Condensed Statements of Operations (Unaudited) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Revenue:
Grant revenue
Collaboration revenue
Total revenue
Operating expenses:
Research and development	7,721,894	3,700,006	12,160,276	7,599,422
General and administrative	2,339,999	1,547,088	4,414,361	3,022,086
Total operating expenses	10,061,893	5,247,094	16,574,637	10,621,508
Loss from operations	(10,061,893)	(5,247,094)	(16,574,637)	(10,621,508)
Other income (expense) net:
Interest income	36,839	1,253	55,864	4,368
Interest expense	(490,645)	(202,175)	(1,188,260)	(451,610)
Other income (expense) net	(3,400)	25,513	(662)	37,692
Net loss	$ (10,519,099)	$ (5,422,503)	$ (17,707,695)	$ (11,031,058)
Net loss per share - basic and diluted	$ (0.35)	$ (5.93)	$ (0.76)	$ (6.33)
Weighted-average number of common shares used in net loss per share calculation - basic and diluted	29,693,004	914,580	23,335,731	1,743,522