Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Effective Tax Rate For Provision of Income Tax Differs to Federal Statutory Rate

The effective tax rate of the provision for income taxes differs from the federal statutory rate as follows:

	Year Ended December, 31
	2015			2014			2013
Federal statutory income tax rate		34.0	%		34.0	%		34.0	%
State income taxes, net of federal benefit	—				5.8			5.8
Federal and state tax credits		2.1			1.1			3.8
Other permanent differences		(1.9	)	—			—
Change in valuation allowance		(34.2	)		(40.9	)		(43.6	)
		0	%		0	%		0	%

Schedule of Components of Deferred Tax Assets and Liabilities

The components of the deferred tax assets and liabilities are as follows (in thousands):

	Year Ended December, 31
	2015			2014
Deferred tax assets:
Net operating loss carryforwards	$	28,871		$	19,323
Tax credits		2,193			1,512
Accrued liabilities		754			712
Stock based compensation		536			21
Other		509			241
Gross deferred tax assets		32,863			21,809
Valuation allowance		(32,863	)		(21,809	)
Net deferred tax assets	$	-		$	-

Schedule of Companies Unrecognized Tax Benefits

As of December 31, 2015, the Company’s total unrecognized tax benefit was $1.7 million, of which none of the tax benefit, if recognized, would affect the effective income tax rate due to the valuation allowance that currently offsets deferred tax assets. A reconciliation of the Company’s unrecognized tax benefits for the years ended December 31, 2015, 2014 and 2013 is as follows (in thousands):

	Year Ended December, 31
	2015		2014		2013
Balance at beginning of year	$	1,194	$	773	$	388
Additions based on tax positions related to current year		520		421		385
Balance at end of year	$	1,714	$	1,194	$	773