STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended		95 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011
Research contract revenue	$ 200		$ 267		$ 267
Operating expenses:
Research and development, including costs of research contracts	9,125	2,222	33,766	4,161	105,582
General and administrative	3,923	2,894	7,275	5,524	61,086
Total operating expenses	13,048	5,116	41,041	9,685	166,668
Loss from operations	(12,848)	(5,116)	(40,774)	(9,685)	(166,401)
Other income, net	9	13	7	22	4,682
Change in fair value of warrants	2,115	14,142	(8,965)	1,049	(11,827)
Net income (loss)	$ (10,724)	$ 9,039	$ (49,732)	$ (8,614)	$ (173,546)
Net income (loss) per share - basic	$ (0.16)	$ 0.21	$ (0.78)	$ (0.21)
Net income (loss) per share - diluted	$ (0.16)	$ 0.19	$ (0.78)	$ (0.21)
Weighted average common shares outstanding to compute net income (loss) per share - basic	67,229,098	42,364,791	63,839,723	41,253,076
Weighted average common shares outstanding to compute net income (loss) per share - diluted	67,229,098	48,822,686	63,839,723	41,253,076