Note 8 - Stock-Based Compensation

9 Months Ended

Sep. 30, 2014

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

8.   Stock-based compensation

Total stock-based compensation expense is recognized for stock options granted to employees and non-employees and has been reported in the Company’s statements of operations as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
Research and development	$	47	$	14	$	68	$	98
General and administrative		138		7		166		28
Total	$	185	$	21	$	234	$	126

The following table summarizes stock option activity for employees and nonemployees:

	Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (years)		Aggregate Intrinsic Value
Outstanding at December 31, 2013		607,017		$	2.22		5.2	$	1,627
Granted		527,718		$	4.92
Exercised		(709	)	$	1.27
Cancelled or forfeited		-		$	-
Outstanding at September 30, 2014		1,134,026		$	3.49		6.9	$	8,716
Exercisable at September 30, 2014		581,438		$	2.38		4.5	$	5,123
Vested or expected to vest at September 30, 2014		1,067,423		$	3.33		6.8	$	8,264