Income Taxes (Tables)

12 Months Ended

Dec. 31, 2024

Income Tax Disclosure [Abstract]

Summary of Income (Loss) Before Income Tax Expense

Loss before income tax expense consists of the following:

	Year Ended December 31,
	2024			2023			2022
	(in thousands)
Domestic	$	(401,549	)	$	(541,656	)	$	(532,539	)
Foreign		883			167			(245	)
	$	(400,666	)	$	(541,489	)	$	(532,784	)

Summary of Reconciliation of U.S. Statutory Rate to Company's Effective Tax Rate

A reconciliation of the U.S. statutory rate to the Company’s effective tax rate is as follows:

	Year Ended December 31,
	2024			2023			2022
Tax due at statutory rate		21.0	%		21.0	%		21.0	%
State taxes, net of federal		1.9			4.1			1.8
Stock-based compensation		(10.2	)		(1.7	)		(1.9	)
Federal and state tax credits		2.9			2.4			2.1
Change in valuation allowance		(15.4	)		(26.2	)		(23.0	)
Other		(0.2	)		0.4			—
		0.0	%		0.0	%		0.0	%

Summary of Significant Components of Company's Net Deferred Tax Asset

Significant components of the Company’s net deferred tax assets at December 31, 2024 and 2023 are as follows:

	December 31,
	2024			2023
	(in thousands)
Net operating losses	$	490,891		$	428,785
Tax credits		145,113			133,602
Capitalized research and development expenses		128,001			110,690
Stock-based compensation		23,967			53,860
Accrued expenses		5,491			7,018
Depreciation and amortization		1,914			1,456
Lease liability		2,748			1,207
Right of use asset		(2,497	)		(1,042	)
Other		1,090			(382	)
Total net deferred tax asset before valuation    allowance		796,718			735,194
Valuation allowance		(796,718	)		(735,194	)
	$	—		$	—

Summary of Gross Unrecognized Tax Benefits Excluding Interest and Penalties

The following table reconciles the beginning and ending amounts of gross unrecognized tax benefits, excluding interest and penalties, if any, for the years ended December 31, 2024, 2023, and 2022:

	2024		2023		2022
	(in thousands)
Balance as of January 1	$	7,743	$	6,846	$	6,084
Increases related to current year tax positions		520		655		697
Increases related to prior year tax positions		15		242		65
Balance as of December 31	$	8,278	$	7,743	$	6,846