STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 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 three months ended March 31, 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 Three Months Ended March 31, 2016	Stock Option Grants Awarded During the Three Months Ended March 31, 2017
Stock Price	$1.93 to $2.00	$4.36 to $4.37
Dividend Yield	0.00%	0.00%
Expected Volatility	60%	60%
Risk-free interest rate	1.49% - 1.74%	2.09% - 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 three months ended March 31, 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	150,880		4.36		2.63		9.83
Exercised	—		—		—		—
Forfeited	(47,772	)	4.64		3.03		—
Outstanding, March 31, 2017	904,798		$	5.13	$	3.22	7.64

	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	170,418		4.38		2.66		8.92
Exercised	—		—		—		—
Forfeited	(30,276	)	6.20		4.10		—
Exercisable, March 31, 2017	559,316		$	5.45	$	3.48	6.93

Schedule of information related to stock options outstanding and exercisable

The following table presents information related to stock options outstanding and exercisable at March 31, 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	176,818	5.18	65,074
$3.83 – $4.70	220,880	9.75	138,383
$5.06 – $6.00	340,000	5.63	260,866
$6.49 – $7.20	60,000	7.41	38,141
$7.54 – $7.55	69,600	7.67	37,623
$8.06 – $12.98	37,500	7.86	19,229
	904,798	6.93	559,316

Schedule of restricted stock unit activity

A summary of restricted stock unit activity for the three months ended March 31, 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	265,390		4.37
Vested	(310,230	)	3.94
Forfeited	(8,815	)	8.06
Outstanding at March 31, 2017	1,401,903		$	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 March 31, 2016		Three Months Ended March 31, 2017
Research and development
Employees	$	144,000	$	226,000
Non-employees	5,000		26,000
Total research and development	149,000		252,000
General and administrative
Employees and directors	203,000		367,000
Non-employees	6,000		74,000
Total general and administrative	209,000		441,000
Total equity-based compensation	$	358,000	$	693,000