Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Summary of Difference Between Provision for Income Taxes and Amounts Computed by Applying Statutory Federal Income Tax Rate to Income Before Income Taxes

The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows (in thousands):

	Year Ended December 31,
	2020			2019			2018
Tax provision derived by applying the federal statutory rate to income before income taxes	$	(16,988	)	$	(16,433	)	$	(9,313	)
Permanent differences and other		482			(98	)		264
Federal tax credits		(3,905	)		(3,599	)		(1,211	)
State tax credits		(251	)		(229	)		464
Change in the valuation allowance		20,662			20,359			9,796
Income tax expense /(benefit)	$	—		$	—		$	—

Components of Deferred Tax Assets and Liabilities

The components of the deferred tax assets and liabilities consist of the following (in thousands):

	December 31,
	2020			2019
Deferred tax assets
Net operating loss carryforward	$	51,708		$	36,093
Intangible assets		51			45
Accrued expense		598			605
Stock-based compensation		2,087			1,237
Federal tax credits		14,764			10,859
State tax credits		839			588
Other		299			126
Total deferred tax assets		70,346			49,553
Deferred tax liabilities
Depreciable assets		(203	)		(72	)
Total deferred tax liabilities		(203	)		(72	)
Less: Valuation allowance		(70,143	)		(49,481	)
Deferred tax assets, net	$	—		$	—