STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2013

STOCK-BASED COMPENSATION

Summary of option activity

	Number of		Weighted Average
	Shares		Exercise Price
Outstanding at December 31, 2012	5,579,042		$	6.68
Granted	261,915		1.68
Exercised	(3,175	)	1.65
Forfeited	(42,126	)	3.67
Expired	(58,686	)	5.30
Outstanding at March 31, 2013	5,736,970		6.49
Options exercisable at March 31, 2013	3,186,670		$	9.01
Weighted average grant date fair value of options granted during the three months ended March 31, 2013			$	1.19

Schedule of assumptions used in determining fair value of stock options granted using the Black-Scholes option pricing model

	Three Months Ended
	March 31,
	2013	2012
Expected dividend yield	—	—
Risk-free rate	0.92%	0.72% - 1.15%
Expected option term (in years)	5.95	5.36 – 5.47
Volatility	85%	85%-87%