Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Reconciliation of Effective Tax Rate

A reconciliation of our effective tax rate to the statutory U.S. federal rate is as follows:

	Year Ended December 31,
	2022			2021			2020(1)
Statutory rate		21.0	%		21.0	%		21.0	%
Stock-based compensation		1.5	%		2.2	%		0.8	%
Credits		0.8	%		1.1	%		0.6	%
Change in valuation allowance		(21.3	)%		(23.0	)%		(22.1	)%
Section 162(m) limitation		(1.8	)%		(1.1	)%		(0.1	)%
Other		(0.2	)%		(0.2	)%		(0.2	)%
Total		0.0	%		0.0	%		0.0	%

(1)The 2020 effective tax rate reconciliation has been updated to conform to the 2021 and 2022 presentation.

Components of Deferred Tax Assets

The following table presents significant components of our deferred tax assets as of December 31, 2022 and 2021:

	As of December 31,
	2022			2021
	(in thousands)
Deferred tax assets:
Net operating losses		111,555			85,574
Fixed assets		1,062			1,700
Accrued & others(1)		1,103			2,174
R&D Credits		5,436			2,865
Capitalized R&D expenditures		32,873			2,984
Accrued manufacturing expenses		2,063			1,006
Lease liability		5,358			6,674
Intangible assets		6,867			—
Stock compensation(1)		4,474			1,956
Total deferred tax assets		170,791			104,934
Deferred tax liabilities:
ROU asset		(6,357	)		(8,349	)
Total deferred tax liabilities		(6,357	)		(8,349	)
Net deferred tax asset		164,433			96,585
Valuation allowance		(164,433	)		(96,585	)
Net deferred taxes	$	—		$	—

(1)The 2021 Accrued & others and Stock compensation lines have been updated to conform to the 2022 presentation.

Reconciliation of Unrecognized Tax Benefit

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

	December 31,
	2022			2021		2020
	(in thousands)
Balance at the beginning of the year	$	924		$	393	$	271
Additions based on tax positions related to current year		876			461		287
Reductions based on tax positions related to prior years		(46	)		70		(165	)
Balance at end of year	$	1,754		$	924	$	393