Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Taxes

Schedule of domestic and foreign components of net loss

The following table presents domestic and foreign components of net loss before income taxes (in thousands):

	Year Ended December 31,
	2023		2022		2021
Domestic	$	(76,779)	$	(124,208)	$	(125,797)
Foreign		(2,176)		(3,185)		246
Total net loss before taxes	$	(78,955)	$	(127,393)	$	(125,551)

Schedule of federal, state and foreign of the income tax expense (benefit)

	Year Ended December 31,
	2023		2022		2021
Current:
Federal	$	—	$	—	$	—
State		—		—		—
Foreign		—		—		—
Total current tax expense		—		—		—
Deferred:
Federal		—		—		—
State		—		—		—
Foreign		—		—		—
Total deferred tax expense		—		—		—
Total income tax expense	$	—	$	—	$	—

Schedule of provision differences from federal statutory rate

	Year Ended December 31,
	2023		2022		2021
Federal statutory income tax rate	21.0	%	21.0	%	21.0	%
State taxes, net of federal benefit	8.1		1.4		1.9
Research and development credits	8.5		5.9		4.3
Foreign tax rate difference	0.2		0.2		—
Change in valuation allowance	(34.4)		(25.8)		(28.0)
Other	(3.4)		(2.7)		0.8
Provision for income taxes	—	%	—	%	—	%

Schedule of components of deferred tax assets

The components of the deferred tax assets are as follows (in thousands):

	December 31,
	2023		2022
Deferred tax assets:
Net operating loss carryforwards	$	70,469	$	76,133
Depreciation		950		893
Accruals/other		12,202		8,304
Operating lease liability		265		769
Research and development and foreign credits		38,759		30,387
Section 174 capitalized R&D expenditure		43,841		22,296
Total deferred tax assets		166,486		138,782
Deferred tax liabilities:
Operating right-of-use asset		(221)		(644)
Total deferred tax liabilities		(221)		(644)
Valuation allowance		(166,265)		(138,138)
Net deferred tax assets	$	—	$	—

Schedule of reconciliation of beginning and ending unrecognized tax benefits

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

	Year Ended December 31,
	2023		2022		2021
Balance at beginning of year	$	25,295	$	33,159	$	19,885
Decreases based on tax positions related to prior years		—		(10,779)		—
Increases based on tax positions related to current year		2,730		2,915		13,274
Balance at end of year	$	28,025	$	25,295	$	33,159