Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income Tax Benefit Attributable to Our Loss from Operations

Income tax benefit attributable to our loss from operations before income taxes differs from the amounts computed by applying the U.S. federal statutory income tax rate of 34% for 2016 and 2015, as a result of the following (in thousands):

	Years ended December 31,
	2016			2015
U.S. federal income tax benefit at statutory rates	$	(5,591	)	$	(3,891	)
State income tax benefit, net of federal benefit		(502	)		(350	)
Research and experimentation credits		(268	)		(181	)
Deferred tax asset adjustment		65			76
Other		137			188
Change in valuation allowance		6,159			4,158
	$	—		$	—

Net Deferred Tax Assets

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting and the amounts used for income tax purposes, as well as operating loss and tax credit carryforwards. The income tax effects of temporary differences and carryforwards that give rise to significant portions of the Company’s net deferred tax assets consisted of the following (in thousands):

	Years ended December 31,
	2016			2015
Net operating loss carryforwards	$	51,758		$	46,056
Charitable contribution carryforwards		552			454
Research and experimentation credits		1,440			1,172
Capitalized intangibles		781			746
Stock based compensation		193			162
Depreciation and amortization		6			2
Vacation accrual		35			28
Other		14			—
Total deferred tax assets		54,779			48,620
Valuation allowance		(54,779	)		(48,620	)
Net deferred tax assets	$	—		$	—