Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Product sales	$ 7	$ 312
Grant revenue	980	2,523
Total revenues	987	2,835
Expenses:
Cost of product sales	929	2,671
Research and development	28,888	26,690
Selling, general, and administrative	11,004	16,732
Total expenses	40,821	46,093
Operating loss	(39,834)	(43,258)
Change in fair value of common stock warrant liability	851	3,791
Other income / (expense):
Loss on debt extinguishment	(11,758)	0
Interest and other income	237	6
Interest and other expense	(4,666)	(4,597)
Other income / (expense), net	(16,187)	(4,591)
Net loss	$ (55,170)	$ (44,058)
Net loss per common share
Basic (in dollars per share)	$ (7.98)	$ (7.28)
Diluted (in dollars per share)	$ (7.98)	$ (7.84)
Weighted average number of common shares outstanding
Basic (in shares)	6,967	6,078
Diluted (in shares)	6,967	6,145