Note 10 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Notes Tables

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

	Year Ended December 31,
	2015			2014
Income tax provision (benefit) at statutory rate		(34	)%		(34	)%
State income taxes, net of federal benefit		(6	)%		(6	)%
Merger transaction costs		0	%		6	%
Change in valuation allowance		39	%		37	%
Other		1	%		(3	)%
Effective tax rate		0	%		0	%

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

	December 31,
	2015			2014
Deferred tax assets:
Net operating loss carryforwards	$	10,726		$	5,770
Capitalized start up costs		7,225			7,751
Research and development credits		248			189
Accruals and reserves		497			169
Total deferred tax assets		18,696			13,879
Deferred tax liabilities:
Fixed assets and depreciation		(8	)		(13	)
Valuation allowance		(18,688	)		(13,866	)
Net deferred tax assets	$	-		$	-

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	Year Ended December 31,
	2015		2014
Balance at the beginning of the year	$	97	$	83
Additions based upon tax positions related to the current year		31		14
Balance at the end of the year	$	128	$	97