STOCK-BASED COMPENSATION (Tables)

9 Months Ended

Sep. 30, 2017

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

Schedule of fair values of stock options granted, estimated using Black-Scholes option valuation model assumptions

We estimated the fair value of stock options awarded during the nine months ended September 30, 2016 and 2017 using the Black-Scholes option valuation model. The fair values of stock options granted for the periods were estimated using the following assumptions: 

	Stock Option Grants Awarded During the Nine Months Ended September 30, 2016	Stock Option Grants Awarded During the Nine Months Ended September 30, 2017
Stock Price	$1.93 to $5.26	$4.36 to $4.68
Dividend Yield	0.00%	0.00%
Expected Volatility	60%	60%
Risk-free interest rate	1.30% - 1.78%	1.95% - 2.14%
Expected Life	7 years	7 years

Summary of stock option activity

The following is a summary of our stock option activity during the nine months ended September 30, 2017: 

	Number of Stock Options		Weighted Average Exercise Price		Weighted Average Grant Date Fair Value		Weighted Average Remaining Life In Years
Outstanding, January 1, 2017	801,690		$	5.25	$	3.32	7.40
Granted	299,880		4.44		2.67		9.54
Exercised	(27,818	)	1.95		1.16		—
Forfeited	(165,192	)	6.32		4.15		—
Outstanding, September 30, 2017	908,560		$	4.94	$	3.06	8.23

	Number of Stock Options		Weighted Average Exercise Price		Weighted Average Grant Date Fair Value		Weighted Average Remaining Life In Years
Exercisable, January 1, 2017	419,174		$	5.94	$	3.86	6.00
Vested	329,733		4.55		2.76		8.57
Exercised	(27,818	)	1.95		1.16		—
Forfeited	(129,901	)	7.13		4.69		—
Exercisable, September 30, 2017	591,188		$	5.30	$	3.32	7.98

Schedule of information related to stock options outstanding and exercisable

The following table presents information related to stock options outstanding and exercisable at September 30, 2017: 

Stock Options Outstanding		Stock Options Exercisable
Exercise Price	Outstanding Number of Stock Options	Weighted Average Remaining Life In Years	Exercisable Number of Stock Options
$1.93 – $2.00	149,000	8.35	55,884
$3.83 – $4.70	369,880	9.40	242,854
$5.06 – $6.00	250,000	6.87	192,509
$6.49 – $7.20	50,000	6.93	37,820
$7.54 – $7.55	57,800	7.21	38,202
$8.06 – $12.98	31,880	4.52	23,919
	908,560	7.98	591,188

Schedule of restricted stock unit activity

A summary of restricted stock unit activity for the nine months ended September 30, 2017 is as follows: 

	Number of Restricted Share Units		Weighted- Average Grant-Date Fair Value
Outstanding at January 1, 2017	1,455,558		$	3.64
Granted	529,907		4.48
Vested	(532,031	)	4.20
Forfeited	(51,741	)	5.40
Outstanding at September 30, 2017	1,401,693		$	4.53

Schedule of stock-based compensation

Total equity-based compensation costs recorded in the condensed consolidated statements of operations is allocated as follows: 

	Three Months Ended September 30, 2016		Three Months Ended September 30, 2017		Nine Months Ended September 30, 2016		Nine Months Ended September 30, 2017
Research and development
Employees	$	172,000	$	304,000	$	497,000	$	839,000
Non-employees	5,000		20,000		18,000		61,000
Total research and development	177,000		324,000		515,000		900,000
General and administrative
Employees and directors	281,000		314,000		705,000		998,000
Non-employees	94,000		28,000		130,000		126,000
Total general and administrative	375,000		342,000		835,000		1,124,000
Total equity-based compensation	$	552,000	$	666,000	$	1,350,000	$	2,024,000