Monte Rosa Therapeutics (GLUE) 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. 06, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Entity Registrant Name	Monte Rosa Therapeutics, Inc.
Entity Central Index Key	0001826457
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		50,081,023
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Security12b Title	Common stock, par value $0.0001 per share
Trading Symbol	GLUE
Security Exchange Name	NASDAQ
Entity File Number	001-40522
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	84-3766197
Entity Address Address Line1	321 Harrison Avenue
Entity Address, Address Line Two	Suite 900
Entity Address City Or Town	Boston
Entity Address State Or Province	MA
Entity Address Postal Zip Code	02118
City Area Code	617
Local Phone Number	949-2643
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 59,055	$ 54,912
Marketable securities	119,422	207,914
Other receivables	294	7,656
Prepaid expenses and other current assets	4,140	4,444
Current restricted cash	0	960
Total current assets	182,911	275,886
Property and equipment, net	34,992	27,075
Operating lease right-of-use assets	29,408	34,832
Restricted cash, net of current	4,522	4,318
Other long-term assets	270	278
Total assets	252,103	342,389
Current liabilities:
Accounts payable	5,500	7,862
Accrued expenses and other current liabilities	14,228	14,580
Current portion of operating lease liability	2,881	3,127
Total current liabilities	22,609	25,569
Defined benefit plan liability	1,453	1,533
Operating lease liability	43,517	43,874
Total liabilities	67,579	70,976
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.0001 par value, 10,000,000 shares authorized, no shares issued and outstanding	0	0
Common stock, $0.0001 par value; 500,000,000 shares authorized, 50,085,167 shares issued and 50,065,680 shares outstanding as of September 30, 2023; and 500,000,000 shares authorized, 49,445,802 shares issued and 49,323,531 shares outstanding as of December 31, 2022	5	5
Additional paid-in capital	518,610	503,696
Accumulated other comprehensive loss	(1,455)	(1,752)
Accumulated deficit	(332,636)	(230,536)
Total stockholders' equity	184,524	271,413
Total liabilities and stockholders' equity	$ 252,103	$ 342,389

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par or stated value per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares, issued	50,085,167	49,445,802
Common stock shares outstanding	50,065,680	49,323,531

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - 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	$ 28,306	$ 21,342	$ 84,137	$ 60,193
General and administrative	8,662	7,020	24,311	19,702
Total operating expenses	36,968	28,362	108,448	79,895
Loss from operations	(36,968)	(28,362)	(108,448)	(79,895)
Other income (expense):
Interest income	2,227	997	6,966	1,774
Foreign currency exchange gain (loss), net	27	63	(151)	293
Gain (loss) on disposal of fixed assets	0	(16)	24	109
Loss on sale of marketable securities	0	0	(131)	0
Total other income	2,254	1,044	6,708	2,176
Net loss before income taxes	(34,714)	(27,318)	(101,740)	(77,719)
Provision for income taxes	(170)	0	(360)	0
Net loss	$ (34,884)	$ (27,318)	$ (102,100)	$ (77,719)
Net loss per share attributable to common stockholders-basic	$ (0.7)	$ (0.58)	$ (2.06)	$ (1.67)
Net loss per share attributable to common stockholders-diluted	$ (0.7)	$ (0.58)	$ (2.06)	$ (1.67)
Weighted-average number of shares outstanding used in computing net loss per common share-basic	49,814,903	46,732,353	49,533,143	46,666,000
Weighted-average number of shares outstanding used in computing net loss per common share-diluted	49,814,903	46,732,353	49,533,143	46,666,000
Comprehensive loss:
Provision for pension benefit obligation	$ 14	$ 32	$ 42	$ 99
Unrealized gain (loss) on available-for-sale securities	171	(176)	255	(680)
Comprehensive loss	$ (34,699)	$ (27,462)	$ (101,803)	$ (78,300)

Condensed Combined and Consolid

Condensed Combined and Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance (in shares) beginning at Dec. 31, 2021		46,535,966
Balance beginning period at Dec. 31, 2021	$ 347,515	$ 5	$ 471,566	$ (2,021)	$ (122,035)
Restricted common stock vesting, Shares		34,505
Exercise of common stock options	153		153
Exercise of common stock options, Shares		60,240
Provision for pension benefit obligation	34			34
Stock-based compensation expense	2,251		2,251
Unrealized loss on available-for-sale securities	(146)			(146)
Net loss before income taxes	(23,932)				(23,932)
Balance end period at Mar. 31, 2022	325,875	$ 5	473,970	(2,133)	(145,967)
Balance (in shares) period end at Mar. 31, 2022		46,630,711
Balance (in shares) beginning at Dec. 31, 2021		46,535,966
Balance beginning period at Dec. 31, 2021	347,515	$ 5	471,566	(2,021)	(122,035)
Net loss before income taxes	(77,719)
Balance end period at Sep. 30, 2022	291,092	$ 5	493,443	(2,602)	(199,754)
Balance (in shares) period end at Sep. 30, 2022		48,372,781
Balance (in shares) beginning at Mar. 31, 2022		46,630,711
Balance beginning period at Mar. 31, 2022	325,875	$ 5	473,970	(2,133)	(145,967)
Restricted common stock vesting, Shares		34,508
Exercise of common stock options	96		96
Exercise of common stock options, Shares		19,439
Provision for pension benefit obligation	33			33
Stock-based compensation expense	2,873		2,873
Unrealized loss on available-for-sale securities	(358)			(358)
Net loss before income taxes	(26,469)				(26,469)
Balance end period at Jun. 30, 2022	302,050	$ 5	476,939	(2,458)	(172,436)
Balance (in shares) period end at Jun. 30, 2022		46,684,658
Restricted common stock vesting, Shares		33,850
Exercise of common stock options	79		79
Exercise of common stock options, Shares		16,047
Issuance of common stock, net of issuance costs Shares		$ 1,638,226
Provision for pension benefit obligation	32			32
Stock-based compensation expense	3,214		3,214
Unrealized loss on available-for-sale securities	(176)			(176)
Issuance of shares under employee stock purchase plan	13,211		13,211
Net loss before income taxes	(27,318)				(27,318)
Balance end period at Sep. 30, 2022	291,092	$ 5	493,443	(2,602)	(199,754)
Balance (in shares) period end at Sep. 30, 2022		48,372,781
Balance (in shares) beginning at Dec. 31, 2022		49,323,531
Balance beginning period at Dec. 31, 2022	271,413	$ 5	503,696	(1,752)	(230,536)
Restricted common stock vesting, Shares		33,192
Exercise of common stock options	18		18
Exercise of common stock options, Shares		4,261
Provision for pension benefit obligation	14			14
Stock-based compensation expense	3,974		3,974
Unrealized loss on available-for-sale securities	(345)			(345)
Net loss before income taxes	(32,038)				(32,038)
Balance end period at Mar. 31, 2023	243,726	$ 5	507,688	(1,393)	(262,574)
Balance (in shares) period end at Mar. 31, 2023		49,360,984
Balance (in shares) beginning at Dec. 31, 2022		49,323,531
Balance beginning period at Dec. 31, 2022	$ 271,413	$ 5	503,696	(1,752)	(230,536)
Exercise of common stock options, Shares	549,508
Net loss before income taxes	$ (102,100)
Balance end period at Sep. 30, 2023	184,524	$ 5	518,610	(1,455)	(332,636)
Balance (in shares) period end at Sep. 30, 2023		50,065,680
Balance (in shares) beginning at Mar. 31, 2023		49,360,984
Balance beginning period at Mar. 31, 2023	243,726	$ 5	507,688	(1,393)	(262,574)
Restricted common stock vesting, Shares		32,185
Exercise of common stock options	897		897
Exercise of common stock options, Shares		147,333
Issuance of shares under employee stock purchase plan, Shares		51,977
Provision for pension benefit obligation	14			14
Stock-based compensation expense	4,153		4,153
Unrealized loss on available-for-sale securities	(261)			(261)
Issuance of shares under employee stock purchase plan	303		303
Net loss before income taxes	(35,178)				(35,178)
Balance end period at Jun. 30, 2023	213,654	$ 5	513,041	(1,640)	(297,752)
Balance (in shares) period end at Jun. 30, 2023		49,592,479
Restricted common stock vesting, Shares		75,287
Exercise of common stock options	1,101		1,101
Exercise of common stock options, Shares		397,914
Provision for pension benefit obligation	14			14
Stock-based compensation expense	4,468		4,468
Unrealized loss on available-for-sale securities	(171)			(171)
Net loss before income taxes	(34,884)				(34,884)
Balance end period at Sep. 30, 2023	$ 184,524	$ 5	$ 518,610	$ (1,455)	$ (332,636)
Balance (in shares) period end at Sep. 30, 2023		50,065,680

Condensed Combined and Consol_2

Condensed Combined and Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands	3 Months Ended
	Sep. 30, 2022 USD ($)
Common Stock
Issuance of common stock, net of issuance costs of $714	$ 714

Condensed Combined and Consol_3

Condensed Combined and Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (102,100)	$ (77,719)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation expense	12,595	8,338
Depreciation	4,376	2,675
Noncash lease expense	0	3,202
Net accretion of discounts/premiums on marketable securities	(3,177)	(685)
Loss on sale of marketable securities	131	0
Gain on disposal of property and equipment	(24)	(109)
Changes in operating assets and liabilities
Other receivables	2,233	(177)
Prepaid expenses and other current assets	312	(2,122)
Accounts payable	(10)	(899)
Accrued expenses and other current liabilities	2,268	(1,041)
Defined benefit plan liability	(39)	50
Right-of-use assets and operating lease liabilities	9,999	(18)
Net cash used in operating activities	(73,436)	(68,505)
Cash flows from investing activities:
Purchases of property and equipment	(17,352)	(5,640)
Proceeds from sale of property and equipment	62	109
Purchases of marketable securities	(75,637)	(290,049)
Proceeds From Sale Of Marketable Securities	45,631	0
Proceeds From Maturity Of Marketable Securities	121,800	130,300
Net cash provided by (used in) investing activities	74,504	(165,280)
Cash flows from financing activities:
Proceeds from exercise of employee stock options	2,016	328
Proceeds from employee stock purchase plan	303	0
Payment of common stock issuance costs	0	(296)
Net cash provided by financing activities	2,319	32
Net (decrease) increase in cash, cash equivalents and restricted cash	3,387	(233,753)
Cash, cash equivalents and restricted cash—beginning of period	60,190	351,409
Cash, cash equivalents and restricted cash-end of period	63,577	117,656
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	59,055	112,394
Restricted cash	4,522	5,262
Total cash, cash equivalents and restricted cash	63,577	117,656
Supplemental disclosure of noncash items
Common stock issuance costs in accounts payable and accrued expenses		31
Aggregate gross proceeds		13,507
Reduction of right-of-use assets for lease incentives receivable	5,128	3,872
Purchases of property and equipment in accounts payable and accrued expenses	$ 1,270	$ 4,750

Description of Business, Contri

Description of Business, Contribution and Exchange, and Liquidity	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Description of Business, Contribution and Exchange, and Liquidity	1. Description of business and liquidity Business Monte Rosa Therapeutics, Inc. is a biotechnology company developing a portfolio of novel small molecule precision medicines that employ the body’s natural mechanisms to selectively degrade therapeutically-relevant proteins. As used in these condensed consolidated financial statements, unless the context otherwise requires, references to the Company or Monte Rosa refer to Monte Rosa Therapeutics, Inc. and its wholly owned subsidiaries Monte Rosa Therapeutics AG, or Monte Rosa AG, and Monte Rosa Therapeutics Securities Corp. Monte Rosa Therapeutics AG, a Swiss operating company, was incorporated under the laws of Switzerland in April 2018. Monte Rosa Therapeutics, Inc. was incorporated in Delaware in November 2019. The Company is headquartered in Boston, Massachusetts with research operations in both Boston and Basel, Switzerland. Liquidity considerations Since inception, the Company has devoted substantially all its efforts to business planning, research and development, recruiting management and technical staff, and raising capital and has financed its operations primarily through the issuance of convertible preferred shares and public offerings of the Company's common stock. The Company’s continued discovery and development of its product candidates will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. As of September 30, 2023, the Company had an accumulated deficit of $ 332.6 million. The Company has incurred losses and negative cash flows from operations since inception, including net losses of $ 102.1 million and $ 77.7 million for the nine months ended September 30, 2023 and 2022, respectively. The Company expects that its operating losses and negative cash flows will continue for the foreseeable future as the Company continues to develop its product candidates. The Company currently expects that its cash, cash equivalents, and marketable securities of $ 178.5 million as of September 30, 2023 will be sufficient to fund operating expenses and capital requirements for at least 12 months from the date the third quarter interim condensed consolidated financial statements are issued. However, additional funding will be necessary to fund future discovery research, pre-clinical and clinical activities. The Company will seek additional funding through public financings, debt financings, collaboration agreements, strategic alliances and licensing arrangements. Although it has been successful in raising capital in the past, there is no assurance that the Company will be successful in obtaining such additional financing on terms acceptable to it, if at all, and the Company may not be able to enter into collaborations or other arrangements. If the Company is unable to obtain funding, it could be forced to delay, reduce or eliminate its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect the Company’s business prospects, even the ability to continue operations.

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 Basis of presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the U.S., or GAAP, and are stated in U.S. dollars. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification and Accounting Standards Updates, or ASUs, of the Financial Accounting Standards Board, or FASB. All intercompany balances and transactions have been eliminated in consolidation. Unaudited Financial Information The Company’s condensed consolidated financial statements included herein have been prepared in conformity with GAAP and pursuant to the rules and regulations of the Securities and Exchange Commission, or the SEC. In the Company’s opinion, the information furnished 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. Recently issued accounting pronouncements The Company has elected to use the extended transition period for complying with new or revised accounting standards as available under the Jumpstart Our Business Startups Act, or the JOBS Act. 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 . ASU 2020-06 will simplify the accounting for convertible instruments by reducing the number of accounting models for convertible debt instruments and convertible preferred stock. Limiting the accounting models results in fewer embedded conversion features being separately recognized from the host contract as compared with current GAAP. Convertible instruments that continue to be subject to separation models are (i) those with embedded conversion features that are not clearly and closely related to the host contract, that meet the definition of a derivative, and that do not qualify for a scope exception from derivative accounting and (ii) convertible debt instruments issued with substantial premiums for which the premiums are recorded as paid-in capital. ASU 2020-06 also amends the guidance for the derivatives scope exception for contracts in an entity’s own equity to reduce form-over-substance-based accounting conclusions. ASU 2020-06 will be effective for the Company for fiscal years beginning after December 15, 2023. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. The Company is currently assessing the impact adoption of ASU 2020-06 will have on its financial statements and disclosures. Recently adopted accounting pronouncements On January 1, 2023, the Company adopted Accounting Standards Update No. 2016-13, Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments . ASU 2016-13 requires measurement and recognition of expected credit losses for financial assets. In April 2019, the FASB issued clarification to ASU 2016-13 within ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging , and Topic 825, Financial Instruments , or ASU 2016-13. The guidance is effective for fiscal years beginning after December 15, 2022. The adoption of the standard was immaterial to the accompanying condensed consolidated financial statements. \\\

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 and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): As of September 30, 2023 Level 1 Level 2 Level 3 Total Current assets Money market funds $ 58,434 $ — $ — $ 58,434 Pension plan assets — 5,862 — 5,862 Corporate debt securities — 114,454 — 114,454 U.S Treasury securities — 4,968 — 4,968 Total assets measured at fair value $ 58,434 $ 125,284 $ — $ 183,718 As of December 31, 2022 Level 1 Level 2 Level 3 Total Current assets Money market funds $ 50,633 $ — $ — $ 50,633 Pension plan assets — 5,320 — 5,320 Corporate debt securities — 127,351 — 127,351 U.S Treasury securities — 80,563 — 80,563 Total assets measured at fair value $ 50,633 $ 213,234 $ — $ 263,867 Money market funds are highly liquid investments and are actively traded. The pricing information on the Company’s money market funds are based on quoted prices in active markets for identical securities. This approach results in the classification of these securities as Level 1 of the fair value hierarchy. The fair value of pension plan assets has been determined as the surrender value of the portfolio of active insured members held within the Swiss Life Collective BVG Foundation collective investment fund and are classified within Level 2 of the fair value hierarchy. Marketable securities consist of corporate debt securities and U.S. Treasury securities which are classified as available-for-sale pursuant to ASC 320, Investments—Debt and Equity Securities . Marketable securities are classified within Level 2 of the fair value hierarchy because pricing inputs are other than quoted prices in active markets. The fair values of these investments are estimated by taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income- and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads, benchmark securities based on historical data and other observable inputs. There were no transfers among Level 1, Level 2 or Level 3 categories in the nine months ended September 30, 2023 and 2022 .

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	4. Marketable Securities Marketable securities as of September 30, 2023 consisted of the following (in thousands) : Amortized Unrealized Unrealized Fair Cost Gains Losses Value Description Corporate debt securities $ 114,624 $ 6 $ ( 176 ) 114,454 U.S Treasury securities 4,991 — ( 23 ) 4,968 Total $ 119,615 $ 6 $ ( 199 ) $ 119,422 Market securities as of December 31, 2022 consisted of the following (in thousands): Amortized Unrealized Unrealized Fair Cost Gains Losses Value Description Corporate debt securities $ 127,565 $ 27 $ ( 241 ) 127,351 U.S Treasury securities 80,798 2 ( 237 ) 80,563 Total $ 208,363 $ 29 $ ( 478 ) $ 207,914 As of September 30, 2023, the Company held 31 marketable securities, 20 of which were in an unrealized loss position. The aggregate fair value of securities in a loss position is $ 82.3 million. There were no individual securities that were in a significant unrealized loss position as of September 30, 2023. The Company evaluates securities for other-than-temporary impairments based on quantitative and qualitative factors, and considers the decline in market value as of September 30, 2023 , to be primarily attributable to the then current economic and market conditions. The Company neither intends to sell these investments nor concludes that it is more-likely-than-not that the Company will have to sell them before recovery of their carrying values. The Company also believes that it will be able to collect both principal and interest amounts due to it at maturity.

Property and Equipment, net

Property and Equipment, net	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, net	5. Property and Equipment, net Property and equipment, net, consist of the following (in thousands): September 30, December 31, Laboratory equipment $ 21,701 $ 17,766 Computer hardware and software 1,052 499 Furniture and fixtures 1,099 388 Leasehold improvements 20,794 2,660 Construction in process 744 12,013 Total property and equipment, at cost $ 45,390 $ 33,326 Less: accumulated depreciation ( 10,398 ) ( 6,251 ) Property and equipment, net $ 34,992 $ 27,075 The following table summarizes depreciation expense incurred (in thousands): Three months ended Nine months ended 2023 2022 2023 2022 Depreciation expense $ 1,834 $ 1,033 $ 4,376 $ 2,675

Accrued expenses and other curr

Accrued expenses and other current liabilities	9 Months Ended
	Sep. 30, 2023
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued Expenses And Other Current Liabilities	6. Accrued expenses and other current liabilities Accrued expenses and other current liabilities consist of the following (in thousands): September 30, December 31, 2023 2022 Compensation and benefits $ 6,145 $ 5,624 Accrued research and development 5,175 3,936 Other 2,908 5,020 Total other current liabilities $ 14,228 $ 14,580

Leases

Leases	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Leases	7. Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use, or ROU, assets and operating lease liabilities in the condensed consolidated balance sheets. The Company has no finance leases as of September 30, 2023. ROU assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As the Company’s leases do not provide an implicit rate, management estimated the incremental borrowing rate based on the rate of interest the Company would have to pay to borrow a similar amount on a collateralized basis over a similar term. The Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. Klybeck Lease In March 2021, the Company entered into an operating lease agreement for office and lab space with Wincasa AG, or the landlord, that occupies approximately 21,422 square feet located at Klybeckstrasse 191, 4057 Basel, Basel-City, Switzerland. In April 2023, the Company and the Landlord amended the Klybeck Lease which increased the office and lab space square footage from 21,422 square feet to 44,685 square feet and extended the term of the lease through June 30, 2027. The amendment was accounted for as a lease modification and resulted in an increases to the related ROU asset and operating lease liability of $ 1.8 million. Harrison Avenue Lease In December 2021, the Company entered into a non-cancelable lease agreement for 63,327 square feet of office and laboratory space to support its expanding operations, or the Harrison Avenue Lease. The term of the lease commenced on April 1, 2022 and the Company’s obligation to pay rent began on December 21, 2022, which resulted in noncash lease expense of $ 3.2 million for the nine months ended September 30, 2022 . The initial term of the lease is 128 months following the commencement date at which point the Company has the option to extend the lease an additional 5 years . As of the lease commencement date, the Company has determined that it is not reasonably certain to exercise the option to extend the lease and has not included the extension period in the lease term. The annual base rent under the Harrison Avenue Lease is $ 95.00 per square foot for the first year, which is subject to scheduled annual increases of 3 %, plus certain costs, operating expenses and property management fees. Pursuant to the terms of the Harrison Avenue Lease, the landlord will reimburse the Company for $ 13 million of tenant improvements. The Company will reduce the ROU asset and record an asset for construction in progress as costs are incurred and reimbursed. These costs were reclassified from construction in progress to leasehold improvements upon completion of the project. As of September 30, 2023, the Company had $ 0.1 million receivable in reimbursable tenant improvements which is recorded as an other receivable on the condensed consolidated balance sheet. The components of lease expense for the nine months ended September 30, 2023 are as follows (in thousands): Nine months ended 2023 2022 Operating lease expense $ 5,552 $ 4,857 Variable lease expense 1,700 1,128 Total lease expense $ 7,252 $ 5,985 The variable lease expenses generally include common area maintenance and property taxes. For nine months ended September 30, 2023, $ 6.2 million lease expense was recorded within research and development and $ 1.2 million lease expense was recorded within general and administrative in the condensed consolidated statements of operations and comprehensive loss. Short-term lease costs for the nine months ended September 30, 2023 were immaterial. The weighted average remaining lease term and discount rate related to the Company's leases are as follows: September 30, December 31, Weighted average remaining lease term (years) 8.9 9.7 Weighted average discount rate 9.8 % 9.9 % Supplemental cash flow information relating to the Company's leases for the nine months ended September 30, 2023 are as follows (in thousands): Nine months ended 2023 2022 Right-of-use assets obtained in exchange for operating lease obligations $ 1,871 $ 48,488 Cash paid for amounts included in the measurement of lease liabilities $ 2,382 $ 1,181 The amortization of the ROU assets for the nine months ended September 30, 2023 and 2022 was $ 2.0 million and $ 2.4 million, respectively. Future minimum lease payments under non-cancelable leases as of September 30, 2023 for each of the years ending December 31 are as follows (in thousands): Undiscounted lease payments Remaining 2023 $ 1,714 2024 7,373 2025 7,663 2026 7,863 2027 7,614 Thereafter 38,386 Total undiscounted minimum lease payments 70,613 Less: Imputed interest ( 24,215 ) Total operating lease liability $ 46,398

Commitments and contigencies

Commitments and contigencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and contingencies License, collaboration and investment agreements In April 2018, the Company entered into license, collaboration and investment agreements, or the License Agreement, with Cancer Research Technology Limited, or CRT, and The Institute of Cancer Research, or the ICR, for the purpose of development in the field of cereblon-mediated protein degradation, to support the Company’s early product development activities as the Company built its internal capabilities or the License and Collaboration. Pursuant to the License and Collaboration, CRT and the ICR granted the Company exclusive and non-exclusive, worldwide, and sublicensable licenses under CRT’s and the ICR’s intellection property rights in the field of cereblon mediated protein degradation to discover, research, develop, have developed, use, keep, make, have made, market, import, offer for sale, and sell products in the field of cereblon-mediated protein degradation. In consideration for the rights granted under the License Agreement, the Company issued an aggregate of 1,132,984 common shares to CRT, the ICR and affiliated founding scientists pursuant to the Formation and Investment Agreement and paid CRT a technology access fee. The License Agreement will remain effective until terminated by written agreement between the Company, CRT and the ICR. Upon execution of the License Agreement, the Company paid an immaterial access fee which was expensed to research and development in 2018. The research program conducted with the ICR with respect to cereblon-mediated protein degradation was completed as of December 31, 2020. However, the License and Collaboration Agreement continues until it is otherwise terminated under the terms and conditions stated within the agreement. There was no activity under this agreement for the three and nine months ended September 30, 2023. Under the License Agreement, the Company may be obligated to make certain milestone payments for achieving specific clinical progression events for certain products, solely to the extent such products are subject to the License and Collaboration. If owed, such milestones would aggregate up to $ 7 million for any covered first product candidate and $ 3.5 million for any covered subsequent product candidate. In addition, the Company may be obligated to pay low single-digit royalties on net sales for any covered product successfully developed and commercialized in the field of cereblon-mediated protein degradation under the terms of the License and Collaboration on a country by country basis until the later of (i) the date when the manufacture, use, offer for sale, sale or importation of such product is no longer covered by a valid claim in the country of sale, use or manufacture; (ii) ten years from the first commercial sale of such product in the relevant country; and (iii) the expiry of any extended exclusivity period granted with respect to an orphan drug designation, pediatric designation or other exclusivity in the relevant country. The License and Collaboration will remain effective until (i) the termination by either the Company or the ICR and CRT upon the bankruptcy or uncured breach of the other party, (ii) by the ICR and CRT if the Company should abandon all discovery, development and commercialization efforts for all products covered under the License and Collaboration; (iii) by the Company if it is determined the continued development of products covered under the License and Collaboration would be commercially unreasonable, scientifically unviable, illegal, unethical or impossible, with a 90-day notification period; or (iv) for any/no reason by written agreement of the Company and the ICR and CRT. Indemnification The Company, as permitted under Delaware law and in accordance with its certification of incorporation and bylaws and pursuant to indemnification agreements with certain of its officers and directors, indemnifies its officers and directors for certain events or occurrences, subject to certain limits, which the officer or director is or was serving at the Company’s request in such capacity. The Company enters into certain types of contracts that contingently require the Company to indemnify various parties against claims from third parties. These contracts primarily relate to (i) the Company’s bylaws, under which the Company must indemnify directors and executive officers, and may indemnify other officers and employees, for liabilities arising out of their relationship, (ii) contracts under which the Company must indemnify directors and certain officers and consultants for liabilities arising out of their relationship, and (iii) procurement, service or license agreements under which the Company may be required to indemnify vendors, service providers or licensees for certain claims, including claims that may be brought against them arising from the Company’s acts or omissions with respect to the Company’s products, technology, intellectual property or services. From time to time, the Company may receive indemnification claims under these contracts in the normal course of business. In the event that one or more of these matters were to result in a claim against the Company, an adverse outcome, including a judgment or settlement, may cause a material adverse effect on the Company’s future business, operating results or financial condition. As of September 30, 2023 , the Company was not aware of any claims under indemnification arrangements and does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible. Therefore, no related reserves have been established.

Equity

Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Equity	9. Equity Undesignated Preferred Stock The Company had 10,000,000 shares authorized of undesignated preferred stock, par value of $ 0.0001 , of which no shares were issued and outstanding as of September 30, 2023. Common Stock The Company had 500,000,000 shares of common stock authorized, of which 50,085,167 shares were issued and 50,065,680 shares were outstanding as of September 30, 2023. The holders of common stock are entitled to dividends when and if declared by the board of directors, subject to the preferences applicable to any outstanding shares of preferred stock. The board of directors has no t declared any dividends and the Company has no t paid any dividends. The holders of common stock are entitled to one vote per share on all matters to be voted upon by the stockholders. The Company has issued restricted stock to founders, employees and consultants, and expense for this restricted stock is recognized on a straight-line basis (see Note 10). The restricted stock generally vests monthly over 4 years . As of September 30, 2023, and December 31, 2022, the Company has reserved the following shares of common stock for the vesting of restricted stock and exercise of stock options: September 30, December 31, Options to purchase common stock 9,489,119 7,436,339 Unvested restricted common stock awards 19,487 122,271 Unvested restricted common stock units 250,265 91,000 9,758,871 7,649,610 At-the-Market Offering In July 2022, the Company entered into a sales agreement, or the Sales Agreement, with Jefferies LLC, or Jefferies, pursuant to which the Company may offer and sell shares of its common stock having aggregate gross proceeds of up to $ 100 million from time to time in “at-the-market” offerings through Jefferies, as the Company’s sales agent. The Company agreed to pay Jefferies a commission of up to 3.0 % of the gross proceeds of any shares sold by Jefferies under the Sales Agreement. During the nine months ended September 30, 2023 , the Company did no t sell shares of its common stock under the Sales Agreement. During the nine months ended September 30, 2022 , the Company sold 1,638,226 shares of common stock under the Sales Agreement for aggregate gross proceeds of $ 13.9 million, or aggregate net proceeds of $ 13.2 after deducting underwriter discounts and commissions and other offering costs. The proceeds from the ATM offering were receivable as of September 30, 2022 and the transaction was settled on October 5, 2022.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	10. Stock-based compensation 2020 Stock incentive plan The Company’s 2020 Stock Option and Grant Plan, or the 2020 Plan, provided for the Company to grant stock options, restricted stock and other stock awards, to employees, non-employee directors, and consultants. Upon the effectiveness of the 2021 Plan (as defined below), no further issuances were made under the 2020 Plan. 2021 Stock incentive plan The Company’s 2021 Stock Option and Incentive Plan, or the 2021 Plan, was approved by the Company’s board of directors on May 28, 2021 and the Company’s stockholders on June 17, 2021 and became effective on the date immediately prior to the date on which the registration statement for the Company’s IPO was declared effective. The 2021 Plan provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock units, restricted stock awards, unrestricted stock awards, cash-based awards and dividend equivalent rights to the Company’s officers, employees, directors and consultants. The number of shares initially reserved for issuance under the 2021 Plan was 4,903,145 . Under the evergreen provision of the 2021 Plan, the shares available for issuance under the 2021 Plan will be automatically increased each January 1st by 5 % of the outstanding number of shares of the Company’s common stock on the immediately preceding December 31st or such lesser number of shares as may be determined by the Company’s compensation, nomination and corporate governance committee. Effective January 1, 2023 the number of shares available under the 2021 Plan automatically increased by 2,466,176 shares pursuant to the evergreen provision of the 2021 Plan. As of September 30, 2023, 3,227,124 shares were available for issuance under the 2021 Plan. 2021 Employee stock purchase plan The Company’s 2021 Employee Stock Purchase Plan, or the 2021 ESPP, was approved by the Company’s board of directors on May 28, 2021 and the Company’s stockholders on June 17, 2021 and became effective on the date immediately prior to the date on which the registration statement for the Company’s IPO was declared effective. A total of 439,849 shares of the Company’s common stock were initially reserved for issuance under the 2021 ESPP. The shares available for issuance under the 2021 ESPP will be automatically increased on each January 1st, through January 1, 2031, by the least of (i) 439,849 shares of the Company’s common stock, (ii) 1 % of the outstanding number of shares of the Company’s common stock on the immediately preceding December 31st or (iii) such lesser number of shares of the Company’s common stock as determined by the plan administrator of the 2021 ESPP. Effective January 1, 2023 the number of shares available under the 2021 ESPP automatically increased by 439,849 shares pursuant to the evergreen provision of the 2021 ESPP. As of September 30, 2023, 1,215,623 shares were available for issuance under the 2021 ESPP. Stock option activity The following summarizes stock option activity: Number of Weighted Weighted Aggregate Outstanding—December 31, 2022 7,436,339 $ 9.14 8.5 $ 12,440 Granted 3,241,800 7.54 — — Exercised ( 549,508 ) 3.67 — — Forfeited ( 639,512 ) 8.37 — — Outstanding—September 30, 2023 9,489,119 $ 8.93 8.1 $ 3,401 Vested or expected to vest—September 30, 2023 9,489,119 $ 8.93 8.1 $ 3,401 Exercisable—September 30, 2023 3,700,455 $ 9.02 7.2 $ 2,452 The aggregate intrinsic value of options granted is calculated as the difference between the exercise price of the options and the estimated fair value of the Company’s common stock. Restricted stock award activity Unvested restricted stock awards were granted to employees under the 2020 Plan. Restricted stock awards generally vest over a four year period provided the individual remains in continuous service of the Company. The following summarizes restricted stock award activity: Number Weighted Unvested restricted stock as of December 31, 2022 122,271 $ 1.04 Vested ( 97,064 ) $ 0.75 Forfeited ( 5,720 ) $ 2.00 Unvested restricted stock as of September 30, 2023 19,487 $ 2.18 The aggregate fair value of restricted stock awards that vested during the nine months ended September 30, 2023 and 2022 was $ 0.2 million and $ 1.2 million, respectively. The weighted average grant date fair value of restricted stock awards that vested during the nine months ended September 30, 2023 and 2022 was $ 0.75 and $ 0.77 , respectively. Restricted stock unit activity Starting in 2022, the Company granted restricted stock units, or RSUs, to employees under the 2021 Plan. Each of the RSUs represents the right to receive one share of the Company’s common stock upon vesting. The RSUs will vest over two years provided the individual remains in continuous service of the Company. Accordingly, stock-based compensation expense for each RSU is recognized on a straight-line basis over the vesting term. The fair value of each RSU is based on the closing price of the Company’s common stock on the date of grant. The following summarizes restricted stock unit activity: Number Weighted Unvested restricted stock units as of December 31, 2022 91,000 $ 10.11 Granted 206,665 $ 7.55 Vested ( 43,600 ) $ 10.11 Forfeited ( 3,800 ) $ 10.11 Unvested as of September 30, 2023 250,265 $ 8.00 The aggregate fair value of restricted stock units that vested during the nine months ended September 30, 2023 was $ 0.3 million. The weighted average grant date fair value of restricted stock units that vested during nine months ended September 30, 2023 was $ 10.11 . No restricted stock units vested during the nine months ended September 30, 2022. Stock-based compensation expense Stock-based compensation expense is classified as follows (in thousands): Nine months ended 2023 2022 Research and development $ 6,729 $ 4,289 General and administrative 5,866 4,049 Total stock-based compensation expense $ 12,595 $ 8,338 As of September 30, 2023 total unrecognized stock–based compensation cost related to unvested stock options and restricted stock units was $ 33.1 million and $ 1.6 million, respectively. The Company expects to recognize this remaining cost over a weighted average period of 2.5 years and 1.5 years, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income taxes	11. Income taxes During the nine months ended September 30, 2023, the Company recorded an income tax provision of $ 0.4 million. The income tax provision is primarily related to interest income on marketable securities in Massachusetts and the US taxable income generated from the capitalization of research and development expenses. The Company did no t record a provision or benefit for income taxes during the nine months ended September 30, 2022. The Company continues to maintain a full valuation allowance against all of its deferred tax assets. The Company has evaluated the positive and negative evidence involving its ability to realize our deferred tax assets. The Company has considered its history of cumulative net losses incurred since inception and its lack of any commercial products. The Company has concluded that it is more likely than not that it will not realize the benefits of its deferred tax assets. The Company reevaluates the positive and negative evidence at each reporting period.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net Loss Per Common Share	12. Net loss per common share Basic and diluted net loss per share attributable to common stockholders is calculated as follows (in thousands except share and per share amounts): Three months ended Nine months ended 2023 2022 2023 2022 Net loss $ ( 34,884 ) $ ( 27,318 ) $ ( 102,100 ) $ ( 77,719 ) Net loss per share attributable to common stockholders—basic and diluted $ ( 0.70 ) $ ( 0.58 ) $ ( 2.06 ) $ ( 1.67 ) Weighted-average number of common shares used in computing net loss 49,814,903 46,732,353 49,533,143 46,666,000 The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per common share, as their effect is anti-dilutive: September 30, September 30, 2023 2022 Stock options to purchase common stock 9,489,119 7,207,043 Restricted common stock 19,487 155,466 Restricted stock units 250,265 91,000

Employee Retirement Plan

Employee Retirement Plan	9 Months Ended
	Sep. 30, 2023
Retirement Benefits [Abstract]
Employee Retirement Plan	13. Employee retirement plans The Company, in compliance with Swiss Law, is contracted with the Swiss Life Collective BVG Foundation for the provision of pension benefits in a defined benefit plan. All benefits are reinsured in their entirety with Swiss Life Ltd within the framework of the contract. The technical administration and management of the savings account are guaranteed by Swiss Life on behalf of the collective foundation. Insurance benefits due are paid directly to the entitled persons by Swiss Life in the name of and for the account of the collective foundation. The pension plan is financed by contributions of both employees and employer. The contract between the Company and the collective foundation can be terminated by either side. In the event of a termination, the Company would have an obligation to find alternative pension arrangements for its employees. Because there is no guarantee that the employee pension arrangements would be continued under the same conditions, there is a risk, albeit remote, that a pension obligation may fall on the Company. The pension assets are pooled for all affiliated companies; the investment of assets is done by the governing bodies of the collective foundation or by mandated parties. The risks of disability, death and longevity are reinsured in their entirety with Swiss Life Ltd. The following table summarizes pension expense incurred (in thousands): Three months ended Nine months ended 2023 2022 2023 2022 Pension expense $ 251 $ 210 $ 702 $ 612 In February 2021, the Company adopted a defined contribution plan intended to qualify under Section 401(k) of the Internal Revenue Code covering all eligible U.S. based employees of the Company. All employees are eligible to become participants of the plan immediately upon hire. Each active employee may elect, voluntarily, to contribute a percentage of their compensation to the plan each year, subject to certain limitations. The Company reserves the right, but is not obligated, to make additional contributions to this plan. The Company makes safe-harbor match contributions of 100 % of the first 4 % of each participant’s eligible compensation. The following table summarize 401(k) expense incurred (in thousands): Three months ended Nine months ended 2023 2022 2023 2022 401(k) expense $ 99 $ 72 $ 488 $ 407

Subsequent events

Subsequent events	9 Months Ended
	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent events	14. Subsequent events Collaboration and License Agreement On October 16, 2023, the Company entered into a Collaboration and License Agreement, or the Collaboration Agreement, with F. Hoffmann-La Roche Ltd and an affiliate, or Roche, for the discovery and development of molecular glue degraders against targets in cancer and neurological diseases. Under the Collaboration Agreement, the Company will lead the discovery and certain preclinical activities against multiple select targets. Following the completion of certain preclinical studies, Roche has the option to continue the further development and potential commercialization of compounds identified and generated under the collaboration and products containing such compounds at its sole responsibility and at its own cost. The initial scope of the arrangement is limited to a specified number of targets but may be expanded to include additional targets subject to certain conditions and additional compensation payable to the Company. Pursuant to the terms of the Collaboration Agreement, the Company granted to Roche an exclusive license to use certain of its platform technology for the exploitation of compounds and products discovered and developed under the arrangement The Company will receive an upfront payment of $ 50.0 million from Roche under the terms of the Collaboration Agreement. Additionally, the Company is eligible to receive contingent payments from Roche upon the occurrence of defined research, development, regulatory and sales-based events exceeding $ 3 billion. The Company is also entitled to tiered royalties on sales of products containing compounds identified and generated from activities conducted under the arrangement. The Collaboration Agreement term commences on the execution date and continues until no payment obligations remain, unless otherwise terminated earlier. Registered Direct Offering On October 30, 2023, the Company sold in a registered direct offering pursuant to a securities purchase agreement pre-funded warrants to purchase 10,000,400 shares of the Company’s common stock to an accredited investor at a purchase price of $ 2.4999 per pre-funded warrant for aggregate gross proceeds of $ 25.0 million, before paying estimated offering expenses. The pre-funded warrants are immediately exercisable at an exercise price of $ 0.0001 per share, and may be exercised at any time until the pre-funded warrants are exercised in full.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the U.S., or GAAP, and are stated in U.S. dollars. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification and Accounting Standards Updates, or ASUs, of the Financial Accounting Standards Board, or FASB. All intercompany balances and transactions have been eliminated in consolidation.
Liquidity Consideration	Liquidity considerations Since inception, the Company has devoted substantially all its efforts to business planning, research and development, recruiting management and technical staff, and raising capital and has financed its operations primarily through the issuance of convertible preferred shares and public offerings of the Company's common stock. The Company’s continued discovery and development of its product candidates will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. As of September 30, 2023, the Company had an accumulated deficit of $ 332.6 million. The Company has incurred losses and negative cash flows from operations since inception, including net losses of $ 102.1 million and $ 77.7 million for the nine months ended September 30, 2023 and 2022, respectively. The Company expects that its operating losses and negative cash flows will continue for the foreseeable future as the Company continues to develop its product candidates. The Company currently expects that its cash, cash equivalents, and marketable securities of $ 178.5 million as of September 30, 2023 will be sufficient to fund operating expenses and capital requirements for at least 12 months from the date the third quarter interim condensed consolidated financial statements are issued. However, additional funding will be necessary to fund future discovery research, pre-clinical and clinical activities. The Company will seek additional funding through public financings, debt financings, collaboration agreements, strategic alliances and licensing arrangements. Although it has been successful in raising capital in the past, there is no assurance that the Company will be successful in obtaining such additional financing on terms acceptable to it, if at all, and the Company may not be able to enter into collaborations or other arrangements. If the Company is unable to obtain funding, it could be forced to delay, reduce or eliminate its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect the Company’s business prospects, even the ability to continue operations.
Unaudited Financial Information	Unaudited Financial Information The Company’s condensed consolidated financial statements included herein have been prepared in conformity with GAAP and pursuant to the rules and regulations of the Securities and Exchange Commission, or the SEC. In the Company’s opinion, the information furnished 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.
Recently Issued Accounting Pronouncements	Recently issued accounting pronouncements The Company has elected to use the extended transition period for complying with new or revised accounting standards as available under the Jumpstart Our Business Startups Act, or the JOBS Act. 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 . ASU 2020-06 will simplify the accounting for convertible instruments by reducing the number of accounting models for convertible debt instruments and convertible preferred stock. Limiting the accounting models results in fewer embedded conversion features being separately recognized from the host contract as compared with current GAAP. Convertible instruments that continue to be subject to separation models are (i) those with embedded conversion features that are not clearly and closely related to the host contract, that meet the definition of a derivative, and that do not qualify for a scope exception from derivative accounting and (ii) convertible debt instruments issued with substantial premiums for which the premiums are recorded as paid-in capital. ASU 2020-06 also amends the guidance for the derivatives scope exception for contracts in an entity’s own equity to reduce form-over-substance-based accounting conclusions. ASU 2020-06 will be effective for the Company for fiscal years beginning after December 15, 2023. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. The Company is currently assessing the impact adoption of ASU 2020-06 will have on its financial statements and disclosures. Recently adopted accounting pronouncements On January 1, 2023, the Company adopted Accounting Standards Update No. 2016-13, Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments . ASU 2016-13 requires measurement and recognition of expected credit losses for financial assets. In April 2019, the FASB issued clarification to ASU 2016-13 within ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging , and Topic 825, Financial Instruments , or ASU 2016-13. The guidance is effective for fiscal years beginning after December 15, 2022. The adoption of the standard was immaterial to the accompanying condensed consolidated financial statements. \\\

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured On Recurring Basis	The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): As of September 30, 2023 Level 1 Level 2 Level 3 Total Current assets Money market funds $ 58,434 $ — $ — $ 58,434 Pension plan assets — 5,862 — 5,862 Corporate debt securities — 114,454 — 114,454 U.S Treasury securities — 4,968 — 4,968 Total assets measured at fair value $ 58,434 $ 125,284 $ — $ 183,718 As of December 31, 2022 Level 1 Level 2 Level 3 Total Current assets Money market funds $ 50,633 $ — $ — $ 50,633 Pension plan assets — 5,320 — 5,320 Corporate debt securities — 127,351 — 127,351 U.S Treasury securities — 80,563 — 80,563 Total assets measured at fair value $ 50,633 $ 213,234 $ — $ 263,867

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Marketable securities	Marketable securities as of September 30, 2023 consisted of the following (in thousands) : Amortized Unrealized Unrealized Fair Cost Gains Losses Value Description Corporate debt securities $ 114,624 $ 6 $ ( 176 ) 114,454 U.S Treasury securities 4,991 — ( 23 ) 4,968 Total $ 119,615 $ 6 $ ( 199 ) $ 119,422 Market securities as of December 31, 2022 consisted of the following (in thousands): Amortized Unrealized Unrealized Fair Cost Gains Losses Value Description Corporate debt securities $ 127,565 $ 27 $ ( 241 ) 127,351 U.S Treasury securities 80,798 2 ( 237 ) 80,563 Total $ 208,363 $ 29 $ ( 478 ) $ 207,914

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment, net, consist of the following (in thousands): September 30, December 31, Laboratory equipment $ 21,701 $ 17,766 Computer hardware and software 1,052 499 Furniture and fixtures 1,099 388 Leasehold improvements 20,794 2,660 Construction in process 744 12,013 Total property and equipment, at cost $ 45,390 $ 33,326 Less: accumulated depreciation ( 10,398 ) ( 6,251 ) Property and equipment, net $ 34,992 $ 27,075
Schedule of Depreciation Expense	The following table summarizes depreciation expense incurred (in thousands): Three months ended Nine months ended 2023 2022 2023 2022 Depreciation expense $ 1,834 $ 1,033 $ 4,376 $ 2,675

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	9 Months Ended
	Sep. 30, 2023
Accounts Payable and Accrued Liabilities, Current [Abstract]
Schedule Of Accrued Expenses And Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): September 30, December 31, 2023 2022 Compensation and benefits $ 6,145 $ 5,624 Accrued research and development 5,175 3,936 Other 2,908 5,020 Total other current liabilities $ 14,228 $ 14,580

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Summary of Lease Expense	The components of lease expense for the nine months ended September 30, 2023 are as follows (in thousands): Nine months ended 2023 2022 Operating lease expense $ 5,552 $ 4,857 Variable lease expense 1,700 1,128 Total lease expense $ 7,252 $ 5,985
Schedule of Lease Terms and Discount Rate	The weighted average remaining lease term and discount rate related to the Company's leases are as follows: September 30, December 31, Weighted average remaining lease term (years) 8.9 9.7 Weighted average discount rate 9.8 % 9.9 %
Schedule Of Supplemental Cash Flow Information Related To Leases	Supplemental cash flow information relating to the Company's leases for the nine months ended September 30, 2023 are as follows (in thousands): Nine months ended 2023 2022 Right-of-use assets obtained in exchange for operating lease obligations $ 1,871 $ 48,488 Cash paid for amounts included in the measurement of lease liabilities $ 2,382 $ 1,181
Schedule of Future Minimum Payments Under Non -cancelable Operating Leases	Future minimum lease payments under non-cancelable leases as of September 30, 2023 for each of the years ending December 31 are as follows (in thousands): Undiscounted lease payments Remaining 2023 $ 1,714 2024 7,373 2025 7,663 2026 7,863 2027 7,614 Thereafter 38,386 Total undiscounted minimum lease payments 70,613 Less: Imputed interest ( 24,215 ) Total operating lease liability $ 46,398

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Common Stock Reserved for Potential Conversion of Outstanding Preferred Stock, Vesting of Restricted Stock and Exercise of Stock Options	As of September 30, 2023, and December 31, 2022, the Company has reserved the following shares of common stock for the vesting of restricted stock and exercise of stock options: September 30, December 31, Options to purchase common stock 9,489,119 7,436,339 Unvested restricted common stock awards 19,487 122,271 Unvested restricted common stock units 250,265 91,000 9,758,871 7,649,610

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Stock Option Activity	The following summarizes stock option activity: Number of Weighted Weighted Aggregate Outstanding—December 31, 2022 7,436,339 $ 9.14 8.5 $ 12,440 Granted 3,241,800 7.54 — — Exercised ( 549,508 ) 3.67 — — Forfeited ( 639,512 ) 8.37 — — Outstanding—September 30, 2023 9,489,119 $ 8.93 8.1 $ 3,401 Vested or expected to vest—September 30, 2023 9,489,119 $ 8.93 8.1 $ 3,401 Exercisable—September 30, 2023 3,700,455 $ 9.02 7.2 $ 2,452
Schedule of Restricted Stock Award Activity	The following summarizes restricted stock award activity: Number Weighted Unvested restricted stock as of December 31, 2022 122,271 $ 1.04 Vested ( 97,064 ) $ 0.75 Forfeited ( 5,720 ) $ 2.00 Unvested restricted stock as of September 30, 2023 19,487 $ 2.18
Schedule of Restricted Stock Unit Activity	The following summarizes restricted stock unit activity: Number Weighted Unvested restricted stock units as of December 31, 2022 91,000 $ 10.11 Granted 206,665 $ 7.55 Vested ( 43,600 ) $ 10.11 Forfeited ( 3,800 ) $ 10.11 Unvested as of September 30, 2023 250,265 $ 8.00
Schedule of Stock Based Compensation Expense	Stock-based compensation expense is classified as follows (in thousands): Nine months ended 2023 2022 Research and development $ 6,729 $ 4,289 General and administrative 5,866 4,049 Total stock-based compensation expense $ 12,595 $ 8,338

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Basic and diluted net loss per share attributable to common stockholders is calculated as follows (in thousands except share and per share amounts): Three months ended Nine months ended 2023 2022 2023 2022 Net loss $ ( 34,884 ) $ ( 27,318 ) $ ( 102,100 ) $ ( 77,719 ) Net loss per share attributable to common stockholders—basic and diluted $ ( 0.70 ) $ ( 0.58 ) $ ( 2.06 ) $ ( 1.67 ) Weighted-average number of common shares used in computing net loss 49,814,903 46,732,353 49,533,143 46,666,000
Schedule of Antidilutive Securities Excluded from Earnings Per Share Calculation	The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per common share, as their effect is anti-dilutive: September 30, September 30, 2023 2022 Stock options to purchase common stock 9,489,119 7,207,043 Restricted common stock 19,487 155,466 Restricted stock units 250,265 91,000

Employee retirement plans (Tabl

Employee retirement plans (Tables)	9 Months Ended
	Sep. 30, 2023
Retirement Benefits [Abstract]
Schedule of pension expense incurred	The following table summarizes pension expense incurred (in thousands): Three months ended Nine months ended 2023 2022 2023 2022 Pension expense $ 251 $ 210 $ 702 $ 612
Schedule of 401(k) expense incurred	The following table summarize 401(k) expense incurred (in thousands): Three months ended Nine months ended 2023 2022 2023 2022 401(k) expense $ 99 $ 72 $ 488 $ 407

Description of Business, Cont_2

Description of Business, Contribution and Exchange, and Liquidity - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended						9 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
Subsidiary Or Equity Method Investee [Line Items]
Restricted Cash and Cash Equivalents	$ 178,500						$ 178,500
Accumulated deficit	(332,636)						(332,636)		$ (230,536)
Net loss before income taxes	$ (34,884)	$ (35,178)	$ (32,038)	$ (27,318)	$ (26,469)	$ (23,932)	$ (102,100)	$ (77,719)

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets
Total assets measured at fair value	$ 183,718	$ 263,867
Level 1 [Member]
Current assets
Total assets measured at fair value	58,434	50,633
Level 2 [Member]
Current assets
Total assets measured at fair value	125,284	213,234
Level 3 [Member]
Current assets
Total assets measured at fair value	0	0
US Treasury Securities Member
Current assets
Total assets measured at fair value	4,968	80,563
US Treasury Securities Member | Level 1 [Member]
Current assets
Total assets measured at fair value	0	0
US Treasury Securities Member | Level 2 [Member]
Current assets
Total assets measured at fair value	4,968	80,563
US Treasury Securities Member | Level 3 [Member]
Current assets
Total assets measured at fair value	0	0
Money Market Funds [Member]
Current assets
Total assets measured at fair value	58,434	50,633
Money Market Funds [Member] | Level 1 [Member]
Current assets
Total assets measured at fair value	58,434	50,633
Money Market Funds [Member] | Level 2 [Member]
Current assets
Total assets measured at fair value	0	0
Money Market Funds [Member] | Level 3 [Member]
Current assets
Total assets measured at fair value	0	0
Pension Plan Assets [Member]
Current assets
Total assets measured at fair value	5,862	5,320
Pension Plan Assets [Member] | Level 1 [Member]
Current assets
Total assets measured at fair value	0	0
Pension Plan Assets [Member] | Level 2 [Member]
Current assets
Total assets measured at fair value	5,862	5,320
Pension Plan Assets [Member] | Level 3 [Member]
Current assets
Total assets measured at fair value	0	0
Corporate Debt Securities Member
Current assets
Total assets measured at fair value	114,454	127,351
Corporate Debt Securities Member | Level 1 [Member]
Current assets
Total assets measured at fair value	0	0
Corporate Debt Securities Member | Level 2 [Member]
Current assets
Total assets measured at fair value	114,454	127,351
Corporate Debt Securities Member | Level 3 [Member]
Current assets
Total assets measured at fair value	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Measure at fair value, transfers among Level 1, Level 2 or Level 3	$ 0	$ 0

Marketable Securities (Addition

Marketable Securities (Additional Information) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($) Security
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Available-for-Sale, Unrealized Loss Position | $	$ 82.3
Number of marketable securities held | Security	31

Marketable Securities - Summary

Marketable Securities - Summary of Marketable securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
Amortized Cost	$ 119,615	$ 208,363
Unrealized Gains	6	29
Unrealized Losses	(199)	(478)
Fair Value	119,422	207,914
Corporate Debt Securities Member
Marketable Securities [Line Items]
Amortized Cost	114,624	127,565
Unrealized Gains	6	27
Unrealized Losses	(176)	(241)
Fair Value	114,454	127,351
US Treasury Securities Member
Marketable Securities [Line Items]
Amortized Cost	4,991	80,798
Unrealized Gains	0	2
Unrealized Losses	(23)	(237)
Fair Value	$ 4,968	$ 80,563

Property and Equipment, net - S

Property and Equipment, net - Schedule of Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Total property and equipment, at cost	$ 45,390	$ 33,326
Less: accumulated depreciation	(10,398)	(6,251)
Property and equipment, net	34,992	27,075
Laboratory Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, at cost	21,701	17,766
Computer Hardware and Software
Property Plant And Equipment [Line Items]
Total property and equipment, at cost	1,052	499
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment, at cost	1,099	388
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment, at cost	20,794	2,660
Construction in process
Property Plant And Equipment [Line Items]
Total property and equipment, at cost	$ 744	$ 12,013

Property and Equipment, net -_2

Property and Equipment, net - Schedule of Depreciation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 1,834	$ 1,033	$ 4,376	$ 2,675

Accrued expenses and other cu_3

Accrued expenses and other current liabilities - Summery Of Accrued Expenses And Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accounts Payable and Accrued Liabilities, Current [Abstract]
Compensation and benefits	$ 6,145	$ 5,624
Accrued research and development	5,175	3,936
Other	2,908	5,020
Accrued expenses and other current liabilities	$ 14,228	$ 14,580

Leases (Additional Information)

Leases (Additional Information) (Details)		1 Months Ended	9 Months Ended
	Dec. 14, 2021 USD ($) ft²	Apr. 30, 2023 USD ($) ft²	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Mar. 01, 2021 ft²
Lessee, Lease, Description [Line Items]
Finance Lease			$ 0
Amortization of the ROU assets			2,000,000	$ 2,400,000
Noncash lease expense			0	3,202,000
Tenant improvements			13,000,000
Receivable in Tenant Improvements			100,000
Research and Development
Lessee, Lease, Description [Line Items]
Short-Term Lease			6,200,000
General and Administrative
Lessee, Lease, Description [Line Items]
Short-Term Lease			$ 1,200,000
Hochbergerstrasse [Member]
Lessee, Lease, Description [Line Items]
Land Subject to Ground Leases | ft²					21,422
Right of Use Assets Decreased Limit, Amount		$ 1,800,000
Hochbergerstrasse [Member] | Maximum [Member]
Lessee, Lease, Description [Line Items]
Land Subject to Ground Leases | ft²		44,685
Hochbergerstrasse [Member] | Minimum [Member]
Lessee, Lease, Description [Line Items]
Land Subject to Ground Leases | ft²		21,422
Harrison Street [Member]
Lessee, Lease, Description [Line Items]
Noncash lease expense				$ 3,200,000
Land Subject to Ground Leases | ft²	63,327
Lease commencement date	Apr. 01, 2022
Initial lease term	128 months
Renewal term	5 years
Lease annual base rent per square foot	$ 95
Increase in annual base rent (Percentage)	3%

Leases - Summary of Lease Expen

Leases - Summary of Lease Expense (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Leases [Abstract]
Operating lease expense	$ 5,552	$ 4,857
Variable lease expense	1,700	1,128
Total lease expense	$ 7,252	$ 5,985

Leases - Schedule of Lease Term

Leases - Schedule of Lease Terms and Discount Rate (Details)	Sep. 30, 2023	Dec. 31, 2022
Leases [Abstract]
Weighted average remaining lease term (years)	8 years 10 months 24 days	9 years 8 months 12 days
Weighted average discount rate	9.80%	9.90%

Leases - Schedule Of Supplement

Leases - Schedule Of Supplemental Cash Flow Information Related To Leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Leases [Abstract]
Right-of-use assets obtained in exchange for operating lease obligations	$ 1,871	$ 48,488
Cash paid for amounts included in the measurement of lease liabilities	$ 2,382	$ 1,181

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Payments Under Non -cancelable Operating Leases (Details) - Non-cancelable leases [Member] $ in Thousands	Sep. 30, 2023 USD ($)
Finite-Lived Intangible Assets [Line Items]
Remaining 2023	$ 1,714
2024	7,373
2025	7,663
2026	7,863
2027	7,614
Thereafter	38,386
Total undiscounted minimum lease payments	70,613
Less: Imputed interest	(24,215)
Total operating lease liability	$ 46,398

Commitments and Contingencies (

Commitments and Contingencies (Additional Information) (Details) - USD ($) $ in Millions	Apr. 30, 2018	Sep. 30, 2023	Dec. 31, 2022
Common stock, shares, issued		50,085,167	49,445,802
Maximum [Member]
Milestone Payments, Maximum	$ 7
CRT
Common stock, shares, issued	1,132,984
Milestone Payments	$ 3.5

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Details) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock price per share	$ 0.0001	$ 0.0001
Preferred stock shares issued	0	0

Equity - Additional Information

Equity - Additional Information (Details) - USD ($)		9 Months Ended
	Jul. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Class of Stock [Line Items]
Common stock, shares authorized		500,000,000		500,000,000
Common stock shares issued		50,085,167		49,445,802
Preferred stock, shares authorized		10,000,000		10,000,000
Common stock, shares, issued during the period		0
Preferred stock, par value		$ 0.0001		$ 0.0001
Preferred stock shares issued		0		0
Preferred stock, shares outstanding		0		0
Common stock shares outstanding		50,065,680		49,323,531
Dividends declared		$ 0
Dividends paid		$ 0
Common stock, voting rights		one
Unvested Restricted Common Stock Awards
Class of Stock [Line Items]
Vesting term		4 years
Jefferies LLC [Member]
Class of Stock [Line Items]
Common stock, shares, issued during the period			1,638,226
Percentage of Commission payable to Related Party	3%
Offering Costs			$ 13,200,000
Gross Proceeds from sale of Common Stock	$ 100,000,000		$ 13,900,000
Undesignated Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized		10,000,000
Preferred stock, par value		$ 0.0001
Preferred stock shares issued		0
Preferred stock, shares outstanding		0

Equity - Schedule of Common Sto

Equity - Schedule of Common Stock for Potential Conversion Outstanding Preferred Stock (Details) - shares	Sep. 30, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Common stock reserved for future issuance	9,758,871	7,649,610
Options to Purchase Common Stock
Class Of Stock [Line Items]
Common stock reserved for future issuance	9,489,119	7,436,339
Unvested Restricted Common Stock Awards
Class Of Stock [Line Items]
Common stock reserved for future issuance	19,487	122,271
Unvested restricted common stock units
Class Of Stock [Line Items]
Common stock reserved for future issuance	250,265	91,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Jan. 01, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance	9,758,871		7,649,610
Restricted common stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate fair value of restricted stock vested	$ 0.2	$ 1.2
Weighted average grant fair value, granted	$ 0.75	$ 0.77
Unrecognized stock based compensation cost, units	$ 1.6
Expected remaining cost, weighted average period, units	1 year 6 months
Unvested Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock based compensation cost	$ 33.1
Expected remaining cost, weighted average period	2 years 6 months
Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate fair value of restricted stock vested	$ 0.3
Weighted average grant fair value, granted	$ 10.11
2021 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance				4,903,145
Increase in share percentage	5%
Number of share increase	2,466,176
Shares Issued	3,227,124
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance	439,849
Increase in share percentage	1%
Number of share increase	439,849
Shares Issued	1,215,623

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock Option Activity (Details) $ / 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 Payment Arrangement [Abstract]
Number of options, beginning balance | shares	7,436,339
Number of options, granted | shares	3,241,800
Number of options, exercised | shares	(549,508)
Number of shares, forfeited | shares	(639,512)
Number of options, ending balance | shares	9,489,119	7,436,339
Number of options, vested or expected to vest | shares	9,489,119
Number of options, exercisable | shares	3,700,455
Weighted average exercise price, beginning balance | $ / shares	$ 9.14
Weighted average exercise price, granted | $ / shares	7.54
Weighted average exercise price, exercised | $ / shares	3.67
Weighted average exercise price, forfeited | $ / shares	8.37
Weighted average exercise price, ending balance | $ / shares	8.93	$ 9.14
Weighted average exercise price, vested or expected to vest | $ / shares	8.93
Weighted average exercise price, exercisable | $ / shares	$ 9.02
Weighted average remaining contractual term (years), balance	8 years 1 month 6 days	8 years 6 months
Weighted average remaining contractual term (years), vested or expected to vest	8 years 1 month 6 days
Weighted average remaining contractual term (years), exercisable	7 years 2 months 12 days
Aggregate intrinsic value, beginning balance | $	$ 12,440
Aggregate intrinsic value, ending balance | $	3,401	$ 12,440
Aggregate intrinsic value, vested or expected to vest | $	3,401
Aggregate intrinsic value, exercisable | $	$ 2,452

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Restricted Stock Award Activity (Details) - Restricted common stock	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares, Unvested restricted stock, beginning balance | shares	122,271
Number of shares, Vested | shares	(97,064)
Number of shares, Forfeited | shares	(5,720)
Number of shares, Unvested, ending balance | shares	19,487
Weighted average grant date fair value, beginning balance | $ / shares	$ 1.04
Weighted average grant date fair value, vested | $ / shares	0.75
Weighted average grant date fair value, Forfeited | $ / shares	2
Weighted average grant date fair value, ending balance | $ / shares	$ 2.18

Stock-based compensation - Sc_3

Stock-based compensation - Schedule of Restricted Stock Unit Activity (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares, forfeited	(639,512)
Restricted stock units
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares, Unvested restricted stock, beginning balance	91,000
Number of shares, Granted	206,665
Number of shares, Vested	(43,600)
Number of shares, forfeited	(3,800)
Number of shares, Unvested, ending balance	250,265
Weighted average grant date fair value, beginning balance | $ / shares	$ 10.11
Weighted average grant date fair value, Granted | $ / shares	7.55
Weighted average grant date fair value, Vested | $ / shares	10.11
Weighted average grant date fair value, Forfeited | $ / shares	10.11
Weighted average grant date fair value, ending balance | $ / shares	$ 8

Stock-Based Compensation - Sc_4

Stock-Based Compensation - Schedule of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 12,595	$ 8,338
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	6,729	4,289
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 5,866	$ 4,049

Income taxes - Additional Infor

Income taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Provision for income taxes	$ 170	$ 0	$ 360	$ 0
Interest Income [Member]
Provision for income taxes			$ 400

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 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
Earnings Per Share [Abstract]
Net loss before income taxes	$ (34,884)	$ (35,178)	$ (32,038)	$ (27,318)	$ (26,469)	$ (23,932)	$ (102,100)	$ (77,719)
Net loss per share attributable to common stockholders-basic	$ (0.7)			$ (0.58)			$ (2.06)	$ (1.67)
Net loss per share attributable to common stockholders-diluted	$ (0.7)			$ (0.58)			$ (2.06)	$ (1.67)
Weighted-average number of common shares used in computing net loss per share-basic	49,814,903			46,732,353			49,533,143	46,666,000
Weighted-average number of common shares used in computing net loss per share-diluted	49,814,903			46,732,353			49,533,143	46,666,000

Net Loss Per Share - Schedule_2

Net Loss Per Share - Schedule of Anti-Dilutive Shares Excluded from Earnings Per Share Calculation (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of EPS	9,489,119	7,207,043
Restricted common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of EPS	19,487	155,466
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of EPS	250,265	91,000

Employee Retirement Plan - Addi

Employee Retirement Plan - Additional Information (Details)	9 Months Ended
	Sep. 30, 2023
Retirement Benefits [Abstract]
Percentage of company's matching contribution with respect to each participant's contribution	4%
Company matching contributions to maximum employees eligible compensation	100%

Employee retirement plans - Sch

Employee retirement plans - Schedule of Pension Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Retirement Benefits [Abstract]
Pension expense	$ 251	$ 210	$ 702	$ 612

Employee retirement plans - S_2

Employee retirement plans - Schedule of expense incurred (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Retirement Benefits [Abstract]
401 (K) expense	$ 99	$ 72	$ 488	$ 407

Subsequent events (Additional I

Subsequent events (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Thousands			9 Months Ended
	Oct. 30, 2023	Oct. 16, 2023	Sep. 30, 2022
Subsequent Event [Line Items]
Aggregate gross proceeds			$ 13,507
Subsequent Event | Collaboration and License Agreement
Subsequent Event [Line Items]
Initial multiple targets an upfront payment		$ 50,000
Contingent payments, Received		$ 3,000,000
Subsequent Event | Securities purchase agreement
Subsequent Event [Line Items]
Pre-funded warrants to purchase	10,000,400
Aggregate gross proceeds	$ 25,000
Pre-funded warrants exercisable, exercise price	$ 0.0001
Common stock, purchase price	$ 2.4999