Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Summary of Total Deferred Income Tax Assets, Net of Valuation Allowance

Total deferred income tax assets, net of valuation allowance, at December 31, 2021 and 2020 were as follows (in thousands):

	December 31,
	2021			2020
Deferred tax assets
Net operating loss carryforwards	$	157,277		$	87,124
Research and development credits		33,341			18,139
Accruals and reserves		3,889			1,368
Stock-based compensation		4,932			5,661
Lease liability		10,854			9,151
Gross deferred tax assets		210,293			121,443
Less: valuation allowance		(203,516	)		(112,680	)
Deferred tax assets, net of valuation allowance		6,777			8,763
Deferred tax liabilities
Fixed and intangible assets		84			360
Right-of-use asset		6,693			8,403
Gross deferred tax liabilities		6,777			8,763
Net deferred tax assets	$	—		$	—

Summary of Effective Tax Rate Differs From Federal Statutory Tax Rate

The Company’s effective tax rate differs from the federal statutory tax rate as follows:

	Year Ended December 31,
	2021			2020
Federal statutory tax rate		21.0	%		21.0	%
Change in deferred tax asset valuation allowance		(33.7	)%		(34.4	)%
State taxes, net of federal benefit		1.9	%		0.8	%
Research and development tax credits		5.2	%		5.6	%
Stock-based compensation		6.9	%		6.9	%
Other		(1.3	)%		0.1	%
Effective tax rate		—	%		—	%

Reconciliation of Beginning and Ending Amount of Unrecognized Benefits

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

	Year Ended December 31,
	2021			2020
Balance at the beginning of the year	$	6,932		$	3,545
Increase related to current year tax positions		5,345			3,387
Increase related to prior year tax positions		(324	)		—
Balance at the end of the year	$	11,953		$	6,932