Consolidated Statements Of Cash Flows (USD $)	12 Months Ended			117 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011
Operating activities:
Net loss	$ (50,452,165)	$ (37,330,069)	$ (25,771,914)	$ (183,325,501)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash stock-based compensation	2,648,741	1,986,755	1,673,165	8,990,656
Depreciation and amortization	116,465	75,610	69,431	421,979
Stock issued for license fee				575,023
Non-cash interest expense				34,020
Other-than temporary impairment (gain on recovery) of short-term and long-term investments			(4,390,487)
Gain on disposition of fixed assets				(2,208)
Fair value of warrants for finder's fee				433,750
Changes in operating assets and liabilities:
Prepaid contract research and manufacturing expenses, other prepaid expenses and other assets	(404,377)	(139,164)	303,665	(967,114)
Accounts payable, accrued contract research and manufacturing expenses and other accrued expenses	(200,603)	2,882,709	(2,588,850)	11,818,460
Accrued compensation and related expenses	252,355	272,386	314,821	1,419,437
Net cash used in operating activities	(48,039,584)	(32,251,773)	(30,390,169)	(160,601,498)
Investing activities:
Acquisitions of property and equipment	(227,468)	(151,836)	(14,037)	(714,473)
Proceeds from sale of assets				3,677
Purchases of short-term investments	(65,605,570)			(115,143,906)
Redemptions of short-term investments	61,105,570	11,450,000	14,575,000	110,643,906
Security deposits	(172)	38,855		(38,267)
Net cash (used in) provided by investing activities	(4,727,640)	11,337,019	14,560,963	(5,249,063)
Financing activities:
Proceeds from borrowings from affiliate				1,745,000
(Repayment of) borrowings from line of credit		(11,466,012)	4,188,544
Proceeds from exercise of stock options				80,729
Proceeds from exercise of common stock warrants	8,480,135	275,331		9,054,546
Proceeds from sales of equity securities, net of issuance costs	37,726,538	57,403,841	12,402,758	196,398,165
Receipt of recovery of short-swing profits	73,797			73,797
Recapitalization of the Company				(400,000)
Receipt of cash for stock subscription receivable				4,625
Net cash provided by financing activities	46,280,470	46,213,160	16,591,302	206,956,862
Net (decrease) increase in cash and cash equivalents	(6,486,754)	25,298,406	762,096	41,106,301
Cash and cash equivalents, beginning of period	47,593,055	22,294,649	21,532,553
Cash and cash equivalents, end of period	41,106,301	47,593,055	22,294,649	41,106,301
Supplemental disclosure of cash flow information:
Cash paid for interest		$ 70,389	$ 149,019	$ 224,328