Income Tax (Tables)

12 Months Ended

Dec. 31, 2025

Income Tax Disclosure [Abstract]

Summary of Provision for Income Taxes

The provision for income taxes consists of the following (in thousands):

	YEAR ENDED DECEMBER 31,
	2025		2024		2023
Current:
Federal	$	—	$	—	$	—
State		278		18		—
Total Current		278		18		—
Deferred:
Federal		—		—		—
State		—		—		—
Total Deferred		—		—		—
Total Provision	$	278	$	18	$	—

Summary of Income Taxes Paid by Jurisdiction

The income taxes paid by jurisdiction consisted of the following:

	YEAR ENDED DECEMBER 31,
	2025		2024		2023
Income Taxes Paid
Massachusetts	$	—	$	360	$	—
Total Current	$	—	$	360	$	—

Schedule of the difference between the effective tax rate and the U.S. federal tax rate

The difference between the effective tax rate and the U.S. federal tax rate were as follows:

	YEAR ENDED DECEMBER 31,
	2025						2024						2023
	Amount			Percent			Amount			Percent			Amount			Percent
U.S. federal statutory tax rate	$	(53,669	)		(21.0	)%	$	(38,247	)		(21.0	)%	$	(17,637	)		(21.0	)%
State and local income taxes, net of federal income tax benefit (1)		(195	)		(0.1	)%		(542	)		(0.3	)%		(147	)		(0.2	)%
Tax credits
Research and development tax credits		(6,308	)		(2.5	)%		(7,801	)		(4.3	)%		(2,151	)		(2.6	)%
Change in valuation allowance		53,013			20.7	%		41,309			22.7	%		17,882			21.3	%
Nontaxable or nondeductible items		4,775			1.9	%		2,738			1.5	%		1,222			1.5	%
Changes in unrecognized tax benefits		2,049			0.8	%		2,551			1.4	%		865			1.0	%
Other adjustments		613			0.3	%		10			—	%		(34	)		—	%
Effective tax rate	$	278			0.1	%	$	18			0.0	%	$	—			0.0	%

(1)State taxes in Massachusetts made up the majority (greater than 50%) of the tax effect in this category.

Schedule of the company's deferred tax assets and liabilities

The significant components of the Company’s deferred tax assets and liabilities consisted of the following (in thousands):

	YEAR ENDED DECEMBER 31,
	2025			2024			2023
Deferred tax assets:
Capitalized license and research and development payments	$	52,758		$	46,240		$	21,034
Net operating loss carryforwards		58,580			16,095			5,370
Research and development credits		14,864			9,947			2,415
Intangible assets		1,199			1,342			1,244
Stock compensation		5,599			2,352			186
Lease liability		2,063			2,849			502
Fixed asset basis differences		81			—			—
Other		74			13			1
Total deferred tax assets		135,218			78,838			30,752
Deferred tax liabilities:
Fixed asset basis differences		—			(18	)		—
Right-of-use asset		(2,025	)		(2,737	)		(574	)
Total deferred tax liabilities		(2,025	)		(2,755	)		(574	)
Valuation allowance		(133,193	)		(76,083	)		(30,178	)
Net deferred tax assets	$	—		$	—		$	—

Reconciliation of gross unrecognized tax benefits

A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands):

	2025		2024
Beginning balance	$	3,603	$	904
Changes related to tax positions taken in the prior year		42		28
Changes related to tax positions taken in the current year		2,117		2,671
Ending balance	$	5,762	$	3,603