Condensed Statements of Comprehensive Loss (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Product revenues				$ 114
Operating expenses:
Research and development	603	1,080	1,349	1,734
General and administrative	1,052	1,199	2,187	2,531
Restructuring		(2)		11
Total operating expenses	1,655	2,277	3,536	4,276
Loss from operations	(1,655)	(2,277)	(3,536)	(4,162)
Change in fair value of warrants		4		5
Investment income	1	3	2	8
Other (expense) income, net		4		(8)
Net loss	(1,654)	(2,266)	(3,534)	(4,157)
Non-cash deemed dividend to preferred stock	(2,481)		(2,481)
Net loss attributable to common stock	(4,135)	(2,266)	(6,015)	(4,157)
Comprehensive loss	$ (1,654)	$ (2,266)	$ (3,534)	$ (4,157)
Basic and diluted net loss per share attributable to common stock	$ (1.86)	$ (1.65)	$ (2.89)	$ (3.10)
Weighted-average number of common shares outstanding	2,227	1,374	2,082	1,342