Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		127 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014
Research contract revenue	$ 200	$ 200	$ 2,467
Operating expenses:
Research and development, including costs of research contracts	6,542	19,112	261,739
General and administrative	3,442	4,671	107,421
Total operating expenses	9,984	23,783	369,160
Loss from operations	(9,784)	(23,583)	(366,693)
Other income (expense), net	(9)	(4)	4,113
Change in fair value of warrants	82	10,788	12,038
Net loss	$ (9,711)	$ (12,799)	$ (350,542)
Net loss per share - basic and diluted	$ (0.10)	$ (0.15)
Weighted average common shares outstanding to compute net loss per share - basic and diluted	100,229,200	82,906,080