Income Taxes Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Summary of Components of the Provision for Income Taxes

The provision for income taxes for the years ended December 31, 2019 and 2018 was comprised as follows (in thousands):



	Year Ended December 31,
	2019		2018
Current taxes:
Federal	$	—	$	—
State	46		46
Total current taxes	46		46
Deferred taxes:
Federal	—		—
State	—		—
Total deferred taxes	—		—
Total provision for income taxes	$	46	$	46

Reconciliation of the Federal Statutory Income Tax Rate to the Effective Tax Rate

A reconciliation of the federal statutory income tax rate to the Company’s effective tax rate is as follows:



	Year Ended December 31,
	2019		2018
Income tax computed at federal statutory tax rate	21.0	%	21.0	%
State taxes, net of federal benefit	4.8	%	10.3	%
Tax credit carryforwards	(5.4	)%	12.2	%
Change in valuation allowance	(21.4	)%	(42.7	)%
Other	1.1	%	(1.0	)%
Effective tax rate	0.1	%	(0.2	)%

Schedule of Components of Deferred Tax Assets and Liabilities

The principal components of the Company’s deferred tax assets and liabilities as of December 31, 2019 and 2018 were comprised as follows (in thousands):



	December 31,
	2019			2018
Deferred tax assets:
Net operating loss carryforwards	$	33,008		$	37,417
Tax credit carryforwards	17,185			12,751
Deferred revenue	—			26,739
Deferred lease incentive	—			103
Deferred rent	—			476
Operating lease liability	5,407			—
Intangibles	519			552
Accrued expenses and other	1,358			1,091
Unrealized loss on available-for-sale securities	17			39
Stock-based compensation	3,376			2,119
Total deferred tax assets	60,870			81,287
Less: valuation allowance	(43,219		)	(55,348		)
Net deferred tax assets	17,651			25,939
Deferred tax liabilities:
Section 481(a) method change	(12,827		)	(25,653		)
Operating lease right-of-use asset	(4,812		)	—
Depreciation	(12		)	(286		)
Total deferred tax liabilities	(17,651		)	(25,939		)
Net deferred taxes	$	—		$	—