Condensed Statements of Opertations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Operating costs and expenses(1) :
Research and development	$ 1,499	$ 3,348	$ 3,182	$ 7,533
General and administrative	1,401	1,678	2,786	3,381
Restructuring				510
Total operating costs and expenses	2,900	5,026	5,968	11,424
Loss from operations	(2,900)	(5,026)	(5,968)	(11,424)
Change in fair value of warrants and other financial instruments	(31)	7,539	2,179	2,906
Investment income	1	4	2	11
Other (expense) income, net	(2)	20	(8)	16
Net (loss) income	(2,932)	2,537	(3,795)	(8,491)
Basic and diluted net (loss) income per share	$ (0.32)	$ 0.73	$ (0.49)	$ (2.54)
Weighted-average number of common shares outstanding - Basic and diluted	9,110	3,477	7,820	3,348
(1) Includes share based compensation expense as follows:
Research and development	1,499	3,348	3,182	7,533
General and administrative	1,401	1,678	2,786	3,381
Total share based compensation expense			486	474
Stock Based Compensation [Member]
Operating costs and expenses(1) :
Research and development	118	13	166	47
General and administrative	211	270	320	427
(1) Includes share based compensation expense as follows:
Research and development	118	13	166	47
General and administrative	211	270	320	427
Total share based compensation expense	$ 329	$ 283	$ 486	$ 474