Quarterly report pursuant to Section 13 or 15(d)

Stock Plans (Tables)

Stock Plans (Tables)

9 Months Ended

Sep. 30, 2015

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

The following table summarizes the stock-based compensation expense recorded for awards under the stock option plans for the three and nine month periods ended September 30, 2015 and 2014:

	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands, except per share amounts)	2015		2014		2015		2014
Research and development	$	42	$	33	$	280	$	206
General and administrative		50		38		379		251
Total stock-based compensation expenses	$	92	$	71	$	659	$	457

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]

We use the Black-Scholes-Merton option-pricing model with the following assumptions to estimate the stock-based compensation expense for the three and nine month periods ended September 30, 2015 and 2014:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
Weighted-average risk-free interest rate		1.7	%		1.7	%		1.8	%		2.0	%
Expected dividend payments		—			—			—			—
Expected holding period (years) ¹		4.5			4.2			6.4			6.5
Weighted-average volatility factor ²		1.65			1.66			1.61			1.66
Estimated forfeiture rates ³		30	%		31	%		30	%		31	%

(1)	Expected holding periods are based on the simplified method provided in Staff Accounting Bulletin No. 107 for “plain vanilla options.”
(2)	Weighted average volatility is based on the historical volatility of our common stock.
(3)	Estimated forfeiture rates are based on historical data.

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

The following table summarizes option activity for the nine month period ended September 30, 2015:

(in thousands, except per share amounts)	Options		Weighted Average Exercise Price		Weighted Average Remaining Option Term		Aggregate Intrinsic Value
Outstanding at January 1, 2015		1,204	$	6.75		5.14	$	1
Granted		250		3.30
Exercised		—		—
Expired or cancelled		(20)		13.27
Forfeited		—		—

Outstanding at September 30, 2015		1,434	$	6.06		5.34	$	202

Exercisable at September 30, 2015		1,311	$	6.32		4.96	$	111

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

The following table summarizes restricted stock activity for the nine month period ended September 30, 2015:

(in thousands, except per share amounts)	Restricted Stock		Weighted Average Exercise Price		Weighted Average Remaining Term		Aggregate Intrinsic Value
Outstanding at January 1, 2015		65	$	—		9.12	$	166
Granted		—		—
Released		(65)		—
Expired or cancelled		—		—
Forfeited		—		—

Outstanding at September 30, 2015		—	$	—		—	$	—

Exercisable at September 30, 2015		—	$	—		—	$	—