Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Reconciliation of Federal Income Tax Rate to Losses Before Income Tax Benefit

The reasons for the difference between actual income tax benefit for the years ended December 31, 2018 and 2017, and the amount computed by applying the statutory federal income tax rate to losses before income tax benefit are as follows:



	Year Ended December 31,
	2018			2017

Income tax benefit at federal statutory rate	$	(2,661	)	$	(12,451	)
State income taxes, net of federal benefit	(570		)	(751		)
Non-deductible expenses	154			235
Federal rate impact	—			18,894
Change in fair value of warrants	(3,479		)	—
Research and development tax credits	(1,254		)	(1,732		)
Other	380			431
Change in valuation allowance	7,430			(4,626		)
Total income tax provision	$	—		$	—

Significant Components of Company's Deferred Tax Assets and Deferred Tax Liabilities

Significant components of the Company’s deferred tax assets and deferred tax liabilities are as follows:



	As of December 31,
	2018			2017
Deferred tax assets:
Accrued compensation	$	184		$	329
Accrued liabilities	149			121
Tax loss carryforwards	37,986			32,395
Intangible assets	286			307
Share-based compensation	814			728
Tax credits	6,917			5,662
Facility financing lease obligation	1,847			1,861
Deferred revenue	588			—
Other	10			13
Total deferred tax assets	48,781			41,416
Less valuation allowance	(46,604		)	(39,174		)
Net deferred tax asset	2,177			2,242
Deferred tax liabilities:
Fixed assets	(2,032		)	(2,067		)
Other	(145		)	(175		)
Net noncurrent deferred tax asset (liability)	$	—		$	—