Consolidated Balance Sheets (USD $)	Dec. 31, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 41,106,301	$ 47,593,055
Short-term investments, net	4,500,000
Prepaid contract research and manufacturing	173,592	316,363
Other prepaid expenses and other current assets	793,521	246,374
Total current assets	46,573,414	48,155,792
Property and equipment, net	291,024	180,021
Other assets	38,267	38,095
Total Assets	46,902,705	48,373,908
Liabilities and Stockholders' Equity
Accounts payable	4,866,356	2,288,241
Accrued compensation and related expenses	1,419,437	1,167,082
Accrued contract research and manufacturing	5,245,339	8,950,469
Other accrued expenses	1,706,763	780,352
Total current liabilities	13,237,895	13,186,144
Commitments
Stockholders' equity:
Preferred stock, $0.0001 par value, 5,000,000 shares authorized, no shares issued and outstanding
Common stock, $0.0001 par value, 100,000,000 shares authorized and 62,034,146 and 49,790,975 shares issued and outstanding, respectively	6,203	4,979
Additional paid-in capital	216,984,108	168,056,121
Deficit accumulated during the development stage	(183,325,501)	(132,873,336)
Total stockholders' equity	33,664,810	35,187,764
Total liabilities and stockholders' equity	$ 46,902,705	$ 48,373,908