Unaudited 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
Expenses:
Research and development	$ 700	$ 336	$ 1,355	$ 370
General and administrative	2,463	2,877	6,011	3,514
Total expenses	3,163	3,213	7,366	3,884
Loss from operations	(3,163)	(3,213)	(7,366)	(3,884)
Other income (expense):
Adjustments to fair value of derivative liabilities		(4,485)		1,469
Other income (expense), net	1	1	2	2
Net loss	(3,162)	(7,697)	(7,364)	(2,413)
Preferred stock dividends	(562)	(76)	(562)	(76)
Net loss attributable to common stockholders	$ (3,724)	$ (7,773)	$ (7,926)	$ (2,489)
Net loss per share basic and diluted	$ (0.14)	$ (0.67)	$ (0.35)	$ (0.36)
Shares used in computing basic and diluted net loss per share	27,515	11,603	22,545	6,886