Condensed Statements of Comprehensive Loss (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Condensed Statements of Comprehensive Loss [Abstract]
Product revenues			$ 114
Operating expenses:
Research and development	1,015	1,098	2,749	4,280
General and administrative	1,220	1,309	3,751	4,095
Restructuring (Note 2)	4	1,146	15	1,146
Total operating expenses	2,239	3,553	6,515	9,521
Loss from operations	(2,239)	(3,553)	(6,401)	(9,521)
Change in fair value of warrants		40	5	2,219
Investment income	2	1	10	3
Other (expense) income, net	(10)	(1)	(18)	(9)
Net loss	(2,247)	(3,513)	(6,404)	(7,308)
Comprehensive loss	$ (2,247)	$ (3,513)	$ (6,404)	$ (7,308)
Basic and diluted net loss per share	$ (0.13)	$ (0.25)	$ (0.38)	$ (0.74)
Weighted-average number of common shares outstanding	17,819	13,969	16,675	9,870