CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 28,424,631	$ 41,106,301
Short-term investments, net	0	4,500,000
Prepaid contract research and manufacturing	175,192	173,592
Other prepaid expenses and other current assets	176,181	793,521
Total current assets	28,776,004	46,573,414
Property and equipment, net	151,544	291,024
Other assets	0	38,267
Total Assets	28,927,548	46,902,705
Liabilities and Stockholders' Equity
Accounts payable	788,073	4,866,356
Accrued compensation and related expenses	199,935	1,419,437
Accrued restructuring	841,184	0
Accrued contract research and manufacturing	496,901	5,245,339
Other accrued expenses	685,305	1,706,763
Total current liabilities	3,011,398	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 and 67,075,779 and 62,034,146 shares issued and outstanding, respectively	6,708	6,203
Additional paid-in capital	240,970,852	216,984,108
Deficit accumulated during the development stage	(215,061,410)	(183,325,501)
Total stockholders' equity	25,916,150	33,664,810
Total liabilities and stockholders' equity	$ 28,927,548	$ 46,902,705