Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

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,
	2019			2018			2017
Tax provision derived by applying the federal statutory rate to income before income taxes	$	(16,433	)	$	(9,313	)	$	(9,260	)
Permanent differences and other		(98	)		264			296
Federal tax credits		(3,599	)		(1,211	)		(1,294	)
State tax credits		(229	)		464			(284	)
Change in tax rate		—			—			7,869
Change in the valuation allowance		20,359			9,796			2,673
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,
	2019			2018
Deferred tax assets
Net operating loss carryforward	$	36,093		$	20,276
Intangible assets		45			38
Accrued expense		605			508
Stock-based compensation		1,237			682
Federal tax credits		10,859			7,260
State tax credits		588			359
Other		126			73
Total deferred tax assets		49,553			29,196
Deferred tax liabilities
Depreciable assets	$	(72	)	$	(74	)
Total deferred tax liabilities		(72	)		(74	)
Less: Valuation allowance		(49,481	)		(29,122	)
Deferred tax assets, net	$	—		$	—