CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Jun. 30, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 40,823,594	$ 41,106,301
Short-term investments	0	4,500,000
Prepaid contract research and manufacturing	669,940	173,592
Other prepaid expenses and other current assets	651,162	793,521
Total current assets	42,144,696	46,573,414
Property and equipment, net	246,029	291,024
Other assets	0	38,267
Total Assets	42,390,725	46,902,705
Liabilities and Stockholders' Equity
Accounts payable	2,174,401	4,866,356
Accrued compensation and related expenses	379,919	1,419,437
Accrued contract research and manufacturing	4,784,609	5,245,339
Other accrued expenses	1,384,949	1,706,763
Total liabilities	8,723,878	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	240,417,146	216,984,108
Deficit accumulated during the development stage	(206,757,003)	(183,325,501)
Total stockholders' equity	33,666,847	33,664,810
Total liabilities and stockholders' equity	$ 42,390,725	$ 46,902,705