CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 33,037,780	$ 41,106,301
Short-term investments	0	4,500,000
Prepaid contract research and manufacturing	362,930	173,592
Other prepaid expenses and other current assets	224,980	793,521
Total current assets	33,625,690	46,573,414
Property and equipment, net	181,454	291,024
Other assets	0	38,267
Total Assets	33,807,144	46,902,705
Liabilities and Stockholders' Equity
Accounts payable	1,244,081	4,866,356
Accrued compensation and related expenses	209,761	1,419,437
Accrued restructuring	1,026,931	0
Accrued contract research and manufacturing	2,718,170	5,245,339
Other accrued expenses	913,940	1,706,763
Total current liabilities	6,112,883	13,237,895
Commitments
Stockholders' equity:
Preferred stock, $0.0001 par value, 5,000,000 shares authorized, no shares issued and outstanding	0	0
Common stock, $0.0001 par value, 100,000,000 shares authorized, 67,040,569 and 62,034,146 shares issued and outstanding, respectively	6,704	6,203
Additional paid-in capital	240,520,858	216,984,108
Deficit accumulated during the development stage	(212,833,301)	(183,325,501)
Total stockholders' equity	27,694,261	33,664,810
Total liabilities and stockholders' equity	$ 33,807,144	$ 46,902,705