Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income Tax Disclosure [Abstract]

Schedule of Reconcilation of Differences Between Income Taxes

The following reconciles the differences between income taxes computed at the federal income tax rate and the provision for income taxes:

	Year Ended December 31,
	2013			2014
Expected income tax benefit at the federal statutory rate		34.0	%		34.0	%
State taxes, net of federal benefit		1.5			3.7
Change in effective tax rate		0.0			1.3
Non-deductible items and other		(2.1	)		0.4
Federal and state credits		2.0			1.2
Change in valuation allowance		(35.4	)		(40.6	)
Total		0.0	%		0.0	%

Schedule of Deferred Tax Assets

The principal components of the Company’s net deferred tax assets consisted of the following at December 31, 2013 and 2014 (in thousands):

	December 31,
	2013			2014
Net operating loss carryforwards	$	33,248		$	46,024
Research and development tax credits		2,041			2,441
Reserves and accruals		2,728			724
Other		376			2,948
		38,393			52,137
Total deferred tax assets		(38,393	)		(52,137	)
Net deferred tax assets	$	—		$	—