STOCK-BASED COMPENSATION (Tables)

9 Months Ended

Sep. 30, 2017

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

Schedule of non-cash stock-based compensation expense

Non-cash stock-based compensation expense included in cost of goods sold, research and development expenses and selling, general and administrative expenses is summarized in the following table: 

	Three Months Ended September 30,				Nine Months Ended September 30,
(In thousands)	2017		2016		2017		2016
Cost of goods sold	$	119	$	117	$	316	$	330
Research and development	177		133		$	391	$	392
Selling, general and administrative	459		404		1,346		1,251
Total non-cash stock-based compensation expense	$	755	$	654	$	2,053	$	1,973

Schedule of weighted average assumptions used to estimate fair value of each service-based stock option grant

The fair value of each service-based stock option grant for the reported periods is estimated on the date of the grant using the Black-Scholes option-pricing model using the weighted average assumptions noted in the following table.

	Nine Months Ended September 30,
Service-Based Stock Options	2017		2016
Expected dividend rate	—	%	—	%
Expected stock price volatility	80.1 – 88.2%		78.7 – 92.2%
Risk-free interest rate	1.8 – 2.3%		1.1 – 1.8%
Expected life (years)	5.5 – 6.3		5.5 – 6.3

Summary of activity for service-based stock options

The following table summarizes the activity for service-based stock options for the indicated periods:

Service-Based Stock Options	Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding at December 31, 2016	3,355,692		$	4.66	8.2	$	610
Granted	1,677,760		$	2.82
Exercised	(165,678	)	$	3.12		$	362
Expired	(100,131	)	$	16.31
Forfeited	(190,766	)	$	3.35
Outstanding at September 30, 2017	4,576,877		$	3.84	8.2	$	13,336
Exercisable at September 30, 2017	1,870,011		$	5.18	7.5	$	4,988