Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue:
Collaboration and license revenue	$ 18,720	$ 2,424	$ 37,581	$ 3,307
Grant revenue	426	62	1,022	189
Total revenue	19,146	2,486	38,603	3,496
Operating expenses:
Research and development	11,813	5,858	35,992	15,990
General and administrative	6,908	1,980	19,000	5,498
Total operating expenses	18,721	7,838	54,992	21,488
Income (loss) from operations	425	(5,352)	(16,389)	(17,992)
Loss from remeasurement of fair value of warrants		(157)	(26,077)	(282)
Gain on extinguishment of convertible promissory notes				3,553
Interest income (expense), net	139	(30)	156	(2,375)
Other income, net	3	855	1	1,002
Net income (loss)	$ 567	$ (4,684)	$ (42,309)	$ (16,094)
Net income (loss) per common share, basic	$ 0.01	$ (14.24)	$ (1.09)	$ (52.47)
Net income (loss) per common share, diluted	$ 0.01	$ (14.24)	$ (1.09)	$ (52.47)
Weighted average common shares outstanding, basic	62,274,438	328,929	38,674,889	306,764
Weighted average common shares outstanding, diluted	71,726,118	328,929	38,674,889	306,764