STOCKHOLDERS' EQUITY (Tables)

3 Months Ended

Mar. 31, 2017

Stockholders' Equity Note [Abstract]

Schedule of assumptions used in the Black-Scholes Model of stock options

The assumptions used in the Black-Scholes Model for options granted during the three months ended March 31, 2017 and 2016 are set forth in the table below.

	Three Months Ended March 31, 2017		Three Months Ended March 31, 2016
Risk-free interest rate		1.90%		1.70%
Volatility		61.56-62.83%		71.22%
Term (in years)		6-6.25		6.25
Dividend yield		0.00%		0.00%

Schedule of plan activity

A summary of activity under the 2009 and 2012 Plans and related information follows:

	Number of Shares Underlying Stock Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life in Years		Aggregate Intrinsic Value
Balance at December 31, 2016		21,767,854		$	3.56		5.8	$	60,495,730
Granted		1,730,500		$	6.83
Exercised		(95,046	)	$	2.02			$	421,767
Expired/Forfeited		(116,375	)	$	7.46
Balance at March 31, 2017		23,286,933		$	3.78		5.9	$	85,606,859
Vested and Exercisable at March 31, 2017		18,514,058		$	3.09		5.1	$	81,091,380
Unvested at March 31, 2017		4,772,875		$	6.48		9.2	$	4,515,479