CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			86 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012
Costs and Expenses:
Research and development	$ 29,294	$ 13,419	$ 9,559	$ 57,707
Purchased in-process research and development	1,000			29,157
General and administrative	7,941	6,745	6,562	27,585
Loss from Operations	(38,235)	(20,164)	(16,121)	(114,449)
Other Income /(Loss)
Interest and investment income	218	90	109	496
Interest expense		(12)		(12)
Other income	506	362	494	1,363
Change in fair value of derivative instruments-warrants	(1,933)	5,257	297	3,621
Total Other Income/(loss)	(1,209)	5,697	900	5,468
Loss from Continuing Operations	(39,444)	(14,467)	(15,221)	(108,981)
Loss from discontinued operations				(72)
Net loss	$ (39,444)	$ (14,467)	$ (15,221)	$ (109,053)
Weighted Average Common Shares Outstanding, Basic and Diluted (restated for stock split) (in shares)	61,702,277	47,598,240	44,875,356
Net Loss per Common Share, Basic and Diluted
Net Loss per Common Share, Basic and Diluted (in dollars per share)	$ (0.64)	$ (0.30)	$ (0.34)