UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Contract revenue	$ 962,451	$ 3,488,142	$ 8,363,909	$ 14,258,680
Operating expenses:
Research and development	1,728,929	2,556,383	7,528,616	11,192,403
General and administrative	3,192,427	4,086,348	8,289,788	8,698,873
Depreciation	37,125	44,593	113,272	139,049
Total operating expenses	4,958,481	6,687,324	15,931,676	20,030,325
Loss from operations	(3,996,030)	(3,199,182)	(7,567,767)	(5,771,645)
Other income (expense):
Interest income	8	31	690	2,470
Interest expense	(46,938)	(89,817)	(174,046)	(289,635)
Change in fair value of derivative instruments	(560,487)	(628,622)	464,703	(1,181,575)
Other income (expense)	80	507	(1,470)	(3,506)
Total other income (expense)	(607,337)	(717,901)	289,877	(1,472,246)
Net loss before income taxes	(4,603,367)	(3,917,083)	(7,277,890)	(7,243,891)
Income tax provision	(25,068)	(28,804)	(48,105)	(49,753)
Net loss	$ (4,628,435)	$ (3,945,887)	$ (7,325,995)	$ (7,293,644)
Basic and diluted net loss per share	$ (0.08)	$ (0.08)	$ (0.13)	$ (0.15)
Weighted average shares used in calculation of basic and diluted net loss per share	58,952,731	52,166,733	55,577,550	50,105,641