STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data	3 Months Ended		9 Months Ended		85 Months Ended
	Sep. 30, 2010	Sep. 30, 2009	Sep. 30, 2010	Sep. 30, 2009	Sep. 30, 2010
Research contract revenue
Operating expenses:
Research and development, including costs of research contracts	5,711	1,231	9,872	3,340	68,778
General and administrative	2,789	1,339	8,313	4,754	50,488
Total operating expenses	8,500	2,570	18,185	8,094	119,266
Loss from operations	(8,500)	(2,570)	(18,185)	(8,094)	(119,266)
Other income, net	7	(1)	29	1	3,939
Change in fair value of warrants	(3,712)	(304)	(2,663)	(520)	3,364
Net loss	$ (12,205)	$ (2,875)	$ (20,819)	$ (8,613)	$ (111,963)
Net loss per share - basic	$ (0.26)	$ (0.13)	$ (0.48)	$ (0.40)
Net loss per share - diluted	$ (0.26)	$ (0.13)	$ (0.48)	$ (0.40)
Weighted average common shares outstanding used to compute net loss per share - basic	47,426,991	21,759,309	43,333,663	21,458,150
Weighted average common shares outstanding used to compute net loss per share - diluted	47,426,991	21,759,309	43,333,663	21,458,150