CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 20,881,716	$ 28,424,631
Prepaid contract research and manufacturing	908,808	175,192
Other prepaid expenses and other current assets	290,804	176,181
Total current assets	22,081,328	28,776,004
Property and equipment, net	63,676	151,544
Total Assets	22,145,004	28,927,548
Liabilities and Stockholders' Equity
Accounts payable	1,204,006	788,073
Accrued compensation and related expenses	185,090	199,935
Accrued restructuring	394,949	841,184
Accrued contract research and manufacturing	467,505	496,901
Other accrued expenses	702,180	685,305
Total current liabilities	2,953,730	3,011,398
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, 200,000,000 and 100,000,000 shares authorized, respectively; 68,109,960 and 67,075,779 shares issued and outstanding, respectively	6,811	6,708
Additional paid-in capital	245,341,659	240,970,852
Deficit accumulated during the development stage	(226,157,196)	(215,061,410)
Total stockholders' equity	19,191,274	25,916,150
Total liabilities and stockholders' equity	$ 22,145,004	$ 28,927,548