Income Taxes Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Summary of Components of the Provision for Income Taxes

The provision for income taxes for the years ended December 31, 2018 and 2017 was comprised as follows (in thousands):



	Year Ended December 31,
	2018		2017
Current taxes:
Federal	$	—	$	—
State	46		36
Total current taxes	46		36
Deferred taxes:
Federal	—		—
State	—		—
Total deferred taxes	—		—
Total provision for income taxes	$	46	$	36

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,
	2018		2017
Income tax computed at federal statutory tax rate	21.0	%	34.0	%
Deferred tax effects from the Tax Act	—	%	(57.2	)%
State taxes, net of federal benefit	10.3	%	4.7	%
Tax credit carryforwards	12.2	%	26.8	%
Non-deductible income (expense)	—	%	(4.9	)%
Change in valuation allowance	(42.7	)%	(1.8	)%
Other	(1.0	)%	(1.8	)%
Effective tax rate	(0.2	)%	(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, 2018 and 2017 were comprised as follows (in thousands):



	December 31,
	2018			2017
Deferred tax assets:
Net operating loss carryforwards	$	37,417		$	26,926
Tax credit carryforwards	12,751			8,432
Deferred revenue	26,739			31,735
Deferred lease incentive	103			120
Deferred rent	476			431
Intangibles	552			237
Accrued expenses and other	1,091			995
Unrealized loss on available-for-sale securities	39			112
Stock-based compensation	2,119			713
Total deferred tax assets	81,287			69,701
Less: valuation allowance	(55,348		)	(30,850		)
Net deferred tax assets	25,939			38,851
Deferred tax liabilities:
Section 481(a) method change	(25,653		)	(38,481		)
Depreciation	(286		)	(370		)
Total deferred tax liabilities	(25,939		)	(38,851		)
Net deferred taxes	$	—		$	—