Third Harmonic Bio (THRD) 10-Q 9 Nov 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Nov. 03, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2023
Document Period End Date	Sep. 30, 2023
Current Fiscal Year End Date	--12-31
Entity Registrant Name	THIRD HARMONIC BIO, INC.
Entity Central Index Key	0001923840
Entity File Number	001-41498
Entity Tax Identification Number	83-4553503
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Incorporation, State or Country Code	DE
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Address, Address Line One	1700 Montgomery Street
Entity Address, Address Line Two	Suite 210
Entity Address, State or Province	CA
Entity Address City Or Town	San Francisco
Entity Address, Postal Zip Code	94111
City Area Code	209
Local Phone Number	727-2457
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Entity Common Stock, Shares Outstanding		40,362,572
Trading Symbol	THRD
Security Exchange Name	NASDAQ

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 273,892,000	$ 288,877,000
Prepaid expenses and other current assets	2,837,000	3,958,000
Total current assets	276,729,000	292,835,000
Restricted cash	441,000	441,000
Property and equipment, net	181,000	35,000
Right of use asset	3,931,000	4,327,000
Other assets, noncurrent	968,000	1,037,000
Total assets	282,250,000	298,675,000
Current liabilities:
Accounts payable	1,971,000	2,087,000
Accrued expenses and other current liabilities	3,198,000	3,181,000
Operating lease liability, current	719,000	385,000
Total current liabilities	5,888,000	5,653,000
Operating lease liability, noncurrent	3,403,000	3,954,000
Total liabilities	9,291,000	9,607,000
Commitments and contingencies (Note 12)
Stockholders' equity:
Common stock, $0.0001 par value, 500,000,000 shares authorized at December 31, 2022 and September 30, 2023; 39,377,222 and 39,734,656 shares issued and outstanding at December 31, 2022 and September 30, 2023, respectively	4,000	4,000
Additional paid-in capital	380,339,000	372,460,000
Accumulated deficit	(107,384,000)	(83,396,000)
Total stockholders' equity	272,959,000	289,068,000
Total liabilities and stockholders 'equity	$ 282,250,000	$ 298,675,000

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Common Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	500,000,000	500,000,000
Common stock issued (in shares)	39,734,656	39,377,222
Common Stock, Shares, Outstanding	39,734,656	39,377,222

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ 5,969	$ 4,757	$ 18,046	$ 15,150
General and administrative	4,878	3,831	15,503	9,008
Total operating expenses	10,847	8,588	33,549	24,158
Loss from operations	10,847	8,588	33,549	24,158
Other income, net:
Interest income	(3,470)	(383)	(9,533)	(493)
Other (income) expense	(34)	0	(28)	0
Total other (income) expense, net	(3,504)	(383)	(9,561)	(493)
Net loss	$ 7,343	$ 8,205	$ 23,988	$ 23,665
Net loss per share of common stock, basic	$ 0.19	$ 0.9	$ 0.61	$ 3.99
Net loss per share of common stock, diluted	$ 0.19	$ 0.9	$ 0.61	$ 3.99
Weighted-average number of common stock outstanding, basic	39,689,819	9,118,937	39,567,206	5,935,206
Weighted-average number of common stock outstanding, diluted	39,689,819	9,118,937	39,567,206	5,935,206

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY - USD ($) $ in Thousands	Total	Redeemable Convertible Preferred Stock Series A-1 Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock Series A-2 Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock Series A-3 Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock Series B Redeemable Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2021	$ (46,706)	$ 12,574	$ 19,476	$ 33,288	$ 104,846	$ 1	$ 1,534	$ (48,241)
Beginning balance, shares at Dec. 31, 2021		13,970,000	13,750,000	7,812,501	14,091,686	4,237,290
Vesting of restricted stock	0	$ 0	$ 0	$ 0	$ 0	$ 0	0	0
Vesting of restricted stock, shares		0	0	0	0	84,024
Stock-based compensation expense	450	$ 0	$ 0	$ 0	$ 0	$ 0	450	0
Net loss	(7,784)	0	0	0	0	0	0	(7,784)
Ending balance at Mar. 31, 2022	(54,040)	$ 12,574	$ 19,476	$ 33,288	$ 104,846	$ 1	1,984	(56,025)
Ending balance, shares at Mar. 31, 2022		13,970,000	13,750,000	7,812,501	14,091,686	4,321,314
Beginning balance at Dec. 31, 2021	(46,706)	$ 12,574	$ 19,476	$ 33,288	$ 104,846	$ 1	1,534	(48,241)
Beginning balance, shares at Dec. 31, 2021		13,970,000	13,750,000	7,812,501	14,091,686	4,237,290
Net loss	(23,665)
Ending balance at Sep. 30, 2022	298,422	$ 0	$ 0	$ 0	$ 0	$ 4	370,324	(71,906)
Ending balance, shares at Sep. 30, 2022		0	0	0	0	39,270,140
Beginning balance at Mar. 31, 2022	(54,040)	$ 12,574	$ 19,476	$ 33,288	$ 104,846	$ 1	1,984	(56,025)
Beginning balance, shares at Mar. 31, 2022		13,970,000	13,750,000	7,812,501	14,091,686	4,321,314
Vesting of restricted stock	0	$ 0	$ 0	$ 0	$ 0	$ 0	0	0
Vesting of restricted stock, shares		0	0	0	0	94,740
Stock-based compensation expense	1,159	$ 0	$ 0	$ 0	$ 0	$ 0	1,159	0
Net loss	(7,676)	0	0	0	0	0	0	(7,676)
Ending balance at Jun. 30, 2022	(60,557)	$ 12,574	$ 19,476	$ 33,288	$ 104,846	$ 1	3,143	(63,701)
Ending balance, shares at Jun. 30, 2022		13,970,000	13,750,000	7,812,501	14,091,686	4,416,054
Vesting of restricted stock	0	$ 0	$ 0	$ 0	$ 0	$ 0	0	0
Vesting of restricted stock, shares		0	0	0	0	338,488
Stock-based compensation expense	1,006	$ 0	$ 0	$ 0	$ 0	$ 0	1,006	0
Exercise of stock options	107	$ 0	$ 0	$ 0	$ 0	$ 0	107	0
Exercise of stock options, shares		0	0	0	0	13,282
Conversion of convertible preferred stock into common stock upon closing of initial public offering	170,186	$ (12,574)	$ (19,476)	$ (33,288)	$ (104,846)	$ 2	170,184	0
Conversion of convertible preferred stock into common stock upon closing of initial public offering, shares		(13,970,000)	(13,750,000)	(7,812,501)	(14,091,686)	21,967,316
Issuance of common stock upon closing of initial public offering, net of issuance costs and underwriting fees of $2.3M	195,885	$ 0	$ 0	$ 0	$ 0	$ 1	195,884	0
Issuance of common stock upon closing of initial public offering, net of issuance costs and underwriting fees of $2.3M, shares		0	0	0	0	12,535,000
Net loss	(8,205)	$ 0	$ 0	$ 0	$ 0	$ 0	0	(8,205)
Ending balance at Sep. 30, 2022	298,422	$ 0	$ 0	$ 0	$ 0	$ 4	370,324	(71,906)
Ending balance, shares at Sep. 30, 2022		0	0	0	0	39,270,140
Beginning balance at Dec. 31, 2022	289,068	$ 0	$ 0	$ 0	$ 0	$ 4	372,460	(83,396)
Beginning balance, shares at Dec. 31, 2022		0	0	0	0	39,377,222
Vesting of restricted stock	0	$ 0	$ 0	$ 0	$ 0	$ 0	0	0
Vesting of restricted stock, shares		0	0	0	0	107,181
Stock-based compensation expense	2,682	$ 0	$ 0	$ 0	$ 0	$ 0	2,682	0
Net loss	(9,085)	0	0	0	0	0	0	(9,085)
Ending balance at Mar. 31, 2023	282,665	$ 0	$ 0	$ 0	$ 0	$ 4	375,142	(92,481)
Ending balance, shares at Mar. 31, 2023		0	0	0	0	39,484,403
Beginning balance at Dec. 31, 2022	289,068	$ 0	$ 0	$ 0	$ 0	$ 4	372,460	(83,396)
Beginning balance, shares at Dec. 31, 2022		0	0	0	0	39,377,222
Net loss	(23,988)
Ending balance at Sep. 30, 2023	272,959	$ 0	$ 0	$ 0	$ 0	$ 4	380,339	(107,384)
Ending balance, shares at Sep. 30, 2023		0	0	0	0	39,734,656
Beginning balance at Mar. 31, 2023	282,665	$ 0	$ 0	$ 0	$ 0	$ 4	375,142	(92,481)
Beginning balance, shares at Mar. 31, 2023		0	0	0	0	39,484,403
Vesting of restricted stock	0	$ 0	$ 0	$ 0	$ 0	$ 0	0	0
Vesting of restricted stock, shares		0	0	0	0	107,093
Stock-based compensation expense	2,845	$ 0	$ 0	$ 0	$ 0	$ 0	2,845	0
Exercise of stock options	58	$ 0	$ 0	$ 0	$ 0	$ 0	58	0
Exercise of stock options, shares		0	0	0	0	37,268
Net loss	(7,560)	$ 0	$ 0	$ 0	$ 0	$ 0	0	(7,560)
Ending balance at Jun. 30, 2023	278,008	$ 0	$ 0	$ 0	$ 0	$ 4	378,045	(100,041)
Ending balance, shares at Jun. 30, 2023		0	0	0	0	39,628,764
Vesting of restricted stock	0	$ 0	$ 0	$ 0	$ 0	$ 0	0	0
Vesting of restricted stock, shares		0	0	0	0	104,146
Stock-based compensation expense	2,291	$ 0	$ 0	$ 0	$ 0	$ 0	2,291	0
Exercise of stock options	3	$ 0	$ 0	$ 0	$ 0	$ 0	3	0
Exercise of stock options, shares		0	0	0	0	1,746
Net loss	(7,343)	$ 0	$ 0	$ 0	$ 0	$ 0	0	(7,343)
Ending balance at Sep. 30, 2023	$ 272,959	$ 0	$ 0	$ 0	$ 0	$ 4	$ 380,339	$ (107,384)
Ending balance, shares at Sep. 30, 2023		0	0	0	0	39,734,656

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY (Parenthetical) $ in Millions	3 Months Ended
	Sep. 30, 2022 USD ($)
Issuance costs	$ 2.3

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (23,988)	$ (23,665)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	7,818	2,618
Depreciation expense	22	0
Noncash operating lease expense	396	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,121	(3,169)
Other assets	467	(1,193)
Accounts payable	(141)	1,204
Accrued expenses and other current liabilities	(296)	(1,425)
Operating lease liabilities	(217)	0
Net cash used in operating activities	(14,818)	(25,630)
Cash flows from investing activities:
Purchase of property and equipment	(168)	0
Net cash used in investing activities	(168)	0
Cash flows from financing activities:
Payment of offering costs	(60)	(1,419)
Proceeds from issuance of common stock in initial public offering, net of issuance costs and underwriting fees	0	198,178
Proceeds from the exercise of stock options	61	107
Net cash provided by financing activities	1	196,866
Net increase (decrease) in cash, cash equivalents and restricted cash	(14,985)	171,236
Cash, cash equivalents and restricted cash at beginning of period	289,318	128,280
Cash, cash equivalents and restricted cash at end of period	$ 274,333	$ 299,516
Supplemental disclosure of cash flows:
Conversion of preferred stock into common stock	0	170,184
Offering costs in accounts payable and accrued expenses	$ 338	$ 875

Nature of the Business

Nature of the Business	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business Third Harmonic Bio, Inc., or the Company, is a biopharmaceutical company focused on advancing the next wave of medicine for dermal, respiratory, and gastrointestinal inflammatory diseases. The Company was incorporated in 2019 as a Delaware corporation, and it has offices located in San Francisco, California and Cambridge, Massachusetts. In December 2021, the Company formed THB MS, Inc., a Delaware corporation and wholly-owned subsidiary of the Company, which is classified as a Security Corporation in Massachusetts. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, completion and success of clinical testing, development by competitors of new technological innovations, compliance with governmental regulations, dependence on key personnel and protection of proprietary technology and the ability to secure additional capital to fund operations. The development of a drug candidate requires extensive research, development and clinical testing prior to regulatory approval and commercialization. These efforts require significant amounts of additional capital, adequate personnel, and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s drug development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. Initial public offering On September 19, 2022, the Company closed its initial public offering, or the IPO, and issued 12,535,000 shares of common stock, including the exercise in full by the underwriters of their option to purchase up to 1,635,000 additional shares of common stock, at a public offering price of $ 17.00 per share. The Company received $ 198.2 million, net of underwriting discounts and commissions, but before deducting offering costs payable by the Company, which were $ 2.3 million. Immediately prior to the closing of the IPO, all outstanding shares of redeemable convertible preferred stock converted into 21,967,316 shares of common stock (see Note 7). In connection with the closing of its IPO, on September 19, 2022, the Company amended its certificate of incorporation to authorize the issuance of up to 500,000,000 shares of $ 0.0001 par value common stock and 10,000,000 shares of $ 0.0001 par value preferred stock. Liquidity In accordance with Accounting Standards Codification, or ASC 205-40, Going Concern , the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the accompanying condensed consolidated financial statements were issued. As an emerging growth entity, the Company has devoted substantially all of its resources since inception to organizing and staffing the Company, business planning, raising capital, establishing its intellectual property portfolio, acquiring or discovering product candidates, research and development activities for THB335 or any future KIT inhibitor and other compounds, establishing arrangements with third parties for the manufacture of its product candidates and component materials, and providing general and administrative support for these operations. As a result, the Company has incurred significant operating losses and negative cash flows from operations since its inception and anticipates such losses and negative cash flows will continue for the foreseeable future. Since its inception, the Company has funded its operations primarily with proceeds from sales of shares of its redeemable convertible preferred stock and most recently with proceeds from the IPO. The Company has incurred recurring losses since its inception, including net losses of $ 8.2 million and $ 7.3 million for the three months ended September 30, 2022 and 2023, respectively, and net losses of $ 23.7 million and $ 24.0 million for the nine months ended September 30, 2022 and 2023, respectively. As of September 30, 2023, the Company had an accumulated deficit of approximately $ 107.4 million. To date the Company has not generated any revenues and expects to continue to generate operating losses for the foreseeable future. As of the issuance date of these condensed consolidated financial statements, the Company expects that its existing cash and cash equivalents of $ 273.9 million as of September 30, 2023, will be sufficient to fund its operating expenses and capital expenditure requirements for at least the next 12 months from the issuance date of these condensed consolidated financial statements. Correction of Previously Reported Interim and Annual Consolidated Financial Statements As previously reported by the Company in its Quarterly Report on Form 10-Q for the period ended June 30, 2023, management determined that the weighted average shares outstanding, or WASO, of the Company’s common stock used in the calculation of basic and fully diluted loss per share was misstated for certain previously reported interim, year-to-date, and annual consolidated financial statements, or the previously reported periods. This resulted in the incorrect presentation of WASO and basic and fully diluted loss per share, collectively the error, on the Company’s Condensed Consolidated Statements of Operations and within the related notes thereto for the impacted previously reported periods. The cause of the error was due to clerical errors that were symptomatic to the previously disclosed material weakness related to the lack of segregation of duties, certain system limitations in our accounting software, and the overall control environment. Management prepared a quantitative and qualitative analysis of the error in accordance with SEC Staff Accounting Bulletin Nos. 99 and 108, or SAB 99/108, and concluded the impact of the error was not material to any of the previously reported periods. As a result, and in accordance with SAB 99/108, management has corrected the error in this Quarterly Report on Form 10-Q by presenting the correct WASO and basic and fully diluted loss per share on the face of the Company’s Condensed Consolidated Statements of Operations impacted by the error. Management also plans to correct the error for any relevant future periods. The correction of the error had no impact on the Company’s previously reported interim, year-to-date, or annual Condensed Consolidated Balance Sheet, Condensed Consolidated Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders’ (Deficit) Equity, or Condensed Consolidated Statements of Cash Flows. With respect to the Company’s previously reported interim, year-to-date, and annual Condensed Consolidated Statements of Operations impacted by the error, the correction of the error had no impact on the Company’s previously reported net loss in any of those periods. The correction of the error was limited to correcting the presentation of WASO and basic and fully diluted loss per share. A summary of the impact of the correction of the error on the Company’s previously reported interim, year-to-date, and annual Condensed Consolidated Statements of Operations impacted by the error that will be corrected and disclosed on a prospective basis the next time such previously reported periods and the related notes thereto are issued is, as follows: For the three months ended September 30, 2021 For the three months ended September 30, 2022 For the nine months ended September 30, 2022 As Previously Reported As Corrected As Previously Reported As Corrected As Previously Reported As Corrected Net loss per share of common stock, basic and diluted $ 0.90 $ 1.80 $ 0.69 $ 0.90 $ 2.26 $ 3.99 Weighted-average number of common shares used in net loss per share, basic and diluted 8,159,044 4,103,241 11,827,663 9,118,937 10,451,300 5,935,206 For the three months ended March 31, 2022 For the three months ended March 31, 2023 As Previously Reported As Corrected As Previously Reported As Corrected Net loss per share of common stock, basic and diluted $ 0.81 $ 1.82 $ 0.40 $ 0.23 Weighted-average number of common shares used in net loss per share, basic and diluted 9,643,963 4,271,681 22,792,781 39,438,572 For the Year Ended December 31, 2022 As Previously Reported As Corrected Net loss per share of common stock, basic and diluted $ 2.62 $ 2.45 Weighted-average number of common shares used in net loss per share, basic and diluted 13,426,066 14,353,102

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated annual financial statements for the years ended December 31, 2022, and notes thereto, which are included in the Company's Annual Report on Form 10-K that was filed with the Securities and Exchange Commission on March 29, 2023. Since the date of those annual financial statements, there have been no changes to the Company’s significant accounting policies, except as noted below. Unaudited Interim Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP, for interim financial reporting and as required by Regulation S-X, Rule 10-01. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated annual financial statements for the years ended December 31, 2021 and 2022 and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the Company’s condensed consolidated balance sheet as of September 30, 2023, the condensed consolidated statements of operations for the three and nine months ended September 30, 2022 and 2023, the condensed consolidated statement of changes in redeemable convertible preferred stock and stockholders' (deficit) equity for the three and nine months ended September 30, 2022 and 2023, and condensed consolidated statements of cash flows for the nine months ended September 30, 2022 and 2023. The financial data and other information disclosed in these notes related to the three and nine months ended September 30, 2022 and 2023 are unaudited. The results for the nine months ended September 30, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023 , any other interim periods, or any future year or period. Recently Issued Accounting Pronouncements Not Yet Adopted Management evaluated recently issued accounting pronouncements and does not believe that any of these pronouncements will have a significant impact on the condensed consolidated financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The following tables present information about the Company’s financial assets measured at fair value on a recurring basis (in thousands): December 31, 2022 Description Total Quoted Prices in Significant Other Significant Other Money market funds $ 286,580 $ 286,580 $ — $ — Total financial assets $ 286,580 $ 286,580 $ — $ — September 30, 2023 Description Total Quoted Prices in Active Markets for Identical Significant Other Significant Other Money market funds $ 197,292 $ 197,292 $ — $ — U.S. treasury securities 74,862 74,862 — — Total financial assets $ 272,154 $ 272,154 $ — $ — As of December 31, 2022 and September 30, 2023 , the Company had no financial liabilities that required fair value measurement. As of December 31, 2022 and September 30, 2023, the Company’s cash equivalents consisted of money market funds classified as Level 1 financial assets, as these assets are valued using quoted market prices in active markets without any valuation adjustment. As of September 30, 2023, the Company held U.S. treasury bills, which are included in cash, cash equivalents and restricted cash as their maturity is 90 days or less at acquisition and are considered Level 1 category assets as there are quoted prices in active markets. During the year ended December 31, 2022 and the nine months ended September 30, 2023 , there were no transfers or reclassifications between fair value measurement levels of assets or liabilities. The carrying values of prepaid and other current assets, accounts payable and accrued expenses and other current liabilities approximate their fair values due to the short-term nature of these assets and liabilities.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	4. Property, Plant and Equipment Property, plant and equipment consisted of the following (in thousands): December 31, September 30, Construction in progress $ 16 $ — Leasehold improvement — 109 Office furniture — 44 Computer equipment 20 51 Property, plant and equipment, gross 36 204 Less: Accumulated depreciation ( 1 ) ( 23 ) Property, plant and equipment, net $ 35 $ 181 There was no depreciation expense for the three and nine months ended September 30, 2022. Depreciation expense was immaterial for each of the three and nine months ended September 30, 2023 .

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2023
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	5. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): December 31, September 30, Accrued research and development expenses $ 1,444 $ 785 Employee compensation and related benefits 1,165 1,885 Professional fees 339 509 Other 233 19 Total accrued expenses and other current liabilities $ 3,181 $ 3,198

Novartis License Agreement

Novartis License Agreement	9 Months Ended
	Sep. 30, 2023
License Agreement [Abstract]
Novartis License Agreement	6. Novartis License Agreement On June 28, 2019, the Company entered into a License Agreement, or the Novartis License Agreement, with Novartis Pharma AG, formerly known as Novartis International Pharmaceutical Ltd, or Novartis. Pursuant to the Novartis License Agreement, the Company has been granted an exclusive, worldwide, royalty-bearing, sublicensable license under specified patent rights and know-how related to two licensed compounds, to develop, make, use and sell certain products incorporating or comprising a licensed compound, including THB001 and THB335, to certain intellectual property rights owned or controlled by Novartis, or the Licensed IP, to research, develop, make, use, sell, and commercialize products containing the Licensed IP. Under the Novartis License Agreement, the Company is solely responsible for all research, development, regulatory and commercialization activities related to the Licensed IP. The Company is required to use commercially reasonable efforts to develop and seek regulatory approval for, and commercialize, at least one licensed product in each of the United States, France, Germany, Italy, Spain, the United Kingdom, and Japan. In exchange for these rights, the Company made an upfront cash payment of $ 0.4 million and issued 3,449,808 shares of Series A-1 Preferred Stock with a fair value of $ 3.0 million to Novartis. Upon entering into the Novartis License Agreement in 2019, the total initial consideration of $ 3.4 million transferred to Novartis was charged to expenses as research and development expense. The Company determined that the Novartis License Agreement represented an asset acquisition as it did not meet the definition of a business. The Company recorded the initial consideration transferred to Novartis as research and development expense in the statement of operations because the acquired Licensed IP represented in-process research and development with no alternative future use. In addition, under the Novartis License Agreement, an anti-dilution right was issued to Novartis, in which Novartis is entitled to receive shares of Series A-1 Preferred Stock, guaranteeing them a 15 % ownership interest of the fully diluted capitalization of the Company. The Company was obligated to issue additional shares of Series A-1 Preferred Stock until the Company had (1) raised aggregate cumulative proceeds of $ 30.0 million from sales of equity securities since its inception; or (2) issued and sold any securities that generate proceeds in excess of $ 30.0 million. Additionally, the Company was not obligated to issue more than 6,383,142 shares of the Series A-1 Preferred Stock to Novartis under the anti-dilution right. The Company assessed the Novartis anti-dilution right and determined that the right (i) meets the definition of a freestanding financial instrument that is not indexed to the Company’s own stock and (ii) meets the definition of a derivative and does not qualify for equity classification. The initial fair value of the anti-dilution right liability of $ 1.0 million was recorded as research and development expense in July 2019, as part of the initial consideration in the license agreement. The Company remeasured the liability associated with the anti-dilution right at each reporting date and at each issuance of Series A-1 Preferred Stock under the anti-dilution right. Changes in the fair value were recorded as other income and expense in the statement of operations until the anti-dilution right was satisfied in February 2021 upon the Company raising aggregate cumulative proceeds of $ 30.0 million in sales of equity securities. As part of the anti-dilution right, the Company issued a total of 5,970,000 shares of Series A-1 Preferred Stock to Novartis. No expense has been recognized in any periods subsequent to the satisfaction of the anti-dilution liability which was satisfied in February 2021. Under the Novartis License Agreement, the Company is obligated to make aggregate milestone payments of up to $ 231.7 million related to the achievement of specified development, commercialization, and sales milestones. The Company records the milestone payments as research and development expenses when the milestones occur and consideration is paid or becomes payable. As of September 30, 2023 , the Company has made two development milestone payments under the Novartis License Agreement totaling $ 1.0 million, of which $ 0.4 million was achieved and paid in 2019, and $ 0.6 million was achieved and paid in 2020, which were recorded as research and development expense. No other milestones have occurred or have been paid under the Novartis License Agreement. As part of the Novartis License Agreement, the Company also agreed to pay tiered royalties based on future net sales of all Licensed IP, of which the royalty percentage ranged within the single digits.

Stockholder's Equity

Stockholder's Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Stockholder's Equity	7. Stockholder's Equity Common stock As of December 31, 2022 and September 30, 2023, the Company’s Amended and Restated Certificate of Incorporation authorized the Company to issue 500,000,000 shares of common stock, with a par value of $ 0.0001 . The holders of the common stock are entitled to one vote for each share of common stock held on all matters submitted to a vote of stockholders. There are not cumulative voting rights for the election of directors in the restated certificate of incorporation, which means that holders of a majority of the shares of the common stock will be able to elect all of the directors. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, or the Board, if any, subject to the preferential dividend rights of redeemable convertible preferred stock. Through September 30, 2023 , no cash dividends had been declared or paid. On September 19, 2022, the Company completed its IPO, at which time the Company issued 12,535,000 shares of common stock, including the exercise in full by the underwriters of their option to purchase up to 1,635,000 additional shares of common stock, at a public offering price of $ 17.00 per share. The Company received $ 198.2 million, net of underwriting discounts and commissions, but before deducting offering costs payable by the Company, which were $ 2.3 million. Upon the closing of the IPO, all outstanding shares of redeemable convertible preferred stock converted into 21,967,316 shares of common stock. Undesignated preferred stock As of December 31, 2022 and September 30, 2023 , the Company’s Amended and Restated Certificate of Incorporation authorized the Company to issue up to 10,000,000 shares of undesignated preferred stock, par value $ 0.0001 per share. There were no undesignated preferred shares issued or outstanding as of December 31, 2022 and September 30, 2023 .

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	8. Stock-Based Compensation 2019 Stock Incentive Plan The Company's 2019 Stock Incentive Plan, or the 2019 Plan, provided for the Company to grant incentive stock options, stock appreciation rights, restricted stock, restricted stock units, and other stock-based awards. The 2019 Plan was administered by the Board or, at the discretion of the Board, by a committee delegated by Board. The exercise prices, vesting and other restrictions were determined at the discretion of the Board, or its committee if so delegated. The Company’s Board valued the Company’s common stock, taking into consideration its most recently available valuation of common stock performed by third party valuation specialists as well as additional factors which may have changed since the date of the most recent contemporaneous valuation through the date of grant. The total number of shares of common stock that could have been issued under the 2019 Plan was 5,317,559 shares, of which 474,951 shares remained available for grant on September 19, 2022, the date that the Company's 2022 Equity Incentive Plan, or the 2022 Plan, became effective. Upon the effectiveness of the 2022 Plan, the 474,951 remaining shares available under the 2019 Plan were transferred and became available for issuance under the 2022 Plan. Shares of common stock underlying outstanding awards under the 2019 Plan that are forfeited, cancelled, held back upon exercise or settlement of an award to satisfy the exercise price or tax withholding, reacquired by the Company prior to vesting, satisfied without the issuance of stock, expire or are otherwise terminated (other than by exercise) will be added to the shares of common stock available for issuance under the 2022 Plan. 2022 Plan The 2022 Plan was approved by the Board and stockholders in August 2022. The 2022 Plan became effective on September 14, 2022 and replaced the Company's 2019 Plan on that date. The 2022 Plan authorizes the award of incentive stock options, or ISOs, non-qualified stock options, or NQSOs, Restricted Stock Awards, or RSAs, Stock Appreciation Rights, or SARs, Restricted Stock Units, or RSUs, performance awards and stock bonus awards. Pursuant to the 2022 Plan, ISOs may be granted only to employees. The number of shares initially reserved for issuance under the 2022 Plan is 4,901,688 shares of common stock, which includes the 474,951 shares transferred from the 2019 Plan, and shall automatically increase on January 1 of each of 2023 through 2032 by the number of shares equal of the lesser of 5 % of the aggregate number of shares of all classes of the common stock, plus the total number of shares of common stock issuable upon conversion of any preferred stock (if any) or exercise of any pre-funded warrants, as issued and outstanding as of the immediately preceding December 31, or a number as may be determined by the Board. The 2022 Plan is administered by the Board or, at the discretion of the Board, by a committee of the Board. The exercise prices, vesting and other restrictions are determined at the discretion of the Board, or its committee if so delegated, except that the exercise price per share of stock options may not be less than 100 % of the fair market value of the share of common stock on the date of grant and the term of stock option may not be greater than ten years . Shares that are expired terminated, surrendered or cancelled under the 2022 Plan without having been fully exercised will be available for future awards. Stock Options The assumptions that the Company used to determine the grant-date fair value of stock options awarded to employees, were as follows for the three and nine months ended September 30, 2022 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 Expected term (in years) 6.5 5.6 - 6.1 5.7 - 6.5 5.2 - 7.0 Expected volatility 83.5 % 87.2 - 87.6 % 81.9 - 83.5 % 85.7 - 88.2 % Risk-free interest rate 2.7 % 4.1 - 4.3 % 1.7 - 2.7 % 3.6 - 4.3 % Expected dividend yield — — — — The following table summarizes the Company’s stock option activity since December 31, 2022: Number of Shares Weighted-Average Weighted-Average Aggregate Intrinsic Outstanding as of December 31, 2022 3,644,500 $ 10.45 9.5 $ 1,283 Granted 1,603,390 4.36 Exercised ( 39,014 ) 1.56 Forfeited or cancelled ( 297,585 ) 3.88 Outstanding as of September 30, 2023 4,911,291 4.11 8.9 11,274 Options vested and exercisable as of September 30, 2023 1,273,931 3.88 8.6 3,224 Options unvested as of September 30, 2023 3,637,360 4.20 9.0 8,050 The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The weighted-average grant-date fair value per share of stock options granted during the nine months ended September 30, 2023 was $ 3.30 . As of September 30, 2023, there was $ 22.6 million of unrecognized stock-based compensation expense related to unvested stock options, to be recognized over a weighted-average period of 2.8 years. The total fair value of options vested during the nine months ended September 30, 2023 was $ 2.1 million. Repricing of Stock Options On March 6, 2023, the Board approved the reduction in exercise price of certain options that had been granted under the 2019 Plan and the 2022 Plan, that have an exercise price greater than or equal to $ 8.61 per share, which were each repriced at an exercise price of $ 4.20 effective March 21, 2023. There were no changes in the vesting schedule or maturity term of the options. Options representing 3,085,468 underlying shares were included in this repricing and the total incremental stock-based compensation expense associated with the modification of these options was $ 2.1 million. The incremental expense as a result of the repricing was recognized immediately for vested awards, and the incremental expense for the unvested awards will be recognized over the remaining requisite service period. Restricted Common Stock Awards The Company has granted restricted common stock awards with service and performance and service based vesting conditions to employees of the Company. Unvested shares of restricted common stock may not be sold or transferred by the holder, except for transfers for estate planning purposes in which the transferee agrees to remain bound by all restrictions set forth in the original common stock purchase agreement. These restrictions lapse over the vesting term of each award, which is typically four years . The purchase price of each share of restricted common stock was $ 0.0001 per share. On August 9, 2021, the Company’s chief executive office, or CEO, purchased 1,218,836 shares of common stock at a purchase price of $ 1.44 per share, under the terms of a restricted common stock award granted under the 2019 Plan. These shares were purchased in exchange for a promissory note, or the Promissory Note, of $ 1.8 million. The shares granted include both service and performance-based vesting criteria and accrued at an interest rate of 0.76 % per annum, compounded annually and were accounted for as restricted stock. On August 22, 2022, the Company forgave the entire promissory note, including principal and accrued and unpaid interest. As a result this is considered a modification to the original awards, and the Company recognized the grant date fair value plus any incremental fair value due to the modification. The incremental cost was measured as the difference between the fair value of the award at modification date and the fair value of the original award immediately prior to modification. As a result of accounting for the modification, the Company recorded an incremental stock-based compensation charge of $ 1.0 million, which will be recognized over the remaining requisite service period of award from the date of the modification. The CEO was paid a one-time special bonus of $ 1.9 million to offset the CEO’s tax liability as a result of the forgiveness of the promissory note, or the Tax Payment, which is subject to a three-year vesting schedule with six-month cliffs . The Company is allowed to claw-back the unvested portion of the Tax Payment in the event that the CEO’s employment is terminated before the end of the three-year vesting period, provided that the CEO’s employment is terminated by the Company other than for cause, or if the CEO resigns for a good reason (a) within 12 months following a change of control, or (b) within 3 months preceding a change in control but as to only if the separation occurs after a potential change in control. In the event the CEO’s employment is terminated, the unvested portion of the Tax Payment will accelerate and will not be subject to the claw back provision. The claw-back provision will be accounted for if and when the CEO leaves under the relevant circumstances and the payment amount will be capitalized and recognized over the related service period as G&A employee salary expense. A summary of the activity of the restricted common stock since December 31, 2022: Number of Shares Weighted-Average Unvested at December 31, 2022 964,992 $ 1.34 Granted — — Vested ( 318,420 ) 1.24 Cancelled or forfeited ( 11,052 ) 0.71 Unvested at September 30, 2023 635,520 $ 1.40 No restricted common stock awards were granted during the nine months ended September 30, 2023. Stock-Based Compensation Expense Stock-based compensation expense included in the Company’s condensed consolidated statements of operations was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 Research and development $ 343 $ 923 $ 723 $ 2,996 General and administrative 663 1,368 1,892 4,822 Total stock-based compensation expense $ 1,006 $ 2,291 $ 2,615 $ 7,818

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes During the three and nine months ended September 30, 2022 and 2023 , the Company recorded no income tax provision or benefit. The Company has evaluated the positive and negative evidence bearing upon its ability to realize its deferred tax assets, which primarily consist of net operating loss carryforwards. The Company has considered its history of cumulative net losses, estimated future taxable income and prudent and feasible tax planning strategies and has concluded that it is more likely than not that the Company will not realize the benefits of its deferred tax assets. As a result, as of September 30, 2023 , the Company has maintained a full valuation allowance against its remaining net deferred tax assets.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net Loss Per Share	10. Net Loss Per Share The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 Numerator: Net loss $ 8,205 $ 7,343 $ 23,665 $ 23,988 Net loss attributable to common stockholders, basic and diluted $ 8,205 $ 7,343 $ 23,665 $ 23,988 Denominator: Weighted-average number of common shares used in net loss per share, basic and diluted 9,118,937 39,689,819 5,935,206 39,567,206 Net loss per share of common stock, basic and diluted $ 0.90 $ 0.19 $ 3.99 $ 0.61 The Company excluded the following shares from the computation of diluted net loss per share attributable to common stockholders during the three and nine months ended September 30, 2022 and 2023 because including them would have had an anti-dilutive effect: For the Three and Nine Months Ended September 30, 2022 2023 Options to purchase common stock 2,542,936 4,911,291 Unvested restricted stock 1,072,054 635,520 Total 3,614,990 5,546,811

Leases

Leases	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Leases	11. Leases Operating Leases In October 2022, the Company entered into an office space lease approximating 10,356 of rentable square feet, located at 130 Prospect Street in Cambridge, Massachusetts. The lease commenced on December 1, 2022 when the Company took occupancy of the space, and has an initial lease term of 63 months , expiring on February 29, 2028 with no renewal options. Also in October 2022, the Company entered into an office space lease approximating 4,703 of rentable square feet located at 1700 Montgomery Street in San Francisco, California. The lease commenced on December 20, 2022 when the Company took occupancy of the space, and has an initial lease term of 63 months , expiring on February 20, 2028 with no renewal options. The Company also leased various office suites on a month-to month basis from Atlas Venture Life Science Advisors, or Atlas, and other third parties during the year ended December 31, 2022. During the three and nine months ended September 30, 2022 , the Company incurred immaterial short-term lease expense associated with the month-to-month lease. As the Company elected to not recognize leases with a lease term of 12 months or less on the balance sheet, no operating lease right of use assets and liabilities were recognized. During the three and nine months ended September 30, 2023 , the Company did no t incur any short-term lease costs. During the three and nine months ended September 30, 2022 and 2023, the components of operating lease cost were as follows, and are reflected in general and administrative expenses and research and development expenses, as determined by the underlying activities: Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 Lease Cost: Operating lease cost $ — $ 274 $ — $ 822 Variable operating lease cost — — — — Total operating lease cost $ — $ 274 $ — $ 822 There was no cash paid and $ 0.3 million paid for amounts included in the measurement of operating lease liabilities for each of the three months ended September 30, 2022 and 2023 , respectively. There was no cash paid and $ 0.6 million paid for the nine months ended September 30, 2022 and 2023, respectively. Maturities of operating lease liabilities at September 30, 2023 are as follows (in thousands): 2023 (remaining) $ 272 2024 1,116 2025 1,145 2026 1,176 2027 1,207 Thereafter 238 Total lease payments 5,154 Less: interest ( 1,032 ) Total lease liability $ 4,122

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. Commitments and Contingencies Legal Proceedings From time to time, in the ordinary course of business, the Company is subject to litigation and regulatory examinations as well as information gathering requests, inquiries and investigations. As of December 31, 2022 and September 30, 2023, there were no litigation matters which would have a material impact on the Company’s financial results.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	13. Related Party Transactions Entities Affiliated with Atlas Venture Fund XI, L.P . Entities affiliated with Atlas Venture Fund XI, L.P. are a significant beneficial owner of the Company, holding more than 5 % of the total outstanding stock of the Company, as of December 31, 2022 and September 30, 2023. The Company leased various office space from Atlas for use in its daily operations through September 2022. During each of the three and nine months ended September 30, 2022 , the Company made immaterial payments associated with the lease agreements with Atlas, which were recorded within the general and administrative expense. No payments related to the lease agreements with Atlas were made during each of the three and nine months ended September 30, 2023. Novartis Novartis is a significant beneficial owner of the Company, holding more than 5 % of the total outstanding stock of the Company, as of December 31, 2022 and September 30, 2023. The Company has an in-license agreement with Novartis, which required the Company to make an upfront payment and issue shares of Series A-1 Preferred Stock to Novartis, and further includes future milestone payments upon the occurrence of certain events and royalty payments upon future sales. Refer to Note 6. CEO Promissory Note On August 9, 2021, the Company entered into the Promissory Note with the CEO for an amount of $ 1.8 million, which was used to allow the CEO to purchase 1,218,836 shares of common stock granted in the form of a restricted stock award under the 2019 Plan. The Promissory Note had a stated interest rate of 0.76 %, which was compounded annually. The entire Promissory Note, including principal and accrued and unpaid interest, was forgiven on August 22, 2022. The Company has paid the CEO a one-time special bonus of $ 1.9 million, which was paid to offset the CEO's tax liability as a result of the forgiveness of the Promissory Note. This is subject to a three-year vesting schedule with six-month cliffs , as well as continued employment with the company on the relevant vesting dates. Refer to Note 8.

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2023
Retirement Benefits [Abstract]
Employee Benefit Plans	14. Employee Benefit Plans Effective January 1, 2019, the Company adopted a 401(k) Plan for its employees, which is designed to be qualified under Section 401(k) of the Internal Revenue Code. Eligible employees are permitted to contribute to the 401(k) Plan within statutory and 401(k) Plan limits. Since inception of the plan and through the nine months ended September 30, 2023 , the Company has not made any contributions to the 401(k) Plan.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP, for interim financial reporting and as required by Regulation S-X, Rule 10-01. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated annual financial statements for the years ended December 31, 2021 and 2022 and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the Company’s condensed consolidated balance sheet as of September 30, 2023, the condensed consolidated statements of operations for the three and nine months ended September 30, 2022 and 2023, the condensed consolidated statement of changes in redeemable convertible preferred stock and stockholders' (deficit) equity for the three and nine months ended September 30, 2022 and 2023, and condensed consolidated statements of cash flows for the nine months ended September 30, 2022 and 2023. The financial data and other information disclosed in these notes related to the three and nine months ended September 30, 2022 and 2023 are unaudited. The results for the nine months ended September 30, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023 , any other interim periods, or any future year or period.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted Management evaluated recently issued accounting pronouncements and does not believe that any of these pronouncements will have a significant impact on the condensed consolidated financial statements and related disclosures.

Nature of the Business (Tables)

Nature of the Business (Tables)	9 Months Ended
	Sep. 30, 2023
Accounting Changes and Error Corrections [Abstract]
Schedule of Financial Statements	A summary of the impact of the correction of the error on the Company’s previously reported interim, year-to-date, and annual Condensed Consolidated Statements of Operations impacted by the error that will be corrected and disclosed on a prospective basis the next time such previously reported periods and the related notes thereto are issued is, as follows: For the three months ended September 30, 2021 For the three months ended September 30, 2022 For the nine months ended September 30, 2022 As Previously Reported As Corrected As Previously Reported As Corrected As Previously Reported As Corrected Net loss per share of common stock, basic and diluted $ 0.90 $ 1.80 $ 0.69 $ 0.90 $ 2.26 $ 3.99 Weighted-average number of common shares used in net loss per share, basic and diluted 8,159,044 4,103,241 11,827,663 9,118,937 10,451,300 5,935,206 For the three months ended March 31, 2022 For the three months ended March 31, 2023 As Previously Reported As Corrected As Previously Reported As Corrected Net loss per share of common stock, basic and diluted $ 0.81 $ 1.82 $ 0.40 $ 0.23 Weighted-average number of common shares used in net loss per share, basic and diluted 9,643,963 4,271,681 22,792,781 39,438,572 For the Year Ended December 31, 2022 As Previously Reported As Corrected Net loss per share of common stock, basic and diluted $ 2.62 $ 2.45 Weighted-average number of common shares used in net loss per share, basic and diluted 13,426,066 14,353,102

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured at Fair Value	The following tables present information about the Company’s financial assets measured at fair value on a recurring basis (in thousands): December 31, 2022 Description Total Quoted Prices in Significant Other Significant Other Money market funds $ 286,580 $ 286,580 $ — $ — Total financial assets $ 286,580 $ 286,580 $ — $ — September 30, 2023 Description Total Quoted Prices in Active Markets for Identical Significant Other Significant Other Money market funds $ 197,292 $ 197,292 $ — $ — U.S. treasury securities 74,862 74,862 — — Total financial assets $ 272,154 $ 272,154 $ — $ —

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Property, plant and equipment consisted of the following (in thousands): December 31, September 30, Construction in progress $ 16 $ — Leasehold improvement — 109 Office furniture — 44 Computer equipment 20 51 Property, plant and equipment, gross 36 204 Less: Accumulated depreciation ( 1 ) ( 23 ) Property, plant and equipment, net $ 35 $ 181

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2023
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): December 31, September 30, Accrued research and development expenses $ 1,444 $ 785 Employee compensation and related benefits 1,165 1,885 Professional fees 339 509 Other 233 19 Total accrued expenses and other current liabilities $ 3,181 $ 3,198

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Stock Options Valuation Assumptions	The assumptions that the Company used to determine the grant-date fair value of stock options awarded to employees, were as follows for the three and nine months ended September 30, 2022 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 Expected term (in years) 6.5 5.6 - 6.1 5.7 - 6.5 5.2 - 7.0 Expected volatility 83.5 % 87.2 - 87.6 % 81.9 - 83.5 % 85.7 - 88.2 % Risk-free interest rate 2.7 % 4.1 - 4.3 % 1.7 - 2.7 % 3.6 - 4.3 % Expected dividend yield — — — —
Summary of Stock Option Activity	The following table summarizes the Company’s stock option activity since December 31, 2022: Number of Shares Weighted-Average Weighted-Average Aggregate Intrinsic Outstanding as of December 31, 2022 3,644,500 $ 10.45 9.5 $ 1,283 Granted 1,603,390 4.36 Exercised ( 39,014 ) 1.56 Forfeited or cancelled ( 297,585 ) 3.88 Outstanding as of September 30, 2023 4,911,291 4.11 8.9 11,274 Options vested and exercisable as of September 30, 2023 1,273,931 3.88 8.6 3,224 Options unvested as of September 30, 2023 3,637,360 4.20 9.0 8,050
Summary of Restricted Common Stock Activity	A summary of the activity of the restricted common stock since December 31, 2022: Number of Shares Weighted-Average Unvested at December 31, 2022 964,992 $ 1.34 Granted — — Vested ( 318,420 ) 1.24 Cancelled or forfeited ( 11,052 ) 0.71 Unvested at September 30, 2023 635,520 $ 1.40
Summary of Stock-Based Compensation Expense	Stock-based compensation expense included in the Company’s condensed consolidated statements of operations was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 Research and development $ 343 $ 923 $ 723 $ 2,996 General and administrative 663 1,368 1,892 4,822 Total stock-based compensation expense $ 1,006 $ 2,291 $ 2,615 $ 7,818

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 Numerator: Net loss $ 8,205 $ 7,343 $ 23,665 $ 23,988 Net loss attributable to common stockholders, basic and diluted $ 8,205 $ 7,343 $ 23,665 $ 23,988 Denominator: Weighted-average number of common shares used in net loss per share, basic and diluted 9,118,937 39,689,819 5,935,206 39,567,206 Net loss per share of common stock, basic and diluted $ 0.90 $ 0.19 $ 3.99 $ 0.61
Schedule of Computation of Diluted Net Loss Per Share Attributable to Common Stockholders Anti-dilutive Effect	The Company excluded the following shares from the computation of diluted net loss per share attributable to common stockholders during the three and nine months ended September 30, 2022 and 2023 because including them would have had an anti-dilutive effect: For the Three and Nine Months Ended September 30, 2022 2023 Options to purchase common stock 2,542,936 4,911,291 Unvested restricted stock 1,072,054 635,520 Total 3,614,990 5,546,811

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Components of Operating Lease Cost	Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 Lease Cost: Operating lease cost $ — $ 274 $ — $ 822 Variable operating lease cost — — — — Total operating lease cost $ — $ 274 $ — $ 822
Maturities of Operating Lease Liabilities	Maturities of operating lease liabilities at September 30, 2023 are as follows (in thousands): 2023 (remaining) $ 272 2024 1,116 2025 1,145 2026 1,176 2027 1,207 Thereafter 238 Total lease payments 5,154 Less: interest ( 1,032 ) Total lease liability $ 4,122

Nature of the Business - Additi

Nature of the Business - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended						9 Months Ended
	Sep. 19, 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
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Proceeds from initial public offering								$ 0	$ 198,178
Offering costs payable								$ 60	1,419
Number of shares authorized for issuance		500,000,000						500,000,000		500,000,000
Par value of common stock		$ 0.0001						$ 0.0001		$ 0.0001
Preferred stock, Par Value		$ 0.0001						$ 0.0001		$ 0.0001
Net loss		$ (7,343)	$ (7,560)	$ (9,085)	$ (8,205)	$ (7,676)	$ (7,784)	$ (23,988)	(23,665)
Accumulated deficit		107,384						107,384		$ 83,396
Cash and cash equivalents		$ 273,892						$ 273,892		$ 288,877
Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Undesignated preferred stock, authorized		10,000,000						10,000,000		10,000,000
IPO
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Initial public offering, Shares	12,535,000
Public offering price	$ 17
Proceeds from initial public offering	$ 198,200
Offering costs payable	$ 2,300
Conversion of convertible preferred stock into common stock	21,967,316
Number of shares authorized for issuance	500,000,000
Par value of common stock	$ 0.0001
Undesignated preferred stock, authorized	10,000,000
Preferred stock, Par Value	$ 0.0001
Net loss		$ (7,300)			$ (8,200)			$ (24,000)	$ (23,700)
Underwrites Option | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Initial public offering, Shares	1,635,000

Nature of the Business - Schedu

Nature of the Business - Schedule of Financial Statements (Details) - $ / shares	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss per share of common stock, basic	$ 0.19	$ 0.23	$ 0.9	$ 1.82	$ 1.8	$ 0.61	$ 3.99	$ 2.45
Net loss per share of common stock, diluted	$ 0.19	$ 0.23	$ 0.9	$ 1.82	$ 1.8	$ 0.61	$ 3.99	$ 2.45
Weighted-average number of common shares used in net loss per share, basic	39,689,819	39,438,572	9,118,937	4,271,681	4,103,241	39,567,206	5,935,206	14,353,102
Weighted-average number of common shares used in net loss per share, diluted	39,689,819	39,438,572	9,118,937	4,271,681	4,103,241	39,567,206	5,935,206	14,353,102
Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss per share of common stock, basic		$ 0.4	$ 0.69	$ 0.81	$ 0.9		$ 2.26	$ 2.62
Net loss per share of common stock, diluted		$ 0.4	$ 0.69	$ 0.81	$ 0.9		$ 2.26	$ 2.62
Weighted-average number of common shares used in net loss per share, basic		22,792,781	11,827,663	9,643,963	8,159,044		10,451,300	13,426,066
Weighted-average number of common shares used in net loss per share, diluted		22,792,781	11,827,663	9,643,963	8,159,044		10,451,300	13,426,066

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets Measured at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	$ 272,154	$ 286,580
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	272,154	286,580
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	0	0
Significant Other Observable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	0	0
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	197,292	286,580
Money Market Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	197,292	286,580
Money Market Funds | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	0	0
Money Market Funds | Significant Other Observable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	0	$ 0
US Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	74,862
US Treasury Securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	74,862
US Treasury Securities | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	0
US Treasury Securities | Significant Other Observable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Fair Value Disclosures [Line Items]
Transfers or reclassifications between fair value measurement levels of assets	$ 0	$ 0
Transfers or reclassifications between fair value measurement levels of liabilities	0	0
Cash and Cash Equivalents
Fair Value Disclosures [Line Items]
Fair value measurement of financial liabilities	$ 0	$ 0

Property, Plant and Equipment -

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 204	$ 36
Less: Accumulated depreciation	(23)	(1)
Property, plant and equipment, net	181	35
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	0	16
Leasehold improvement
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	109	0
Office furniture
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	44	0
Computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 51	$ 20

Property, Plant and Equipment_2

Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Property, Plant and Equipment [Line Items]
Depreciation expense		$ 22	$ 0
General and Administrative Expenses
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 0		$ 0

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued research and development expenses	$ 785	$ 1,444
Employee compensation and related benefits	1,885	1,165
Professional fees	509	339
Other	19	233
Total accrued expenses and other current liabilities	$ 3,198	$ 3,181

Novartis License Agreement - Ad

Novartis License Agreement - Additional Information (Details)			9 Months Ended	12 Months Ended
	Feb. 28, 2021 USD ($)	Jun. 28, 2019 USD ($) License shares	Sep. 30, 2023 USD ($) License	Dec. 31, 2022 USD ($) shares	Feb. 24, 2021 shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
License Agreement [Line Items]
Preferred stock, shares issued | shares				0
Novartis License Agreement | Novartis
License Agreement [Line Items]
Number of licensed compounds | License		2
Number of licensed Product | License		1
Upfront cash payment		$ 400,000
Total initial consideration transferred		3,400,000
Changes in fair value of anti dilution right liability			$ 0	$ 0
Aggregate milestone payments		231,700,000
Number of development milestone payments | License			2
Development milestone payments			$ 1,000,000
Milestone payments achieved and paid						$ 600,000	$ 400,000
Novartis License Agreement | Novartis | Research and Development Expense
License Agreement [Line Items]
Initial fair value of anti-dilution right liability		$ 1,000,000
Novartis License Agreement | Series A-1 Preferred Stock | Maximum
License Agreement [Line Items]
Preferred stock, shares issued | shares		6,383,142
Novartis License Agreement | Series A-1 Preferred Stock | Novartis
License Agreement [Line Items]
Preferred stock, shares issued | shares		3,449,808
Fair value of stock		$ 3,000,000
Ownership interest		15%
Licensing milestone in sales of equity securities	$ 30,000,000	$ 30,000,000
Novartis License Agreement | Series A-1 Preferred Stock | Novartis | Minimum
License Agreement [Line Items]
Licensing milestone in sales of equity securities		$ 30,000,000
Novartis License Agreement | Series A-1 Preferred Stock | Novartis | Maximum
License Agreement [Line Items]
Preferred stock, shares issued | shares					5,970,000

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		9 Months Ended		57 Months Ended
	Sep. 19, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Dec. 31, 2022
Subsidiary, Sale of Stock [Line Items]
Common Stock, Shares Authorized		500,000,000		500,000,000	500,000,000
Common Stock, Par or Stated Value Per Share		$ 0.0001		$ 0.0001	$ 0.0001
Common stock voting rights				one vote for each share
Common stock, cash dividends declared				$ 0
Offering costs		$ 60	$ 1,419
Preferred stock, Par Value		$ 0.0001		$ 0.0001	$ 0.0001
Undesignated preferred shares issued					0
Preferred shares outstanding		0		0
Maximum [Member]
Subsidiary, Sale of Stock [Line Items]
Undesignated preferred stock, authorized		10,000,000		10,000,000	10,000,000
IPO
Subsidiary, Sale of Stock [Line Items]
Common Stock, Shares Authorized	500,000,000
Initial public offering, Shares	12,535,000
Common Stock, Par or Stated Value Per Share	$ 0.0001
Public offering price	$ 17
Proceeds from issuing shares	$ 198,200
Offering costs	$ 2,300
Conversion of convertible preferred stock into common stock	21,967,316
Undesignated preferred stock, authorized	10,000,000
Preferred stock, Par Value	$ 0.0001
Over allotment | Maximum [Member]
Subsidiary, Sale of Stock [Line Items]
Initial public offering, Shares	1,635,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended		9 Months Ended
	Mar. 21, 2023	Aug. 22, 2022	Aug. 09, 2021	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Mar. 06, 2023	Dec. 31, 2022	Sep. 19, 2022	Sep. 14, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense				$ 2,291	$ 1,006	$ 7,818	$ 2,615
CEO Promissory Note
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period						3 years
Special bonus paid		$ 1,900
Award vesting description						subject to a three-year vesting schedule with six-month cliffs
Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Service period						3 months
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value per share of stock options						$ 3.3
Unrecognized stock-based compensation expense related to unvested stock options				$ 22,600		$ 22,600
Unrecognized stock based compensation expense period of recognition						2 years 9 months 18 days
Fair value of options vested						$ 2,100
Outstanding stock options to purchase common stock				4,911,291		4,911,291			3,644,500
Repriced of exercise price	$ 4.2
Number of options included in repricing	3,085,468
Total incremental stock-based compensation expense associated with modification of options	$ 2,100
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period						4 years
Share price				$ 0.0001		$ 0.0001
Remaining unrecognized expense		1,000
Weighted average grant date fair value						$ 0
Granted in period						0
Restricted Stock | Promissory Note
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exchangeable value of shares purchased			$ 1,800
Restricted Stock | Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share price			$ 1.44
Number of shares purchased			1,218,836
Special bonus paid		$ 1,900
Contingency period						12 months
Restricted Stock | Chief Executive Officer [Member] | Promissory Note
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Accrued Interest Rate			0.76%
2019 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock issuable under plan										5,317,559
Conversion of outstanding shares of preferred stock										474,951	474,951
Number of shares transferred				474,951		474,951
2022 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance				4,901,688		4,901,688
Maximum | 2022 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of annual increase in number of shares to classes of common stock under plan						5%
Exercise price per share of stock options as percentage of fair market value of common stock						100%
Stock option expiration period						10 years
Minimum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price								$ 8.61

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Options Valuation Assumptions (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0%	0%	0%	0%
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)		6 years 6 months
Expected volatility		83.50%
Risk-free interest rate		2.70%
Maximum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days		7 years	6 years 6 months
Expected volatility	87.60%		88.20%	83.50%
Risk-free interest rate	4.30%		4.30%	2.70%
Minimum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 7 months 6 days		5 years 2 months 12 days	5 years 8 months 12 days
Expected volatility	87.20%		85.70%	81.90%
Risk-free interest rate	4.10%		3.60%	1.70%

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activity (Details) - Stock Options $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning balance | shares	3,644,500
Shares, Granted | shares	1,603,390
Exercised | shares	(39,014)
Forfeited or cancelled | shares	(297,585)
Ending balance | shares	4,911,291	3,644,500
Options vested and exercisable as of September 30, 2023 | shares	1,273,931
Options unvested as of September 30, 2023 | shares	3,637,360
Beginning balance | $ / shares	$ 10.45
Granted | $ / shares	4.36
Exercised | $ / shares	1.56
Forfeited or cancelled | $ / shares	3.88
Ending balance | $ / shares	4.11	$ 10.45
Options vested and exercisable as of September 30, 2023 | $ / shares	3.88
Options unvested as of September 30, 2023 | $ / shares	$ 4.2
Weighted-Average Remaining Contractual Term (in years)	8 years 10 months 24 days	9 years 6 months
Options vested and exercisable as of September 30, 2023	8 years 7 months 6 days
Options unvested as of September 30, 2023	9 years
Aggregate Intrinsic Value | $	$ 11,274	$ 1,283
Options vested and exercisable as of September 30, 2023 | $	3,224
Options unvested as of September 30, 2023 | $	$ 8,050

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Restricted Common Stock Activity (Details) - Restricted Stock	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning balance | shares	964,992
Granted | shares	0
Vested | shares	(318,420)
Cancelled or forfeited | shares	(11,052)
Ending balance | shares	635,520
Beginning balance | $ / shares	$ 1.34
Granted | $ / shares	0
Vested | $ / shares	1.24
Cancelled or forfeited | $ / shares	0.71
Ending balance | $ / shares	$ 1.4

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 2,291	$ 1,006	$ 7,818	$ 2,615
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	923	343	2,996	723
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,368	$ 663	$ 4,822	$ 1,892

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income tax provision or benefit	$ 0	$ 0	$ 0	$ 0

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (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, 2021	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Earnings Per Share [Abstract]
Net loss	$ 7,343	$ 7,560	$ 9,085	$ 8,205	$ 7,676	$ 7,784		$ 23,988	$ 23,665
Net loss attributable to common stockholders, basic	7,343			8,205				23,988	23,665
Net loss attributable to common stockholders, diluted	$ 7,343			$ 8,205				$ 23,988	$ 23,665
Weighted-average number of common shares used in net loss per share, basic	39,689,819		39,438,572	9,118,937		4,271,681	4,103,241	39,567,206	5,935,206	14,353,102
Weighted-average number of common shares used in net loss per share, diluted	39,689,819		39,438,572	9,118,937		4,271,681	4,103,241	39,567,206	5,935,206	14,353,102
Net loss per share of common stock, basic	$ 0.19		$ 0.23	$ 0.9		$ 1.82	$ 1.8	$ 0.61	$ 3.99	$ 2.45
Net loss per share of common stock, diluted	$ 0.19		$ 0.23	$ 0.9		$ 1.82	$ 1.8	$ 0.61	$ 3.99	$ 2.45

Net Loss Per Share - Schedule_2

Net Loss Per Share - Schedule of Computation of Diluted Net Loss Per Share Attributable to Common Stockholders Anti-dilutive Effect (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti diluted effect of diluted net loss per share	5,546,811	3,614,990	5,546,811	3,614,990
Options to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti diluted effect of diluted net loss per share	4,911,291	2,542,936	4,911,291	2,542,936
Unvested Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti diluted effect of diluted net loss per share	635,520	1,072,054	635,520	1,072,054

Leases - Additional Information

Leases - Additional Information (Details)	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2022 USD ($) ft²	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Leases [Line Items]
Operating lease right of use assets	$ 0
Operating lease liabilities	$ 0	$ 719,000		$ 719,000		$ 385,000
Short-term lease expense		0		0
Cash paid for amounts included in the measurement of operating lease liabilities		$ 300,000	$ 0	$ 600,000	$ 0
130 Prospect Street in Cambridge, Massachusetts
Leases [Line Items]
Area of land | ft²	10,356
Lease commencement date	Dec. 01, 2022
Initial lease term	63 months
Lease expiring date	Feb. 29, 2028
1700 Montgomery Street in San Francisco, California
Leases [Line Items]
Area of land | ft²	4,703
Lease commencement date	Dec. 20, 2022
Initial lease term	63 months
Lease expiring date	Feb. 20, 2028

Leases - Components of Operatin

Leases - Components of Operating Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Lease, Cost [Abstract]
Operating lease cost	$ 274	$ 0	$ 822	$ 0
Variable operating lease cost	0	0	0	0
Total operating lease cost	$ 274	$ 0	$ 822	$ 0

Leases - Maturities of Operatin

Leases - Maturities of Operating Lease Liabilities (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
2023 (remaining)	$ 272
2024	1,116
2025	1,145
2026	1,176
2027	1,207
Thereafter	238
Total lease payments	5,154
Less: interest	(1,032)
Total lease liability	$ 4,122

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)			3 Months Ended	9 Months Ended	12 Months Ended
	Aug. 22, 2022	Aug. 09, 2021	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Common stock issued (in shares)			39,734,656	39,734,656	39,377,222
Atlas Venture Fund XI, L.P
Related Party Transaction [Line Items]
Related Party transaction payment			$ 0	$ 0
Atlas Venture Fund XI, L.P | Minimum
Related Party Transaction [Line Items]
Outstanding stock percentage				5%	5%
Novartis | Minimum
Related Party Transaction [Line Items]
Outstanding stock percentage				5%	5%
CEO Promissory Note
Related Party Transaction [Line Items]
Promissory note agreement amount		$ 1,800,000
Common stock issued (in shares)		1,218,836
Interest rate of promissory note		0.76%
Special bonus paid	$ 1,900,000
Vesting period				3 years
Award vesting description				subject to a three-year vesting schedule with six-month cliffs