Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Components of Federal and State Income Tax Expense

The components of federal and state income tax expense are as follows (in thousands):

	Year Ended December 31,
	2015			2014
Current
Federal	$	—		$	—
State		—			—
Total current		—			—
Deferred
Federal		(3,157	)		(2,727	)
State		(803	)		(583	)
Total deferred		(3,960	)		(3,310	)
Valuation allowance		3,960			3,310
Total income tax expense	$	—		$	—

Effect Income Tax Rate Reconciliation

The differences between the income taxes expected at the Federal statutory income tax rate and the reported income tax (benefit) expense is as follows:

	2015			2014
Federal statutory rate		34.0	%		34.0	%
State income taxes, net of federal benefit		4.8			4.2
Non-deductible expenses		(1.9	)		(2.1	)
Income tax credits		1.9			1.6
Valuation allowance		(38.8	)		(37.7	)
Effective tax rate		0.0	%		0.0	%

Components of Net Deferred Tax Assets

The components of net deferred tax assets are as follows (in thousands):

	As of December 31,
	2015			2014
Net operating loss carryforwards	$	13,552		$	9,805
Tax credit carryforwards		442			261
Stock-based compensation		1,744			1,392
Licensing deduction deferral		5,979			6,367
Other timing differences		178			110
Gross deferred tax assets		21,895			17,935
Valuation allowance		(21,895	)		(17,935	)
Net deferred tax asset	$	—		$	—