Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of Loss Before Income Taxes

The components of the Company's loss before income taxes were as follows (in thousands):

	Year ended December 31,
	2021			2020			2019
United States	$	(87,907	)	$	(76,849	)	$	(36,980	)
International		(2,038	)		—			—
Total	$	(89,945	)	$	(76,849	)	$	(36,980	)

Schedule of Provision for Income Taxes Differs From the Amount Expected by Applying the Federal Statutory Rate to Loss Before Taxes

The provision for income taxes differs from the amount expected by applying the federal statutory rate to the loss before taxes as follows:

	Year ended December 31,
	2021				2020				2019
Federal statutory income tax rate		21.00		%		21.00		%		21.00		%
State income taxes		0.96				0.55			-1.12
Income tax credits		2.17				2.14				3.67
Stock based compensation		1.68				0.44				(0.13	)
Non-deductible expenses and others		0.26				—				(0.25	)
Change in valuation allowance		(26.07	)			(24.13	)			(23.17	)
		—		%		—		%		—		%

Schedule of Components of Deferred Tax Assets

As of December 31, 2021 and 2020, the components of the Company’s deferred tax assets are as follows (in thousands):

	Year ended December 31,
	2021			2020
Deferred tax asset:
Federal and State net operating loss carryforwards	$	44,933		$	28,072
Stock based compensation		6,853			2,633
Other accruals		396			566
Tax credits		6,737			3,928
Gross deferred tax asset		58,919			35,199
Valuation allowance		(58,611	)		(35,034	)
Total deferred tax assets		308			165
Deferred tax liabilities:
Property and equipment		(5	)		(14	)
Capitalized leases		(303	)		(151	)
Gross deferred tax liabilities		(308	)		(165	)
Net deferred tax assets	$	—		$	—

Schedule of Reconciliation of Unrecognized Tax Benefits

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

	Year ended December 31,
	2021		2020		2019
Beginning balance	$	1,976	$	1,059	$	356
Additions for tax positions taken in a prior year		—		—		168
Additions for tax positions taken in a current year		1,273		917		535
Ending balance	$	3,249	$	1,976	$	1,059