STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2012

STOCK-BASED COMPENSATION

Schedule of weighted average assumptions used in estimation of the fair value of options granted

	2012	2011	2010
Expected option life (years)	5.5 - 6.25	5.5 - 6.25		6.00
Risk-free interest rate	0.775% - 1.105%	1.175% - 2.57%		2.42	%
Expected stock price volatility	92.97% - 97.20%	69.07% - 72.16%		76.05	%
Dividend yield	—	—		—

Summary of stock option compensation expense for employees and non-employees

	2012		2011		2010
Research and development	$	53,812	$	423,925	$	325,208
General and administrative		671,813		753,758		667,549
Total stock-based compensation expense	$	725,625	$	1,177,683	$	992,757

Summary of activity under the plans

Options	Option Shares		Weighted Average Exercise Price		Weighted Average Remaining Term		Aggregate Intrinsic Value
Outstanding December 31, 2011		906,860	$	18.36		6.97	$	0
Granted		358,582	$	4.08
Exercised		—		—
Forfeited or expired		160,583	$	12.90
Outstanding December 31, 2012		1,104,859	$	14.51		6.45	$	0
Exercisable at December 31, 2012		614,425	$	20.77		4.73	$	0
Vested or expected to vest at December 31, 2012		1,069,890	$	14.69		6.39	$	0