Annual report pursuant to Section 13 and 15(d)

Income Taxes (Tables)

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes and operating loss and credit carryforwards. Significant components of our deferred tax assets are as follows (in thousands):

	December 31,
	2018			2017
Deferred tax assets:
Net operating loss carryforwards	$	62,863		$	62,295
Research credit carryforwards		15,886			15,873
Other, net		1,321			1,705
Total deferred tax assets		80,070			79,873
Valuation allowance		(80,070	)		(79,873	)
Net deferred tax assets	$	—		$	—

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

The provision for income taxes consists of state minimum taxes due. The effective tax rate of our provision (benefit) for income taxes differs from the federal statutory rate as follows (in thousands):

	Year Ending December 31,
	2018			2017			2016
Computed at 21%	$	(1,879	)	$	(4,832	)	$	1,758
State taxes		(167	)		(157	)		(187	)
Change in valuation allowance		197			(28,555	)		(4,439	)
Other		121			388			659
Revaluation of warrant liability		(30	)		(210	)		(280	)
Research and development credits		144			(250	)		(252	)
Net operating loss carryforward expirations		975			1,007			2,741
Impact of 2017 Tax Act		—			32,609			—
Impact of IRC 162m		639			—			—
Total	$	—		$	—		$	—