Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Components of Income Taxes (Benefit)

The Company’s benefit from income taxes is as follows:

	December 31,
	2019		2018		2017
Current:
Federal	$	—	$	—	$	—
State		(816)		(389)		(204)
		(816)		(389)		(204)
Deferred:
Federal		—		—		—
State		—		—		—
		—		—		—
Benefit from income taxes	$	(816)	$	(389)	$	(204)

Schedule of Reconciliation of Income Taxes Computed Using U.S. Federal Statutory Rate to that Reflected in Operations

A reconciliation of income taxes computed using the U.S. federal statutory rate to that reflected in operations is as follows:

	December 31,
	2019		2018		2017
Income taxes using U.S. federal statutory rate	21.00	%	21.00	%	34.00	%
State income taxes, net of federal benefit	(1.99)	%	6.82	%	5.33	%
Tax Cuts and Jobs Act	0.00	%	0.00	%	(44.43)	%
Impact of R&D tax credit on effective tax rate	4.34	%	3.48	%	3.25	%
Stock option shortfalls and cancellations	(0.17)	%	(0.43)	%	0.21	%
Permanent items and other	0.36	%	(0.15)	%	(0.56)	%
Change in valuation allowance	(22.76)	%	(31.76)	%	2.55	%
Provision to return	(0.02)	%	0.03	%	0.00	%
Non-taxable revenue	0.00	%	1.54	%	0.00	%
	0.76	%	0.53	%	0.35	%

Schedule of Significant Components of Company's Deferred Tax Assets and Liabilities

Significant components of the Company’s deferred tax assets and liabilities are as follows:

	December 31,
	2019		2018
Valuation allowance	$	(114,136)	$	(89,815)
Net operating loss carryforwards		84,608		73,578
Federal and state tax credits		16,624		11,108
Deferred revenue		5,994		1,111
Stock-based compensation expense		4,481		3,605
Other		3,409		420
Deferred tax assets		115,116		89,822
Other		(980)		(7)
Deferred tax liabilities:		(980)		(7)
Net deferred tax asset:	$	—	$	—