Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of Income Tax Rate Reconciliation

The following table provides a reconciliation between income taxes computed at the federal statutory rate and the provision for income taxes:

	Year Ended December 31,
	2015			2014			2013
Expected income tax benefit at the federal statutory tax rate		35.0	%		34.0	%		34.0	%
State income taxes, net of federal benefit		(3.9	)		5.4			(4.3	)
Other		3.6			1.7			3.8
Change in valuation allowance		(26.6	)		(42.2	)		(33.5	)
Income tax expense (benefit)		8.1	%		(1.1	%)		0.0	%

Components of Company's Net Deferred Tax Assets

Significant components of the Company’s net deferred tax assets are as follows (in thousands):

	December 31,
	2015			2014
Deferred tax assets:
Net operating loss	$	39,375		$	33,485
Capitalized research and development		13,998			6,045
Research and development tax credit		2,413			1,345
Depreciation and amortization		646			819
Stock-based compensation		2,250			489
Accrued expenses		155			440
Total deferred tax assets		58,837			42,623
Deferred tax liabilities:
Beneficial conversion feature		—			(13	)
Net deferred tax asset		58,837			42,610
Less: valuation allowance		(58,837	)		(42,610	)
Net deferred tax assets	$	—		$	—

Reconciliation of Unrecognized Tax Benefits

A reconciliation of the Company’s unrecognized tax benefits as of December 31, 2015, 2014 and 2013 is as follows (in thousands):

	December 31,
	2015		2014		2013
Unrecognized tax benefits, beginning of period	$	571	$	270	$	—
Additions to tax positions — current year		381		185		270
Additions to tax positions — prior years		—		116		—
Unrecognized tax benefits, end of period	$	952	$	571	$	270