ​ 7,358 Research and development credits ​ 4,977 ​ 3,762 Accruals, reserves and other ​ 1,144 ​ 1,013 Lease liabilities ​ 47 ​ 73 Total gross deferred assets ​ 47,879 ​ 40,556 Valuation allowance ​ (47,834) ​ (40,484) Total deferred tax assets ​ 45 ​ 72 Deferred tax liabilities: ​ ​ Right-of-use assets ​ (45) ​ (72) 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, 2022 and 2021. The valuation allowance increased $7.4 million and $5.6 million during the years ended December 31, 2022 and 2021, respectively. As of December 31, 2022, the Company had U.S. federal net operating loss (NOL) carryforwards of approximately $128.2 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 $37.2 million will have an indefinite carryforward period, subject to annual limitations. As of December 31, 2022, 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, 2022, the Company had federal research and development tax credit carryforwards of approximately $4.4 million available to reduce future tax liabilities which expire at various years beginning with 2028. As of December 31, 2022, the Company had state credit carryforwards of approximately $2.5 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, 2022, 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, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Unrecognized tax benefits as of the beginning of the year ​ $ 1,035 ​ $ 817 Decrease related to prior year tax positions ​ — ​ (17) Increase related to current year tax positions ​ 499 ​ 235 Unrecognized tax benefits as of the end of the year ​ $ 1,534 ​ $ 1,035 ​ 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, 2022, 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. In December 2017, the Tax Cuts and Jobs Act (TCJA) was signed into law, significantly reforming the IRC. Beginning January 1, 2022, the TCJA eliminated the option to deduct research and development expenditures in the current year and requires taxpayers to capitalize such expenses pursuant to IRC Section 174. The capitalized expenses are amortized over a 5-year period for domestic expenses and a 15-year period for foreign expenses. As a result of this provision of the TCJA, deferred tax assets related to capitalized research expenses increased by $4.6 million. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was enacted in response to the COVID-19 pandemic. The CARES Act, among other things, permits NOL carryovers and carrybacks to offset 100% of taxable income for taxable years beginning before 2021. In addition, the CARES Act allows NOLs incurred in 2018, 2019, and 2020 to be carried back to each of the five preceding taxable years to generate a refund of previously paid income taxes. Due to the Company’s history of NOLs, the CARES Act did not have a material impact on the Company’s financial statements. On February 9, 2022, Governor Gavin Newsom signed California Senate Bill 113 (SB 113) into law. The legislation contains important California tax law changes, including reinstatement of business tax credits and net NOL deductions limited by California Assembly Bill 85 which suspended the net operating loss deduction for certain taxpayers from 2020 to 2022. The new tax law did not impact the Company’s tax provision due to its taxable loss position in the current year. In August 2022, the Inflation Reduction Act of 2022 (IRA) was signed into law in the United States. The IRA created a new corporate alternative minimum tax of 15% on adjusted financial statement income and an excise tax of 1% of the value of certain stock repurchases. The provisions of the IRA will be effective for periods beginning after December 31, 2022. The enactment of the IRA did not result in any material adjustments to the Company’s income tax provisions or net deferred tax assets as of December 31, 2022.

Defined contribution plan

Defined contribution plan	12 Months Ended
	Dec. 31, 2022
Defined contribution plan
Defined contribution plan	13. The Company has a defined-contribution savings plan under Section 401(k) of the IRC. 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 pre-tax basis. The Company has not made any employer contributions to the 401(k) Plan as of December 31, 2022 and 2021.

Subsequent events

Subsequent events	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Subsequent events
Subsequent events	13. Subsequent events The Company has evaluated subsequent events for financial statement purposes occurring through November 13, 2023, the date when these financial statements are available to be issued and noted that there are no subsequent events requiring disclosure in these condensed financial statements. ​	14. The Company has evaluated subsequent events for financial statement purposes occurring through March 24, 2023, the date when these financial statements are available to be issued and July 9, 2023 for the reverse stock split referenced below. No material subsequent events have occurred that require disclosure, except those referenced below. The Company’s board of directors approved a one-for- 79.4784

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Summary of significant accounting policies
Basis of presentation	Basis of presentation The condensed financial statements and accompanying notes have been prepared in accordance with GAAP and the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. These condensed financial statements have been prepared on the same basis as the annual financial statements included elsewhere in this prospectus. In the Company’s opinion, the information furnished in these condensed financial statements reflects all adjustments, all of which are of a normal and recurring nature necessary for a fair presentation of the financial position and results of operations for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period.	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).
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 expenses during the reporting period. Such estimates include accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock, common stock 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.	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 expenses during the reporting period. Such estimates include accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock, common stock 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.
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, 2022 and 2021, 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 The Company had no short-term investments in marketable securities as of September 30, 2023.	Marketable securities The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the balance sheets, with unrealized gains and losses that are determined to be temporary, if any, reported as a component of other comprehensive income (loss) within the statements of operations and comprehensive loss and as a separate component of stockholders’ deficit. The Company classifies marketable securities with remaining maturities greater than three months but less than one year as short-term investments, and those with remaining maturities greater than one year are classified as long-term investments. Investments are regularly reviewed for other-than-temporary declines in fair value. The review includes the consideration of the cause of the impairment, including the creditworthiness of the security issuers, the number of investments in an unrealized loss position, the severity and duration of the unrealized losses and whether it is more likely than not that the Company will be required to sell the investments before the recovery of their amortized cost basis. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the establishment of a new cost basis for the security. The Company invests its excess cash balances primarily in corporate debt securities with strong credit ratings. Realized gains and losses are calculated on the specific identification method and recorded as interest income and were immaterial for all periods presented. As of December 31, 2022, the Company’s short-term marketable securities were invested with Silicon Valley Bank (SVB), and custodied at U.S. bank.
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.	Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash, cash equivalents and marketable securities.
Deferred financing costs	Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s IPO are capitalized and recorded in the accrued expenses and other current liabilities in the condensed balance sheets. Upon closing of the IPO in July 2023, all deferred offering costs were reclassified to additional paid-in-capital in the condensed statements of operations and comprehensive loss, representing a reduction in IPO proceeds. On March 21, 2022, the Company withdrew its prior Registration Statement on Form S-1 initially filed with the SEC on April 16, 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 unaudited condensed statement of operations and comprehensive loss for the nine months ended September 30, 2022.	Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s planned IPO are capitalized and recorded on the balance sheets. The deferred financing costs will be offset against the proceeds received upon the closing of the planned IPO. In the event that the Company’s plans for an IPO are terminated, all of the deferred financing costs will be written off within operating expenses in the Company’s statements of operations and comprehensive loss. As of December 31, 2021, there were $1.4 million of deferred financing costs capitalized related to the Company’s previous IPO plans in 2021. On March 21, 2022, the Company withdrew its Registration Statement on Form S-1 initially filed with the 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. As of December 31, 2022, there were no deferred financing costs capitalized.
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 Accounting Standards Update (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 twelve 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.
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 Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers 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). In January 2022, Ascletis BioScience Co. Ltd. (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 recorded as license revenue in the condensed statements of operations and comprehensive loss (representing the $2.0 million development milestone payment, net of applicable taxes) from Ascletis.	Revenue recognition The Company enters into collaboration and licensing arrangements that generally contain multiple elements or deliverables, which may include (1) licenses to the Company’s technology, (2) research and development activities performed for the collaboration partner, (3) participation on joint steering committees (JSCs), and (4) 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 Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers 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). In January 2022, Ascletis initiated dosing of a Phase 3 trial for recurrent GBM, potentially triggering a $2.0 million development milestone payment under the license agreement. Due to the uncertainty around the achievement of the milestone and ongoing discussions with Ascletis around the consideration for the milestone, the Company concluded it was probable that a significant reversal of the revenue related to the milestone would occur, and therefore, no revenue was recognized.
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 non-alcoholic steatohepatitis (NASH) 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. The CODM evaluates the Company’s financial information and assesses the performance of the Company based on the single operating segment. The Company assesses its determination of operating segments at least annually and continues to evaluate the internal reporting structure and potential impacts of any changes to its segment reporting.
Common stock valuation		Common stock valuation Due to the absence of an active market for the Company’s common stock, the Company utilized methodologies in accordance with the framework of the American Institute of Certified Public Accountants Technical Practice Aid (Valuation of Privately Held Company Equity Securities Issued as Compensation) to estimate the fair value of its common stock. In determining the exercise prices for options granted, the Company has considered the estimated fair value of the common stock as of the measurement date. The estimated fair value of the common stock has been determined at each grant date based upon a variety of factors, including the illiquid nature of the common stock, arm’s-length sales of the Company’s capital stock (including redeemable convertible preferred stock), the effect of the rights and preferences of the redeemable convertible preferred stockholders, and the prospects of a liquidity event. Among other factors are the Company’s financial position and historical financial performance, the status of technological developments within the Company’s research, the composition and ability of the current research and management team, an evaluation or benchmark of the Company’s competition, and the current business climate in the marketplace. Significant changes to the key assumptions underlying the factors used could result in different fair values of common stock at each valuation date.
Redeemable convertible preferred stock		Redeemable convertible preferred stock The Company records redeemable convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The redeemable convertible preferred stock is recorded outside of stockholders’ deficit because the shares contain liquidation features that are not solely within the Company’s control. The Company has not adjusted the carrying values of the redeemable convertible preferred stock to the liquidation preferences of such shares because it is 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. Subsequent adjustments to the carrying values to the liquidation preferences will be made only when it becomes probable that such a liquidation event will occur.
Redeemable convertible preferred stock tranche liability		Redeemable convertible preferred stock tranche liability The Company determined the right of the investors to purchase shares of Series F redeemable convertible preferred stock at a future date met the definition of a freestanding instrument and was recognized as a liability at fair value upon the December 2020 issuance of Series F redeemable convertible preferred stock (Redeemable Convertible Preferred Stock Tranche Liability). The liability was subject to remeasurement at each balance sheet date, with changes in fair value recognized in other income (expense) in the statements of operations and comprehensive loss. Upon closing of the Series F redeemable convertible preferred stock financing in February 2021, the Redeemable Convertible Preferred Stock Tranche Liability was extinguished, and the marked-to-market fair value of the liability was included in the carrying value of redeemable convertible preferred stock issued.
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 Financial Accounting Standards Board (FASB) ASC 815, Derivatives and Hedging Under ASC 815-40, warrants that meet the criteria for equity treatment are recorded in stockholders’ deficit. The warrants are subject to re-evaluation of the proper classification and accounting treatment at each reporting period. If the warrants no longer meet the criteria for equity treatment, they will be recorded as a liability and remeasured each period with changes recorded in the statement of operations and comprehensive loss. When issued in connection with debt, the allocated value related to the warrants is generally recorded as additional interest cost on the related debt. When issued with redeemable convertible preferred stock, the allocated value related to the warrants is recorded as additional issuance costs of the redeemable convertible preferred stock. The Company values warrants using an option pricing model.
Stock-based compensation expense		Stock-based compensation expense The Company accounts for all stock-based payment awards granted to employees and non-employees as stock-based compensation expense at fair value. The Company’s stock-based payments include stock options and grants of common stock, including common stock subject to vesting. The measurement date for employee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight- line basis. Stock-based compensation costs for non-employees are recognized as expense over the vesting period on a straight-line basis. Stock-based compensation expense is classified in the accompanying statements of operations and comprehensive loss based on the function to which the related services are provided. The Company recognizes stock-based compensation expense for the portion of awards that have vested. Forfeitures are recorded as they occur. 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. For awards with service-based vesting conditions only, the Company recognizes share-based compensation expense on a straight-line basis over the requisite service or vesting period. For awards with service- and performance-based vesting conditions, the Company recognizes stock-based compensation expense using the graded vesting method over the requisite service period beginning in the period in which the awards are deemed probable to vest, to the extent such awards are probable to vest. The Company recognizes the cumulative effect of changes in the probability outcomes in the period in which the changes occur.
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, 2022 and 2021, 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’ 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 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 and common and redeemable convertible preferred stock warrants are considered to be potentially dilutive securities. Basic and diluted net loss per share attributable to common stockholders is presented inconformity with the two-class method required for participating securities as the redeemable convertible preferred stock is considered a participating security. 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. As the Company has reported a net loss for the period presented, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders for this period.
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 Financial Accounting Standards Board (FASB) standards’ effective dates.	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	New accounting pronouncements not yet adopted In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments 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

Fair value measurements and f_2

Fair value measurements and fair value of financial instruments (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Fair value measurements and fair value of financial instruments
Schedule of marketable securities, available-for-sale	Marketable securities, all of which are classified as available-for-sale securities, consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ Amortized Unrealized Unrealized Estimated ​ ​ cost ​ Gains ​ Losses ​ Fair Value Commercial paper ​ $ 15,950 ​ $ — ​ $ — ​ $ 15,950 Corporate debt securities ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ 4,035 ​ — ​ (19) ​ 4,016 Total ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187	Marketable securities, all of which are classified as available-for-sale securities, consisted of the following at December 31, 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ ​ Cost ​ Gains ​ Losses ​ Fair Value Commercial paper $ 15,950 $ — $ — $ 15,950 Corporate debt securities ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ 4,035 ​ — ​ (19) ​ 4,016 Total ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187
Schedule of fair value of financial instruments	The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ fair value Level 1 Level 2 Level 3 Liabilities: ​ ​ ​ ​ Series A Common Stock Warrant Liability ​ $ 1 ​ $ — ​ $ — ​ $ 1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ value ​ Level 1 ​ Level 2 ​ Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents - money market funds ​ $ 38 ​ $ 38 ​ $ — ​ $ — Commercial paper ​ 15,950 ​ — ​ 15,950 ​ — Corporate debt securities ​ 12,221 ​ — ​ 12,221 ​ — U.S. Treasury securities ​ 4,016 ​ — ​ 4,016 ​ — Total ​ $ 32,225 ​ $ 38 ​ $ 32,187 ​ $ — Liabilities: ​ ​ ​ ​ Redeemable Convertible Preferred Stock Warrant Liability ​ $ 4 ​ $ — ​ $ — ​ $ 4	The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ value ​ Level 1 ​ Level 2 ​ Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents – money market funds ​ $ 38 ​ $ 38 ​ $ — ​ $ — Commercial paper ​ 15,950 ​ — ​ 15,950 ​ — Corporate debt securities ​ 12,221 ​ — ​ 12,221 ​ — U.S. Treasury securities ​ 4,016 ​ — ​ 4,016 ​ — Total ​ $ 32,225 ​ $ 38 ​ $ 32,187 ​ $ — Liabilities: ​ ​ ​ ​ Redeemable convertible preferred stock warrant liability ​ $ 4 ​ $ — ​ $ — ​ $ 4 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ value Level 1 Level 2 Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents – money market funds ​ $ 56,631 ​ $ 56,631 ​ $    — ​ $ — Liabilities: ​ ​ ​ ​ Redeemable convertible preferred stock warrant liability ​ $ 7 ​ $ — ​ $ — ​ $ 7 ​
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, 2023 $ 4 Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ 1 Change in fair value of Series A Common Stock Warrant Liability ​ ​ (4) Balance - September 30, 2023 ​ $ 1 Balance - January 1, 2022 ​ $ 7 Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ (3) Balance - December 31, 2022 ​ $ 4	The following table provides a summary of changes in the estimated fair value of the financial instruments using significant Level 3 inputs (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Redeemable Redeemable ​ ​ convertible ​ convertible ​ ​ preferred ​ preferred ​ ​ stock ​ stock ​ ​ warrant ​ tranche ​ ​ liability ​ liability Balance – January 1, 2021 ​ $ 9 ​ $ — Change in fair value of redeemable convertible preferred stock warrant liability and establishment of Redeemable Convertible Preferred Stock Tranche Liability ​ (2) ​ 751 Extinguishment of Redeemable Convertible Stock Tranche Liability upon subsequent issuance of Series F redeemable convertible preferred stock ​ — ​ (751) Balance – December 31, 2021 ​ $ 7 ​ $ — Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ (3) ​ — Balance – December 31, 2022 ​ $ 4 ​ $ —

Prepaid expenses and other cu_2

Prepaid expenses and other current assets (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 Prepaid insurance ​ $ 865 ​ $ 61 Prepaid clinical expenses ​ ​ 32 ​ ​ 352 Other ​ 77 ​ 34 Total ​ $ 974 ​ $ 447 ​	Prepaid expenses and other current assets as of December 31, 2022 and 2021 consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Prepaid clinical expenses ​ $ 352 ​ $ 423 Deferred financing costs ​ — ​ 1,425 Other ​ 95 ​ 84 Total ​ $ 447 ​ $ 1,932 ​

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 Accrued clinical costs ​ $ 2,239 ​ $ 3,162 Employees’ compensation ​ 689 ​ 636 Accrued research ​ ​ 221 ​ ​ — Accrued preclinical costs ​ — ​ 166 Other ​ 95 ​ 57 Total ​ $ 3,244 ​ $ 4,021 ​	Accrued expenses and other current liabilities as of December 31, 2022 and 2021 consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Accrued clinical costs ​ $ 3,162 ​ $ 852 Employees’ compensation ​ 636 ​ 463 Accrued pre-clinical costs ​ 166 ​ — Accrued deferred financing costs ​ — ​ 55 Other ​ 57 ​ 185 Total ​ $ 4,021 ​ $ 1,555 ​

Commitments and contingencies (

Commitments and contingencies (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Commitments and contingencies
Schedule of future maturities of operating lease liabilities	The following are schedules by year of future maturities of the Company’s operating lease liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ 2023 Remainder of 2023 $ 27 2024 ​ 79 Total lease payments ​ 106 Less: interest ​ (3) Total ​ $ 103 ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2023 $ 157 2024 ​ 80 Total lease payments ​ 237 Less: interest ​ (26) Total ​ $ 211	The following is a schedule by year of future maturities of the Company’s operating lease liabilities as of December 31, 2022 (in thousands): ​ ​ ​ ​ 2023 $ 157 2024 ​ ​ 80 Total lease payments ​ ​ 237 Less: interest ​ ​ (26) Total ​ $ 211
Schedule of supplemental cash flow information related to leases	Supplemental cash flow information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ Nine Months Ended September 30, ​ 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 118 ​ $ 118	Supplemental cash flow information related to leases was as follows for the years ended December 31, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year ended Year ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 157 ​ $ 157 Right-of-use assets obtained in exchange for lease obligations (non-cash): ​ ​ Operating leases ​ $ — ​ $ 282

Redeemable convertible prefer_2

Redeemable convertible preferred stock (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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	The authorized, issued and outstanding shares of the redeemable convertible preferred stock, liquidation preferences and carrying values as of December 31, 2022 and 2021 were as follows (in thousands, except share numbers): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 and 2021 ​ ​ ​ ​ Issued and ​ ​ ​ ​ ​ ​ ​ ​ Authorized ​ Outstanding ​ Liquidation ​ Carrying Series 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' deficit (Tables)

Stockholders' deficit (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Stockholders' equity (deficit)
Schedule of shares of common stock reserved for future issuance	​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ 2023 2022 Options to purchase Series A common stock 3,766,505 3,190,450 Options authorized and available for issuance 2,585,968 181,191 Warrant to purchase Series A Common Stock ​ 1,000 ​ — Redeemable convertible preferred stock — 1,322,399,477 Series D redeemable convertible preferred stock warrant — 79,545 Warrants to purchase common stock — 40,268 Total 6,353,473 1,325,890,931	​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Redeemable convertible preferred stock 1,322,399,477 1,322,399,477 Series D redeemable convertible preferred stock warrants 79,545 79,545 Options authorized and available for issuance 181,191 810,604 Options to purchase common stock 3,190,450 2,138,110 Warrants to purchase common stock 40,268 40,268 Total 1,325,890,931 1,325,468,004
Schedule of outstanding warrants	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, 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 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ Fair Value on ​ 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 ​	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 and 2021 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ Fair Value ​ Fair Value ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ on Issuance ​ Recorded Issuance Date Shares Share Date for (in thousands) Against June 2013 26,846 ​ $ 0.79 June 2023 Common ​ $ 339 Redeemable January 2014 13,422 ​ $ 0.79 January 2024 Common ​ 223 Redeemable April 2015 79,545 ​ $ 0.88 April 2025 Series D ​ 68 Debt ​

Stock-based compensation (Table

Stock-based compensation (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Stock-based compensation
Schedule of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 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 (498) ​ ​ 4.77 ​ Options expired (1,752) ​ ​ 0.79 ​ Outstanding, September 30, 2023 3,766,505 ​ $ 8.11 7.69 ​ $ 17,737 Shares vested and exercisable as of September 30, 2023 1,784,725 ​ $ 6.98 6.34 ​ $ 10,206	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ Number of Shares ​ Weighted- ​ Remaining ​ ​ ​ ​ ​ Underlying ​ Average ​ Contractual ​ Aggregate ​ ​ Outstanding ​ Exercise ​ Term ​ Intrinsic ​ ​ Options ​ Price ​ (in Years) ​ Value Outstanding, January 1, 2022 2,138,110 ​ $ 7.15 8.1 ​ $ 4,670 Options granted 1,080,304 ​ $ 7.15 ​ Options exercised (1,627) ​ $ 7.24 ​ Options cancelled (887) ​ $ 31.46 ​ Options expired (25,450) ​ $ 12.75 ​ Outstanding, December 31, 2022 3,190,450 ​ $ 7.10 8.1 ​ 3,998 Shares vested and exercisable as of December 31, 2022 1,510,555 ​ $ 7.15 6.8 ​ 2,303
Schedule of stock-based compensation expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, Nine Months Ended September 30, ​ ​ 2023 2022 ​ 2023 ​ 2022 General and administrative expense ​ $ 1,649 ​ $ 220 ​ $ 3,103 ​ $ 663 Research and development expense ​ 206 ​ 169 ​ 576 ​ 496 Total stock-based compensation expense ​ $ 1,855 ​ $ 389 ​ $ 3,679 ​ $ 1,159	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 General and administrative ​ $ 1,204 ​ $ 1,325 Research and development ​ 676 ​ 579 Total stock-based compensation ​ $ 1,880 ​ $ 1,904
Schedule of fair value assumptions	​ ​ ​ ​ Nine Months Ended Nine Months Ended ​ ​ ​ September 30, 2023 ​ September 30, 2022 ​ Expected volatility ​ 89 - 91 % 88 - 90 % Risk-free interest rate ​ 3.6 % 2.3 – 3.0 % Dividend yield ​ — ​ — ​ Expected term ​ 5.0 – 7.0 years 5.4 – 7.0 years	​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2022 Expected volatility 88 – 90 % Risk-free interest rate 3.0 – 4.2 ​ Dividend yield — ​ Expected term 5.4 7.0 ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 Expected volatility 89 – 94 % Risk-free interest rate 0.4 – 1.3 ​ Dividend yield — ​ Expected term 5.0 ​
Time-based options
Stock-based compensation
Schedule of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ ​ ​ Shares ​ ​ ​ ​ ​ Underlying ​ Weighted- ​ ​ Outstanding ​ Average ​ ​ Options ​ Exercise Price Outstanding, January 1, 2023 2,570,708 ​ $ 7.56 Options granted 585,919 ​ 13.51 Options exercised ​ (7,614) ​ ​ 0.79 Options cancelled (498) ​ 4.77 Options expired (1,752) ​ 0.79 Outstanding, September 30, 2023 3,146,763 ​ $ 8.69 Shares vested and exercisable as of September 30, 2023 1,186,212 ​ $ 14.42	​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Weighted- ​ ​ Shares Underlying ​ Average ​ ​ Outstanding ​ Exercise ​ ​ Options ​ Price Outstanding, January 1, 2022 1,537,241 $ 7.95 Options granted 1,061,431 ​ $ 7.15 Options exercised (1,627) ​ $ 7.24 Options cancelled (887) ​ $ 31.46 Options expired (25,450) ​ $ 12.75 Outstanding, December 31, 2022 2,570,708 ​ $ 7.56 Vested, December 31, 2022 1,459,480 ​
Performance-based options
Stock-based compensation
Schedule of stock option activity		​ ​ ​ ​ ​ ​ ​ ​ Number of Weighted- ​ ​ Shares Underlying ​ Average ​ ​ Outstanding ​ Exercise ​ ​ Options ​ Price Outstanding, January 1, 2022 600,869 ​ $ 6.36 Options Granted 18,873 ​ $ 7.15 Options Exercised — ​ — Outstanding, December 31, 2022 619,742 ​ $ 6.38 Vested, December 31, 2022 51,075 ​

Net loss per share attributab_2

Net loss per share attributable to common stockholders (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Net loss per share attributable to common stockholders
Schedule of basic and diluted loss per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Three Months Nine Months Nine Months ​ ​ Ended ​ Ended ​ Ended ​ Ended ​ ​ September 30, ​ September 30, ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to common stockholders ​ $ — ​ $ (7,467) ​ $ — ​ $ (23,304) Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted ​ — ​ 185,084 ​ — ​ 184,756 Net loss per share attributable to common stockholders, basic and diluted ​ $ — ​ $ (40.34) ​ $ — ​ $ (126.13) Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to Series A and Series B common stockholders ​ $ (6,353) ​ $ — ​ $ (19,725) ​ $ — Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to Series A and Series B common stockholders, basic and diluted ​ 18,194,682 ​ — ​ 6,131,541 ​ — Net loss per share attributable to Series A and Series B common stockholders, basic and diluted ​ $ (0.35) ​ $ — ​ $ (3.22) ​ $ —	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Numerator: ​ ​ Net loss attributable to common stockholders ​ $ (30,499) ​ $ (24,442) Denominator: ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted ​ 184,619 ​ 122,579 Net loss per share attributable to common stockholders, basic and diluted ​ $ (165.20) ​ $ (199.40) ​
Schedule of potentially dilutive securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months ​ Three Months ​ Nine Months ​ Nine Months ​ ​ Ended ​ Ended ​ Ended ​ Ended ​ ​ September 30, ​ September 30, ​ September 30, ​ September 30, ​ 2023 2022 2023 2022 Options to purchase Series A common stock 3,766,505 2,198,675 3,766,505 2,198,675 Warrant to purchase Series A Common Stock ​ 1,000 ​ — ​ 1,000 ​ — Redeemable convertible preferred stock — 16,638,476 — 16,638,476 Warrants to purchase common stock — 40,268 — 40,268 Warrant to purchase redeemable convertible preferred stock — 79,545 — 79,545 Total 3,767,505 18,956,964 3,767,505 18,956,964 ​	​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Redeemable convertible preferred stock 16,638,476 16,638,476 Options to purchase common stock 3,190,450 2,138,110 Warrants to purchase common stock 40,268 40,268 Warrants to purchase redeemable convertible preferred stock 79,545 79,545 Total 19,948,739 18,896,399 ​

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income taxes
Schedule of reconciliation of the provision for income taxes to the amount computed by applying the statutory income tax rate	​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Federal income taxes at statutory rates 21.00 % 21.00 % State income tax, net of federal benefit 0.43 0.40 ​ Research and development credits 3.48 3.08 ​ Stock-based compensation (0.81) (1.19) ​ Change in valuation allowance (24.10) (22.64) ​ Other permanent items — (0.65) ​ Effective income tax rate — % — %
Schedule of net deferred tax assets	​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2022 ​ 2021 Deferred tax assets: ​ ​ Net operating loss carryforwards ​ $ 28,707 ​ $ 28,350 Capitalized start-up costs and research expenses ​ 13,004 ​ 7,358 Research and development credits ​ 4,977 ​ 3,762 Accruals, reserves and other ​ 1,144 ​ 1,013 Lease liabilities ​ 47 ​ 73 Total gross deferred assets ​ 47,879 ​ 40,556 Valuation allowance ​ (47,834) ​ (40,484) Total deferred tax assets ​ 45 ​ 72 Deferred tax liabilities: ​ ​ Right-of-use assets ​ (45) ​ (72) Net deferred tax assets ​ $ — ​ $ —
Schedule of reconciliation of the unrecognized tax benefits	A reconciliation of the unrecognized tax benefits is as follows for the years ended December 31, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Unrecognized tax benefits as of the beginning of the year ​ $ 1,035 ​ $ 817 Decrease related to prior year tax positions ​ — ​ (17) Increase related to current year tax positions ​ 499 ​ 235 Unrecognized tax benefits as of the end of the year ​ $ 1,534 ​ $ 1,035

Organization and description _2

Organization and description of business (Details) $ / shares in Units, $ in Thousands			3 Months Ended						9 Months Ended		12 Months Ended
	Jul. 18, 2023 USD ($) Vote $ / shares shares	Jul. 07, 2023	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2023 USD ($) Vote	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Organization and description of business
Reverse stock split ratio		0.012582
Net proceeds									$ 86,161
Net loss			$ 6,353	$ 6,785	$ 6,587	$ 7,467	$ 7,102	$ 8,735	19,725	$ 23,304	$ 30,499	$ 24,442
Cash flows from operations									$ 16,683	$ 17,037	24,490	$ 21,710
Cash equivalents and short-term investments											$ 32,300
Series A Common Stock
Organization and description of business
Shares issued upon conversion (in number of shares) | shares	15,117,912
Number of votes per share | Vote	1								1
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_3

Summary of significant accounting policies (Details)	1 Months Ended			3 Months Ended	9 Months Ended	12 Months Ended
	Aug. 31, 2023 USD ($)	Jul. 31, 2023 USD ($)	Jan. 31, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($) segment	Dec. 31, 2021 USD ($)
Summary of significant accounting policies
Short-term investments in marketable securities				$ 0	$ 0	$ 32,187,000
Deferred financing costs writeoff						0	$ 1,400,000
Revenue		$ 2,000,000	$ 0	$ 2,000,000	$ 2,000,000	$ 0
Number of Operating Segments | segment						1
Number of Reportable Segments | segment						1
Impairment of long lived assets						$ 0
Investor | Ascletis
Summary of significant accounting policies
Development milestone payment trigger	$ 1,700,000		$ 2,000,000
Revenue		$ 2,000,000
Proceeds from license fees	$ 2,000,000

Fair value measurements and f_3

Fair value measurements and fair value of financial instruments - Marketable securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Fair value measurements and fair value of financial instruments
Fair value cash and cash equivalents	$ 101,800	$ 200	$ 56,700
Amortized Cost		32,271
Unrealized Losses		(84)
Estimated Fair Value	$ 0	32,187	$ 0
Commercial paper
Fair value measurements and fair value of financial instruments
Amortized Cost		15,950
Estimated Fair Value		15,950
Corporate debt securities
Fair value measurements and fair value of financial instruments
Amortized Cost		12,286
Unrealized Losses		(65)
Estimated Fair Value		12,221
U.S. Treasury securities
Fair value measurements and fair value of financial instruments
Amortized Cost		4,035
Unrealized Losses		(19)
Estimated Fair Value		$ 4,016

Fair value measurements and f_4

Fair value measurements and fair value of financial instruments - Recurring (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial instruments that were measured at fair value on a recurring basis by level
Assets		$ 32,225
Redeemable Convertible Preferred Stock Warrant
Financial instruments that were measured at fair value on a recurring basis by level
Liabilities		4	$ 7
Series A Common Stock Warrants
Financial instruments that were measured at fair value on a recurring basis by level
Liabilities	$ 1
Cash and cash equivalents - money market funds
Financial instruments that were measured at fair value on a recurring basis by level
Assets		38	56,631
Commercial paper
Financial instruments that were measured at fair value on a recurring basis by level
Assets		15,950
Corporate debt securities
Financial instruments that were measured at fair value on a recurring basis by level
Assets		12,221
U.S. Treasury securities
Financial instruments that were measured at fair value on a recurring basis by level
Assets		4,016
Level 1
Financial instruments that were measured at fair value on a recurring basis by level
Assets		38
Level 1 | Cash and cash equivalents - money market funds
Financial instruments that were measured at fair value on a recurring basis by level
Assets		38	56,631
Level 2
Financial instruments that were measured at fair value on a recurring basis by level
Assets		32,187
Level 2 | Commercial paper
Financial instruments that were measured at fair value on a recurring basis by level
Assets		15,950
Level 2 | Corporate debt securities
Financial instruments that were measured at fair value on a recurring basis by level
Assets		12,221
Level 2 | U.S. Treasury securities
Financial instruments that were measured at fair value on a recurring basis by level
Assets		4,016
Level 3 | Redeemable Convertible Preferred Stock Warrant
Financial instruments that were measured at fair value on a recurring basis by level
Liabilities		$ 4	$ 7
Level 3 | Series A Common Stock Warrants
Financial instruments that were measured at fair value on a recurring basis by level
Liabilities	$ 1

Fair value measurements and f_5

Fair value measurements and fair value of financial instruments - Level 3 (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Summary of changes
Beginning balance	$ 4	$ 7
Establishment of Redeemable Convertible Preferred Stock Tranche Liability			$ 751
Ending balance	1	4	7
Redeemable convertible preferred stock tranche liability
Summary of changes
Establishment of Redeemable Convertible Preferred Stock Tranche Liability			751
Extinguishment of Redeemable Convertible Stock Tranche Liability upon subsequent issuance of Series F redeemable convertible preferred stock			(751)
Redeemable Convertible Preferred Stock Warrant
Summary of changes
Beginning balance	4	7	9
Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability	1	(3)	(2)
Ending balance		$ 4	$ 7
Series A Common Stock Warrants
Summary of changes
Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability	$ (4)

Fair value measurements and f_6

Fair value measurements and fair value of financial instruments - Additional information (Details)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 28, 2021 USD ($) $ / shares	Sep. 30, 2023 USD ($) Y dividend $ / shares shares	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) Y dividend $ / shares shares	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) $ / shares	Dec. 31, 2022 shares	Dec. 31, 2022 $ / shares	Dec. 31, 2022	Dec. 31, 2022 Y	Dec. 31, 2022 dividend	Apr. 30, 2015 $ / shares shares	Apr. 10, 2015 $ / shares shares
Redeemable Convertible Preferred Stock Warrant Liability
Change in fair value of redeemable convertible preferred stock warrants						$ (3,000)	$ (2,000)
Change in fair value of redeemable convertible preferred stock tranche liability							751,000
Series F
Redeemable Convertible Preferred Stock Warrant Liability
Fair value of Redeemable Convertible Preferred Stock Tranche Liability	$ 800,000
Intrinsic value per share | $ / shares	$ 0.1391
Change in fair value of redeemable convertible preferred stock tranche liability							800,000
Series D redeemable convertible preferred stock warrants
Redeemable Convertible Preferred Stock Warrant Liability
Number of warrants issued | shares		1,000		1,000				79,545					79,545	79,545
Fair value of warrant liability		$ 68,000		$ 68,000		68,000	$ 68,000
Exercise price of warrant | $ / shares		$ 69.94		$ 69.94			$ 0.88		$ 0.88				$ 0.88	$ 0.88
Warrants term														10 years
Series A Common Stock Warrants
Redeemable Convertible Preferred Stock Warrant Liability
Fair value of warrant liability		$ 1,400		$ 1,400
Number of securities called by warrants | shares		1,000		1,000
Exercise price of warrant | $ / shares		$ 69.94		$ 69.94
Change in fair value of redeemable convertible preferred stock warrants		$ (4,000)		$ (4,000)
Series A Common Stock Warrants | Volatility rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input		91.5		91.5
Series A Common Stock Warrants | Expected term
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input | Y		2.80		2.80
Series A Common Stock Warrants | Dividends
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input | dividend		0		0
Series A Common Stock Warrants | Risk-free interest rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input		4.87		4.87
Redeemable Convertible Preferred Stock Warrant
Redeemable Convertible Preferred Stock Warrant Liability
Fair value of warrant liability						4,000	$ 7,000
Change in fair value of redeemable convertible preferred stock warrants			$ (1,000)	$ 1,000	$ (3,000)	$ 3,000	$ 2,000
Redeemable Convertible Preferred Stock Warrant | Volatility rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input							0.872			97.3
Redeemable Convertible Preferred Stock Warrant | Expected term
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input						2.28	3.27				2.28
Redeemable Convertible Preferred Stock Warrant | Dividends
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input							0			0		0
Redeemable Convertible Preferred Stock Warrant | Risk-free interest rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input							1.01			4.36

Prepaid expenses and other cu_3

Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Prepaid expenses and other current assets
Prepaid Insurance	$ 865	$ 61
Prepaid clinical expenses	32	352	$ 423
Deferred financing costs			1,425
Other		95	84
Total	$ 974	$ 447	$ 1,932

Accrued expenses and other cu_3

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Accrued expenses and other current liabilities
Accrued clinical costs	$ 2,239	$ 3,162	$ 852
Employees' compensation	689	636	463
Accrued research	221
Accrued preclinical costs		166
Accrued deferred financing costs			55
Other	95	57	185
Total	$ 3,244	$ 4,021	$ 1,555

Related parties (Details)

Related parties (Details) - USD ($)	1 Months Ended					3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2023	Jul. 31, 2023	Jan. 31, 2022	Jan. 31, 2019	Apr. 30, 2007	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Related parties
Research and development expense paid						$ 4,958,000	$ 6,838,000	$ 14,121,000	$ 19,072,000	$ 24,919,000	$ 19,340,000
Revenue		$ 2,000,000	$ 0			$ 2,000,000		2,000,000		0
Investor | Ascletis
Related parties
Amount received as reimbursement								0	28,100	60,000	100,000
Maximum eligible development and commercial milestone payments				$ 122,000,000
Research and development expense paid										$ 4,000	$ 900,000
Amount paid								$ 0	$ 4,000
Development milestone payment trigger	$ 1,700,000		2,000,000
Development Milestone Payment Amount Triggered, Net of Taxes	$ 2,000,000		$ 2,000,000
Revenue		$ 2,000,000
Investor | ETH Zurich
Related parties
Shares issued (in shares)					192
Investor | University of Zurich
Related parties
Shares issued (in shares)					96

Commitments and contingencies_2

Commitments and contingencies (Details)		3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 12, 2019 USD ($) ft²	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Commitments and contingencies
Operating lease term	38 months
Rented area (in square feet) | ft²	3,030
Monthly lease payments	$ 12,000
Deposit held by lessor						$ 27,000	$ 27,000
Operating lease cost		$ 37,000	$ 38,000	$ 111,000	$ 113,000	$ 200,000	$ 100,000

Commitments and contingencies -

Commitments and contingencies - Lease maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Commitments and contingencies
Remainder of 2023	$ 27
2023	79	$ 157
2024		80
Total lease payments	106	237
Less: interest	(3)	(26)
Total	$ 103	$ 211

Commitments and contingencies_3

Commitments and contingencies - Lease cash flow (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 118	$ 118	$ 157	$ 157
Right-of-use assets obtained in exchange for lease obligations (non-cash):
Operating leases				$ 282
Weighted-average remaining lease term	9 months		1 year 2 months 12 days	2 years 6 months
Discount rate	7%		7%	7%

Redeemable convertible prefer_3

Redeemable convertible preferred stock (Details) - USD ($) $ in Thousands	Jul. 18, 2023	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized		0	1,373,810,170	1,373,810,170
Redeemable convertible preferred stock, issued		0	1,373,730,625	1,373,730,625
Redeemable convertible preferred stock, outstanding		0	1,373,730,625	1,373,730,625
Redeemable convertible preferred stock, liquidation preference			$ 232,963
Redeemable convertible preferred stock, carrying value			$ 214,620	$ 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

Redeemable convertible prefer_4

Redeemable convertible preferred stock - Additional Information (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Feb. 10, 2021 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares	Feb. 28, 2021 $ / shares
Redeemable convertible preferred stock
Dividends declared, preferred stock | $		$ 0
Series A
Redeemable convertible preferred stock
Preferred stock, liquidation preference per share		$ 10
Series B
Redeemable convertible preferred stock
Preferred stock, liquidation preference per share		11.50
Series B-1
Redeemable convertible preferred stock
Preferred stock, liquidation preference per share		0.88
Series C
Redeemable convertible preferred stock
Preferred stock, liquidation preference per share		0.88
Series D
Redeemable convertible preferred stock
Preferred stock, liquidation preference per share		0.88
Series D-1
Redeemable convertible preferred stock
Convertible preferred stock, conversion price per share		$ 69.94
Value of redeemable convertible preferred stock redeemed | $		$ 18,000
Preferred stock, liquidation preference per share		$ 0.88
Series E
Redeemable convertible preferred stock
Preferred stock, liquidation preference per share		0.09219
Series F
Redeemable convertible preferred stock
Value of shares issued | $	$ 11,000
Number of shares issued | shares	84,485,407
Share issue price	$ 0.13020
Convertible preferred stock, conversion price per share			$ 0.1391
Preferred stock, liquidation preference per share		$ 0.13020
Redeemable convertible preferred stock except D-1 shares
Redeemable convertible preferred stock
Preferred stock, dividend rate percentage		8%
Preferred stock, conversion ratio		0.012580
Convertible preferred stock, minimum conversion price ratio		1.25
Proceeds from issuance of redeemable convertible preferred stock | $		$ 50,000

Stockholders' deficit - Stock (

Stockholders' deficit - Stock (Details)		9 Months Ended
	Jul. 18, 2023 Vote	Sep. 30, 2023 Vote shares	Dec. 31, 2022 shares	Dec. 31, 2021 shares
Stockholders' deficit
Common stock, shares authorized		0	1,608,370,000	1,590,550,754
Preferred stock, shares authorized		10,000,000	0
Common stock shares reserved for future issuance		6,353,473	1,325,890,931	1,325,468,004
Series A Common Stock Warrants
Stockholders' deficit
Common stock shares reserved for future issuance		1,000
Series D redeemable convertible preferred stock warrants
Stockholders' deficit
Common stock shares reserved for future issuance			79,545	79,545
Series A Common Stock
Stockholders' deficit
Common stock, shares authorized		500,000,000	0
Number of votes per share | Vote	1	1
Beneficial ownership stock held (as a percent)		4.99%
Options to purchase common stock
Stockholders' deficit
Common stock shares reserved for future issuance		3,766,505	3,190,450	2,138,110
Options authorized and available for issuance
Stockholders' deficit
Common stock shares reserved for future issuance		2,585,968	181,191	810,604
Warrants
Stockholders' deficit
Common stock shares reserved for future issuance			40,268	40,268
Warrants | Series D redeemable convertible preferred stock warrants
Stockholders' deficit
Common stock shares reserved for future issuance			79,545
Redeemable convertible preferred stock
Stockholders' deficit
Common stock shares reserved for future issuance			1,322,399,477	1,322,399,477

Stockholders' deficit - Stock w

Stockholders' deficit - Stock warrants (Details)	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Apr. 30, 2015 $ / shares shares	Apr. 10, 2015 $ / shares shares
Stock warrants
Warrants voting rights	0
Redeemable Convertible Preferred Stock Warrant Liability
Stock warrants
Number of warrants issued					79,545
Exercise Price per Share | $ / shares					$ 0.88
Warrants term					10 years
Common warrants issued on June 2013
Stock warrants
Number of warrants issued		26,846
Number of Warrant Shares		26,846	26,846
Exercise Price per Share | $ / shares		$ 0.79	$ 0.79
Fair Value on Issuance | $		$ 339,000	$ 339,000
Common warrants issued on January 2014
Stock warrants
Number of warrants issued		13,422
Number of Warrant Shares		13,422	13,422
Exercise Price per Share | $ / shares		$ 0.79	$ 0.79
Fair Value on Issuance | $		$ 223,000	$ 223,000
Common warrants issued on April 2015
Stock warrants
Number of warrants issued	1,000	79,545		79,545	79,545
Number of Warrant Shares		79,545	79,545
Exercise Price per Share | $ / shares	$ 69.94	$ 0.88	$ 0.88	$ 0.88	$ 0.88
Fair Value on Issuance | $	$ 68,000	$ 68,000	$ 68,000
Warrants term					10 years
Series A Common Stock Warrants
Stock warrants
Exercise Price per Share | $ / shares	$ 69.94
Fair Value on Issuance | $	$ 1,400
Number of securities called by warrants	1,000

Stock-based compensation (Detai

Stock-based compensation (Details) - shares		9 Months Ended	12 Months Ended
	Jul. 13, 2023	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock-based compensation
Common stock shares reserved for future issuance		6,353,473	1,325,890,931	1,325,468,004
Maximum | Employee stock option
Stock-based compensation
Contractual term			5 years
Shareholder having 10% holding
Stock-based compensation
Percentage of shareholder not having exercise price not less than 100% of fair value			10%
2023 Equity incentive plan
Stock-based compensation
Common stock shares reserved for future issuance	2,585,968	2,585,968	181,191	810,604
Increase in outstanding shares (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
Increase in outstanding shares (as a percent)	1%
Number of shares Issued under 2023 ESPP		0
Equity Incentive Plan2017 | Maximum | Employee stock option
Stock-based compensation
Contractual term			10 years
Equity Incentive Plan2017 | Minimum | Employee stock option
Stock-based compensation
Percentage of price on estimated fair value			100%
Equity Incentive Plan2017 | Shareholder having 10% holding | Minimum | Employee stock option
Stock-based compensation
Percentage of price on estimated fair value			110%

Stock-based compensation - Stoc

Stock-based compensation - Stock options (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Number of Shares underlying Outstanding Options
Balance at the beginning	3,190,450	2,138,110
Options granted	585,919	1,080,304
Options exercised	(7,614)	(1,627)
Options cancelled	(498)	(887)
Options expired	(1,752)	(25,450)
Balance at the end	3,766,505	3,190,450	2,138,110
Shares vested and exercisable at the end	1,784,725	1,510,555
Weighted-Average Exercise Price
Balance at the beginning (in dollars per share)	$ 7.10	$ 7.15
Options granted (in dollars per share)	13.51	7.15
Options exercised (in dollars per share)	0.79	7.24
Options cancelled (in dollars per share)	4.77	31.46
Options expired (in dollars per share)	0.79	12.75
Balance at the end (in dollars per share)	8.11	7.10	$ 7.15
Vested and Exercisable at the end (in dollars per share)	$ 6.98	$ 7.15
Weighted- Average Remaining Contractual Term (in Years) and Aggregate Intrinsic Value
Weighted- Average Remaining Contractual Term, Outstanding	7 years 8 months 8 days	8 years 1 month 6 days	8 years 1 month 6 days
Weighted- Average Remaining Contractual Term, Exercisable	6 years 4 months 2 days	6 years 9 months 18 days
Aggregate Intrinsic Value, Outstanding	$ 17,737,000	$ 3,998,000	$ 4,670,000
Aggregate Intrinsic Value, Exercisable	$ 10,206,000	$ 2,303,000
Fair value of options granted		$ 6.36
Fair value of options vested		$ 1,800,000
Total unrecognized compensation cost		$ 9,100,000
Remaining weighted-average period for unrecognized compensation cost		3 years 2 months 12 days
Time-based options
Number of Shares underlying Outstanding Options
Balance at the beginning	2,570,708	1,537,241
Options granted	585,919	1,061,431
Options exercised	(7,614)	(1,627)
Options cancelled	(498)	(887)
Options expired	(1,752)	(25,450)
Balance at the end	3,146,763	2,570,708	1,537,241
Shares vested and exercisable at the end	1,186,212	1,459,480
Weighted-Average Exercise Price
Balance at the beginning (in dollars per share)	$ 7.56	$ 7.95
Options granted (in dollars per share)	13.51	7.15
Options exercised (in dollars per share)	0.79	7.24
Options cancelled (in dollars per share)	4.77	31.46
Options expired (in dollars per share)	0.79	12.75
Balance at the end (in dollars per share)	8.69	$ 7.56	$ 7.95
Vested and Exercisable at the end (in dollars per share)	$ 14.42
Weighted- Average Remaining Contractual Term (in Years) and Aggregate Intrinsic Value
Vesting period	4 years	4 years
Fair value of options vested	$ 1,800,000
Total unrecognized compensation cost	$ 12,000,000
Remaining weighted-average period for unrecognized compensation cost	2 years 4 months 24 days
Performance-based options
Number of Shares underlying Outstanding Options
Balance at the beginning	619,742	600,869
Options granted		18,873
Balance at the end	619,742	619,742	600,869
Shares vested and exercisable at the end	598,513	51,075
Weighted-Average Exercise Price
Balance at the beginning (in dollars per share)	$ 6.38	$ 6.36
Options granted (in dollars per share)		7.15
Balance at the end (in dollars per share)	$ 6.38	6.38	$ 6.36
Weighted- Average Remaining Contractual Term (in Years) and Aggregate Intrinsic Value
Fair value of options granted		$ 7.15
Fair value of options vested	$ 11,100	$ 82,000
Total unrecognized compensation cost	$ 28,200	$ 0
Remaining weighted-average period for unrecognized compensation cost	1 year	1 year

Stock-based compensation - Expe

Stock-based compensation - Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Stock-based compensation
Total stock-based compensation	$ 1,855	$ 389	$ 3,679	$ 1,159	$ 1,880	$ 1,904
General and administrative
Stock-based compensation
Total stock-based compensation	1,649	220	3,103	663	1,204	1,325
Research and development
Stock-based compensation
Total stock-based compensation	$ 206	$ 169	$ 576	$ 496	$ 676	$ 579

Stock-based compensation - Fair

Stock-based compensation - Fair value input (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Stock-based compensation
Risk-free interest rate	3.60%
Employee stock option
Stock-based compensation
Expected volatility, minimum	89%	88%	88%	89%
Expected volatility, maximum	91%	90%	90%	94%
Dividend yield	0%		0%
Minimum | Employee stock option
Stock-based compensation
Risk-free interest rate		2.30%	3%	0.40%
Expected term	5 years	5 years 4 months 24 days	5 years 4 months 24 days	5 years
Maximum | Employee stock option
Stock-based compensation
Risk-free interest rate		3%	4.20%	1.30%
Expected term	7 years	7 years	7 years	6 years 1 month 6 days

Net loss per share attributab_3

Net loss per share attributable to common stockholders - EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net loss attributable to common stockholders	$ (6,353)	$ (6,785)	$ (6,587)	$ (7,467)	$ (7,102)	$ (8,735)	$ (19,725)	$ (23,304)	$ (30,499)	$ (24,442)
Denominator:
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic				185,084				184,756	184,619	122,579
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted	18,194,682			185,084			6,131,541	184,756	184,619	122,579
Net loss per share attributable to common stockholders, basic				$ (40.34)				$ (126.13)	$ (165.20)	$ (199.40)
Net loss per share attributable to common stockholders, diluted	$ (0.35)			$ (40.34)			$ (3.22)	$ (126.13)	$ (165.20)	$ (199.40)
Series A and Series B
Denominator:
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic	18,194,682						6,131,541
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted	18,194,682						6,131,541
Net loss per share attributable to common stockholders, basic	$ (0.35)						$ (3.22)
Net loss per share attributable to common stockholders, diluted	$ (0.35)						$ (3.22)

Net loss per share attributab_4

Net loss per share attributable to common stockholders - Dilutive (Details) - shares	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Antidilutive securities
Redeemable convertible preferred stock					16,638,476	16,638,476
Options to purchase common stock					3,190,450	2,138,110
Warrants to purchase common stock					40,268	40,268
Warrants to purchase redeemable convertible preferred stock					79,545	79,545
Total	3,767,505	18,956,964	3,767,505	18,956,964	19,948,739	18,896,399
Redeemable Convertible Preferred Stock Warrant
Antidilutive securities
Total		16,638,476		16,638,476
Options to purchase common stock | Series A Common Stock Warrants
Antidilutive securities
Total	3,766,505	2,198,675	3,766,505	2,198,675
Warrants | Series A Common Stock Warrants
Antidilutive securities
Total	1,000		1,000
Warrants | Common stock warrants
Antidilutive securities
Total		40,268		40,268
Warrants | Redeemable Convertible Preferred Stock Warrant
Antidilutive securities
Total		79,545		79,545

Income taxes (Details)

Income taxes (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income taxes
Federal income taxes at statutory rates	21%	21%
State income tax, net of federal benefit	0.43%	0.40%
Research and development credits	3.48%	3.08%
Stock-based compensation	(0.81%)	(1.19%)
Change in valuation allowance	(24.10%)	(22.64%)
Other permanent items		(0.65%)

Income taxes - Net deferred tax

Income taxes - Net deferred tax assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 28,707	$ 28,350
Capitalized start-up costs and research expenses	13,004	7,358
Research and development credits	4,977	3,762
Accruals, reserves and other	1,144	1,013
Lease liabilities	47	73
Total gross deferred assets	47,879	40,556
Valuation allowance	(47,834)	(40,484)
Total deferred tax assets	45	72
Deferred tax liabilities:
Right-of-use assets	(45)	(72)
Increase in valuation allowance	7,400	$ 5,600
Federal net operating loss (NOL) carryforwards available to offset future federal income	128,200
Net operating loss carryforwards subject to expiration	91,000
Net operating loss carryforwards not subject to expiration	37,200
State net operating loss (NOL) carryforwards available to offset future state income	25,500
Federal research and development tax credit carryforwards available to reduce future tax liabilities subject to expire	4,400
State credit carryforwards of available to reduce future tax liabilities which do not expire	$ 2,500

Income taxes - Unrecognized tax

Income taxes - Unrecognized tax benefits (Details) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2022	Dec. 31, 2021
Unrecognized tax benefits
Unrecognized tax benefits as of the beginning of the year		$ 1,035,000	$ 817,000
Decrease related to prior year tax positions			(17,000)
Increase related to current year tax positions		499,000	235,000
Unrecognized tax benefits as of the end of the year		1,534,000	$ 1,035,000
Accrued interest or penalties related to uncertain tax positions		$ 0
Amortization period for capitalized domestic expenses	5 years
Amortization period for capitalized foreign expenses	15 years
Increase in deferred tax assets related to capitalized research expenses	$ 4,600,000

Defined contribution plan (Deta

Defined contribution plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Defined contribution plan
Contributions by employer	$ 0	$ 0

Subsequent events (Details)

Subsequent events (Details)	Jul. 07, 2023
Subsequent Event [Line Items]
Reverse stock split ratio	0.012582
Subsequent event
Subsequent Event [Line Items]
Reverse stock split ratio	0.012582

CONDENSED BALANCE SHEETS_2

CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 101,842			$ 158				$ 56,731
Short-term investments in marketable securities	0			32,187
Prepaid expenses and other current assets	974			447				1,932
Total current assets	102,816			32,792				58,663
Operating lease right-of-use assets	109			212				342
Deposits				27				27
Total assets	102,925			33,031				59,032
Current liabilities:
Accounts payable	1,702			1,125				761
Accrued expenses and other current liabilities	3,244			4,021				1,555
Operating lease liabilities	103			133				124
Total current liabilities	5,049			5,279				2,440
Long-term liabilities
Operating lease liabilities, less current portion				78				224
Stock warrant liability				4				7
Total liabilities	5,050			5,361				2,671
Commitments and contingencies (Note 7)
Redeemable convertible preferred stock: $0.0001 par value; no shares and 1,373,810,170 shares authorized at September 30, 2023 and December 31, 2022, respectively; no shares and 1,373,730,625 shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively; liquidation value of $232,963 at December 31, 2022				214,620				214,620
Stockholders' equity (deficit):
Undesignated preferred stock, $0.0001 par value; 10,000,000 shares and no shares authorized at September 30, 2023 and December 31, 2022, respectively; no shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively
Common stock				1				1
Additional paid-in capital	339,466			35,001				33,109
Accumulated other comprehensive loss				(84)
Accumulated deficit	(241,593)			(221,868)				(191,369)
Total stockholders' equity (deficit)	97,875	$ (198,414)	$ (192,699)	(186,950)	$ (180,554)	$ (173,420)	$ (166,595)	(158,259)	$ (135,910)
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)	102,925			33,031				$ 59,032
Series A Common Stock
Stockholders' equity (deficit):
Common stock	2
Series A Common Stock Warrants
Long-term liabilities
Stock warrant liability	$ 1
Redeemable Convertible Preferred Stock Warrant
Long-term liabilities
Stock warrant liability				$ 4

CONDENSED BALANCE SHEETS (Par_2

CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Redeemable convertible preferred stock, par value	$ 0.0001	$ 0.0001	$ 0.0001
Redeemable convertible preferred stock, shares authorized	0	1,373,810,170	1,373,810,170
Redeemable convertible preferred stock, issued	0	1,373,730,625	1,373,730,625
Redeemable convertible preferred stock, outstanding	0	1,373,730,625	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	1,590,550,754
Common stock, shares issued	0	185,084	183,457
Common stock, shares outstanding		185,084
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		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

CONDENSED STATEMENTS OF OPERA_2

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($)	1 Months Ended		3 Months Ended						9 Months Ended		12 Months Ended
	Jul. 31, 2023	Jan. 31, 2022	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Revenue:
Revenue	$ 2,000,000	$ 0	$ 2,000,000						$ 2,000,000		$ 0
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]			us-gaap:LicenseMember						us-gaap:LicenseMember
Operating expenses:
Research and development			$ 4,958,000			$ 6,838,000			$ 14,121,000	$ 19,072,000	24,919,000	$ 19,340,000
General and administrative			4,494,000			848,000			9,153,000	4,595,000	6,136,000	4,379,000
Total operating expenses			9,452,000			7,686,000			23,274,000	23,667,000	31,055,000	23,719,000
Loss from operations			(7,452,000)			(7,686,000)			(21,274,000)	(23,667,000)	(31,055,000)	(23,719,000)
Other income, net:
Change in fair value of stock warrant liability											3,000	2,000
Interest income and other			1,095,000			218,000			1,546,000	360,000	553,000	26,000
Total other income, net			1,099,000			219,000			1,549,000	363,000	556,000	(723,000)
Net loss			(6,353,000)	$ (6,785,000)	$ (6,587,000)	(7,467,000)	$ (7,102,000)	$ (8,735,000)	(19,725,000)	(23,304,000)	(30,499,000)	(24,442,000)
Other comprehensive (loss) gain:
Net unrealized (loss) gain on investments in marketable securities				$ 13,000	$ 71,000	(56,000)	$ (106,000)		84,000	(162,000)	(84,000)
Total other comprehensive (loss) gain						(56,000)			84,000	(162,000)	(84,000)
Comprehensive loss			$ (6,353,000)			$ (7,523,000)			$ (19,641,000)	$ (23,466,000)	$ (30,583,000)	$ (24,442,000)
Net loss per share attributable to common stockholders, basic						$ (40.34)				$ (126.13)	$ (165.20)	$ (199.40)
Net loss per share attributable to common stockholders, diluted			$ (0.35)			$ (40.34)			$ (3.22)	$ (126.13)	$ (165.20)	$ (199.40)
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic						185,084				184,756	184,619	122,579
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted			18,194,682			185,084			6,131,541	184,756	184,619	122,579
Series A and Series B
Other comprehensive (loss) gain:
Net loss per share attributable to common stockholders, basic			$ (0.35)						$ (3.22)
Net loss per share attributable to common stockholders, diluted			$ (0.35)						$ (3.22)
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic			18,194,682						6,131,541
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted			18,194,682						6,131,541
Redeemable Convertible Preferred Stock Warrant
Other income, net:
Change in fair value of stock warrant liability						$ 1,000			$ (1,000)	$ 3,000	$ (3,000)	$ (2,000)
Series A Common Stock Warrants
Other income, net:
Change in fair value of stock warrant liability			$ 4,000						$ 4,000

CONDENSED STATEMENT OF REDEEM_4

CONDENSED STATEMENT 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, 2020			$ 1	$ 31,016	$ (166,927)				$ (135,910)
Beginning balance (in shares) at Dec. 31, 2020			96,507
Increase (Decrease) In Stockholders' Deficit
Net loss					(24,442)				(24,442)
Issuance of Series A Common Stock upon exercise of stock options				149					149
Issuance of Series A Common Stock upon exercise of stock options (in shares)			23,266
Exercise of common stock warrants				40					40
Exercise of common stock warrants (in shares)			63,684
Stock-based compensation expense				1,904					1,904
Ending balance at Dec. 31, 2021			$ 1	33,109	(191,369)				(158,259)
Ending balance (in shares) at Dec. 31, 2021			183,457
Increase (Decrease) In Stockholders' Deficit
Net loss					(8,735)				(8,735)
Issuance of Series A Common Stock upon exercise of stock options				12					12
Issuance of Series A Common Stock upon exercise of stock options (in shares)			1,627
Stock-based compensation expense				387					387
Ending balance at Mar. 31, 2022			$ 1	33,508	(200,104)				(166,595)
Ending balance (in shares) at Mar. 31, 2022			185,084
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 loss									(23,304)
Unrealized gain (loss) on investments in marketable securities									(162)
Ending balance at Sep. 30, 2022			$ 1	34,280	(214,673)	$ (162)			(180,554)
Ending balance (in shares) at Sep. 30, 2022			185,084
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 loss					(30,499)				(30,499)
Issuance of Series A Common Stock upon exercise of stock options				12					$ 12
Issuance of Series A Common Stock upon exercise of stock options (in shares)			1,627						1,627
Unrealized gain (loss) on investments in 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
Beginning balance at Mar. 31, 2022			$ 1	33,508	(200,104)				$ (166,595)
Beginning balance (in shares) at Mar. 31, 2022			185,084
Increase (Decrease) In Stockholders' Deficit
Net loss					(7,102)				(7,102)
Unrealized gain (loss) on investments in marketable securities						(106)			(106)
Stock-based compensation expense				383					383
Ending balance at Jun. 30, 2022			$ 1	33,891	(207,206)	(106)			(173,420)
Ending balance (in shares) at Jun. 30, 2022			185,084
Increase (Decrease) In Stockholders' Deficit
Net loss					(7,467)				(7,467)
Unrealized gain (loss) on investments in marketable securities						(56)			(56)
Stock-based compensation expense				389					389
Ending balance at Sep. 30, 2022			$ 1	34,280	(214,673)	(162)			(180,554)
Ending balance (in shares) at Sep. 30, 2022			185,084
Beginning balance at Dec. 31, 2022			$ 1	35,001	(221,868)	(84)			$ (186,950)
Beginning balance (in shares) at Dec. 31, 2022			185,084				0	0	185,084
Increase (Decrease) In Stockholders' Deficit
Net loss					(6,587)				$ (6,587)
Unrealized gain (loss) on investments in marketable securities						71			71
Stock-based compensation expense				767					767
Ending balance at Mar. 31, 2023			$ 1	35,768	(228,455)	(13)			(192,699)
Ending balance (in shares) at Mar. 31, 2023			185,084
Beginning balance at Dec. 31, 2022			$ 1	35,001	(221,868)	(84)			$ (186,950)
Beginning balance (in shares) at Dec. 31, 2022			185,084				0	0	185,084
Increase (Decrease) In Stockholders' Deficit
Net loss									$ (19,725)
Issuance of Series A Common Stock upon exercise of stock options (in shares)									7,614
Unrealized gain (loss) on investments in marketable securities									$ 84
Ending balance at Sep. 30, 2023	$ 2			339,466	(241,593)				97,875
Ending balance (in shares) at Sep. 30, 2023	21,375,402	1,520,490						1,520,490
Beginning balance at Mar. 31, 2023			$ 1	35,768	(228,455)	(13)			(192,699)
Beginning balance (in shares) at Mar. 31, 2023			185,084
Increase (Decrease) In Stockholders' Deficit
Net loss					(6,785)				(6,785)
Exercise of common stock warrants (in shares)			25,231
Unrealized gain (loss) on investments in marketable securities						$ 13			13
Stock-based compensation expense				1,057					1,057
Ending balance at Jun. 30, 2023			$ 1	36,825	(235,240)				(198,414)
Ending balance (in shares) at Jun. 30, 2023			210,315
Increase (Decrease) In Stockholders' Deficit
Net loss					(6,353)				(6,353)
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
Reclass of Common Stock to Series A Common Stock	$ 1		$ (1)
Reclass 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				86,161					86,161
Sale of Series A Common Stock in public offering, net of issuance costs (in shares)	6,026,772
Issuance of Series A Common Stock upon exercise of stock options				6					6
Issuance of Series A Common Stock upon exercise of stock options (in shares)	7,614
Exercise of common stock warrants (in shares)	12,789
Stock-based compensation expense				1,855					1,855
Ending balance at Sep. 30, 2023	$ 2			$ 339,466	$ (241,593)				$ 97,875
Ending balance (in shares) at Sep. 30, 2023	21,375,402	1,520,490						1,520,490

CONDENSED STATEMENT OF REDEEM_5

CONDENSED STATEMENT OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - Temporary Equity - USD ($)	Redeemable convertible preferred stock	Total
Beginning balance, Temporary equity at Dec. 31, 2021	$ 214,620,000	$ 214,620,000
Beginning balance, Temporary equity (in shares) at Dec. 31, 2021	1,373,730,625	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Ending balance, Temporary equity at Mar. 31, 2022	$ 214,620,000
Ending balance, Temporary equity (in shares) at Mar. 31, 2022	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Ending balance, Temporary equity at Jun. 30, 2022	$ 214,620,000
Ending balance, Temporary equity (in shares) at Jun. 30, 2022	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Ending balance, Temporary equity at Sep. 30, 2022	$ 214,620,000
Ending balance, Temporary equity (in shares) at Sep. 30, 2022	1,373,730,625
Beginning balance, Temporary equity at Dec. 31, 2022	$ 214,620,000	$ 214,620,000
Beginning balance, Temporary equity (in shares) at Dec. 31, 2022	1,373,730,625	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Ending balance, Temporary equity at Mar. 31, 2023	$ 214,620,000
Ending balance, Temporary equity (in shares) at Mar. 31, 2023	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Ending balance, Temporary equity at Jun. 30, 2023	$ 214,620,000
Ending balance, Temporary equity (in shares) at Jun. 30, 2023	1,373,730,625
Increase (Decrease) in Temporary Equity
Net loss	$ 0
Conversion of Redeemable Convertible Preferred Stock to Series A and Series B Common Stock	$ 1,373,730,625	$ 214,620,000
Conversion of Redeemable Convertible Preferred Stock to Series A and Series B Common Stock (in shares)	214,620,000
Ending balance, Temporary equity (in shares) at Sep. 30, 2023		0

CONDENSED STATEMENT OF REDEEM_6

CONDENSED STATEMENT OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) ( Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2021
CONDENSED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT)
Issuance costs	$ 10,267	$ 16

CONDENSED STATEMENTS OF CASH _2

CONDENSED STATEMENTS OF CASH FLOWS - USD ($)	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (19,725,000)	$ (23,304,000)	$ (30,499,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Accretion of discount on marketable securities, net	(39,000)	(129,000)	(212,000)
Non-cash lease expense	103,000	97,000	130,000
Stock-based compensation expense	3,679,000	1,159,000	1,880,000
Change in the fair value of warrant liability			(3,000)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(390,000)	1,326,000	1,436,000
Accounts payable and accrued liabilities	(200,000)	3,920,000	2,915,000
Operating lease liabilities	(108,000)	(103,000)	(137,000)
Net cash used in operating activities	(16,683,000)	(17,037,000)	(24,490,000)
Cash flows from investing activities:
Purchases of marketable securities		(41,446,000)	(41,446,000)
Sales of marketable securities	32,200,000	4,000,000	9,436,000
Net cash provided (used in) by investing activities	32,200,000	(37,446,000)	(32,010,000)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriters' commissions and discounts	86,161,000
Payment of deferred financing costs		(30,000)	(85,000)
Proceeds from exercise of stock options	6,000	12,000	12,000
Net cash provided by (used in) financing activities	86,167,000	(18,000)	(73,000)
Net increase (decrease) in cash and cash equivalents	101,684,000	(54,501,000)	(56,573,000)
Cash and cash equivalents, beginning	158,000	56,731,000	56,731,000
Cash and cash equivalents, ending	101,842,000	2,230,000	158,000
Series A Common Stock Warrants
Adjustments to reconcile net loss to net cash used in operating activities:
Change in the fair value of warrant liability	(4,000)
Redeemable Convertible Preferred Stock Warrant
Adjustments to reconcile net loss to net cash used in operating activities:
Change in the fair value of warrant liability	$ 1,000	$ (3,000)	$ 3,000

Organization and description _3

Organization and description of business	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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 9. 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 September 30, 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, including net losses of $19.7 million for the nine months ended September 30, 2023 and $23.3 million for the nine months ended September 30, 2022. For the nine months ended September 30, 2023, and 2022, the Company had negative cash flows from operations of $16.7 million and $17.0 million, respectively. As of September 30, 2023, the Company had cash and cash equivalents of $101.8 million. The Company expects to incur additional losses and negative cash flows from operations for the next twelve months. As of November 13, 2023, the issuance date of these unaudited condensed financial statements, the Company expects that its cash and cash equivalents as of September 30, 2023 will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance of these condensed 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. Impact of COVID-19 pandemic on financial statements We experienced modest delays in our development activities as a result of the COVID-19 pandemic, primarily due to temporary closures of certain clinical sites that delayed patient enrollment in our FASCINATE-2 trial. Although the public health emergency declarations related to COVID-19 in the United States ended on May 11, 2023, the extent to which the COVID-19 pandemic will continue to impact our operations or those of our consultants and collaborators, will depend on future developments, including the global macroeconomic effects of the virus. Economic recessions, increased inflation and/or interest rates, and any disruptions to our operations or workforce availability, including those brought on by the continued effects of the COVID-19 pandemic or a similar health epidemic may have a negative effect on our operating results. Unaudited interim financial information The accompanying condensed balance sheet as of September 30, 2023, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 and 2022, the condensed statements of redeemable convertible preferred stock and stockholders’ equity (deficit) for the three and nine months ended September 30, 2023 and 2022, the condensed statements of cash flows for the nine months ended September 30, 2023 and 2022, and the related disclosures are unaudited. These unaudited condensed financial statements include all adjustments necessary, consisting of only normal recurring adjustments, to fairly state the financial position and the results of the Company’s operations and cash flows for interim periods in accordance with accounting principles generally accepted in the United States of America (GAAP). Interim period results are not necessarily indicative of results of operations or cash flows for a full year or any subsequent interim period. The condensed balance sheet as of December 31, 2022 has been derived from the audited financial statements of the Company. The accompanying unaudited condensed financial statements should be read in conjunction with the Company’s audited financial statements included elsewhere in this prospectus.	SAGIMET BIOSCIENCES INC. NOTES TO THE FINANCIAL STATEMENTS 1. 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 focused on developing a portfolio of in-house discovered, selective fatty acid synthase (FASN) inhibitors for the treatment of diseases that result from dysfunctional lipid metabolism pathways. 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. To date, the Company has relied on private equity and debt financings to fund its operations. The Company has incurred net losses and negative cash flows from operations since inception, including net losses of $30.5 million and $24.4 million for the years ended December 31, 2022 and 2021, respectively. For the years ended December 31, 2022 and 2021, the Company had negative cash flows from operations of $24.5 million and $21.7 million, respectively. As of December 31, 2022, the Company had cash, cash equivalents and short-term investments in marketable securities of $32.3 million. The Company expects to incur additional losses and negative cash flows from operations for the next twelve months. Based on its recurring losses from operations incurred since inception, expectation of continuing operating losses for the foreseeable future, and need to raise additional capital to finance its future operations, the Company has concluded that there is substantial doubt regarding the Company’s ability to continue as a going concern within one year after the date that these financial statements are issued. The Company will require substantial additional capital to fund its research and development and ongoing operating expenses. The Company is seeking to complete an initial public offering (IPO) of its Series A common stock. In the event the Company does not complete an IPO, the Company expects to seek additional funding through private equity financings, debt financings or other sources. The Company may not be able to obtain funding on acceptable terms, or at all. The terms of any future financing may adversely affect the holdings or the rights of the Company’s existing stockholders. If the Company is unable to raise additional funds when needed, it may be required to delay, reduce or eliminate its research and development. The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. These financial statements do not include any adjustments that might result from the outcome of this uncertainty. Impact of COVID-19 pandemic on financial statements The outbreak of the 2019 novel coronavirus disease (COVID-19), which was declared a global pandemic by the World Health Organization on March 11, 2020, and the related responses by public health and governmental authorities to contain and combat its outbreak and spread has severely impacted the U.S. and world economies during the end of the first quarter of 2020 and continuing through the end of 2022. COVID-19 and the U.S. response to the pandemic are significantly affecting the economy. There are no comparable events that provide guidance as to the effect the COVID-19 pandemic may have, and, as a result, the ultimate effect of the pandemic is highly uncertain and subject to change. The Company does not yet know the full extent of the effects on the economy, the markets it serves, its business, or its operations. Moving forward, economic recessions, increased inflation and/or interest rates, including those brought on by the continued COVID-19 outbreak may have a negative effect on the Company’s operating results. Any prolonged disruption to our operations or workforce availability is likely to have a significant adverse effect on the Company’s results of operations and cash flows. All of the above may be exacerbated in the future as the COVID-19 outbreak and the governmental responses thereto continue.

Summary of significant accoun_4

Summary of significant accounting policies	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Summary of significant accounting policies
Summary of significant accounting policies	2. Summary of significant accounting policies Basis of presentation The condensed financial statements and accompanying notes have been prepared in accordance with GAAP and the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. These condensed financial statements have been prepared on the same basis as the annual financial statements included elsewhere in this prospectus. In the Company’s opinion, the information furnished in these condensed financial statements reflects all adjustments, all of which are of a normal and recurring nature necessary for a fair presentation of the financial position and results of operations for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period. 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 expenses during the reporting period. Such estimates include accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock, common stock 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. Significant accounting policies The Company’s significant accounting policies are disclosed in the audited financial statements for the year ended December 31, 2022, included elsewhere in this prospectus, and the unaudited financial statements as of March 31, 2023 filed with the SEC. Since the date of those financial statements, there have been no changes to the Company’s significant accounting policies except as disclosed below in recently adopted accounting pronouncements. 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 The Company had no short-term investments in marketable securities as of September 30, 2023. Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s IPO are capitalized and recorded in the accrued expenses and other current liabilities in the condensed balance sheets. Upon closing of the IPO in July 2023, all deferred offering costs were reclassified to additional paid-in-capital in the condensed statements of operations and comprehensive loss, representing a reduction in IPO proceeds. On March 21, 2022, the Company withdrew its prior Registration Statement on Form S-1 initially filed with the SEC on April 16, 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 unaudited condensed statement of operations and comprehensive loss for the nine months ended September 30, 2022. 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 Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers 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). In January 2022, Ascletis BioScience Co. Ltd. (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 recorded as license revenue in the condensed statements of operations and comprehensive loss (representing the $2.0 million development milestone payment, net of applicable taxes) from Ascletis. Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash, cash equivalents and marketable securities. 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 Financial Accounting Standards Board (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	2. 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). 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 expenses during the reporting period. Such estimates include accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock, common stock 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. 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, 2022 and 2021, 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 securities as available-for-sale and records such assets at estimated fair value in the balance sheets, with unrealized gains and losses that are determined to be temporary, if any, reported as a component of other comprehensive income (loss) within the statements of operations and comprehensive loss and as a separate component of stockholders’ deficit. The Company classifies marketable securities with remaining maturities greater than three months but less than one year as short-term investments, and those with remaining maturities greater than one year are classified as long-term investments. Investments are regularly reviewed for other-than-temporary declines in fair value. The review includes the consideration of the cause of the impairment, including the creditworthiness of the security issuers, the number of investments in an unrealized loss position, the severity and duration of the unrealized losses and whether it is more likely than not that the Company will be required to sell the investments before the recovery of their amortized cost basis. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the establishment of a new cost basis for the security. The Company invests its excess cash balances primarily in corporate debt securities with strong credit ratings. Realized gains and losses are calculated on the specific identification method and recorded as interest income and were immaterial for all periods presented. As of December 31, 2022, the Company’s short-term marketable securities were invested with Silicon Valley Bank (SVB), and custodied at U.S. bank. Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash, cash equivalents and marketable securities. Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s planned IPO are capitalized and recorded on the balance sheets. The deferred financing costs will be offset against the proceeds received upon the closing of the planned IPO. In the event that the Company’s plans for an IPO are terminated, all of the deferred financing costs will be written off within operating expenses in the Company’s statements of operations and comprehensive loss. As of December 31, 2021, there were $1.4 million of deferred financing costs capitalized related to the Company’s previous IPO plans in 2021. On March 21, 2022, the Company withdrew its Registration Statement on Form S-1 initially filed with the 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. As of December 31, 2022, there were no deferred financing costs capitalized. 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 Accounting Standards Update (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 twelve 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. Revenue recognition The Company enters into collaboration and licensing arrangements that generally contain multiple elements or deliverables, which may include (1) licenses to the Company’s technology, (2) research and development activities performed for the collaboration partner, (3) participation on joint steering committees (JSCs), and (4) 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 Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers 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). In January 2022, Ascletis initiated dosing of a Phase 3 trial for recurrent GBM, potentially triggering a $2.0 million development milestone payment under the license agreement. Due to the uncertainty around the achievement of the milestone and ongoing discussions with Ascletis around the consideration for the milestone, the Company concluded it was probable that a significant reversal of the revenue related to the milestone would occur, and therefore, no revenue was recognized. 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 non-alcoholic steatohepatitis (NASH) 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. The CODM evaluates the Company’s financial information and assesses the performance of the Company based on the single operating segment. The Company assesses its determination of operating segments at least annually and continues to evaluate the internal reporting structure and potential impacts of any changes to its segment reporting. Common stock valuation Due to the absence of an active market for the Company’s common stock, the Company utilized methodologies in accordance with the framework of the American Institute of Certified Public Accountants Technical Practice Aid (Valuation of Privately Held Company Equity Securities Issued as Compensation) to estimate the fair value of its common stock. In determining the exercise prices for options granted, the Company has considered the estimated fair value of the common stock as of the measurement date. The estimated fair value of the common stock has been determined at each grant date based upon a variety of factors, including the illiquid nature of the common stock, arm’s-length sales of the Company’s capital stock (including redeemable convertible preferred stock), the effect of the rights and preferences of the redeemable convertible preferred stockholders, and the prospects of a liquidity event. Among other factors are the Company’s financial position and historical financial performance, the status of technological developments within the Company’s research, the composition and ability of the current research and management team, an evaluation or benchmark of the Company’s competition, and the current business climate in the marketplace. Significant changes to the key assumptions underlying the factors used could result in different fair values of common stock at each valuation date. Redeemable convertible preferred stock The Company records redeemable convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The redeemable convertible preferred stock is recorded outside of stockholders’ deficit because the shares contain liquidation features that are not solely within the Company’s control. The Company has not adjusted the carrying values of the redeemable convertible preferred stock to the liquidation preferences of such shares because it is 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. Subsequent adjustments to the carrying values to the liquidation preferences will be made only when it becomes probable that such a liquidation event will occur. Redeemable convertible preferred stock tranche liability The Company determined the right of the investors to purchase shares of Series F redeemable convertible preferred stock at a future date met the definition of a freestanding instrument and was recognized as a liability at fair value upon the December 2020 issuance of Series F redeemable convertible preferred stock (Redeemable Convertible Preferred Stock Tranche Liability). The liability was subject to remeasurement at each balance sheet date, with changes in fair value recognized in other income (expense) in the statements of operations and comprehensive loss. Upon closing of the Series F redeemable convertible preferred stock financing in February 2021, the Redeemable Convertible Preferred Stock Tranche Liability was extinguished, and the marked-to-market fair value of the liability was included in the carrying value of redeemable convertible preferred stock issued. 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 Financial Accounting Standards Board (FASB) ASC 815, Derivatives and Hedging Under ASC 815-40, warrants that meet the criteria for equity treatment are recorded in stockholders’ deficit. The warrants are subject to re-evaluation of the proper classification and accounting treatment at each reporting period. If the warrants no longer meet the criteria for equity treatment, they will be recorded as a liability and remeasured each period with changes recorded in the statement of operations and comprehensive loss. When issued in connection with debt, the allocated value related to the warrants is generally recorded as additional interest cost on the related debt. When issued with redeemable convertible preferred stock, the allocated value related to the warrants is recorded as additional issuance costs of the redeemable convertible preferred stock. The Company values warrants using an option pricing model. Stock-based compensation expense The Company accounts for all stock-based payment awards granted to employees and non-employees as stock-based compensation expense at fair value. The Company’s stock-based payments include stock options and grants of common stock, including common stock subject to vesting. The measurement date for employee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight- line basis. Stock-based compensation costs for non-employees are recognized as expense over the vesting period on a straight-line basis. Stock-based compensation expense is classified in the accompanying statements of operations and comprehensive loss based on the function to which the related services are provided. The Company recognizes stock-based compensation expense for the portion of awards that have vested. Forfeitures are recorded as they occur. 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. For awards with service-based vesting conditions only, the Company recognizes share-based compensation expense on a straight-line basis over the requisite service or vesting period. For awards with service- and performance-based vesting conditions, the Company recognizes stock-based compensation expense using the graded vesting method over the requisite service period beginning in the period in which the awards are deemed probable to vest, to the extent such awards are probable to vest. The Company recognizes the cumulative effect of changes in the probability outcomes in the period in which the changes occur. 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, 2022 and 2021, 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’ 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 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 and common and redeemable convertible preferred stock warrants are considered to be potentially dilutive securities. Basic and diluted net loss per share attributable to common stockholders is presented inconformity with the two-class method required for participating securities as the redeemable convertible preferred stock is considered a participating security. 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. As the Company has reported a net loss for the period presented, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders for this period. 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 In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments 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

Fair value measurements and f_7

Fair value measurements and fair value of financial instruments	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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 September 30, 2023 and December 31, 2022, financial assets measured at fair value on a recurring basis consist of cash and cash equivalents. The carrying amount of cash and cash equivalents was $101.8 million and $0.2 million as of September 30, 2023 and December 31, 2022, respectively, which approximates the fair value and was determined based upon Level 1 inputs. The fair value of short-term investments 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. Marketable securities, all of which are classified as available-for-sale securities, consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ Amortized Unrealized Unrealized Estimated ​ ​ cost ​ Gains ​ Losses ​ Fair Value Commercial paper ​ $ 15,950 ​ $ — ​ $ — ​ $ 15,950 Corporate debt securities ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ 4,035 ​ — ​ (19) ​ 4,016 Total ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187 ​ There were no investments in marketable securities as of September 30, 2023. The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ fair value Level 1 Level 2 Level 3 Liabilities: ​ ​ ​ ​ Series A Common Stock Warrant Liability ​ $ 1 ​ $ — ​ $ — ​ $ 1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ value ​ Level 1 ​ Level 2 ​ Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents - money market funds ​ $ 38 ​ $ 38 ​ $ — ​ $ — Commercial paper ​ 15,950 ​ — ​ 15,950 ​ — Corporate debt securities ​ 12,221 ​ — ​ 12,221 ​ — U.S. Treasury securities ​ 4,016 ​ — ​ 4,016 ​ — Total ​ $ 32,225 ​ $ 38 ​ $ 32,187 ​ $ — Liabilities: ​ ​ ​ ​ Redeemable Convertible Preferred Stock Warrant Liability ​ $ 4 ​ $ — ​ $ — ​ $ 4 ​ 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, 2023 $ 4 Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ 1 Change in fair value of Series A Common Stock Warrant Liability ​ ​ (4) Balance - September 30, 2023 ​ $ 1 Balance - January 1, 2022 ​ $ 7 Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ (3) Balance - December 31, 2022 ​ $ 4 ​ 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. See Note 9. 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. The exercise was deemed a cashless exercise. 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 September 30, 2023, the fair value of the Series A Common Stock Warrant Liability was determined to be $1.4 thousand assuming a volatility rate of 91.5%, an expected term of 2.80 years, no dividends, and a risk-free interest rate of 4.87%. As of December 31, 2022, the fair value of the Redeemable Convertible Preferred Stock Warrant Liability was determined to be $4.0 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%. For the change in fair value of the Series A Common Stock Warrant Liability, the Company recorded other income of $4.0 thousand for both the three and nine months ended September 30, 2023, respectively, in its unaudited condensed statement of operations and comprehensive loss. For the change in fair value of the Redeemable Convertible Preferred Stock Warrant Liability, the Company recorded other expense of $1.0 thousand for the nine months ended September 30, 2023, and other income of $1.0 thousand and $3.0 thousand for the three and nine months ended September 30, 2022, respectively, in its unaudited condensed statement of operations and comprehensive loss.	3. 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— During the years ended December 31, 2022 and 2021, financial assets measured at fair value on a recurring basis consist of cash and cash equivalents which include deposits in a money market fund and short-term investments including commercial paper, corporate debt and U.S. Treasury securities. The carrying amount of cash and cash equivalents was $0.2 million and $56.7 million as of December 31, 2022 and 2021, respectively, which approximates the fair value and was determined based upon Level 1 inputs. The fair value of short-term investments 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 consist of the redeemable convertible preferred stock warrant liability and Redeemable Convertible Preferred Stock Tranche Liability. Marketable securities, all of which are classified as available-for-sale securities, consisted of the following at December 31, 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ ​ Cost ​ Gains ​ Losses ​ Fair Value Commercial paper $ 15,950 $ — $ — $ 15,950 Corporate debt securities ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ 4,035 ​ — ​ (19) ​ 4,016 Total ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187 ​ There were no marketable securities at December 31, 2021. The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ value ​ Level 1 ​ Level 2 ​ Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents – money market funds ​ $ 38 ​ $ 38 ​ $ — ​ $ — Commercial paper ​ 15,950 ​ — ​ 15,950 ​ — Corporate debt securities ​ 12,221 ​ — ​ 12,221 ​ — U.S. Treasury securities ​ 4,016 ​ — ​ 4,016 ​ — Total ​ $ 32,225 ​ $ 38 ​ $ 32,187 ​ $ — Liabilities: ​ ​ ​ ​ Redeemable convertible preferred stock warrant liability ​ $ 4 ​ $ — ​ $ — ​ $ 4 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ value Level 1 Level 2 Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents – money market funds ​ $ 56,631 ​ $ 56,631 ​ $    — ​ $ — Liabilities: ​ ​ ​ ​ Redeemable convertible preferred stock warrant liability ​ $ 7 ​ $ — ​ $ — ​ $ 7 ​ The following table provides a summary of changes in the estimated fair value of the financial instruments using significant Level 3 inputs (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Redeemable Redeemable ​ ​ convertible ​ convertible ​ ​ preferred ​ preferred ​ ​ stock ​ stock ​ ​ warrant ​ tranche ​ ​ liability ​ liability Balance – January 1, 2021 ​ $ 9 ​ $ — Change in fair value of redeemable convertible preferred stock warrant liability and establishment of Redeemable Convertible Preferred Stock Tranche Liability ​ (2) ​ 751 Extinguishment of Redeemable Convertible Stock Tranche Liability upon subsequent issuance of Series F redeemable convertible preferred stock ​ — ​ (751) Balance – December 31, 2021 ​ $ 7 ​ $ — Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ (3) ​ — Balance – December 31, 2022 ​ $ 4 ​ $ — ​ 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 In April 2015, the Company entered into a debt agreement with a financial institution which was repaid in full on May 15, 2019. In connection with the debt agreement, the Company issued to the lender 79,545 warrants to purchase Series D redeemable convertible preferred stock with an exercise price of $0.88 per share exercisable immediately with a contractual term of 10 years. The Company estimates the fair value of 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, as well as assumptions for fair value of the underlying redeemable convertible preferred stock, expected volatility, expected life, dividends and risk-free interest rate. The Company will continue to adjust the liability for changes in fair value of these warrants until the earlier of: (i) exercise of warrants; (ii) expiration of warrants; (iii) a change of control of the Company; or (iv) the consummation of an IPO. 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%. As of December 31, 2021, the fair value of the Redeemable Convertible Preferred Stock Warrant Liability was determined to be $7 thousand assuming a volatility rate of 87.2%, an expected term of 3.27 years, no dividends, and a risk-free interest rate of 1.01%. The Company recorded other income of $3 thousand and $2 thousand for the change in fair value of the Redeemable Convertible Preferred Stock Warrant Liability in its statement of operations and comprehensive loss for the years ended December 31, 2022 and 2021, respectively. Redeemable Convertible Preferred Stock Tranche Liability The Company determined the right of an investor to purchase shares of Series F redeemable convertible preferred stock in December 2020 met the definition of a freestanding instrument and was classified as a liability. The fair value in December 2020 was determined to be negligible. Immediately prior to the issuance and sale of Series F redeemable convertible preferred stock in February 2021, the fair value of the Redeemable Convertible Preferred Stock Tranche Liability was calculated to be $0.8 million. The fair value of the Redeemable Convertible Preferred Stock Tranche Liability was estimated using the intrinsic value of the Series F redeemable convertible preferred stock of $0.1391 per share. In February 2021, upon the issuance and sale of shares of Series F redeemable convertible preferred stock, the Redeemable Convertible Preferred Stock Tranche Liability was extinguished. The Company recorded other expense of $0.8 million for the change in fair value of the Series F Redeemable Convertible Preferred Stock Tranche Liability in its statement of operations and comprehensive loss for the year ended December 31, 2021.

Prepaid expenses and other cu_4

Prepaid expenses and other current assets	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 Prepaid insurance ​ $ 865 ​ $ 61 Prepaid clinical expenses ​ ​ 32 ​ ​ 352 Other ​ 77 ​ 34 Total ​ $ 974 ​ $ 447 ​	4. Prepaid expenses and other current assets as of December 31, 2022 and 2021 consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Prepaid clinical expenses ​ $ 352 ​ $ 423 Deferred financing costs ​ — ​ 1,425 Other ​ 95 ​ 84 Total ​ $ 447 ​ $ 1,932 ​

Accrued expenses and other cu_4

Accrued expenses and other current liabilities	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 Accrued clinical costs ​ $ 2,239 ​ $ 3,162 Employees’ compensation ​ 689 ​ 636 Accrued research ​ ​ 221 ​ ​ — Accrued preclinical costs ​ — ​ 166 Other ​ 95 ​ 57 Total ​ $ 3,244 ​ $ 4,021 ​	5. Accrued expenses and other current liabilities as of December 31, 2022 and 2021 consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Accrued clinical costs ​ $ 3,162 ​ $ 852 Employees’ compensation ​ 636 ​ 463 Accrued pre-clinical costs ​ 166 ​ — Accrued deferred financing costs ​ — ​ 55 Other ​ 57 ​ 185 Total ​ $ 4,021 ​ $ 1,555 ​

Related parties_2

Related parties	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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, a subsidiary of Ascletis Pharma Inc. (Ascletis Pharma), biotechnology company incorporated in the Cayman Islands and headquartered in Hangzhou, China and a Company investor. 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 $28.1 thousand as reimbursement pursuant to the license agreement for Greater China patent prosecution costs during the nine months ended September 30, 2022. The Company did not receive any reimbursements pursuant to the license agreement for Greater China patent prosecution costs during the nine months ended September 30, 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. Ascletis Pharma, through a subsidiary, also led the Series E preferred stock financing in February 2019. As noted below, the Company received $2.0 million related to a development milestone in August, 2023. 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 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 condensed statement of operations and comprehensive loss) from Ascletis. There were no payments made to Ascletis during the nine months ended September 30, 2023. The Company paid Ascletis under their manufacturing arrangement $4.0 thousand during the nine months ended September 30, 2022. Assignment and Assumption Agreement In July 2023, the Company entered into an Assignment and Assumption Agreement with Ascletis and Ascletis’ affiliate 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.	6. University of Zurich and ETH Zurich In April 2007, the Company entered into a license agreement with the University of Zurich and ETH Zurich, both Company investors, for exclusive rights in the United States to certain know-how and patents related to antiviral drug testing. The license agreement remains in force until the last patent expires or the agreement is canceled by either party. Upon execution of the agreement, the Company issued 192 shares of common stock to ETH Zurich and issued 96 shares of common stock to the University of Zurich. Ascletis BioScience Co. Ltd In January 2019, the Company entered into a license agreement that became effective in February 2019 with Ascletis, a subsidiary of Ascletis Pharma Inc. (Ascletis Pharma), biotechnology company incorporated in the Cayman Islands and headquartered in Hangzhou, China and a Company investor. 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 and $0.1 million as reimbursement pursuant to the license agreement for Greater China patent prosecution costs during the years ended December 31, 2022 and 2021, respectively. 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. Ascletis Pharma, through a subsidiary, also led the Series E preferred stock financing in February 2019. Under a separate manufacturing agreement with Ascletis, during the years ended December 31, 2022 and 2021, the Company paid $4 thousand and $0.9 million, respectively for the manufacture of denifanstat drug supply. The Company recorded these payments as research and development expense in the statement of operations and comprehensive loss for the respective year. 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 GBM, potentially triggering a $2.0 million development milestone payment under the license agreement. Due to the uncertainty around the achievement of the milestone and ongoing discussions with Ascletis around the consideration for the milestone, the Company concluded it was probable that a significant reversal of the revenue related to the milestone would occur, and therefore, no revenue was recognized.

Commitments and contingencies_4

Commitments and contingencies	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Commitments and contingencies
Commitments and contingencies	7. Commitments and contingencies 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 for the three months ended September 30, 2023, and 2022 was $37.0 thousand and $38.0 thousand, respectively, and for the nine months ended September 30, 2023 and 2022 was $111.0 thousand and $113.0 thousand, respectively. The following are schedules by year of future maturities of the Company’s operating lease liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ 2023 Remainder of 2023 $ 27 2024 ​ 79 Total lease payments ​ 106 Less: interest ​ (3) Total ​ $ 103 ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2023 $ 157 2024 ​ 80 Total lease payments ​ 237 Less: interest ​ (26) Total ​ $ 211 ​ Supplemental cash flow information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ Nine Months Ended September 30, ​ 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 118 ​ $ 118 ​ The weighted-average remaining lease term and discount rate related to the Company’s lease liabilities as of September 30, 2023 and December 31, 2022 were 0.75 years and 7% and 1.2 years and 7%, respectively. The Company’s lease discount rate is based on estimates of its incremental borrowing rate, as the discount rate implicit in the Company’s lease cannot be readily determined. As the Company does not have any outstanding debt, the Company estimates the incremental borrowing rate based on its estimated credit rating and available market information. 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 September 30, 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.	7. Facility lease agreement On March 12, 2019, the Company executed a 38 Operating lease cost for the years ended December 31, 2022 and 2021 was $0.2 million and $0.1 million, respectively. The following is a schedule by year of future maturities of the Company’s operating lease liabilities as of December 31, 2022 (in thousands): ​ ​ ​ ​ 2023 $ 157 2024 ​ ​ 80 Total lease payments ​ ​ 237 Less: interest ​ ​ (26) Total ​ $ 211 ​ Supplemental cash flow information related to leases was as follows for the years ended December 31, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year ended Year ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 157 ​ $ 157 Right-of-use assets obtained in exchange for lease obligations (non-cash): ​ ​ Operating leases ​ $ — ​ $ 282 ​ The weighted-average remaining lease term and discount rate related to the Company’s lease liabilities as of December 31, 2022 and 2021 were 1.2 years and 7% and 2.5 years and 7%, respectively. The Company’s lease discount rate is based on estimates of its incremental borrowing rate, as the discount rate implicit in the Company’s lease cannot be readily determined. As the Company does not have any outstanding debt, the Company estimates the incremental borrowing rate based on its estimated credit rating and available market information. 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. 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, 2022, and 2021, 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.

Redeemable convertible prefer_5

Redeemable convertible preferred stock	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Redeemable convertible preferred stock
Redeemable convertible preferred stock	8. 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.	8. The authorized, issued and outstanding shares of the redeemable convertible preferred stock, liquidation preferences and carrying values as of December 31, 2022 and 2021 were as follows (in thousands, except share numbers): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 and 2021 ​ ​ ​ ​ Issued and ​ ​ ​ ​ ​ ​ ​ ​ Authorized ​ Outstanding ​ Liquidation ​ Carrying Series 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 ​ Issuance of Series F redeemable convertible preferred stock On February 10, 2021, the Company received $11.0 million net of issuance costs from a closing of its Series F financing from new and existing investors, resulting in the issuance of 84,485,407 shares of Series F redeemable convertible preferred stock at $0.13020 per share (the Series F Original Issue Price). Rights, preferences and privileges of the redeemable convertible preferred stock The rights, preferences and privileges of the redeemable convertible preferred stock were as follows: Dividends. Company’s board of directors. Dividends on redeemable convertible preferred stock shall be payable in preference to and prior to any payments of any dividends on common stock. No dividends have been declared to date. Conversion. All of the redeemable convertible preferred stock will automatically convert into common stock, at the then-applicable conversion rate, in the event of either (i) the affirmative vote of the holders of a majority of the then-outstanding shares of series preferred, voting together as a single class on an as-converted to common stock basis, and the affirmative vote of the holders of a majority of the then-outstanding shares of Series F redeemable convertible preferred stock, or (ii) the closing of an underwritten IPO of the Company’s common stock pursuant to a registration statement on Form S-1 under the Securities Act of 1933, as amended, at a price of at least 1.25 times the Series F Original Issue Price, with aggregate gross proceeds of not less than $50.0 million. The Series D-1 is convertible into that number of fully-paid and nonassessable shares of common stock that is equal to $69.94 (as adjusted for stock splits, business combinations and reorganizations), divided by $18.0 million, subject to adjustments. Voting rights Liquidation. pari passu Deemed liquidation. The holders of Series A, B, B-1, C, D, D-1, E and F redeemable convertible preferred stock have certain liquidation rights in the event of a deemed liquidation that, in certain situations, are not solely within the control of the Company and would call for the redemption of the then outstanding Series A, B, B-1, C, D, D-1, E and F redeemable convertible preferred stock. Therefore, the Series A, B, B-1, C, D, D-1, E and F redeemable convertible preferred stock are classified outside of stockholders’ deficit on the balance sheets. The carrying value of the redeemable convertible preferred stock is not subsequently remeasured to the redemption value until the contingent redemption events are considered to be probable of occurring.

Stockholders' equity (deficit)

Stockholders' equity (deficit)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Stockholders' equity (deficit)
Stockholders' equity (deficit)	9. 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: ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ 2023 2022 Options to purchase Series A common stock 3,766,505 3,190,450 Options authorized and available for issuance 2,585,968 181,191 Warrant to purchase Series A Common Stock ​ 1,000 ​ — Redeemable convertible preferred stock — 1,322,399,477 Series D redeemable convertible preferred stock warrant — 79,545 Warrants to purchase common stock — 40,268 Total 6,353,473 1,325,890,931 ​ 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 with an exercise price of $0.88 per share. The warrant has a term of 10 years and are exercisable in whole or in part, at any time on or before the expiration date of April 10, 2025. At the time of issuance, the fair value of the Redeemable Convertible Preferred Stock Warrant Liability was determined using an option pricing model and assumptions that are based on the individual characteristics of the warrant on the valuation date, as well as assumptions for fair value of the underlying redeemable convertible preferred stock, expected volatility, expected life, dividends and risk-free interest rate. The Company completed its IPO on July 18, 2023. Subsequently, the Redeemable Convertible Preferred Stock Warrant was converted to a warrant to purchase 1,000 shares of Series A common stock at an exercise price of $69.94 per share and the expiration date was automatically extended until July 18, 2026, the third anniversary date of the closing of the Company’s IPO. If the warrant has not been exercised prior to the expiration date, the warrant will be deemed to have been automatically exercised on the expiration date by cashless conversion. The holder of the warrant has no voting rights, or other rights as a stockholder of the Company. The warrant is subject to adjustment in the event of any diluting dividends or distributions of the common stock, or any stock split, reverse stock split, recapitalization, reorganization or similar transaction. Upon any reclassification, exchange, substitution or other event, the number and or class of the securities and property that the holder would have received for the shares if this warrant had been issued immediately before such event will be adjusted. Stock warrants The following tables summarize the Company’s outstanding Series A Common Stock Warrant, Common Stock warrants and redeemable convertible preferred stock warrants: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, 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 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ Fair Value on ​ 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 ​	9. Common stock In connection with the adoption of an amendment to the Company’s tenth amended and restated certificate of incorporation filed September 27, 2022, the number of shares of common stock that the Company is authorized to issue increased from 1,590,550,754 to 1,608,370,000. The Company’s reserved shares of common stock for future issuance related to potential conversion of the redeemable convertible preferred stock, exercise of warrants and exercise of stock options as of December 31, 2022 and 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Redeemable convertible preferred stock 1,322,399,477 1,322,399,477 Series D redeemable convertible preferred stock warrants 79,545 79,545 Options authorized and available for issuance 181,191 810,604 Options to purchase common stock 3,190,450 2,138,110 Warrants to purchase common stock 40,268 40,268 Total 1,325,890,931 1,325,468,004 ​ Redeemable Convertible Preferred 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 79,545 Series D redeemable convertible preferred stock warrants with an exercise price of $0.88 per share. The warrants have a term of 10 years and are exercisable in whole or in part, at any time on or before the expiration date of April 10, 2025. At the time of issuance, the fair value of the Redeemable Convertible Preferred Stock Warrant Liability was determined using an option pricing model and assumptions that are based on the individual characteristics of the warrant on the valuation date, as well as assumptions for fair value of the underlying redeemable convertible preferred stock, expected volatility, expected life, dividends and risk-free interest rate (see Note 2). The Series D redeemable convertible preferred stock warrant has no voting rights, or other rights as a stockholder of the Company. The warrant is subject to adjustment in the event of any diluting dividends or distributions of the common stock, or any stock split, reverse stock split, recapitalization, reorganization or similar transaction. Upon any reclassification, exchange, substitution or other event, the number and or class of the securities and property that the holder would have received for the shares if this warrant had been issued immediately before such event will be adjusted. If the Company completes an IPO within the three-year period immediately prior to the expiration date, the expiration date will automatically be extended until the third anniversary of the effective date of the Company’s IPO. If the warrant has not been exercised prior to the expiration date, the warrant will be deemed to have been automatically exercised on the expiration date by cashless conversion. Stock warrants As of December 31, 2022 and 2021, the following tables summarize the Company’s outstanding common and redeemable convertible preferred stock warrants: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 and 2021 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ Fair Value ​ Fair Value ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ on Issuance ​ Recorded Issuance Date Shares Share Date for (in thousands) Against June 2013 26,846 ​ $ 0.79 June 2023 Common ​ $ 339 Redeemable January 2014 13,422 ​ $ 0.79 January 2024 Common ​ 223 Redeemable April 2015 79,545 ​ $ 0.88 April 2025 Series D ​ 68 Debt ​

Stock-based compensation_2

Stock-based compensation	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Stock-based compensation
Stock-based compensation	10. Stock-based compensation In 2007, the Company adopted the 2007 Equity Incentive Plan (2007 Plan), as amended, which allowed for the granting of incentive stock options (ISOs) and non-statutory stock options (NSOs) to the employees, members of the Company’s board of directors, and consultants of the Company. In 2017, the 2007 Plan expired pursuant to its terms and the Company adopted the 2017 Equity Incentive Plan (2017 Plan) which allowed for the granting of ISOs and NSOs as well as stock appreciation rights, restricted stock awards, restricted stock units and other stock awards to employees, members of the Company’s board of directors and consultants. ISOs could be granted only to Company’s employees, including officers and directors who are also employees. NSOs could be granted to employees, directors and consultants. 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 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, 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, which will automatically increase on January 1, 2024 and each January 1 thereafter, 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 September 30, 2023, 2,585,968 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 at prices no 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 (498) ​ ​ 4.77 ​ Options expired (1,752) ​ ​ 0.79 ​ Outstanding, September 30, 2023 3,766,505 ​ $ 8.11 7.69 ​ $ 17,737 Shares vested and exercisable as of September 30, 2023 1,784,725 ​ $ 6.98 6.34 ​ $ 10,206 ​ The aggregate intrinsic value is calculated as the difference between the option exercise price and the estimated fair value of the underlying common stock. Time-based options The Company may award time-based options which vest and become exercisable, subject to the participant’s continued employment or service through the applicable vesting date. Options granted have various vesting schedules including some that vest immediately and some that vest over four years. The following table summarizes time-based stock option activity: ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ ​ ​ Shares ​ ​ ​ ​ ​ Underlying ​ Weighted- ​ ​ Outstanding ​ Average ​ ​ Options ​ Exercise Price Outstanding, January 1, 2023 2,570,708 ​ $ 7.56 Options granted 585,919 ​ 13.51 Options exercised ​ (7,614) ​ ​ 0.79 Options cancelled (498) ​ 4.77 Options expired (1,752) ​ 0.79 Outstanding, September 30, 2023 3,146,763 ​ $ 8.69 Shares vested and exercisable as of September 30, 2023 1,186,212 ​ $ 14.42 ​ The total fair value of the time-based shares vested during the nine months ended September 30, 2023 was $1.8 million. As of September 30, 2023, there was $12.0 million of total unrecognized compensation cost related to the awards. The cost is being recognized over a remaining weighted-average period of 2.4 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 was 619,742 with a weighted-average exercise price of $6.38 as of December 31, 2022 and September 30, 2023, respectively. There were 598,513 shares vested and exercisable as of September 30, 2023. The total fair value of the performance-based shares vested during the nine months ended September 30, 2023 was $11.1 thousand. As of the nine months ended September 30, 2023, there was $28.2 thousand of unrecognized compensation cost related to the awards. The cost is being recognized over a remaining weighted-average period of less than one year. The Company has recorded aggregate stock-based compensation expense related to the issuance of stock option awards to employees and non-employees in the unaudited condensed statements of operations and comprehensive loss as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, Nine Months Ended September 30, ​ ​ 2023 2022 ​ 2023 ​ 2022 General and administrative expense ​ $ 1,649 ​ $ 220 ​ $ 3,103 ​ $ 663 Research and development expense ​ 206 ​ 169 ​ 576 ​ 496 Total stock-based compensation expense ​ $ 1,855 ​ $ 389 ​ $ 3,679 ​ $ 1,159 ​ The expected term of the stock options represents the average of the contractual term of the options and the weighted-average expected vesting period. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The expected volatility rate was based on the historical volatilities of comparable companies in the Company’s industry. The Company has never declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. Consequently, the Company used an expected dividend yield of zero. 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: ​ ​ ​ ​ Nine Months Ended Nine Months Ended ​ ​ ​ September 30, 2023 ​ September 30, 2022 ​ Expected volatility ​ 89 - 91 % 88 - 90 % Risk-free interest rate ​ 3.6 % 2.3 – 3.0 % 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, which will automatically increase on January 1, 2024 and each January 1 thereafter 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 nine months ended September 30, 2023, no shares of Series A common stock were issued under the 2023 ESPP.	10. In 2007, the Company adopted the 2007 Equity Incentive Plan, as amended, which allowed for the granting of incentive stock options (ISOs) and non-statutory stock options (NSOs) to the employees, members of the Company’s board of directors, and consultants of the Company. In 2017, the 2007 Equity Incentive Plan expired pursuant to its terms and the Company adopted the 2017 Equity Incentive Plan (2017 Plan) which allows for the granting of ISOs and NSOs as well as stock appreciation rights, restricted stock awards, restricted stock units and other stock awards to employees, members of the Company’s board of directors and consultants. ISOs may be granted only to Company’s employees, including officers and directors who are also employees. NSOs may be granted to employees, directors and consultants. As of December 31, 2022 and 2021, 181,191 and 810,604 shares are available for future grant under the 2017 Plan, respectively. Options under the 2017 Plan may be granted for periods of up to ten years and at prices no 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 shall 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 for the year ended December 31, 2022 (in thousands, except share and per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ Number of Shares ​ Weighted- ​ Remaining ​ ​ ​ ​ ​ Underlying ​ Average ​ Contractual ​ Aggregate ​ ​ Outstanding ​ Exercise ​ Term ​ Intrinsic ​ ​ Options ​ Price ​ (in Years) ​ Value Outstanding, January 1, 2022 2,138,110 ​ $ 7.15 8.1 ​ $ 4,670 Options granted 1,080,304 ​ $ 7.15 ​ Options exercised (1,627) ​ $ 7.24 ​ Options cancelled (887) ​ $ 31.46 ​ Options expired (25,450) ​ $ 12.75 ​ Outstanding, December 31, 2022 3,190,450 ​ $ 7.10 8.1 ​ 3,998 Shares vested and exercisable as of December 31, 2022 1,510,555 ​ $ 7.15 6.8 ​ 2,303 ​ The aggregate intrinsic value is calculated as the difference between the option exercise price and the estimated fair value of the underlying common stock. Time-based options The Company may award time-based options which vest and become exercisable, subject to the participant’s continued employment or service through the applicable vesting date. Options granted have various vesting schedules including some that vest immediately and some that vest over four years. The following table summarizes time-based stock option activity for the year ended December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Weighted- ​ ​ Shares Underlying ​ Average ​ ​ Outstanding ​ Exercise ​ ​ Options ​ Price Outstanding, January 1, 2022 1,537,241 $ 7.95 Options granted 1,061,431 ​ $ 7.15 Options exercised (1,627) ​ $ 7.24 Options cancelled (887) ​ $ 31.46 Options expired (25,450) ​ $ 12.75 Outstanding, December 31, 2022 2,570,708 ​ $ 7.56 Vested, December 31, 2022 1,459,480 ​ ​ Subsequent to the issuance of the financial statements for the year ended December 31, 2021, the Company identified and corrected an immaterial error related to the total number of shares of outstanding time-based option awards disclosed. Management evaluated the correction on a quantitative and qualitative basis and has determined that it is immaterial to the financial statements as of and for the year ended December 31, 2021. The weighted-average grant date fair value of time-based options granted during the year ended December 31, 2022 was $6.36 per share. The total fair value of the time-based shares vested during the year ended December 31, 2022 was $1.8 million. As of December 31, 2022, there was $9.1 million of total unrecognized compensation cost related to the awards. The cost is being recognized over a remaining weighted-average period of 3.2 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 following table summarizes performance-based stock option activity for the year ended December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ Number of Weighted- ​ ​ Shares Underlying ​ Average ​ ​ Outstanding ​ Exercise ​ ​ Options ​ Price Outstanding, January 1, 2022 600,869 ​ $ 6.36 Options Granted 18,873 ​ $ 7.15 Options Exercised — ​ — Outstanding, December 31, 2022 619,742 ​ $ 6.38 Vested, December 31, 2022 51,075 ​ ​ The weighted-average grant date fair value of performance-based options granted during the year ended December 31, 2022 was $7.15 per share. The total fair value of the performance-based shares vested during the year ended December 31, 2022 was $82 thousand. As of the year ended December 31, 2022, there was no unrecognized compensation cost related to the awards because it was improbable that the performance conditions would be met. The cost is being recognized over a remaining weighted-average period of less than one year. The Company has recorded aggregate stock-based compensation expense related to the issuance of stock option awards to employees and non-employees in the statements of operations and comprehensive loss as follows for the years ended December 31, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 General and administrative ​ $ 1,204 ​ $ 1,325 Research and development ​ 676 ​ 579 Total stock-based compensation ​ $ 1,880 ​ $ 1,904 ​ The fair value of each award granted was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions for the years ended December 31, 2022 and 2021. ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2022 Expected volatility 88 – 90 % Risk-free interest rate 3.0 – 4.2 ​ Dividend yield — ​ Expected term 5.4 7.0 ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 Expected volatility 89 – 94 % Risk-free interest rate 0.4 – 1.3 ​ Dividend yield — ​ Expected term 5.0 ​ ​ The expected term of the stock options represents the average of the contractual term of the options and the weighted-average expected vesting period. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The expected volatility rate was based on the historical volatilities of comparable companies in the Company’s industry. The Company has never declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. Consequently, the Company used an expected dividend yield of zero.

Net loss per share attributab_5

Net loss per share attributable to common stockholders	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Net loss per share attributable to common stockholders
Net loss per share attributable to common stockholders	11. Net loss per share attributable to common stockholders The table below is the calculation of basic and diluted loss per share attributable to common, Series A common and Series B common stockholders (in thousands, except share and per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Three Months Nine Months Nine Months ​ ​ Ended ​ Ended ​ Ended ​ Ended ​ ​ September 30, ​ September 30, ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to common stockholders ​ $ — ​ $ (7,467) ​ $ — ​ $ (23,304) Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted ​ — ​ 185,084 ​ — ​ 184,756 Net loss per share attributable to common stockholders, basic and diluted ​ $ — ​ $ (40.34) ​ $ — ​ $ (126.13) Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to Series A and Series B common stockholders ​ $ (6,353) ​ $ — ​ $ (19,725) ​ $ — Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to Series A and Series B common stockholders, basic and diluted ​ 18,194,682 ​ — ​ 6,131,541 ​ — Net loss per share attributable to Series A and Series B common stockholders, basic and diluted ​ $ (0.35) ​ $ — ​ $ (3.22) ​ $ — ​ The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common, Series A common and Series B common stockholders for the periods presented because including them would have been antidilutive. 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, options prior to the IPO were to purchase common stock, and after the IPO are to purchase Series A common stock. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months ​ Three Months ​ Nine Months ​ Nine Months ​ ​ Ended ​ Ended ​ Ended ​ Ended ​ ​ September 30, ​ September 30, ​ September 30, ​ September 30, ​ 2023 2022 2023 2022 Options to purchase Series A common stock 3,766,505 2,198,675 3,766,505 2,198,675 Warrant to purchase Series A Common Stock ​ 1,000 ​ — ​ 1,000 ​ — Redeemable convertible preferred stock — 16,638,476 — 16,638,476 Warrants to purchase common stock — 40,268 — 40,268 Warrant to purchase redeemable convertible preferred stock — 79,545 — 79,545 Total 3,767,505 18,956,964 3,767,505 18,956,964 ​	11. The table below is the calculation of basic and diluted loss per share attributable to common stockholders for the years ended December 31, 2022 and 2021 (in thousands, except share and per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Numerator: ​ ​ Net loss attributable to common stockholders ​ $ (30,499) ​ $ (24,442) Denominator: ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted ​ 184,619 ​ 122,579 Net loss per share attributable to common stockholders, basic and diluted ​ $ (165.20) ​ $ (199.40) ​ The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been antidilutive: ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Redeemable convertible preferred stock 16,638,476 16,638,476 Options to purchase common stock 3,190,450 2,138,110 Warrants to purchase common stock 40,268 40,268 Warrants to purchase redeemable convertible preferred stock 79,545 79,545 Total 19,948,739 18,896,399 ​

Income taxes_2

Income taxes	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Income taxes
Income taxes	12. Income taxes The provision for income taxes primarily relates to projected federal and state income taxes calculated on the projected taxable income for the period. To determine the quarterly provision for income taxes, the Company uses an estimated annual effective tax rate, which is generally based on expected annual income as well as statutory tax rates in the various jurisdictions in which the Company operates. In addition, the tax effects of certain significant or unusual items are recognized discretely in the quarter during which they occur and can be a source of variability in the effective tax rates from quarter to quarter. As per ASC 740-270, the Company’s interim tax provision is computed based on the estimated annual effective tax rate approach. The estimated annual effective tax rate approach is used to determine the tax related to ordinary income unless certain exceptions apply. The Company records a valuation allowance to reduce its deferred taxes to the amount it believes is more likely than not to be realized. In making such determination, the Company considers all available positive and negative evidence quarterly, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies, and recent financial performance. Forming a conclusion that a valuation allowance is not required is difficult when there is negative evidence such as cumulative losses in recent years. Based upon the Company’s review of all positive and negative evidence, the Company continues to have a full valuation allowance on its deferred tax assets as of September 30, 2023. The Company accounts for the uncertainty in income taxes by utilizing a comprehensive model for the recognition, measurement, presentation and disclosure in financial statements of any uncertain tax positions that have been taken or are expected to be taken on an income tax return. There have been no changes in the estimated uncertain positions or tax benefits recorded as of December 31, 2022.	12. 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, 2022 and 2021 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Federal income taxes at statutory rates 21.00 % 21.00 % State income tax, net of federal benefit 0.43 0.40 ​ Research and development credits 3.48 3.08 ​ Stock-based compensation (0.81) (1.19) ​ Change in valuation allowance (24.10) (22.64) ​ Other permanent items — (0.65) ​ Effective income tax rate — % — % ​ For the years ended December 31, 2022 and 2021, the Company did not record a deferred income tax expense or benefit. Income tax expense has been nominal for the years ended December 31, 2022 and 2021. 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, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2022 ​ 2021 Deferred tax assets: ​ ​ Net operating loss carryforwards ​ $ 28,707 ​ $ 28,350 Capitalized start-up costs and research expenses ​ 13,004 ​ 7,358 Research and development credits ​ 4,977 ​ 3,762 Accruals, reserves and other ​ 1,144 ​ 1,013 Lease liabilities ​ 47 ​ 73 Total gross deferred assets ​ 47,879 ​ 40,556 Valuation allowance ​ (47,834) ​ (40,484) Total deferred tax assets ​ 45 ​ 72 Deferred tax liabilities: ​ ​ Right-of-use assets ​ (45) ​ (72) 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, 2022 and 2021. The valuation allowance increased $7.4 million and $5.6 million during the years ended December 31, 2022 and 2021, respectively. As of December 31, 2022, the Company had U.S. federal net operating loss (NOL) carryforwards of approximately $128.2 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 $37.2 million will have an indefinite carryforward period, subject to annual limitations. As of December 31, 2022, 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, 2022, the Company had federal research and development tax credit carryforwards of approximately $4.4 million available to reduce future tax liabilities which expire at various years beginning with 2028. As of December 31, 2022, the Company had state credit carryforwards of approximately $2.5 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, 2022, 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, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Unrecognized tax benefits as of the beginning of the year ​ $ 1,035 ​ $ 817 Decrease related to prior year tax positions ​ — ​ (17) Increase related to current year tax positions ​ 499 ​ 235 Unrecognized tax benefits as of the end of the year ​ $ 1,534 ​ $ 1,035 ​ 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, 2022, 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. In December 2017, the Tax Cuts and Jobs Act (TCJA) was signed into law, significantly reforming the IRC. Beginning January 1, 2022, the TCJA eliminated the option to deduct research and development expenditures in the current year and requires taxpayers to capitalize such expenses pursuant to IRC Section 174. The capitalized expenses are amortized over a 5-year period for domestic expenses and a 15-year period for foreign expenses. As a result of this provision of the TCJA, deferred tax assets related to capitalized research expenses increased by $4.6 million. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was enacted in response to the COVID-19 pandemic. The CARES Act, among other things, permits NOL carryovers and carrybacks to offset 100% of taxable income for taxable years beginning before 2021. In addition, the CARES Act allows NOLs incurred in 2018, 2019, and 2020 to be carried back to each of the five preceding taxable years to generate a refund of previously paid income taxes. Due to the Company’s history of NOLs, the CARES Act did not have a material impact on the Company’s financial statements. On February 9, 2022, Governor Gavin Newsom signed California Senate Bill 113 (SB 113) into law. The legislation contains important California tax law changes, including reinstatement of business tax credits and net NOL deductions limited by California Assembly Bill 85 which suspended the net operating loss deduction for certain taxpayers from 2020 to 2022. The new tax law did not impact the Company’s tax provision due to its taxable loss position in the current year. In August 2022, the Inflation Reduction Act of 2022 (IRA) was signed into law in the United States. The IRA created a new corporate alternative minimum tax of 15% on adjusted financial statement income and an excise tax of 1% of the value of certain stock repurchases. The provisions of the IRA will be effective for periods beginning after December 31, 2022. The enactment of the IRA did not result in any material adjustments to the Company’s income tax provisions or net deferred tax assets as of December 31, 2022.

Subsequent events_2

Subsequent events	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Subsequent events
Subsequent events	13. Subsequent events The Company has evaluated subsequent events for financial statement purposes occurring through November 13, 2023, the date when these financial statements are available to be issued and noted that there are no subsequent events requiring disclosure in these condensed financial statements. ​	14. The Company has evaluated subsequent events for financial statement purposes occurring through March 24, 2023, the date when these financial statements are available to be issued and July 9, 2023 for the reverse stock split referenced below. No material subsequent events have occurred that require disclosure, except those referenced below. The Company’s board of directors approved a one-for- 79.4784

Summary of significant accoun_5

Summary of significant accounting policies (Policies)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Summary of significant accounting policies
Basis of presentation	Basis of presentation The condensed financial statements and accompanying notes have been prepared in accordance with GAAP and the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. These condensed financial statements have been prepared on the same basis as the annual financial statements included elsewhere in this prospectus. In the Company’s opinion, the information furnished in these condensed financial statements reflects all adjustments, all of which are of a normal and recurring nature necessary for a fair presentation of the financial position and results of operations for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period.	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).
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 expenses during the reporting period. Such estimates include accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock, common stock 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.	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 expenses during the reporting period. Such estimates include accruals of research and development expenses, accrued costs for services rendered in connection with third-party contractor clinical trial activities, preferred stock, common stock 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.
Significant Accounting Policies	Significant accounting policies The Company’s significant accounting policies are disclosed in the audited financial statements for the year ended December 31, 2022, included elsewhere in this prospectus, and the unaudited financial statements as of March 31, 2023 filed with the SEC. Since the date of those financial statements, there have been no changes to the Company’s significant accounting policies except as disclosed below in recently adopted accounting pronouncements.
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, 2022 and 2021, 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 The Company had no short-term investments in marketable securities as of September 30, 2023.	Marketable securities The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the balance sheets, with unrealized gains and losses that are determined to be temporary, if any, reported as a component of other comprehensive income (loss) within the statements of operations and comprehensive loss and as a separate component of stockholders’ deficit. The Company classifies marketable securities with remaining maturities greater than three months but less than one year as short-term investments, and those with remaining maturities greater than one year are classified as long-term investments. Investments are regularly reviewed for other-than-temporary declines in fair value. The review includes the consideration of the cause of the impairment, including the creditworthiness of the security issuers, the number of investments in an unrealized loss position, the severity and duration of the unrealized losses and whether it is more likely than not that the Company will be required to sell the investments before the recovery of their amortized cost basis. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the establishment of a new cost basis for the security. The Company invests its excess cash balances primarily in corporate debt securities with strong credit ratings. Realized gains and losses are calculated on the specific identification method and recorded as interest income and were immaterial for all periods presented. As of December 31, 2022, the Company’s short-term marketable securities were invested with Silicon Valley Bank (SVB), and custodied at U.S. bank.
Deferred financing costs	Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s IPO are capitalized and recorded in the accrued expenses and other current liabilities in the condensed balance sheets. Upon closing of the IPO in July 2023, all deferred offering costs were reclassified to additional paid-in-capital in the condensed statements of operations and comprehensive loss, representing a reduction in IPO proceeds. On March 21, 2022, the Company withdrew its prior Registration Statement on Form S-1 initially filed with the SEC on April 16, 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 unaudited condensed statement of operations and comprehensive loss for the nine months ended September 30, 2022.	Deferred financing costs Deferred financing costs, consisting of legal, accounting and other fees and costs relating to the Company’s planned IPO are capitalized and recorded on the balance sheets. The deferred financing costs will be offset against the proceeds received upon the closing of the planned IPO. In the event that the Company’s plans for an IPO are terminated, all of the deferred financing costs will be written off within operating expenses in the Company’s statements of operations and comprehensive loss. As of December 31, 2021, there were $1.4 million of deferred financing costs capitalized related to the Company’s previous IPO plans in 2021. On March 21, 2022, the Company withdrew its Registration Statement on Form S-1 initially filed with the 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. As of December 31, 2022, there were no deferred financing costs capitalized.
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 Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers 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). In January 2022, Ascletis BioScience Co. Ltd. (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 recorded as license revenue in the condensed statements of operations and comprehensive loss (representing the $2.0 million development milestone payment, net of applicable taxes) from Ascletis.	Revenue recognition The Company enters into collaboration and licensing arrangements that generally contain multiple elements or deliverables, which may include (1) licenses to the Company’s technology, (2) research and development activities performed for the collaboration partner, (3) participation on joint steering committees (JSCs), and (4) 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 Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers 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). In January 2022, Ascletis initiated dosing of a Phase 3 trial for recurrent GBM, potentially triggering a $2.0 million development milestone payment under the license agreement. Due to the uncertainty around the achievement of the milestone and ongoing discussions with Ascletis around the consideration for the milestone, the Company concluded it was probable that a significant reversal of the revenue related to the milestone would occur, and therefore, no revenue was recognized.
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.	Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash, cash equivalents and marketable securities.
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 Accounting Standards Update (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 twelve 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.
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 non-alcoholic steatohepatitis (NASH) 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. The CODM evaluates the Company’s financial information and assesses the performance of the Company based on the single operating segment. The Company assesses its determination of operating segments at least annually and continues to evaluate the internal reporting structure and potential impacts of any changes to its segment reporting.
Redeemable convertible preferred stock		Redeemable convertible preferred stock The Company records redeemable convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The redeemable convertible preferred stock is recorded outside of stockholders’ deficit because the shares contain liquidation features that are not solely within the Company’s control. The Company has not adjusted the carrying values of the redeemable convertible preferred stock to the liquidation preferences of such shares because it is 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. Subsequent adjustments to the carrying values to the liquidation preferences will be made only when it becomes probable that such a liquidation event will occur.
Stock-based compensation expense		Stock-based compensation expense The Company accounts for all stock-based payment awards granted to employees and non-employees as stock-based compensation expense at fair value. The Company’s stock-based payments include stock options and grants of common stock, including common stock subject to vesting. The measurement date for employee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight- line basis. Stock-based compensation costs for non-employees are recognized as expense over the vesting period on a straight-line basis. Stock-based compensation expense is classified in the accompanying statements of operations and comprehensive loss based on the function to which the related services are provided. The Company recognizes stock-based compensation expense for the portion of awards that have vested. Forfeitures are recorded as they occur. 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. For awards with service-based vesting conditions only, the Company recognizes share-based compensation expense on a straight-line basis over the requisite service or vesting period. For awards with service- and performance-based vesting conditions, the Company recognizes stock-based compensation expense using the graded vesting method over the requisite service period beginning in the period in which the awards are deemed probable to vest, to the extent such awards are probable to vest. The Company recognizes the cumulative effect of changes in the probability outcomes in the period in which the changes occur.
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, 2022 and 2021, 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’ 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 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 and common and redeemable convertible preferred stock warrants are considered to be potentially dilutive securities. Basic and diluted net loss per share attributable to common stockholders is presented inconformity with the two-class method required for participating securities as the redeemable convertible preferred stock is considered a participating security. 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. As the Company has reported a net loss for the period presented, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders for this period.
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 Financial Accounting Standards Board (FASB) standards’ effective dates.	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	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	New accounting pronouncements not yet adopted In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments 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

Fair value measurements and f_8

Fair value measurements and fair value of financial instruments (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Fair value measurements and fair value of financial instruments
Schedule of marketable securities, available-for-sale	Marketable securities, all of which are classified as available-for-sale securities, consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ Amortized Unrealized Unrealized Estimated ​ ​ cost ​ Gains ​ Losses ​ Fair Value Commercial paper ​ $ 15,950 ​ $ — ​ $ — ​ $ 15,950 Corporate debt securities ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ 4,035 ​ — ​ (19) ​ 4,016 Total ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187	Marketable securities, all of which are classified as available-for-sale securities, consisted of the following at December 31, 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ ​ Cost ​ Gains ​ Losses ​ Fair Value Commercial paper $ 15,950 $ — $ — $ 15,950 Corporate debt securities ​ 12,286 ​ — ​ (65) ​ 12,221 U.S. Treasury securities ​ 4,035 ​ — ​ (19) ​ 4,016 Total ​ $ 32,271 ​ $ — ​ $ (84) ​ $ 32,187
Schedule of fair value of financial instruments	The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2023 ​ ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ fair value Level 1 Level 2 Level 3 Liabilities: ​ ​ ​ ​ Series A Common Stock Warrant Liability ​ $ 1 ​ $ — ​ $ — ​ $ 1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ value ​ Level 1 ​ Level 2 ​ Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents - money market funds ​ $ 38 ​ $ 38 ​ $ — ​ $ — Commercial paper ​ 15,950 ​ — ​ 15,950 ​ — Corporate debt securities ​ 12,221 ​ — ​ 12,221 ​ — U.S. Treasury securities ​ 4,016 ​ — ​ 4,016 ​ — Total ​ $ 32,225 ​ $ 38 ​ $ 32,187 ​ $ — Liabilities: ​ ​ ​ ​ Redeemable Convertible Preferred Stock Warrant Liability ​ $ 4 ​ $ — ​ $ — ​ $ 4	The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ value ​ Level 1 ​ Level 2 ​ Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents – money market funds ​ $ 38 ​ $ 38 ​ $ — ​ $ — Commercial paper ​ 15,950 ​ — ​ 15,950 ​ — Corporate debt securities ​ 12,221 ​ — ​ 12,221 ​ — U.S. Treasury securities ​ 4,016 ​ — ​ 4,016 ​ — Total ​ $ 32,225 ​ $ 38 ​ $ 32,187 ​ $ — Liabilities: ​ ​ ​ ​ Redeemable convertible preferred stock warrant liability ​ $ 4 ​ $ — ​ $ — ​ $ 4 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Total fair ​ ​ ​ ​ ​ ​ ​ ​ value Level 1 Level 2 Level 3 Assets: ​ ​ ​ ​ Cash and cash equivalents – money market funds ​ $ 56,631 ​ $ 56,631 ​ $    — ​ $ — Liabilities: ​ ​ ​ ​ Redeemable convertible preferred stock warrant liability ​ $ 7 ​ $ — ​ $ — ​ $ 7 ​
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, 2023 $ 4 Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ 1 Change in fair value of Series A Common Stock Warrant Liability ​ ​ (4) Balance - September 30, 2023 ​ $ 1 Balance - January 1, 2022 ​ $ 7 Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ (3) Balance - December 31, 2022 ​ $ 4	The following table provides a summary of changes in the estimated fair value of the financial instruments using significant Level 3 inputs (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Redeemable Redeemable ​ ​ convertible ​ convertible ​ ​ preferred ​ preferred ​ ​ stock ​ stock ​ ​ warrant ​ tranche ​ ​ liability ​ liability Balance – January 1, 2021 ​ $ 9 ​ $ — Change in fair value of redeemable convertible preferred stock warrant liability and establishment of Redeemable Convertible Preferred Stock Tranche Liability ​ (2) ​ 751 Extinguishment of Redeemable Convertible Stock Tranche Liability upon subsequent issuance of Series F redeemable convertible preferred stock ​ — ​ (751) Balance – December 31, 2021 ​ $ 7 ​ $ — Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability ​ (3) ​ — Balance – December 31, 2022 ​ $ 4 ​ $ —

Prepaid expenses and other cu_5

Prepaid expenses and other current assets (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 Prepaid insurance ​ $ 865 ​ $ 61 Prepaid clinical expenses ​ ​ 32 ​ ​ 352 Other ​ 77 ​ 34 Total ​ $ 974 ​ $ 447 ​	Prepaid expenses and other current assets as of December 31, 2022 and 2021 consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Prepaid clinical expenses ​ $ 352 ​ $ 423 Deferred financing costs ​ — ​ 1,425 Other ​ 95 ​ 84 Total ​ $ 447 ​ $ 1,932 ​

Accrued expenses and other cu_5

Accrued expenses and other current liabilities (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 Accrued clinical costs ​ $ 2,239 ​ $ 3,162 Employees’ compensation ​ 689 ​ 636 Accrued research ​ ​ 221 ​ ​ — Accrued preclinical costs ​ — ​ 166 Other ​ 95 ​ 57 Total ​ $ 3,244 ​ $ 4,021 ​	Accrued expenses and other current liabilities as of December 31, 2022 and 2021 consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Accrued clinical costs ​ $ 3,162 ​ $ 852 Employees’ compensation ​ 636 ​ 463 Accrued pre-clinical costs ​ 166 ​ — Accrued deferred financing costs ​ — ​ 55 Other ​ 57 ​ 185 Total ​ $ 4,021 ​ $ 1,555 ​

Commitments and contingencies_5

Commitments and contingencies (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Commitments and contingencies
Schedule of future maturities of operating lease liabilities	The following are schedules by year of future maturities of the Company’s operating lease liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ 2023 Remainder of 2023 $ 27 2024 ​ 79 Total lease payments ​ 106 Less: interest ​ (3) Total ​ $ 103 ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2023 $ 157 2024 ​ 80 Total lease payments ​ 237 Less: interest ​ (26) Total ​ $ 211	The following is a schedule by year of future maturities of the Company’s operating lease liabilities as of December 31, 2022 (in thousands): ​ ​ ​ ​ 2023 $ 157 2024 ​ ​ 80 Total lease payments ​ ​ 237 Less: interest ​ ​ (26) Total ​ $ 211
Schedule of supplemental cash flow information related to leases	Supplemental cash flow information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ Nine Months Ended September 30, ​ 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 118 ​ $ 118	Supplemental cash flow information related to leases was as follows for the years ended December 31, 2022 and 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Year ended Year ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases ​ $ 157 ​ $ 157 Right-of-use assets obtained in exchange for lease obligations (non-cash): ​ ​ Operating leases ​ $ — ​ $ 282

Redeemable convertible prefer_6

Redeemable convertible preferred stock (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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	The authorized, issued and outstanding shares of the redeemable convertible preferred stock, liquidation preferences and carrying values as of December 31, 2022 and 2021 were as follows (in thousands, except share numbers): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 and 2021 ​ ​ ​ ​ Issued and ​ ​ ​ ​ ​ ​ ​ ​ Authorized ​ Outstanding ​ Liquidation ​ Carrying Series 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)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Stockholders' equity (deficit)
Schedule of shares of common stock reserved for future issuance	​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ September 30, ​ December 31, ​ 2023 2022 Options to purchase Series A common stock 3,766,505 3,190,450 Options authorized and available for issuance 2,585,968 181,191 Warrant to purchase Series A Common Stock ​ 1,000 ​ — Redeemable convertible preferred stock — 1,322,399,477 Series D redeemable convertible preferred stock warrant — 79,545 Warrants to purchase common stock — 40,268 Total 6,353,473 1,325,890,931	​ ​ ​ ​ ​ ​ ​ As of As of ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Redeemable convertible preferred stock 1,322,399,477 1,322,399,477 Series D redeemable convertible preferred stock warrants 79,545 79,545 Options authorized and available for issuance 181,191 810,604 Options to purchase common stock 3,190,450 2,138,110 Warrants to purchase common stock 40,268 40,268 Total 1,325,890,931 1,325,468,004
Schedule of outstanding warrants	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, 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 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ Fair Value on ​ 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 ​	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 and 2021 ​ ​ Number of ​ Exercise ​ ​ ​ ​ ​ Fair Value ​ Fair Value ​ ​ Warrant ​ Price per ​ Expiration ​ Exercisable ​ on Issuance ​ Recorded Issuance Date Shares Share Date for (in thousands) Against June 2013 26,846 ​ $ 0.79 June 2023 Common ​ $ 339 Redeemable January 2014 13,422 ​ $ 0.79 January 2024 Common ​ 223 Redeemable April 2015 79,545 ​ $ 0.88 April 2025 Series D ​ 68 Debt ​

Stock-based compensation (Tab_2

Stock-based compensation (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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 (498) ​ ​ 4.77 ​ Options expired (1,752) ​ ​ 0.79 ​ Outstanding, September 30, 2023 3,766,505 ​ $ 8.11 7.69 ​ $ 17,737 Shares vested and exercisable as of September 30, 2023 1,784,725 ​ $ 6.98 6.34 ​ $ 10,206	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ Number of Shares ​ Weighted- ​ Remaining ​ ​ ​ ​ ​ Underlying ​ Average ​ Contractual ​ Aggregate ​ ​ Outstanding ​ Exercise ​ Term ​ Intrinsic ​ ​ Options ​ Price ​ (in Years) ​ Value Outstanding, January 1, 2022 2,138,110 ​ $ 7.15 8.1 ​ $ 4,670 Options granted 1,080,304 ​ $ 7.15 ​ Options exercised (1,627) ​ $ 7.24 ​ Options cancelled (887) ​ $ 31.46 ​ Options expired (25,450) ​ $ 12.75 ​ Outstanding, December 31, 2022 3,190,450 ​ $ 7.10 8.1 ​ 3,998 Shares vested and exercisable as of December 31, 2022 1,510,555 ​ $ 7.15 6.8 ​ 2,303
Schedule of stock-based compensation expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, Nine Months Ended September 30, ​ ​ 2023 2022 ​ 2023 ​ 2022 General and administrative expense ​ $ 1,649 ​ $ 220 ​ $ 3,103 ​ $ 663 Research and development expense ​ 206 ​ 169 ​ 576 ​ 496 Total stock-based compensation expense ​ $ 1,855 ​ $ 389 ​ $ 3,679 ​ $ 1,159	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 General and administrative ​ $ 1,204 ​ $ 1,325 Research and development ​ 676 ​ 579 Total stock-based compensation ​ $ 1,880 ​ $ 1,904
Schedule of fair value assumptions	​ ​ ​ ​ Nine Months Ended Nine Months Ended ​ ​ ​ September 30, 2023 ​ September 30, 2022 ​ Expected volatility ​ 89 - 91 % 88 - 90 % Risk-free interest rate ​ 3.6 % 2.3 – 3.0 % Dividend yield ​ — ​ — ​ Expected term ​ 5.0 – 7.0 years 5.4 – 7.0 years	​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2022 Expected volatility 88 – 90 % Risk-free interest rate 3.0 – 4.2 ​ Dividend yield — ​ Expected term 5.4 7.0 ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 Expected volatility 89 – 94 % Risk-free interest rate 0.4 – 1.3 ​ Dividend yield — ​ Expected term 5.0 ​
Time-based options
Stock-based compensation
Schedule of option activity transactions	​ ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ ​ ​ Shares ​ ​ ​ ​ ​ Underlying ​ Weighted- ​ ​ Outstanding ​ Average ​ ​ Options ​ Exercise Price Outstanding, January 1, 2023 2,570,708 ​ $ 7.56 Options granted 585,919 ​ 13.51 Options exercised ​ (7,614) ​ ​ 0.79 Options cancelled (498) ​ 4.77 Options expired (1,752) ​ 0.79 Outstanding, September 30, 2023 3,146,763 ​ $ 8.69 Shares vested and exercisable as of September 30, 2023 1,186,212 ​ $ 14.42	​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Weighted- ​ ​ Shares Underlying ​ Average ​ ​ Outstanding ​ Exercise ​ ​ Options ​ Price Outstanding, January 1, 2022 1,537,241 $ 7.95 Options granted 1,061,431 ​ $ 7.15 Options exercised (1,627) ​ $ 7.24 Options cancelled (887) ​ $ 31.46 Options expired (25,450) ​ $ 12.75 Outstanding, December 31, 2022 2,570,708 ​ $ 7.56 Vested, December 31, 2022 1,459,480 ​

Net loss per share attributab_6

Net loss per share attributable to common stockholders (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Net loss per share attributable to common stockholders
Schedule of basic and diluted loss per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Three Months Nine Months Nine Months ​ ​ Ended ​ Ended ​ Ended ​ Ended ​ ​ September 30, ​ September 30, ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to common stockholders ​ $ — ​ $ (7,467) ​ $ — ​ $ (23,304) Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted ​ — ​ 185,084 ​ — ​ 184,756 Net loss per share attributable to common stockholders, basic and diluted ​ $ — ​ $ (40.34) ​ $ — ​ $ (126.13) Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to Series A and Series B common stockholders ​ $ (6,353) ​ $ — ​ $ (19,725) ​ $ — Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to Series A and Series B common stockholders, basic and diluted ​ 18,194,682 ​ — ​ 6,131,541 ​ — Net loss per share attributable to Series A and Series B common stockholders, basic and diluted ​ $ (0.35) ​ $ — ​ $ (3.22) ​ $ —	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Numerator: ​ ​ Net loss attributable to common stockholders ​ $ (30,499) ​ $ (24,442) Denominator: ​ ​ Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic and diluted ​ 184,619 ​ 122,579 Net loss per share attributable to common stockholders, basic and diluted ​ $ (165.20) ​ $ (199.40) ​
Schedule of potentially dilutive securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months ​ Three Months ​ Nine Months ​ Nine Months ​ ​ Ended ​ Ended ​ Ended ​ Ended ​ ​ September 30, ​ September 30, ​ September 30, ​ September 30, ​ 2023 2022 2023 2022 Options to purchase Series A common stock 3,766,505 2,198,675 3,766,505 2,198,675 Warrant to purchase Series A Common Stock ​ 1,000 ​ — ​ 1,000 ​ — Redeemable convertible preferred stock — 16,638,476 — 16,638,476 Warrants to purchase common stock — 40,268 — 40,268 Warrant to purchase redeemable convertible preferred stock — 79,545 — 79,545 Total 3,767,505 18,956,964 3,767,505 18,956,964 ​	​ ​ ​ ​ ​ ​ ​ Year Ended Year Ended ​ ​ December 31, ​ December 31, ​ ​ 2022 ​ 2021 Redeemable convertible preferred stock 16,638,476 16,638,476 Options to purchase common stock 3,190,450 2,138,110 Warrants to purchase common stock 40,268 40,268 Warrants to purchase redeemable convertible preferred stock 79,545 79,545 Total 19,948,739 18,896,399 ​

Organization and description _4

Organization and description of business (Details) $ / shares in Units, $ in Thousands			3 Months Ended						9 Months Ended		12 Months Ended
	Jul. 18, 2023 USD ($) Vote $ / shares shares	Jul. 07, 2023	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2023 USD ($) Vote	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Organization and description of business
Reverse stock split ratio		0.012582
Net proceeds									$ 86,161
Net loss			$ 6,353	$ 6,785	$ 6,587	$ 7,467	$ 7,102	$ 8,735	19,725	$ 23,304	$ 30,499	$ 24,442
Cash flows from operations									16,683	$ 17,037	24,490	21,710
Cash and cash equivalents			$ 101,842						$ 101,842		$ 158	$ 56,731
Series A Common Stock
Organization and description of business
Shares issued upon conversion (in number of shares) | shares	15,117,912
Number of votes per share | Vote	1								1
Series B Common Stock
Organization and description of business
Shares issued upon conversion (in number of shares) | shares	1,520,490
Subsequent Event
Organization and description of business
Reverse stock split ratio		0.012582
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_6

Summary of significant accounting policies (Details)	1 Months Ended			3 Months Ended	9 Months Ended	12 Months Ended
	Aug. 31, 2023 USD ($)	Jul. 31, 2023 USD ($)	Jan. 31, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($) segment	Dec. 31, 2021 USD ($)
Summary of significant accounting policies
Short-term investments in marketable securities				$ 0	$ 0	$ 32,187,000
Deferred financing costs writeoff						0	$ 1,400,000
Revenue		$ 2,000,000	$ 0	$ 2,000,000	$ 2,000,000	$ 0
Number of operating segment | segment						1
Number of reportable segment | segment						1
Investor | Ascletis
Summary of significant accounting policies
Development milestone payment trigger	$ 1,700,000		$ 2,000,000
Revenue		$ 2,000,000
Proceeds from license fees	$ 2,000,000

Fair value measurements and f_9

Fair value measurements and fair value of financial instruments - Marketable securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Fair value measurements and fair value of financial instruments
Fair value cash and cash equivalents	$ 101,800	$ 200	$ 56,700
Amortized Cost		32,271
Unrealized Losses		(84)
Estimated Fair Value	$ 0	32,187	$ 0
Commercial paper
Fair value measurements and fair value of financial instruments
Amortized Cost		15,950
Estimated Fair Value		15,950
Corporate debt securities
Fair value measurements and fair value of financial instruments
Amortized Cost		12,286
Unrealized Losses		(65)
Estimated Fair Value		12,221
U.S. Treasury securities
Fair value measurements and fair value of financial instruments
Amortized Cost		4,035
Unrealized Losses		(19)
Estimated Fair Value		$ 4,016

Fair value measurements and _10

Fair value measurements and fair value of financial instruments - Recurring (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial instruments that were measured at fair value on a recurring basis by level
Assets		$ 32,225
Redeemable Convertible Preferred Stock Warrant
Financial instruments that were measured at fair value on a recurring basis by level
Liabilities		4	$ 7
Series A Common Stock Warrants
Financial instruments that were measured at fair value on a recurring basis by level
Liabilities	$ 1
Cash and cash equivalents - money market funds
Financial instruments that were measured at fair value on a recurring basis by level
Assets		38	56,631
Commercial paper
Financial instruments that were measured at fair value on a recurring basis by level
Assets		15,950
Corporate debt securities
Financial instruments that were measured at fair value on a recurring basis by level
Assets		12,221
U.S. Treasury securities
Financial instruments that were measured at fair value on a recurring basis by level
Assets		4,016
Level 1
Financial instruments that were measured at fair value on a recurring basis by level
Assets		38
Level 1 | Cash and cash equivalents - money market funds
Financial instruments that were measured at fair value on a recurring basis by level
Assets		38	56,631
Level 2
Financial instruments that were measured at fair value on a recurring basis by level
Assets		32,187
Level 2 | Commercial paper
Financial instruments that were measured at fair value on a recurring basis by level
Assets		15,950
Level 2 | Corporate debt securities
Financial instruments that were measured at fair value on a recurring basis by level
Assets		12,221
Level 2 | U.S. Treasury securities
Financial instruments that were measured at fair value on a recurring basis by level
Assets		4,016
Level 3 | Redeemable Convertible Preferred Stock Warrant
Financial instruments that were measured at fair value on a recurring basis by level
Liabilities		$ 4	$ 7
Level 3 | Series A Common Stock Warrants
Financial instruments that were measured at fair value on a recurring basis by level
Liabilities	$ 1

Fair value measurements and _11

Fair value measurements and fair value of financial instruments - Level 3 (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Summary of changes
Beginning balance	$ 4	$ 7
Ending balance	1	4	$ 7
Redeemable Convertible Preferred Stock Warrant
Summary of changes
Beginning balance	4	7	9
Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability	1	(3)	(2)
Ending balance		$ 4	$ 7
Series A Common Stock Warrants
Summary of changes
Change in fair value of Redeemable Convertible Preferred Stock Warrant Liability	$ (4)

Fair value measurements and _12

Fair value measurements and fair value of financial instruments - Warrant Liability (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023 USD ($) Y dividend $ / shares shares	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) Y dividend $ / shares shares	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) $ / shares	Dec. 31, 2022 shares	Dec. 31, 2022 $ / shares	Dec. 31, 2022	Dec. 31, 2022 Y	Dec. 31, 2022 dividend	Apr. 30, 2015 $ / shares shares	Apr. 10, 2015 $ / shares shares
Redeemable Convertible Preferred Stock Warrant Liability
Change in the fair value of warrant liability					$ (3,000)	$ (2,000)
Series D redeemable convertible preferred stock warrants
Redeemable Convertible Preferred Stock Warrant Liability
Number of warrants issued | shares	1,000		1,000				79,545					79,545	79,545
Fair value of warrant liability	$ 68,000		$ 68,000		68,000	$ 68,000
Exercise price of warrant | $ / shares	$ 69.94		$ 69.94			$ 0.88		$ 0.88				$ 0.88	$ 0.88
Warrants term													10 years
Series A Common Stock Warrants
Redeemable Convertible Preferred Stock Warrant Liability
Fair value of warrant liability	$ 1,400		$ 1,400
Number of securities called by warrants | shares	1,000		1,000
Exercise price of warrant | $ / shares	$ 69.94		$ 69.94
Change in the fair value of warrant liability	$ (4,000)		$ (4,000)
Series A Common Stock Warrants | Volatility rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input	91.5		91.5
Series A Common Stock Warrants | Expected term
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input | Y	2.80		2.80
Series A Common Stock Warrants | Dividends
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input | dividend	0		0
Series A Common Stock Warrants | Risk-free interest rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input	4.87		4.87
Redeemable Convertible Preferred Stock Warrant
Redeemable Convertible Preferred Stock Warrant Liability
Fair value of warrant liability					4,000	$ 7,000
Change in the fair value of warrant liability		$ (1,000)	$ 1,000	$ (3,000)	$ 3,000	$ 2,000
Redeemable Convertible Preferred Stock Warrant | Volatility rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input						0.872			97.3
Redeemable Convertible Preferred Stock Warrant | Expected term
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input					2.28	3.27				2.28
Redeemable Convertible Preferred Stock Warrant | Dividends
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input						0			0		0
Redeemable Convertible Preferred Stock Warrant | Risk-free interest rate
Redeemable Convertible Preferred Stock Warrant Liability
Warrants, measurement input						1.01			4.36

Prepaid expenses and other cu_6

Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Prepaid expenses and other current assets
Deferred financing costs			$ 1,425
Prepaid Insurance	$ 865	$ 61
Prepaid clinical expenses	32	352	423
Other	77	34
Total	$ 974	$ 447	$ 1,932

Accrued expenses and other cu_6

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Accrued expenses and other current liabilities
Accrued clinical costs	$ 2,239	$ 3,162	$ 852
Accrued deferred financing costs			55
Employees' compensation	689	636	463
Accrued research	221
Accrued preclinical costs		166
Other	95	57	185
Total	$ 3,244	$ 4,021	$ 1,555

Related parties (Details)_2

Related parties (Details) - USD ($)	1 Months Ended				3 Months Ended	9 Months Ended		12 Months Ended
	Aug. 31, 2023	Jul. 31, 2023	Jan. 31, 2022	Jan. 31, 2019	Sep. 30, 2023	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Related parties
Revenue		$ 2,000,000	$ 0		$ 2,000,000	$ 2,000,000		$ 0
Investor | Ascletis
Related parties
Amount received as reimbursement						0	$ 28,100	$ 60,000	$ 100,000
Maximum eligible development and commercial milestone payments				$ 122,000,000
Amount paid						$ 0	$ 4,000
Development milestone payment trigger	$ 1,700,000		2,000,000
Development Milestone Payment Amount Triggered, Net of Taxes	$ 2,000,000		$ 2,000,000
Revenue		$ 2,000,000

Commitments and contingencies_6

Commitments and contingencies (Details)		3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 12, 2019 USD ($) ft²	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Commitments and contingencies
Operating lease term	38 months
Rented area (in square feet) | ft²	3,030
Monthly lease payments	$ 12,000
Operating lease cost		$ 37,000	$ 38,000	$ 111,000	$ 113,000	$ 200,000	$ 100,000

Commitments and contingencies_7

Commitments and contingencies - Lease maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Commitments and contingencies
Remainder of 2023	$ 27
2023/2024	79	$ 157
2024		80
Total lease payments	106	237
Less: interest	(3)	(26)
Total	$ 103	$ 211

Commitments and contingencies_8

Commitments and contingencies - Lease cash flow (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 118	$ 118	$ 157	$ 157
Weighted-average remaining lease term	9 months		1 year 2 months 12 days	2 years 6 months
Discount rate	7%		7%	7%

Redeemable convertible prefer_7

Redeemable convertible preferred stock (Details) - USD ($) $ in Thousands	Jul. 18, 2023	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Redeemable convertible preferred stock
Redeemable convertible preferred stock, shares authorized		0	1,373,810,170	1,373,810,170
Redeemable convertible preferred stock, issued		0	1,373,730,625	1,373,730,625
Redeemable convertible preferred stock, outstanding		0	1,373,730,625	1,373,730,625
Redeemable convertible preferred stock, liquidation preference			$ 232,963
Redeemable convertible preferred stock, carrying value			$ 214,620	$ 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)		9 Months Ended
	Jul. 18, 2023 Vote	Sep. 30, 2023 Vote shares	Dec. 31, 2022 shares	Dec. 31, 2021 shares
Stockholders' deficit
Common stock, shares authorized		0	1,608,370,000	1,590,550,754
Preferred stock, shares authorized		10,000,000	0
Common stock shares reserved for future issuance		6,353,473	1,325,890,931	1,325,468,004
Series A Common Stock Warrants
Stockholders' deficit
Common stock shares reserved for future issuance		1,000
Series D redeemable convertible preferred stock warrants
Stockholders' deficit
Common stock shares reserved for future issuance			79,545	79,545
Series A Common Stock
Stockholders' deficit
Common stock, shares authorized		500,000,000	0
Number of votes per share | Vote	1	1
Beneficial ownership stock held (as a percent)		4.99%
Options to purchase common stock
Stockholders' deficit
Common stock shares reserved for future issuance		3,766,505	3,190,450	2,138,110
Options authorized and available for issuance
Stockholders' deficit
Common stock shares reserved for future issuance		2,585,968	181,191	810,604
Warrants
Stockholders' deficit
Common stock shares reserved for future issuance			40,268	40,268
Warrants | Series D redeemable convertible preferred stock warrants
Stockholders' deficit
Common stock shares reserved for future issuance			79,545
Redeemable convertible preferred stock
Stockholders' deficit
Common stock shares reserved for future issuance			1,322,399,477	1,322,399,477

Stockholders' equity (deficit_3

Stockholders' equity (deficit) - Stock warrants (Details)	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares	Apr. 30, 2015 $ / shares shares	Apr. 10, 2015 $ / shares shares
Stock warrants
Warrants voting rights	0
Common warrants issued on June 2013
Stock warrants
Number of warrants issued | shares		26,846
Exercise price of warrant | $ / shares		$ 0.79	$ 0.79
Fair value of warrant liability | $		$ 339,000	$ 339,000
Common warrants issued on January 2014
Stock warrants
Number of warrants issued | shares		13,422
Exercise price of warrant | $ / shares		$ 0.79	$ 0.79
Fair value of warrant liability | $		$ 223,000	$ 223,000
Common warrants issued on April 2015
Stock warrants
Number of warrants issued | shares	1,000	79,545		79,545	79,545
Exercise price of warrant | $ / shares	$ 69.94	$ 0.88	$ 0.88	$ 0.88	$ 0.88
Fair value of warrant liability | $	$ 68,000	$ 68,000	$ 68,000
Warrants term					10 years
Series A Common Stock Warrants
Stock warrants
Exercise price of warrant | $ / shares	$ 69.94
Fair value of warrant liability | $	$ 1,400
Number of securities called by warrants | shares	1,000

Stock-based compensation (Det_2

Stock-based compensation (Details) - shares		9 Months Ended	12 Months Ended
	Jul. 13, 2023	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock-based compensation
Common stock shares reserved for future issuance		6,353,473	1,325,890,931	1,325,468,004
Shareholder having 10% holding
Stock-based compensation
Percentage of shareholder not having exercise price not less than 100% of fair value			10%
Employee stock option | Maximum
Stock-based compensation
Contractual term			5 years
2017 Equity incentive plan | Employee stock option | Minimum
Stock-based compensation
Percentage of price on estimated fair value			100%
2017 Equity incentive plan | Employee stock option | Maximum
Stock-based compensation
Contractual term			10 years
2017 Equity incentive plan | Employee stock option | Shareholder having 10% holding | Minimum
Stock-based compensation
Percentage of price on estimated fair value			110%
2023 Equity incentive plan
Stock-based compensation
Common stock shares reserved for future issuance	2,585,968	2,585,968	181,191	810,604
Increase in outstanding shares (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
Increase in outstanding shares (as a percent)	1%
Number of shares Issued under 2023 ESPP		0

Stock-based compensation - St_2

Stock-based compensation - Stock options (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Number of Shares underlying Outstanding Options
Balance at the beginning	3,190,450	2,138,110
Options granted	585,919	1,080,304
Options exercised	(7,614)	(1,627)
Options cancelled	(498)	(887)
Options expired	(1,752)	(25,450)
Balance at the end	3,766,505	3,190,450	2,138,110
Shares vested and exercisable at the end	1,784,725	1,510,555
Weighted-Average Exercise Price
Balance at the beginning (in dollars per share)	$ 7.10	$ 7.15
Options granted (in dollars per share)	13.51	7.15
Options exercised (in dollars per share)	0.79	7.24
Options cancelled (in dollars per share)	4.77	31.46
Options expired (in dollars per share)	0.79	12.75
Balance at the end (in dollars per share)	8.11	7.10	$ 7.15
Vested and Exercisable at the end (in dollars per share)	$ 6.98	$ 7.15
Weighted- Average Remaining Contractual Term (in Years) and Aggregate Intrinsic Value
Weighted- Average Remaining Contractual Term, Outstanding	7 years 8 months 8 days	8 years 1 month 6 days	8 years 1 month 6 days
Weighted- Average Remaining Contractual Term, Exercisable	6 years 4 months 2 days	6 years 9 months 18 days
Aggregate Intrinsic Value, Outstanding	$ 17,737,000	$ 3,998,000	$ 4,670,000
Aggregate Intrinsic Value, Exercisable	$ 10,206,000	2,303,000
Fair value of options vested		1,800,000
Total unrecognized compensation cost		$ 9,100,000
Remaining weighted-average period for unrecognized compensation cost		3 years 2 months 12 days
Time-based options
Number of Shares underlying Outstanding Options
Balance at the beginning	2,570,708	1,537,241
Options granted	585,919	1,061,431
Options exercised	(7,614)	(1,627)
Options cancelled	(498)	(887)
Options expired	(1,752)	(25,450)
Balance at the end	3,146,763	2,570,708	1,537,241
Shares vested and exercisable at the end	1,186,212	1,459,480
Weighted-Average Exercise Price
Balance at the beginning (in dollars per share)	$ 7.56	$ 7.95
Options granted (in dollars per share)	13.51	7.15
Options exercised (in dollars per share)	0.79	7.24
Options cancelled (in dollars per share)	4.77	31.46
Options expired (in dollars per share)	0.79	12.75
Balance at the end (in dollars per share)	8.69	$ 7.56	$ 7.95
Vested and Exercisable at the end (in dollars per share)	$ 14.42
Weighted- Average Remaining Contractual Term (in Years) and Aggregate Intrinsic Value
Vesting period	4 years	4 years
Fair value of options vested	$ 1,800,000
Total unrecognized compensation cost	$ 12,000,000
Remaining weighted-average period for unrecognized compensation cost	2 years 4 months 24 days
Performance-based options
Number of Shares underlying Outstanding Options
Balance at the beginning	619,742	600,869
Options granted		18,873
Balance at the end	619,742	619,742	600,869
Shares vested and exercisable at the end	598,513	51,075
Weighted-Average Exercise Price
Balance at the beginning (in dollars per share)	$ 6.38	$ 6.36
Options granted (in dollars per share)		7.15
Balance at the end (in dollars per share)	$ 6.38	$ 6.38	$ 6.36
Weighted- Average Remaining Contractual Term (in Years) and Aggregate Intrinsic Value
Fair value of options vested	$ 11,100	$ 82,000
Total unrecognized compensation cost	$ 28,200	$ 0
Remaining weighted-average period for unrecognized compensation cost	1 year	1 year

Stock-based compensation - Ex_2

Stock-based compensation - Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Stock-based compensation
Total stock-based compensation	$ 1,855	$ 389	$ 3,679	$ 1,159	$ 1,880	$ 1,904
General and administrative
Stock-based compensation
Total stock-based compensation	1,649	220	3,103	663	1,204	1,325
Research and development
Stock-based compensation
Total stock-based compensation	$ 206	$ 169	$ 576	$ 496	$ 676	$ 579

Stock-based compensation - Fa_2

Stock-based compensation - Fair value input (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Stock-based compensation
Risk-free interest rate	3.60%
Employee stock option
Stock-based compensation
Expected volatility, minimum	89%	88%	88%	89%
Expected volatility, maximum	91%	90%	90%	94%
Dividend yield	0%		0%
Minimum | Employee stock option
Stock-based compensation
Risk-free interest rate		2.30%	3%	0.40%
Expected term	5 years	5 years 4 months 24 days	5 years 4 months 24 days	5 years
Maximum | Employee stock option
Stock-based compensation
Risk-free interest rate		3%	4.20%	1.30%
Expected term	7 years	7 years	7 years	6 years 1 month 6 days

Net loss per share attributab_7

Net loss per share attributable to common stockholders - EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net loss attributable to common stockholders	$ (6,353)	$ (6,785)	$ (6,587)	$ (7,467)	$ (7,102)	$ (8,735)	$ (19,725)	$ (23,304)	$ (30,499)	$ (24,442)
Denominator:
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic				185,084				184,756	184,619	122,579
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted	18,194,682			185,084			6,131,541	184,756	184,619	122,579
Net loss per share attributable to common stockholders, basic				$ (40.34)				$ (126.13)	$ (165.20)	$ (199.40)
Net loss per share attributable to common stockholders, diluted	$ (0.35)			$ (40.34)			$ (3.22)	$ (126.13)	$ (165.20)	$ (199.40)
Series A and Series B
Denominator:
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, basic	18,194,682						6,131,541
Weighted-average shares outstanding used in computing net loss per share attributable to common stockholders, diluted	18,194,682						6,131,541
Net loss per share attributable to common stockholders, basic	$ (0.35)						$ (3.22)
Net loss per share attributable to common stockholders, diluted	$ (0.35)						$ (3.22)

Net loss per share attributab_8

Net loss per share attributable to common stockholders - Dilutive (Details) - shares	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Antidilutive securities
Potentially dilutive securities	3,767,505	18,956,964	3,767,505	18,956,964	19,948,739	18,896,399
Redeemable Convertible Preferred Stock Warrant
Antidilutive securities
Potentially dilutive securities		16,638,476		16,638,476
Options to purchase common stock | Series A Common Stock Warrants
Antidilutive securities
Potentially dilutive securities	3,766,505	2,198,675	3,766,505	2,198,675
Warrants | Series A Common Stock Warrants
Antidilutive securities
Potentially dilutive securities	1,000		1,000
Warrants | Common stock warrants
Antidilutive securities
Potentially dilutive securities		40,268		40,268
Warrants | Redeemable Convertible Preferred Stock Warrant
Antidilutive securities
Potentially dilutive securities		79,545		79,545