0001628280-24-033882 | 10-Q | XBRL Viewer

Loss per share (Tables)

6 Months Ended

Jun. 30, 2024

Schedule of diluted net loss per share attributable to common stockholders

The Company excluded the following potential common shares presented based on amounts outstanding at period end from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:


	As of June 30,
	2024	2023
Anti-dilutive common stock equivalents:
Options to purchase common stock	11,645,100	7,929,853

Total anti-dilutive common stock equivalents	11,645,100	7,929,853

Schedule of basic and diluted loss per share

Basic and diluted loss per share is computed by dividing net loss by the weighted-average common shares outstanding for the three and six months ended June 30, 2024 and 2023 (in thousands, except share and per share data):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Numerator:
Net loss	$	(17,716)	$	(35,922)	$	(46,077)	$	(70,702)
Denominator:
Weighted-average number of shares used in computed net loss per share − basic and diluted	68,810,259		49,063,631		68,621,214		49,048,062
Net loss per share − basic and diluted	$	(0.26)	$	(0.73)	$	(0.67)	$	(1.44)

Property and equipment

6 Months Ended

Jun. 30, 2024

Property, Plant and Equipment [Abstract]

Property and equipment

Property and equipment consisted of the following (in thousands):


	June 30, 2024		December 31, 2023
Property and equipment:
Laboratory equipment	$	8,212	$	8,042
Leasehold improvements	4,712		4,712
Furniture and fixtures	1,435		1,422
Office equipment	621		621

Computer equipment	98		98
Total property and equipment	15,078		14,895
Less: accumulated depreciation	(8,507)		(7,763)
Total property and equipment, net	$	6,571	$	7,132

Depreciation expense related to property and equipment is as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Depreciation expense	$	296	$	458	$	744	$	1,003

Cover - shares	6 Months Ended
Cover - shares	Jun. 30, 2024	Jul. 30, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
Document Transition Report	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity File Number	001-39567
Entity Registrant Name	C4 Therapeutics, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-5617627
Entity Address, Address Line One	490 Arsenal Way
Entity Address, Address Line Two	Suite 120
Entity Address, City or Town	Watertown
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02472
City Area Code	617
Local Phone Number	231-0700
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	CCCC
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		69,337,753
Entity Central Index Key	0001662579
Amendment Flag	false

Stock-based compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended	6 Months Ended
	Mar. 07, 2024	Jun. 30, 2024	Jun. 30, 2024
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted (in shares)			3,055,807
Stock options granted, weighted average exercise price (in dollars per share)			$ 6.95
Stock options granted, weighted average grant date fair value (in dollars per share)			$ 5.70
2020 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, weighted average exercise price (in dollars per share)	$ 22.00
New exercise price per share, tranche one (in dollars per share)	19.00
New exercise price per share, tranche two (in dollars per share)	$ 11.88
Share-based payment arrangement, plan modification, incremental cost		$ 0.4	$ 0.5
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs		50.1	$ 50.1
Expected to be recognized over a weighted average period			2 years 4 months 24 days
Performance-based RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs		$ 3.0	$ 3.0
Units vested (in shares)			0
Share-based compensation, number of common stock issuable per RSU vested (in shares)		1	1
Time-based RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs		$ 9.7	$ 9.7
Expected to be recognized over a weighted average period			3 years 3 months 18 days
Units vested (in shares)			136,837
Granted (in shares)			1,013,350
Number of shares retained to cover statutory minimum withholding taxes (in shares)			15,321

Stock-based compensation - Schedule of stock-based compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 6,381	$ 6,425	$ 12,596	$ 12,676
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	2,465	2,644	4,702	5,227
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 3,916	$ 3,781	$ 7,894	$ 7,449

Accrued expenses and other current liabilities

6 Months Ended

Jun. 30, 2024

Payables and Accruals [Abstract]

Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	June 30, 2024		December 31, 2023
Accrued expenses and other current liabilities:
Accrued research and development	$	5,268	$	11,243
Accrued compensation and benefits	3,642		7,344
Other	2,293		2,043
Total accrued expenses and other current liabilities	$	11,203	$	20,630

Stock-based compensation

6 Months Ended

Jun. 30, 2024

Share-Based Payment Arrangement [Abstract]

Stock-based compensation

Stock-based compensation expense for the three and six months ended June 30, 2024 and 2023 was classified in the Company’s condensed consolidated statement of operations and comprehensive loss as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Stock-based compensation expense:
Research and development	$	2,465	$	2,644	$	4,702	$	5,227
General and administrative	3,916		3,781		7,894		7,449
Total stock-based compensation expense	$	6,381	$	6,425	$	12,596	$	12,676

Stock options

During the six months ended June 30, 2024, the Company granted stock options for the purchase of 3,055,807 shares of common stock with a weighted average exercise price of $6.95 per share and a weighted average grant-date fair value of $5.70 per shares. As of June 30, 2024, the unrecognized compensation cost related to outstanding stock options was $50.1 million, which is expected to be recognized over a weighted-average period of 2.4 years.

On March 7, 2024, the Company approved an option repricing program applicable to outstanding option awards granted to current employees of the Company under the Company’s 2020 Stock Option and Incentive Plan, or the 2020 Plan, with an exercise price per share greater than or equal to $22.00. The repriced awards have new exercise prices of $11.88 per share for awards held by employees generally and $19.00 per share for awards held by members of the Company's senior leadership team. To receive the benefit of this reduced exercise price, holders of repriced option awards must not, prior to March 7, 2025, (i) voluntarily leave employment with the Company or (ii) exercise the repriced options. The repriced options otherwise remain on their existing terms and conditions as set forth in the 2020 Plan and applicable award agreements. During the three and six months ended June 30, 2024, the Company recorded an incremental non-cash charge of $0.4 million and $0.5 million related to this option repricing.

Performance-based restricted stock units

During the six months ended June 30, 2024, the Company did not grant any performance-based restricted stock units, or PSUs. In addition, no PSUs vested during the six months ended June 30, 2024 upon their respective achievement of performance-based vesting criteria. Upon vesting, each PSU automatically converts into one share of the Company’s common stock. As of June 30, 2024, the unrecognized compensation cost related to outstanding PSUs with performance-based vesting criteria that are considered not probable of achievement was $3.0 million.

Time-based restricted stock units

During the six months ended June 30, 2024, the Company issued 1,013,350 restricted stock units, or RSUs, that were subject to time-based vesting conditions to its employees. These RSUs are valued on the grant date using the grant date market price of the underlying shares. A total of 136,837 RSUs vested during the six months ended June 30, 2024 upon their respective vesting schedules. Upon vesting, each RSU automatically converts into one share of the Company’s common stock. The Company indirectly repurchased 15,321 shares of its common stock through net-share settlement as consideration for employee tax withholding obligations arising upon vesting of the RSUs, which tax amounts were remitted to the applicable revenue authorities by the Company in cash on behalf of the RSU holders. As of June 30, 2024, the unrecognized compensation cost related to outstanding RSUs was $9.7 million, which is expected to be recognized over a weighted-average period of 3.3 years.

Marketable securities

6 Months Ended

Jun. 30, 2024

Marketable Securities [Abstract]

Marketable securities

Marketable securities as of June 30, 2024 consisted of the following (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Marketable securities, current:
Corporate debt securities	$	151,683	$	1	$	(330)	$	151,354
U.S. Treasury securities	27,739		—		(15)		27,724
U.S. government debt securities	11,929		—		(23)		11,906
Marketable securities, non-current:
Corporate debt securities	29,360		7		(77)		29,290
U.S. government debt securities	2,350		—		(3)		2,347

Total marketable securities, current and non-current	$	223,061	$	8	$	(448)	$	222,621

Marketable securities as of December 31, 2023 consisted of the following (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Marketable securities, current:
Corporate debt securities	$	100,903	$	16	$	(221)	$	100,698
U.S. government debt securities	20,457		14		(43)		20,428
U.S. Treasury securities	5,965		1		—		5,966
Marketable securities, non-current:
Corporate debt securities	27,901		120		(14)		28,007


Total marketable securities, current and non-current	$	155,226	$	151	$	(278)	$	155,099

Marketable securities classified as current have maturities of less than one year and are classified as available-for-sale. Marketable securities classified as non-current are those that: (i) have a maturity of greater than one year, and (ii) are not intended to be liquidated within the next twelve months, although these funds are available for use and, therefore, are

classified as available-for-sale. No available-for-sale debt securities held as of June 30, 2024 or December 31, 2023 had remaining maturities greater than five years.

Based on factors such as historical experience, market data, issuer-specific factors, and current economic conditions, the Company did not record an allowance for credit losses at June 30, 2024 and December 31, 2023, related to these securities.

Marketable securities (Tables)

6 Months Ended

Jun. 30, 2024

Marketable Securities [Abstract]

Summary of marketable securities

Marketable securities as of June 30, 2024 consisted of the following (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Marketable securities, current:
Corporate debt securities	$	151,683	$	1	$	(330)	$	151,354
U.S. Treasury securities	27,739		—		(15)		27,724
U.S. government debt securities	11,929		—		(23)		11,906
Marketable securities, non-current:
Corporate debt securities	29,360		7		(77)		29,290
U.S. government debt securities	2,350		—		(3)		2,347

Total marketable securities, current and non-current	$	223,061	$	8	$	(448)	$	222,621

Marketable securities as of December 31, 2023 consisted of the following (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Marketable securities, current:
Corporate debt securities	$	100,903	$	16	$	(221)	$	100,698
U.S. government debt securities	20,457		14		(43)		20,428
U.S. Treasury securities	5,965		1		—		5,966
Marketable securities, non-current:
Corporate debt securities	27,901		120		(14)		28,007


Total marketable securities, current and non-current	$	155,226	$	151	$	(278)	$	155,099

Collaboration and license agreements - Schedule of supplemental financial information related to collaboration and license agreements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue recognized that was included in the contract liability at the beginning of the period	$ 2,065	$ 2,664	$ 5,003	$ 5,895

Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Stock Purchase Agreement	At-The-Market	Common Stock	Common Stock Stock Purchase Agreement	Common Stock At-The-Market	Additional Paid-In Capital	Additional Paid-In Capital Stock Purchase Agreement	Additional Paid-In Capital At-The-Market	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2022				48,966,216
Beginning balance at Dec. 31, 2022	$ 289,234			$ 5			$ 689,256			$ (4,137)	$ (395,890)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)				11,759
Issuance of common stock upon exercise of stock options	56						56
Issuance of common stock upon vesting of restricted stock units, net of shares repurchased for tax withholding (in shares)				48,730
Issuance of common stock upon vesting of restricted stock units, net of shares repurchased for tax withholding	(94)						(94)
Issuances of common stock under 2020 ESPP (in shares)				20,748
Issuance of common stock under 2020 ESPP	104						104
Stock-based compensation	6,251						6,251
Change in unrealized loss, net on marketable securities	1,667									1,667
Net loss	(34,780)										(34,780)
Other (in shares)				5,056
Other	32						32
Ending balance (in shares) at Mar. 31, 2023				49,052,509
Ending balance at Mar. 31, 2023	262,470			$ 5			695,605			(2,470)	(430,670)
Beginning balance (in shares) at Dec. 31, 2022				48,966,216
Beginning balance at Dec. 31, 2022	289,234			$ 5			689,256			(4,137)	(395,890)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in unrealized loss, net on marketable securities	2,363
Net loss	(70,702)
Ending balance (in shares) at Jun. 30, 2023				49,065,098
Ending balance at Jun. 30, 2023	233,707			$ 5			702,068			(1,774)	(466,592)
Beginning balance (in shares) at Mar. 31, 2023				49,052,509
Beginning balance at Mar. 31, 2023	262,470			$ 5			695,605			(2,470)	(430,670)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)				1,337
Issuance of common stock upon exercise of stock options	2						2
Stock-based compensation	6,425						6,425
Change in unrealized loss, net on marketable securities	696									696
Net loss	(35,922)										(35,922)
Other (in shares)				11,252
Other	36						36
Ending balance (in shares) at Jun. 30, 2023				49,065,098
Ending balance at Jun. 30, 2023	233,707			$ 5			702,068			(1,774)	(466,592)
Beginning balance (in shares) at Dec. 31, 2023				60,467,188
Beginning balance at Dec. 31, 2023	246,114			$ 6			774,618			(127)	(528,383)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net (in shares)					5,567,928	2,500,601
Issuance of common stock, net		$ 20,000	$ 14,089		$ 1			$ 19,999	$ 14,089
Issuance of common stock upon exercise of stock options (in shares)				80,936
Issuance of common stock upon exercise of stock options	519						519
Issuance of common stock upon vesting of restricted stock units, net of shares repurchased for tax withholding (in shares)				121,516
Issuance of common stock upon vesting of restricted stock units, net of shares repurchased for tax withholding	(109)						(109)
Issuances of common stock under 2020 ESPP (in shares)				34,902
Issuance of common stock under 2020 ESPP	84						84
Stock-based compensation	6,215						6,215
Change in unrealized loss, net on marketable securities	(253)									(253)
Net loss	(28,361)										(28,361)
Other (in shares)				5,520
Other	(16)						(16)
Ending balance (in shares) at Mar. 31, 2024				68,778,591
Ending balance at Mar. 31, 2024	258,282			$ 7			815,399			(380)	(556,744)
Beginning balance (in shares) at Dec. 31, 2023				60,467,188
Beginning balance at Dec. 31, 2023	246,114			$ 6			774,618			(127)	(528,383)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in unrealized loss, net on marketable securities	(313)
Net loss	(46,077)
Ending balance (in shares) at Jun. 30, 2024				68,815,642
Ending balance at Jun. 30, 2024	247,058			$ 7			821,951			(440)	(574,460)
Beginning balance (in shares) at Mar. 31, 2024				68,778,591
Beginning balance at Mar. 31, 2024	258,282			$ 7			815,399			(380)	(556,744)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)				32,607
Issuance of common stock upon exercise of stock options	135						135
Stock-based compensation	6,381						6,381
Change in unrealized loss, net on marketable securities	(60)									(60)
Net loss	(17,716)										(17,716)
Other (in shares)				4,444
Other	36						36
Ending balance (in shares) at Jun. 30, 2024				68,815,642
Ending balance at Jun. 30, 2024	$ 247,058			$ 7			$ 821,951			$ (440)	$ (574,460)

Marketable securities - Narrative (Details) - USD ($)	Jun. 30, 2024	Dec. 31, 2023
Marketable Securities [Abstract]
Allowance for credit loss	$ 0	$ 0

Stockholder's equity (Details) - At-The-Market - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended	32 Months Ended
	Mar. 31, 2024	Jun. 30, 2024	Jun. 30, 2024	Nov. 30, 2021
Subsidiary, Sale of Stock [Line Items]
Issuance and sale of common stock	$ 14,089
Equity Distribution Agreement with Cowen and Company, LLC
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)		2,500,601
Sale of stock, consideration received on transaction		$ 14,100
Issuance of common stock, net (in shares)			13,686,743
Price per share (in dollars per share)		$ 5.42	$ 5.42
Issuance and sale of common stock			$ 71,900
Maximum \| Equity Distribution Agreement with Cowen and Company, LLC
Subsidiary, Sale of Stock [Line Items]
Sale of stock, value authorized for sale				$ 200,000

Summary of significant accounting policies	6 Months Ended
Summary of significant accounting policies	Jun. 30, 2024
Accounting Policies [Abstract]
Summary of significant accounting policies	Summary of significant accounting policies Basis of presentation and consolidation The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America, or U.S. GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or the SEC, regarding interim financial reporting, and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These condensed consolidated financial statements include the accounts of C4 Therapeutics, Inc. and its subsidiary, C4T Securities Corporation. All intercompany balances and transactions have been eliminated in consolidation. Unaudited interim financial information The accompanying condensed consolidated balance sheet as of June 30, 2024, the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2024 and 2023, the condensed consolidated statements of stockholders’ equity for the three and six months ended June 30, 2024 and 2023, and the condensed consolidated statements of cash flows for the six months ended June 30, 2024 and 2023, and the related interim disclosures are unaudited. These unaudited condensed consolidated financial statements include all adjustments necessary, consisting of only normal recurring adjustments, to fairly state the financial position and the results of the Company’s operations and cash flows for interim periods in accordance with U.S. GAAP. Interim period results are not necessarily indicative of results of operations or cash flows for a full year or any subsequent interim period. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements as of and for year ended December 31, 2023, and notes thereto, which are included in the Company’s 2023 Annual Report on Form 10-K that was filed with the SEC on February 22, 2024, or the 2023 Annual Report. Use of estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. This process may result in actual results differing materially from those estimated amounts used in the preparation of the condensed consolidated financial statements if these results differ from historical experience or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, amounts and timing of revenues recognized under the Company’s research and development collaboration arrangements, prepaid and accrued research and development expense, incremental borrowing rate used in the measurement of lease liabilities, and estimated volatility used in fair valuation of stock options. The Company assesses estimates on an ongoing basis; however, actual results could materially differ from those estimates. Significant accounting policies The Company’s significant accounting policies are disclosed in the audited condensed consolidated financial statements for the year ended December 31, 2023, which are included in the Company’s 2023 Annual Report on Form 10-K that was filed with the SEC on February 22, 2024. Since the date of those condensed consolidated financial statements, there have been no material changes to the Company’s significant accounting policies.

Loss per share

6 Months Ended

Jun. 30, 2024

Earnings Per Share [Abstract]

Loss per share

For periods in which the Company reports a net loss attributable to common stockholders, potentially dilutive securities have been excluded from the computation of diluted net loss per share as their effects would be anti-dilutive. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share is the same. For purposes of the dilutive net loss per share calculation, stock options, and restricted stock units for which the performance or market vesting conditions have been met are considered to be common stock equivalents, while restricted stock units with performance or market vesting conditions that were not met as of June 30, 2024 are not considered to be common stock equivalents. The Company excluded the following potential common shares presented based on amounts outstanding at period end from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:


	As of June 30,
	2024	2023
Anti-dilutive common stock equivalents:
Options to purchase common stock	11,645,100	7,929,853

Total anti-dilutive common stock equivalents	11,645,100	7,929,853


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Numerator:
Net loss	$	(17,716)	$	(35,922)	$	(46,077)	$	(70,702)
Denominator:
Weighted-average number of shares used in computed net loss per share − basic and diluted	68,810,259		49,063,631		68,621,214		49,048,062
Net loss per share − basic and diluted	$	(0.26)	$	(0.73)	$	(0.67)	$	(1.44)

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Revenue from collaboration agreements	$ 12,006	$ 2,664	$ 15,045	$ 6,423
Operating expenses:
Research and development	23,753	29,926	46,286	58,968
General and administrative	9,695	10,306	19,983	21,251
Restructuring	0	0	2,437	0
Total operating expenses	33,448	40,232	68,706	80,219
Loss from operations	(21,442)	(37,568)	(53,661)	(73,796)
Other income, net:
Interest expense and amortization of long-term debt − related party	0	(600)	0	(1,206)
Interest and other income, net	3,726	2,246	7,584	4,300
Total other income (expense), net	3,726	1,646	7,584	3,094
Loss before income taxes	(17,716)	(35,922)	(46,077)	(70,702)
Income tax expense	0	0	0	0
Net loss	$ (17,716)	$ (35,922)	$ (46,077)	$ (70,702)
Net loss per share − basic (in dollars per share)	$ (0.26)	$ (0.73)	$ (0.67)	$ (1.44)
Net loss per share − diluted (in dollars per share)	$ (0.26)	$ (0.73)	$ (0.67)	$ (1.44)
Weighted-average number of shares used in computed net loss per share − basic	68,810,259	49,063,631	68,621,214	49,048,062
Weighted-average number of shares used in computed net loss per share − diluted	68,810,259	49,063,631	68,621,214	49,048,062
Other comprehensive income (loss)
Unrealized (loss) gain on marketable securities	$ (60)	$ 696	$ (313)	$ 2,363
Comprehensive loss	$ (17,776)	$ (35,226)	$ (46,390)	$ (68,339)
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]			Collaborative Arrangement [Member]	Collaborative Arrangement [Member]

Collaboration and license agreements - Narrative (Details) $ / shares in Units, $ in Thousands					1 Months Ended						3 Months Ended		6 Months Ended		40 Months Ended
	Jun. 30, 2024 USD ($) target performanceObligation	Mar. 01, 2024 USD ($) target	Dec. 11, 2023 USD ($) target performanceObligation	May 29, 2023 USD ($) $ / shares shares	Apr. 30, 2024 USD ($)	Aug. 31, 2021 USD ($)	Nov. 30, 2020 USD ($) target	Feb. 29, 2020 USD ($) protein	Dec. 31, 2018 USD ($) target performanceObligation	Mar. 31, 2017 USD ($)	Jun. 30, 2024 USD ($) target performanceObligation	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) target performanceObligation	Jun. 30, 2023 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2023 USD ($) target
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of performance obligations \| performanceObligation									12
Contract with customer, liability	$ 53,502										$ 53,502		$ 53,502			$ 37,285
Revenue from collaboration agreements											12,006	$ 2,664	15,045	$ 6,423
Revenue recognized that was included in the contract liability at the beginning of the period											2,065	2,664	5,003	5,895
Transaction price allocated to performance obligation	$ 19,064										$ 19,064		19,064
Foreign Tax Authority
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payments for tax withholdings													$ 1,200
MKDG Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of potential research and development targets \| target	2	2									2		2
Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of agreement				90 days
MKDG Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment		$ 16,000
Number of performance obligations \| performanceObligation	2										2		2
Contract with customer, liability	$ 15,219										$ 15,219		$ 15,219
Revenue from collaboration agreements											1,894	0	1,949	0
Transaction price allocated to performance obligation	16,000										16,000		16,000
MKDG Agreement \| Discovery, Regulatory, and Commercial Milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive	740,000										740,000		740,000
MKDG Agreement \| Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of agreement		60 days
Merck Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment			$ 10,000
Number of performance obligations \| performanceObligation			1
Contract with customer, liability	8,253										8,253		8,253			10,000
Option to include number of additional targets \| target			3
Potential proceeds from collaboration			$ 2,500,000
Revenue from collaboration agreements											1,102	$ 0	1,747	$ 0
Merck Agreement \| Research and development milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive			$ 600,000
Merck Agreement \| Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of agreement			60 days
Betta Agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment	10,000			$ 10,000									15,800
Contract with customer, liability	17,000										$ 17,000		$ 17,000			$ 12,000
Stock repurchase program, number of shares authorized to be repurchased (in shares) \| shares				5,567,928
Stock repurchase program, authorized amount				$ 25,000
Share price (in dollars per share) \| $ / shares				$ 4.49
Transaction price from closing of the stock purchase agreement	5,000
Regulatory milestone achieved	$ 2,000
Stock repurchase program, premium percentage				25.00%
Duration of trading day volume weighted average closing price				60 days
Trading days prior to the effective date of the Stock Purchase Agreement				2 days
Betta Agreements \| Research and development milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive				$ 357,000
Betta Agreements \| Drug Application Approval
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive				$ 40,000
Restated Roche Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of targets \| target							2									2
Additional upfront consideration received									$ 40,000
Number of potential targets \| target							5		6
Annual research plan payments receivables							$ 1,000
Option exercise fees							$ 8,000
Restated Roche Agreement \| Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of agreement							90 days
Restated Roche Agreement \| Maximum \| Research, development and commercial milestone payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive							$ 273,000
Restated Roche Agreement \| Maximum \| One-time sales-based payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive							150,000
Restated Roche Agreement \| Lead series identification achievement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fees							$ 2,000
Biogen Research and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of targets \| performanceObligation	5										5		5
Research agreement, period								54 months
Nonrefundable upfront payment								$ 45,000
Revenue recognized that was included in the contract liability at the beginning of the period					$ 8,000
Number of performance obligation \| performanceObligation	1										1		1
Biogen Research and License Agreement \| Research and development services
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized that was included in the contract liability at the beginning of the period													$ 55,000
Biogen Research and License Agreement \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of targeted protein degradation \| protein								5
Biogen Research and License Agreement \| Maximum \| Research and development milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received								$ 35,000
Biogen Research and License Agreement \| Maximum \| One-time sales-based payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received								$ 26,000
Calico License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment															$ 5,000
Research term										5 years
Research extend term						1 year
Amount payable for extend research term option						$ 1,000
Annual payments															$ 5,000
Calico License Agreement \| Maximum \| One-time sales-based payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received										$ 65,000
Calico License Agreement \| Maximum \| Potential research, development and commercial milestone payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received										$ 132,000
Restated Roche Agreement And Biogen License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price allocated to performance obligation	$ 57,100										$ 57,100		$ 57,100

Collaboration and license agreements

6 Months Ended

Jun. 30, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Collaboration and license agreements

MKDG Collaboration and License Agreement

On March 1, 2024, the Company entered into a license and collaboration agreement with MKDG, or the MKDG Agreement, to discover two targeted protein degraders against critical oncogenic proteins.

Under the terms of the MKDG Agreement, the Company grants MKDG a worldwide, exclusive license under certain of the Company's intellectual property rights to develop, manufacture, and commercialize two targeted protein degraders against critical oncogenic proteins. MKDG is responsible for all development, regulatory approval, manufacturing and commercialization costs. Under the terms of the MKDG Agreement, MKDG agreed to make an upfront cash payment of $16.0 million and to fund the Company's discovery research efforts. The Company is eligible to receive approximately $740 million in the aggregate in discovery, regulatory, and commercial milestone payments across the collaboration, plus

tiered royalties on net sales. Royalties payable from MKDG to the Company range from mid-single digit to low-double digit percent, subject to reductions under certain circumstances as described in the MKDG Agreement.

The collaboration is managed by a joint research committee, or MKDG JRC, and a joint steering committee, or MKDG JSC, each of which is comprised of representatives of MKDG and the Company. Under the MKDG Agreement, MKDG has final decision-making authority over the JSC, which has the authority to decide matters that cannot be resolved by the JRC. MKDG may terminate the MKDG Agreement on a project-by-project basis or in its entirety upon 60 days’ prior written notice. Each party also has various termination rights under certain circumstances, including but not limited to patent challenges, insolvency, or a material breach by the other party, subject to certain conditions.

MKDG Agreement Accounting

The Company identified two performance obligations at the outset of the MKDG Agreement, represented by the two potential research and development targets. While the Company is obligated under the MKDG Agreement to provide the exclusive license and perform certain research activities, the Company determined that the license, the research activities, and participation on the MKDG JRC and MKDG JSC are considered promised services. Participation on the MKDG JRC and MKDG JSC to oversee the research activities contemplated under the MKDG Agreement were determined to be quantitatively and qualitatively immaterial and, therefore, were excluded from the performance obligations. The total transaction price of the MKDG Agreement is allocated to the performance obligations based on their relative standalone selling price. The Company recognizes the transaction price allocated to the performance obligations as the research and development services are provided, using an input method, in proportion to costs incurred to date for each research development target as compared to total costs incurred and expected to be incurred in the future to satisfy the underlying obligation. Incremental fees for research and development services are paid at agreed upon FTE rates and recognized as revenue in the period incurred.

As of June 30, 2024, the total transaction price of $16.0 million is allocated to the two performance obligations and $15.2 million remains unsatisfied.

Amounts due to the Company that have not yet been received are recorded as accounts receivable and amounts received that have not yet been recognized as revenue are recorded in deferred revenue on the Company’s condensed consolidated balance sheet.

Merck License and Collaboration Agreement

On December 11, 2023, the Company entered into an exclusive license and collaboration agreement with Merck, or the Merck Agreement, to develop degrader-antibody conjugates, or DACs, an emerging modality designed to selectively target and neutralize disease-causing proteins in cancer cells.

Under the terms of the Merck Agreement, the Company received a $10.0 million upfront payment. The Company and Merck will collaborate to develop DACs directed to an initial undisclosed oncology target that is exclusive to the collaboration. For DACs directed to this initial target, the Company is eligible to receive milestone payments totaling approximately $600 million, as well as tiered royalties on future sales. The agreement also provides Merck with the option to extend the collaboration to include three additional targets that would be exclusive to the collaboration, which could yield option exercise payments as well as potential milestones and royalties. If Merck exercises all of its options to extend the collaboration, the Company would be eligible to receive up to approximately $2.5 billion in potential payments across the entire collaboration.

The collaboration is managed by a joint research committee, or Merck JRC, which is comprised of representatives from both Merck and the Company. Merck may terminate the Merck Agreement, in its entirety or as to a given target, for convenience upon at least 60 days’ prior notice. Each party also has various termination rights under certain circumstances, including but not limited to regulatory safety stoppages, patent challenges, insolvency, or a material breach by the other party, subject to certain conditions.

Merck Agreement Accounting

The Company identified one performance obligation at the outset of the Merck Agreement, which consists of: (1) the exclusive license and (2) the research activities for the initial undisclosed oncology target and the joint research plan. The Company determined that the license and research activities were not distinct from one another, as the license has limited value without the performance of the research activities by the Company. Participation on the Merck JRC to oversee the research activities and the technology transfer associated with the Merck Agreement were determined to be quantitatively and qualitatively immaterial and therefore are excluded from performance obligations. The Company recognizes the transaction price allocated to this performance obligation as the research and development services are provided, using an input method, in proportion to costs incurred to date for each research development target as compared to total costs

incurred and expected to be incurred in the future to satisfy the underlying obligation. The transfer of control occurs over this period and, in management’s judgment, is the best measure of progress towards satisfying the performance obligation.

As of June 30, 2024, the total transaction price of $10.0 million is allocated to the research and development services performance obligation and $8.3 million of the allocated transaction price remains unsatisfied.

Amounts due to the Company that have not yet been received are recorded as accounts receivable and amounts received that have not yet been recognized as revenue are recorded as deferred revenue on the Company’s consolidated balance sheet.

Betta Pharma License and Collaboration Agreement

On May 29, 2023, the Company entered into a license and collaboration agreement, or the Betta Pharma License Agreement, with Betta Pharma to collaborate on the development and commercialization of CFT8919 in Greater China, comprised of mainland China, Hong Kong SAR, Macau SAR and Taiwan, with the Company retaining rights to CFT8919 in the rest of the world other than Greater China, or the C4T Territory.

Under the terms of the Betta Pharma License Agreement, the Company grants Betta Pharma an exclusive license under certain of the Company's intellectual property rights to develop, manufacture and commercialize CFT8919 for all uses in humans in Greater China. Betta Pharma is responsible for all development, regulatory approval, manufacturing and commercialization costs in Greater China except where Betta Pharma acts as the Company's agent in Greater China in connection with a global trial sponsored by the Company. As part of the collaboration, Betta Pharma made an upfront cash payment of $10.0 million to the Company and has agreed to make up to $357.0 million in aggregate milestone payments, plus tiered royalties on net sales of CFT8919 in Greater China. These payments are subject to a withholding tax by the State Taxing Authority of the People's Republic of China. Royalties payable from Betta Pharma to the Company range from low to mid double-digit percent, subject to certain reductions under certain circumstances as described in the Betta Pharma License Agreement. In addition, as part of the collaboration, the Company has agreed to make milestone payments to Betta Pharma of up to $40.0 million following the Company's receipt of approval of a New Drug Application for CFT8919 from the FDA, with the milestone amount based on the percentage of patients in contemplated clinical trials that were enrolled by Betta Pharma and the line of therapy of the approval. In addition, the Company has agreed to pay Betta Pharma tiered royalties on net sales of CFT8919 in the C4T Territory in the low single digit percent range, subject to reductions under certain circumstances as described in the Betta Pharma License Agreement.

In connection with the execution of the Betta Pharma License Agreement, the Company, Betta Pharma, and an affiliate of Betta Pharma, (Betta Investment (Hong Kong) Limited, or Betta Investment), entered into a stock purchase agreement dated May 29, 2023, or the Betta Stock Purchase Agreement, and together with the Betta Pharma License Agreement, or the Betta Agreements, pursuant to which Betta Investment agreed to purchase 5,567,928 shares of the Company's common stock, or the Shares, for an aggregate purchase price of approximately $25.0 million, or $4.49 per share, which represented a 25% premium over the 60-trading-day volume weighted average closing price as of two trading days prior to the effective date of the Betta Stock Purchase Agreement. The Betta Stock Purchase Agreement has certain restrictions customary to agreements of this nature. The closing under the Betta Stock Purchase Agreement occurred on January 4, 2024.

The collaboration is managed by a joint steering committee, which is composed of representatives from both Betta Pharma and the Company. Following the completion of the dose escalation phase of the Phase 1 trial of CFT8919, Betta Pharma may terminate the Betta Pharma License Agreement for convenience upon at least 90 days’ prior written notice. Each party also has various termination rights under certain circumstances, including but not limited to regulatory safety stoppages, patent challenges, insolvency, or a material breach by the other party, subject to certain conditions.

Betta Agreements accounting

The Company expects to recognize revenue under the Betta Agreements from one type of arrangement, the licensing agreement. The Betta Agreements will consist of the following activities: (1) license of intellectual property, (2) clinical manufacturing supply agreement, and (3) manufacturing technology transfer, and (4) commercial manufacturing supply agreement. As of June 30, 2024, the total transaction price is currently $17.0 million, consisting of the $10.0 million upfront cash consideration, $5.0 million from the closing of the Betta Stock Purchase Agreement, and a $2.0 million milestone achieved in December 2023 under the Betta Pharma License Agreement. Revenue recognition associated with the Betta Agreements is expected to commence upon the delivery of clinical supply under the clinical manufacturing supply agreement, which has not been executed as of June 30, 2024. The Company has collected a net amount of $15.8 million from the upfront payment from Betta Pharma, after making the related withholding tax payment of $1.2 million to

the Chinese tax authorities. No revenue has been recognized as of June 30, 2024, in respect of the transaction price allocated to the Betta Agreements.

Roche Collaboration and License Agreement

In March 2016, the Company entered into a license agreement with Roche, which was amended in June 2016 and again in March 2017. The Company and Roche amended and restated that agreement (as so amended) in December 2018. This amended and restated agreement is referred to as the Roche Agreement. Under the Roche Agreement, the Company and Roche agreed to collaborate in the research, development, manufacture and commercialization of target-binding degrader medicines using the Company’s proprietary TORPEDO platform for the treatment of cancers and other indications. Under the Roche Agreement, the Company may elect to opt into certain co-development rights, in which case the Company will receive an increased royalty rate on future product sales from products directed to that target. In addition, if the Company opts into certain co-detailing rights, it is also entitled to reimbursement of certain commercialization costs. Upon entry into the Roche Agreement, the Company received additional upfront consideration of $40.0 million.

In November 2020, the Company signed a further amendment, the effect of which was to provide that the parties would develop up to five potential targets, with Roche maintaining its option rights to license and commercialize products directed to those targets. The November 2020 amendment also provides a mechanism through which the Company and Roche can mutually agree to terminate the Roche Agreement on a target-by-target basis by the entry into a Mutual Target Termination Agreement. Upon the entry into a Mutual Target Termination Agreement, the Roche Agreement provides that all rights and responsibilities for know-how and other intellectual property in support of products that use inhibition as their mode of action revert to Roche and all rights and responsibilities for know-how and other intellectual property in support of products that use degradation as their mode of action revert to the Company. In support of this allocation of rights, Roche provides the Company, and the Company provides Roche, with a perpetual irrevocable, fully paid up, exclusive (even as to party granting the license), sublicensable (including in multiple tiers) license to the patents and know-how that are allocated to a party under a Mutual Target Termination Agreement. As the research activities with Roche have progressed and evolved over time, there are now two targets on which the parties continue to collaborate, with Roche maintaining its option rights to license and commercialize products directed to those two targets. In December 2023, the Company signed a second amendment to the Roche Agreement, the effect of which was to update the terms of the agreement as it pertains to the two targets on which the parties continue to collaborate. Under the second amendment to the Roche Agreement, Roche retains its option rights to license and commercialize products directed to those targets but the timing of its option rights are adjusted to begin upon Roche's receipt of the dose range finding data package. There was no material impact to the accounting in 2023 as a result of the second amendment to the Roche Agreement.

Under the Roche Agreement, as amended, the Company receives annual research plan payments of $1.0 million for each active research plan. For the two targets that remain under collaboration among the parties, Roche is required to pay the Company fees of $2.0 million upon the progression of targets to the lead series identification achievement phase. In the event Roche exercises its option rights as to one of these targets, Roche is required to pay the Company an option exercise fee of $8.0 million.

Under the Roche Agreement, as amended, for each target option exercised by Roche, the Company is eligible to receive milestone payments up to $273.0 million upon the achievement of certain development milestones with respect to corresponding products, subject to certain reductions and exclusions based on intellectual property coverage. Roche is also required to pay the Company up to $150.0 million per target in one-time sales-based milestone payments upon the achievement of specified levels of net sales of a product directed to such target. Finally, Roche is required to pay the Company tiered royalties ranging from the mid-single digits to mid-teen percentages on net sales of products sold by Roche pursuant to its exercise of its option rights, subject to certain reductions. For sales of products for which the Company exercises its co-development right, the applicable royalty rates will be increased by a low-single digit percentage.

The collaboration is managed by a joint research committee, or Roche JRC. The Company has control over the Roche JRC prior to Roche’s exercise of its option rights as to a particular target, with Roche assuming control of the Roche JRC thereafter, Roche may terminate the Roche Agreement on a target-by-target or product-by-product basis under several scenarios, upon at least 90 days’ prior written notice. Each party also has various termination rights under certain circumstances, including but not limited to insolvency or a material breach by the other party, subject to certain conditions.

Roche Agreement accounting

At commencement, the Company identified twelve performance obligations within the Roche Agreement, represented by the six potential research and development targets then included in the collaboration and the option rights held by Roche

for each of those six targets. A non-exclusive royalty-free license to use the Company’s intellectual property to conduct research and development activities and participation on Roche JRC were identified as promised services. However, the Company determined that the research and development license and research and development services were not distinct from one another, and participation on the Roche JRC was determined to be quantitatively and qualitatively immaterial.

The total transaction price of the Roche Agreement is allocated to the performance obligations based on their relative standalone selling price. The allocated transaction price is recognized as revenue from collaboration agreements in one of two ways:

•Research and development targets: The Company recognizes the portion of the transaction price allocated to each of the research and development performance obligations as the research and development services are provided, using an input method, in proportion to costs incurred to date for each research development target as compared to total costs incurred and expected to be incurred in the future to satisfy the underlying obligation related to said research and development target. The transfer of control occurs over this period and, in management’s judgment, is the best measure of progress towards satisfying the performance obligation.

•Option rights: The transaction price allocated to the options rights, which are considered material rights, is recognized in the period that Roche elects to exercise or elects to not exercise its option right to license and commercialize the underlying research and development target.

The following table summarizes the allocation of the total transaction price to the identified performance obligations under the arrangement, and the amount of the transaction price unsatisfied as of June 30, 2024 (in thousands):


	Transaction Price Allocated		Transaction Price Unsatisfied
Performance obligations:
Research and development targets	$	16,534	$	14,083
Option rights	2,530		2,530
Total	$	19,064	$	16,613

Biogen Collaboration Research and License Agreement

In December 2018, the Company entered into a collaboration research and license agreement, or the Biogen Agreement, with Biogen. In February 2020, the Company and Biogen amended the Biogen Agreement to provide further clarity around Biogen’s ownership of target binding moieties (which are portions of molecules), and any related intellectual property that are directed at or bind to collaboration targets. This amendment further provided that Biogen licenses to the Company rights to use these Biogen target binding moieties and any related intellectual property as needed in order to conduct the research and development activities contemplated under the Biogen Agreement. Pursuant to the terms of the Biogen Agreement, the Company and Biogen agreed to collaborate on research activities to develop novel treatments for neurological conditions such as Alzheimer's disease and Parkinson's disease through medicines that rely on target protein degradation, or TPD, as their mode of action, all of which are created using the Company’s degrader technology. Under the terms of the Biogen Agreement, the Company was engaged to develop TPD therapeutics that utilize degrader technology for up to five target proteins over a period of 54 months, ending in June 2023. On a target-by-target basis, after successful completion of a defined target evaluation period, Biogen assumes full rights and responsibility for continued development of each target. As of June 30, 2024, the research term of the Biogen Agreement has been fully satisfied.

In exchange for the non-exclusive research license from Biogen, as well as a $45.0 million nonrefundable upfront payment, the Company has granted a license to develop, commercialize, and manufacture products related to each of the targets (which is contingent on not cancelling the agreement), performs initial research services for drug discovery, has provided a non-exclusive research and commercial license to its intellectual property, and participates on the joint steering committee, or the Biogen JSC. The Company was also obligated to participate in early research activities for other potential targets or sandbox activities, at Biogen’s election up to a maximum amount; any work performed for these services is reimbursed by Biogen, and Biogen reimburses the Company for certain full-time equivalent, or FTE, costs. The Company’s obligations under the sandbox activities were completed as of August 31, 2021. For any target, following the achievement of development candidate criteria and prior to any IND-enabling study, Biogen will bear all costs and expenses of and will have sole discretion and decision-making authority with respect to the performance of further activities with respect to any

degrader under development under the Biogen Agreement and all products that incorporate that degrader. Biogen is also required to pay the Company up to $35.0 million per target in development milestones and $26.0 million per target in one-time sales-based payments for the first product to achieve certain levels of net sales. In addition, Biogen is required to pay the Company royalties on a licensed product-by-licensed product basis, on worldwide net product sales. All milestone and sales-based payments are made after the Company has met the defined criteria in the joint research plan for that target, at which time Biogen will have control of the products related to the targets for commercialization; the receipt of these payments is contingent on the further development of products directed to the targets to commercialization by Biogen, without any additional research and development efforts from the Company.

Biogen Agreement accounting

The Company recognizes revenue under the Biogen Agreement for research and development services as follows:

•Research and development services: The Company identified one performance obligation at the outset of the Biogen Agreement, representing a combined performance obligation consisting of (1) the licenses, (2) the research activities for the target evaluation phase for all five targets, and (3) the joint research plan phase for each target. The Company determined that the licenses and research activities were not distinct from one another, as the licenses have limited value without the performance of the research activities by the Company. Participation on the Biogen JSC to oversee the research activities and the technology transfer associated with the Biogen License Agreement were determined to be quantitatively and qualitatively immaterial and therefore are excluded from performance obligations. The Company recognizes the transaction price allocated to this performance obligation as the research and development services are provided, using an input method, in proportion to costs incurred to date for each research development target as compared to total costs incurred and expected to be incurred in the future to satisfy the underlying obligation related to said research and development target. The transfer of control occurs over this period and, in management’s judgment, is the best measure of progress towards satisfying the performance obligation.

As of June 30, 2024, the total transaction price of the Biogen Agreement of $55.0 million was allocated to the research and development services performance obligation, and the transaction price has been fully allocated and satisfied.

In April 2024, the Company earned an $8.0 million milestone payment from Biogen after the company accepted delivery of a development candidate in an undisclosed indication. The Company's performance obligation under the Biogen Agreement is fully satisfied, and the Company has recognized the full amount as revenue during the three months ended June 30, 2024. Biogen is responsible for all future clinical development and commercialization for this program.

Calico Collaboration and License Agreement

In March 2017, the Company entered into a collaboration and license agreement, or the Calico Agreement, with Calico whereby the Company and Calico agreed to collaborate to develop and commercialize small molecule protein degraders for diseases of aging, including cancer, for a five-year period ending in March 2022. In August 2021, the Company provided an extension option to Calico, which Calico exercised in September 2021, resulting in a $1.0 million extension payment to extend the research term with respect to a certain program for up to a one-year period that ended in March 2023. In addition, Calico reimbursed the Company for a number of FTEs, depending on the stage of the research, at specified market rates. As of March 13, 2023, the research term of the Calico Agreement has expired, and the Company's research activities associated with the agreement are complete.

Under the Calico Agreement, Calico paid an upfront amount of $5.0 million and certain annual payments totaling $5.0 million through June 30, 2020 and paid target initiation fees and reimbursed the Company for a number of FTEs, depending on the stage of the research, at specified market rates. For each target, the Company is eligible to receive up to $132.0 million in potential development and commercial milestone payments, on sales of all products resulting from the collaboration efforts. Calico is also required to pay the Company up to $65.0 million in one-time sales-based payments for the first product to achieve certain levels of net sales. In addition, Calico is required to pay the Company royalties, at percentages in the mid-single digits, on a licensed product-by-licensed product basis, on worldwide net product sales. All milestone and sales-based payments are made after the Company has met the defined criteria in the joint research plan for that target, at which time Calico will have control of the products related to targets for commercialization; the receipt of these payments by the Company is contingent on the further development of the targets to commercialized products by Calico, without any additional research and development efforts required by the Company.

Summary of revenue recognized from collaboration agreements

Revenue from collaboration agreements for the three and six months ended June 30, 2024 and 2023 in the condensed consolidated statements of operations and comprehensive loss was as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Revenue from collaboration agreements:
MKDG Agreement	$	1,894	$	—	$	1,949	$	—
Merck Agreement	1,102		—		1,747		—
Roche Agreement	963		160		2,451		513
Biogen Agreement	8,047		2,504		8,898		4,840
Calico Agreement	—		—		—		1,070
Total revenue from collaboration agreements	$	12,006	$	2,664	$	15,045	$	6,423

Financial information related to the collaboration and license agreements consisted of the following in the Company’s condensed consolidated balance sheet as of June 30, 2024 (in thousands):


	Accounts Receivable		Deferred Revenue, Current		Deferred Revenue, Net of Current		Deferred Revenue, Total
Supplemental information:
MKDG Agreement	$	1,167	$	6,733	$	8,486	$	15,219
Merck Agreement	—		8,253		—		8,253
Betta Agreements	—		17,000		—		17,000
Roche Agreement	—		4,606		8,424		13,030

Total	$	1,167	$	36,592	$	16,910	$	53,502

Financial information related to the collaboration and license agreements consisted of the following in the Company’s condensed consolidated balance sheet as of December 31, 2023 (in thousands):


	Accounts Receivable		Deferred Revenue, Current		Deferred Revenue, Net of Current		Deferred Revenue, Total
Supplemental information:
Merck Agreement	$	10,000	$	8,000	$	2,000	$	10,000
Betta Agreement	1,799		4,000		8,000		12,000
Roche Agreement	—		2,667		11,814		13,030
Biogen Agreement	—		804		—		804
Total	$	11,799	$	15,471	$	21,814	$	37,285

Supplemental financial information related to the collaboration and license agreements for the three and six months ended June 30, 2024 and 2023 are (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Revenue recognized that was included in the contract liability at the beginning of the period	$	2,065	$	2,664	$	5,003	$	5,895

As of June 30, 2024, the aggregate amount of the transaction price allocated to performance obligations under the MKDG Agreement, Merck Agreement, Betta Agreements, and Roche Agreement that were partially unsatisfied was $57.1 million.

Commitment and contingencies	6 Months Ended
Commitment and contingencies	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies Legal proceedings The Company is not currently party to any material legal proceedings. At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company expenses as incurred the costs related to such legal proceedings.

Fair value measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	$ 222,621	$ 155,099
Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	295,570	281,223
Recurring \| Corporate debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	180,644	128,705
Recurring \| U.S. government debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	14,253	20,428
Recurring \| U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	27,724	5,966
Money market funds \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	64,918	103,564
Corporate debt securities \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	8,031	7,588
U.S. Treasury securities \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		14,972
Level 1 \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	64,918	103,564
Level 1 \| Recurring \| Corporate debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 1 \| Recurring \| U.S. government debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 1 \| Recurring \| U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 1 \| Money market funds \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	64,918	103,564
Level 1 \| Corporate debt securities \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 1 \| U.S. Treasury securities \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		0
Level 2 \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	230,652	177,659
Level 2 \| Recurring \| Corporate debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	180,644	128,705
Level 2 \| Recurring \| U.S. government debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	14,253	20,428
Level 2 \| Recurring \| U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	27,724	5,966
Level 2 \| Money market funds \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 2 \| Corporate debt securities \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	8,031	7,588
Level 2 \| U.S. Treasury securities \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		14,972
Level 3 \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	0	0
Level 3 \| Recurring \| Corporate debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 3 \| Recurring \| U.S. government debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 3 \| Recurring \| U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level 3 \| Money market funds \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 3 \| Corporate debt securities \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 0	0
Level 3 \| U.S. Treasury securities \| Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		$ 0

Accrued expenses and other current liabilities (Tables)

6 Months Ended

Jun. 30, 2024

Payables and Accruals [Abstract]

Summary of accrued liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	June 30, 2024		December 31, 2023
Accrued expenses and other current liabilities:
Accrued research and development	$	5,268	$	11,243
Accrued compensation and benefits	3,642		7,344
Other	2,293		2,043
Total accrued expenses and other current liabilities	$	11,203	$	20,630

Loss per share - Schedule of diluted net loss per share attributable to common stockholders (Details) - shares	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total anti-dilutive common stock equivalents (in shares)	11,645,100	7,929,853
Options to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total anti-dilutive common stock equivalents (in shares)	11,645,100	7,929,853

Collaboration and license agreements - Schedule of revenue from collaboration agreements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	$ 12,006	$ 2,664	$ 15,045	$ 6,423
MKDG Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	1,894	0	1,949	0
Merck Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	1,102	0	1,747	0
Roche Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	963	160	2,451	513
Biogen Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	8,047	2,504	8,898	4,840
Calico Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	$ 0	$ 0	$ 0	$ 1,070

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (a)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Collaboration and license agreements (Tables)

6 Months Ended

Jun. 30, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of allocation of transaction price


	Transaction Price Allocated		Transaction Price Unsatisfied
Performance obligations:
Research and development targets	$	16,534	$	14,083
Option rights	2,530		2,530
Total	$	19,064	$	16,613

Schedule of revenue from collaboration agreements


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Revenue from collaboration agreements:
MKDG Agreement	$	1,894	$	—	$	1,949	$	—
Merck Agreement	1,102		—		1,747		—
Roche Agreement	963		160		2,451		513
Biogen Agreement	8,047		2,504		8,898		4,840
Calico Agreement	—		—		—		1,070
Total revenue from collaboration agreements	$	12,006	$	2,664	$	15,045	$	6,423

Schedule of financial information related to collaboration and license agreements

Financial information related to the collaboration and license agreements consisted of the following in the Company’s condensed consolidated balance sheet as of June 30, 2024 (in thousands):


	Accounts Receivable		Deferred Revenue, Current		Deferred Revenue, Net of Current		Deferred Revenue, Total
Supplemental information:
MKDG Agreement	$	1,167	$	6,733	$	8,486	$	15,219
Merck Agreement	—		8,253		—		8,253
Betta Agreements	—		17,000		—		17,000
Roche Agreement	—		4,606		8,424		13,030

Total	$	1,167	$	36,592	$	16,910	$	53,502

Financial information related to the collaboration and license agreements consisted of the following in the Company’s condensed consolidated balance sheet as of December 31, 2023 (in thousands):


	Accounts Receivable		Deferred Revenue, Current		Deferred Revenue, Net of Current		Deferred Revenue, Total
Supplemental information:
Merck Agreement	$	10,000	$	8,000	$	2,000	$	10,000
Betta Agreement	1,799		4,000		8,000		12,000
Roche Agreement	—		2,667		11,814		13,030
Biogen Agreement	—		804		—		804
Total	$	11,799	$	15,471	$	21,814	$	37,285

Schedule of supplemental financial information related to collaboration and license agreements

Supplemental financial information related to the collaboration and license agreements for the three and six months ended June 30, 2024 and 2023 are (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Revenue recognized that was included in the contract liability at the beginning of the period	$	2,065	$	2,664	$	5,003	$	5,895

Nature of the business and basis of presentation (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ 46,077	$ 70,702
Accumulated deficit	574,460		$ 528,383
Cash, cash equivalents and marketable securities	$ 295,700

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-2

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481203/810-10-50-1A

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481203/810-10-50-1A

+ Details

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Property and equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Property and equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Property and equipment	$ 15,078		$ 15,078		$ 14,895
Less: accumulated depreciation	(8,507)		(8,507)		(7,763)
Total property and equipment, net	6,571		6,571		7,132
Depreciation expense	296	$ 458	744	$ 1,003
Laboratory equipment
Property Plant And Equipment [Line Items]
Property and equipment	8,212		8,212		8,042
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment	4,712		4,712		4,712
Furniture and fixtures
Property Plant And Equipment [Line Items]
Property and equipment	1,435		1,435		1,422
Office equipment
Property Plant And Equipment [Line Items]
Property and equipment	621		621		621
Computer equipment
Property Plant And Equipment [Line Items]
Property and equipment	$ 98		$ 98		$ 98

Stock-based compensation (Tables)

6 Months Ended

Jun. 30, 2024

Share-Based Payment Arrangement [Abstract]

Schedule of stock-based compensation expense


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Stock-based compensation expense:
Research and development	$	2,465	$	2,644	$	4,702	$	5,227
General and administrative	3,916		3,781		7,894		7,449
Total stock-based compensation expense	$	6,381	$	6,425	$	12,596	$	12,676

Fair value measurements (Tables)

6 Months Ended

Jun. 30, 2024

Fair Value Disclosures [Abstract]

Schedule of financial assets measured at fair value on a recurring basis

The following table presents information about the Company’s financial assets measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of June 30, 2024 (in thousands):


	Fair Value		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	64,918	$	64,918	$	—	$	—
Corporate debt securities	8,031		—		8,031		—

Marketable securities:
Corporate debt securities	180,644		—		180,644		—
U.S. government debt securities	14,253		—		14,253		—
U.S. Treasury securities	27,724		—		27,724		—
Total cash equivalents and marketable securities	$	295,570	$	64,918	$	230,652	$	—

There have been no transfers between fair value levels during the six months ended June 30, 2024.

The following table sets forth the fair value of the Company’s financial assets by level within the fair value hierarchy at

December 31, 2023 (in thousands):


	Fair Value		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	103,564	$	103,564	$	—	$	—
U.S. Treasury securities	14,972		—		14,972		—
Corporate debt securities	7,588		—		7,588		—
Marketable securities:
Corporate debt securities	128,705		—		128,705		—
U.S. government debt securities	20,428		—		20,428		—
U.S. Treasury securities	5,966		—		5,966		—
Total cash equivalents and marketable securities	$	281,223	$	103,564	$	177,659	$	—

Property and equipment (Tables)

6 Months Ended

Jun. 30, 2024

Property, Plant and Equipment [Abstract]

Summary of property and equipment

Property and equipment consisted of the following (in thousands):


	June 30, 2024		December 31, 2023
Property and equipment:
Laboratory equipment	$	8,212	$	8,042
Leasehold improvements	4,712		4,712
Furniture and fixtures	1,435		1,422
Office equipment	621		621

Computer equipment	98		98
Total property and equipment	15,078		14,895
Less: accumulated depreciation	(8,507)		(7,763)
Total property and equipment, net	$	6,571	$	7,132

Depreciation expense related to property and equipment is as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Depreciation expense	$	296	$	458	$	744	$	1,003

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash flows used in operating activities:
Net loss	$ (46,077)	$ (70,702)
Adjustments to reconcile net loss to cash used in operating activities:
Stock-based compensation expense	12,596	12,676
Depreciation and amortization expense	896	1,003
Reduction in carrying amount of right-of-use asset	3,176	3,048
Net accretion of discounts on marketable securities	(2,930)	(1,724)
Amortization of debt discount − related party	0	354
Other	22	68
Changes in operating assets and liabilities:
Accounts receivable	10,632	445
Prepaid expenses and other current and long-term assets	(5,116)	2,096
Accounts payable	(533)	941
Accrued expenses and other current liabilities	(9,414)	(3,133)
Operating lease liability	(2,560)	(2,299)
Deferred revenue	16,216	5,105
Net cash used in operating activities	(23,092)	(52,122)
Cash flows (used in) provided by investing activities:
Proceeds from maturities of marketable securities	110,067	129,708
Purchases of marketable securities	(174,972)	(60,078)
Purchases of property and equipment, net	(197)	(951)
Net cash (used in) provided by investing activities	(65,102)	68,679
Cash flows provided by (used in) financing activities:
Proceeds from exercise of stock options	654	58
Payments for repurchase of common stock for tax withholding	(109)	(94)
Payment of long-term debt − related party	0	(1,500)
Other	84	106
Net cash provided by (used in) financing activities	34,718	(1,430)
Net change in cash, cash equivalents and restricted cash	(53,476)	15,127
Cash, cash equivalents and restricted cash at beginning of period	130,033	33,033
Cash, cash equivalents and restricted cash at end of period	76,557	48,160
Reconciliation of cash, cash equivalents and restricted cash:
Cash, cash equivalents and restricted cash at end of period	76,557	48,160
Less: restricted cash	(3,443)	(3,279)
Cash and cash equivalents at end of the period	73,114	44,881
Supplemental disclosures of cash flow information:
Cash paid for leases	4,399	4,271
Cash paid for interest − related party	0	852
Supplemental disclosures of non-cash investing activities:
Capital expenditures in accounts payable and accrued expenses	13	223
Stock Purchase Agreement
Cash flows provided by (used in) financing activities:
Proceeds from issuance of common stock	20,000	0
At-The-Market
Cash flows provided by (used in) financing activities:
Proceeds from issuance of common stock	$ 14,089	$ 0

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value per share (in dollars per share)	$ 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 value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	68,815,642	60,467,188
Common stock, shares outstanding	68,815,642	60,467,188

Restructuring	6 Months Ended
Restructuring	Jun. 30, 2024
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring In January 2024, the Company implemented a restructuring plan to better align its workforce with the needs of its business and reduce operating costs that included a reduction in the Company's workforce by 30%. The resulting restructuring expense recognized during the six months ended June 30, 2024 was $2.4 million, which has all been substantially paid as of June 30, 2024.

Stockholders equity	6 Months Ended
Stockholders equity	Jun. 30, 2024
Equity [Abstract]
Stockholder's equity	Stockholders’ equity At-The-Market Equity Program In November 2021, the Company filed an automatically effective registration statement on Form S-3, or the Registration Statement, with the SEC that registers the offering, issuance and sale of an unspecified amount of common stock, preferred stock, debt securities, warrants, and/or units of any combination thereof. Simultaneously, the Company entered into an equity distribution agreement with Cowen and Company, LLC, as sales agent, to provide for the issuance and sale by the Company of up to $200.0 million of common stock from time to time in “at-the-market” offerings under the Registration Statement and related prospectus filed with the Registration Statement, or the ATM Program. During the six months ended June 30, 2024, the Company settled 2,500,601 shares for net proceeds of $14.1 million,. There were no sales made under the ATM Program during the three months ended June 30, 2024. As of June 30, 2024, a total of 13,686,743 shares of the Company's common stock at an average purchase price of $5.42 had been sold through the ATM Program, resulting in net proceeds of $71.9 million.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478448/946-505-50-6

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-Subparagraph (i)
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
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-Subparagraph (a)
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
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-Subparagraph (b)
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Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

+ Details

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 73,114	$ 126,590
Marketable securities, current	190,984	127,091
Accounts receivable	1,167	11,799
Prepaid expenses and other current assets	10,779	5,709
Total current assets	276,044	271,189
Marketable securities, non-current	31,637	28,008
Property and equipment, net	6,571	7,132
Right-of-use asset	60,781	63,956
Restricted cash	3,443	3,443
Other assets	2,617	2,723
Total assets	381,093	376,451
Current liabilities:
Accounts payable	913	1,446
Accrued expenses and other current liabilities	11,203	20,630
Deferred revenue, current	36,592	15,471
Operating lease liability, current	5,493	5,219
Total current liabilities	54,201	42,766
Deferred revenue, net of current	16,910	21,814
Operating lease liability, net of current	62,924	65,757
Total liabilities	134,035	130,337
Commitments and contingencies (see Note 11)
Stockholders’ equity:
Preferred stock, par value of $0.0001 per share; 10,000,000 shares authorized, and no shares issued or outstanding as of June 30, 2024 and December 31, 2023, respectively	0	0
Common stock, par value of $0.0001 per share; 150,000,000 shares authorized, and 68,815,642 and 60,467,188 shares issued and outstanding as of June 30, 2024 and December 31, 2023, respectively	7	6
Additional paid-in capital	821,951	774,618
Accumulated other comprehensive loss	(440)	(127)
Accumulated deficit	(574,460)	(528,383)
Total stockholders’ equity	247,058	246,114
Total liabilities and stockholders’ equity	$ 381,093	$ 376,451

Income taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Income taxes (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income tax provision (benefit)	$ 0	$ 0	$ 0	$ 0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482964/270-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-9

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-8

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-10

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(9))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
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-SubTopic 20
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482659/740-20-45-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-SubTopic 10
-Topic 235
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

Leases	6 Months Ended
Leases	Jun. 30, 2024
Leases [Abstract]
Leases	Leases The Company leases office and laboratory space under a non-cancelable operating lease. In addition, the Company subleases a portion of its office and laboratory space. There have been no material changes to the Company’s lease or sublease during the six months ended June 30, 2024. For additional information, please read Note 6, Leases, to the audited condensed consolidated financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2023.

Fair value measurements

6 Months Ended

Jun. 30, 2024

Fair Value Disclosures [Abstract]

Fair value measurements


	Fair Value		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	64,918	$	64,918	$	—	$	—
Corporate debt securities	8,031		—		8,031		—

Marketable securities:
Corporate debt securities	180,644		—		180,644		—
U.S. government debt securities	14,253		—		14,253		—
U.S. Treasury securities	27,724		—		27,724		—
Total cash equivalents and marketable securities	$	295,570	$	64,918	$	230,652	$	—

There have been no transfers between fair value levels during the six months ended June 30, 2024.

The following table sets forth the fair value of the Company’s financial assets by level within the fair value hierarchy at

December 31, 2023 (in thousands):


	Fair Value		Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	103,564	$	103,564	$	—	$	—
U.S. Treasury securities	14,972		—		14,972		—
Corporate debt securities	7,588		—		7,588		—
Marketable securities:
Corporate debt securities	128,705		—		128,705		—
U.S. government debt securities	20,428		—		20,428		—
U.S. Treasury securities	5,966		—		5,966		—
Total cash equivalents and marketable securities	$	281,223	$	103,564	$	177,659	$	—

The Company classifies its money market funds, which are valued based on quoted market prices in active markets, with no valuation adjustment, as Level 1 assets within the fair value hierarchy.

Marketable securities consist of U.S. Treasury securities, U.S. government debt securities, and corporate debt securities, all of 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, which are either directly or indirectly observable as of the reporting date, and fair value is determined using models or other valuation methodologies on a recurring basis.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
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+ Details

Summary of significant accounting policies (Policies)	6 Months Ended
Summary of significant accounting policies (Policies)	Jun. 30, 2024
Accounting Policies [Abstract]
Basis of presentation	The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America, or U.S. GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or the SEC, regarding interim financial reporting, and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements.
Consolidation	These condensed consolidated financial statements include the accounts of C4 Therapeutics, Inc. and its subsidiary, C4T Securities Corporation. All intercompany balances and transactions have been eliminated in consolidation.
Unaudited interim financial information	Unaudited interim financial information The accompanying condensed consolidated balance sheet as of June 30, 2024, the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2024 and 2023, the condensed consolidated statements of stockholders’ equity for the three and six months ended June 30, 2024 and 2023, and the condensed consolidated statements of cash flows for the six months ended June 30, 2024 and 2023, and the related interim disclosures are unaudited. These unaudited condensed consolidated financial statements include all adjustments necessary, consisting of only normal recurring adjustments, to fairly state the financial position and the results of the Company’s operations and cash flows for interim periods in accordance with U.S. GAAP. Interim period results are not necessarily indicative of results of operations or cash flows for a full year or any subsequent interim period. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements as of and for year ended December 31, 2023, and notes thereto, which are included in the Company’s 2023 Annual Report on Form 10-K that was filed with the SEC on February 22, 2024, or the 2023 Annual Report.
Use of estimates	Use of estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. This process may result in actual results differing materially from those estimated amounts used in the preparation of the condensed consolidated financial statements if these results differ from historical experience or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, amounts and timing of revenues recognized under the Company’s research and development collaboration arrangements, prepaid and accrued research and development expense, incremental borrowing rate used in the measurement of lease liabilities, and estimated volatility used in fair valuation of stock options. The Company assesses estimates on an ongoing basis; however, actual results could materially differ from those estimates.

Loss per share - Schedule of basic and diluted loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Numerator:
Net loss	$ (17,716)	$ (28,361)	$ (35,922)	$ (34,780)	$ (46,077)	$ (70,702)
Denominator:
Weighted-average number of shares used in computed net loss per share − basic	68,810,259		49,063,631		68,621,214	49,048,062
Weighted-average number of shares used in computed net loss per share − diluted	68,810,259		49,063,631		68,621,214	49,048,062
Net loss per share − basic (in dollars per share)	$ (0.26)		$ (0.73)		$ (0.67)	$ (1.44)
Net loss per share − diluted (in dollars per share)	$ (0.26)		$ (0.73)		$ (0.67)	$ (1.44)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

Nature of the business and basis of presentation	6 Months Ended
Nature of the business and basis of presentation	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the business and basis of presentation	Nature of the business and basis of presentation C4 Therapeutics, Inc., or, together with its subsidiary, the Company, is a clinical-stage biopharmaceutical company dedicated to the advancement of targeted protein degradation science to develop a new generation of small-molecule medicines to transform how disease is treated. The Company leverages its proprietary technology platform, TORPEDO (Target ORiented ProtEin Degrader Optimizer), to efficiently design and optimize small-molecule medicines that harness the body’s natural protein recycling system to rapidly degrade disease-causing protein, offering the potential to overcome drug resistance, drug undruggable targets, and improve patient outcomes. The Company uses its TORPEDO platform to advance multiple targeted oncology programs to the clinic while expanding its research platform to deliver the next wave of medicines for difficult-to-treat diseases. The Company was incorporated in Delaware on October 7, 2015 and has its principal office in Watertown, Massachusetts. Liquidity and capital resources Since its inception, the Company’s primary activities have been focused on research and development activities, building the Company’s intellectual property, recruiting and retaining personnel, and raising capital to support these activities. To date, the Company has funded its operations primarily with proceeds received from the sales of redeemable convertible preferred stock, public offerings of the Company’s common stock, private placement of the Company's common stock, through its collaboration agreements, and debt financing. The Company has incurred recurring losses since its inception, including net losses of $46.1 million and $70.7 million for the six months ended June 30, 2024 and 2023, respectively. In addition, as of June 30, 2024, the Company had an accumulated deficit of $574.5 million. To date, the Company has not generated any revenue from product sales as none of its product candidates have been approved for commercialization. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash, cash equivalents, and marketable securities of $295.7 million as of June 30, 2024 will be sufficient to fund its operations for at least the next twelve months from the date of issuance of these consolidated financial statements. Accordingly, the condensed consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. Risks and uncertainties The Company is subject to risks common to other life science companies in the early development stage including, but not limited to, uncertainty of ability to raise additional financing, product development and commercialization, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, lack of marketing and sales history, product liability, protection of proprietary technology and intellectual property, and compliance with the Food and Drug Administration, or the FDA, and other government regulations. If the Company does not successfully advance its programs into and through human clinical trials and commercialize any of its product candidates either directly or through collaborations with other companies, the Company may be unable to produce product revenue or achieve profitability. There can be no assurance that the Company’s research and development efforts will be successful, adequate protection for the Company’s intellectual property will be obtained, any products developed will obtain necessary government regulatory approval, or any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies.

Marketable securities - Summary of marketable securities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Marketable securities, current:
Fair Value	$ 190,984	$ 127,091
Marketable securities, non-current:
Fair Value	31,637	28,008
Amortized Cost	223,061	155,226
Gross Unrealized Gains	8	151
Gross Unrealized Losses	(448)	(278)
Fair Value	222,621	155,099
Corporate debt securities
Marketable securities, current:
Amortized Cost	151,683	100,903
Gross Unrealized Gains	1	16
Gross Unrealized Losses	(330)	(221)
Fair Value	151,354	100,698
Marketable securities, non-current:
Amortized Cost	29,360	27,901
Gross Unrealized Gains	7	120
Gross Unrealized Losses	(77)	(14)
Fair Value	29,290	28,007
U.S. Treasury securities
Marketable securities, current:
Amortized Cost	27,739	5,965
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(15)	0
Fair Value	27,724	5,966
U.S. government debt securities
Marketable securities, current:
Amortized Cost	11,929	20,457
Gross Unrealized Gains	0	14
Gross Unrealized Losses	(23)	(43)
Fair Value	11,906	$ 20,428
Marketable securities, non-current:
Amortized Cost	2,350
Gross Unrealized Gains	0
Gross Unrealized Losses	(3)
Fair Value	$ 2,347

Income taxes	6 Months Ended
Income taxes	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Income taxes	Income taxes For the three and six months ended June 30, 2024 and 2023, the Company recorded no income tax provision or benefit due to losses generated where no benefit was recorded due to the valuation allowance. The Company continues to maintain a full valuation allowance for its U.S. federal and state deferred tax assets as of June 30, 2024 due to uncertainty regarding future taxable income.

- Definition

The entire disclosure for income tax.

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-URI https://asc.fasb.org/1943274/2147480990/946-20-50-13

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/740/tableOfContent

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-14

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-21

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-17

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

Collaboration and license agreements - Schedule of financial information related to collaboration and license agreements (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts Receivable	$ 1,167	$ 11,799
Deferred revenue, current	36,592	15,471
Deferred revenue, net of current	16,910	21,814
Deferred revenue, total	53,502	37,285
MKDG Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts Receivable	1,167
Deferred revenue, current	6,733
Deferred revenue, net of current	8,486
Deferred revenue, total	15,219
Merck Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts Receivable	0	10,000
Deferred revenue, current	8,253	8,000
Deferred revenue, net of current	0	2,000
Deferred revenue, total	8,253	10,000
Betta Agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts Receivable	0	1,799
Deferred revenue, current	17,000	4,000
Deferred revenue, net of current	0	8,000
Deferred revenue, total	17,000	12,000
Roche Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts Receivable	0	0
Deferred revenue, current	4,606	2,667
Deferred revenue, net of current	8,424	11,814
Deferred revenue, total	$ 13,030
Biogen Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts Receivable		0
Deferred revenue, current		804
Deferred revenue, net of current		0
Deferred revenue, total		$ 804

Collaboration and license agreements - Summary of allocation of transaction price (Details) $ in Thousands	Jun. 30, 2024 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction Price Allocated	$ 19,064
Transaction Price Unsatisfied	16,613
Research and development targets
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction Price Allocated	16,534
Transaction Price Unsatisfied	14,083
Option rights
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction Price Allocated	2,530
Transaction Price Unsatisfied	$ 2,530

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Accrued expenses and other current liabilities:
Accrued research and development	$ 5,268	$ 11,243
Accrued compensation and benefits	3,642	7,344
Other	2,293	2,043
Total accrued expenses and other current liabilities	$ 11,203	$ 20,630

Restructuring (Details) - USD ($) $ in Millions	1 Months Ended
Restructuring (Details) - USD ($) $ in Millions	Jan. 31, 2024	Jun. 30, 2024
Restructuring and Related Activities [Abstract]
Restructuring and related cost, number of positions eliminated, period percent	30.00%
Restructuring and related cost, cost incurred to date		$ 2.4