Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Schedule of Effective Tax Rate Reconciliation

The effective tax rate of the Company’s provision for income taxes differs from the federal statutory rate and the effective tax rate reconciliation is as follows:

	December 31,
	2023			2022
U.S. federal taxes at statutory rate		21.0	%		21.0	%
State taxes (net of federal benefit)		1.2			1.2
Credits		3.7			2.8
Stock-based compensation		(0.3	)		(0.3	)
Change in valuation allowance		(24.4	)		(24.1	)
Other		(1.2	)		(0.6	)
Total	—%			—%

Schedule of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:

	December 31,
	2023			2022
	(In thousands)
Balance at beginning of year	$	3,141		$	1,470
Additions based on tax positions related to current year		1,423			1,588
Additions based on tax positions related to prior years		—			83
Reductions for tax positions related to prior years		(43	)		—
Balance at end of year	$	4,521		$	3,141

Schedule of Deferred Income Taxes

The tax effects of significant items comprising the Company’s deferred income taxes are as follows:

	December 31,
	2023			2022
	(In thousands)
Deferred tax assets:
Net operating losses	$	52,757		$	41,256
Capitalized research and development expenditure		29,318			17,045
Tax credits		15,047			9,347
Lease liability		2,613			3,176
Stock-based compensation		2,880			1,631
Accrued expenses and other		1,713			1,368
Total deferred tax assets		104,328			73,823
Valuation allowance		(101,290	)		(71,129	)
Deferred tax assets, net of valuation allowance		3,038			2,694
Deferred tax liabilities:
Right-of-use asset		(2,098	)		(2,453	)
Property and equipment		(940	)		(241	)
Net deferred tax assets	$	—		$	—

Summary of Net Operating Loss and Tax Carryforwards

As of December 31, 2023, the Company’s net operating loss and tax carryforwards are summarized as follows:

(In thousands)	Amount		Expiration in years
Net operating losses, federal (post-December 31, 2017)	$	224,796	Do Not Expire
Net operating losses, federal (pre-January 1, 2018)	$	3,093	Begins to Expire 2036
Net operating losses, state	$	63,212	Begins to Expire 2036
Tax credits, federal	$	14,730	Begins to Expire 2036
Tax credits, state	$	6,856	Do Not Expire