Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Product sales	$ 7	$ 28
Grant revenue	184	3
Total revenues	191	31
Expenses:
Cost of product sales	929	781
Research and development	7,082	5,590
Selling, general and administrative	3,353	4,423
Total expenses	11,364	10,794
Operating loss	(11,173)	(10,763)
Change in fair value of common stock warrant liability	(31)	378
Other income / (expense):
Interest and other income	233	2
Interest and other expense	(1,208)	(1,093)
Other income / (expense), net	(975)	(1,091)
Net loss	$ (12,179)	$ (11,476)
Net loss per common share-
Basic and diluted (in dollars per share)	$ (0.14)	$ (0.14)
Weighted-average number of common shares outstanding - basic and diluted (in shares)	85,589	84,728