Consolidated Statements of Operations (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement [Abstract]
Licensing revenue	$ 5,119	$ 302,059	$ 225,868
Other revenue		145,152	202,592
Total revenues	5,119	447,211	428,460
Operating Expenses:
Research and development	8,670,710	3,796,127	2,578,852
Selling, general and administrative	6,374,429	4,905,757	2,760,062
Total operating expenses	15,045,139	8,701,884	5,338,914
Loss from operations	(15,040,020)	(8,254,673)	(4,910,454)
Other Income (Expense):
Interest income	5,466	4,808	1,519
Interest expense	(504,858)	(13,926)	(37,549)
Debt financing costs	(455,000)
Qualified therapeutic research grant			244,480
Gain (loss) on extinguishment of debt/payables		(1,514)	183,863
Gain (loss) on disposals of assets	(21,272)	(1,348)
Gain (loss) on revaluation of derivative warrant liability	3,683,676	(1,762,938)	371,345
Other income (expense), net	2,708,012	(1,774,918)	763,658
Net loss	(12,332,008)	(10,029,591)	(4,146,796)
Deemed dividend on beneficial conversion feature of Series D Convertible Preferred Stock		(1,975,211)
Deemed dividend on repricing of warrants		(4,559,761)
Accretion of dividends on Convertible Perpetual Redeemable Preferred Stock		(157,733)	(131,659)
Net loss applicable to common shareholders	$ (12,332,008)	$ (16,722,296)	$ (4,278,455)
Net loss per common share, basic and diluted	$ (0.31)	$ (0.49)	$ (0.15)
Basic and diluted weighted average common shares outstanding	39,550,464	34,174,895	29,031,158