CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenue:
Government contracts	$ 134	$ 13,720	$ 2,080	$ 22,966
Research and development collaborations	2,371	276	4,643	906
Total revenue	2,505	13,996	6,723	23,872
Expenses:
Research and development	64,904	27,729	133,856	56,076
General and administrative	14,099	7,088	24,627	12,931
Total expenses	79,003	34,817	158,483	69,007
Loss from operations	(76,498)	(20,821)	(151,760)	(45,135)
Other income (expense):
Investment income	670	134	1,147	256
Interest expense	(3,512)	(26)	(5,946)	(62)
Other income (expense)	(11)	72	(44)	(70)
Net loss	$ (79,351)	$ (20,641)	$ (156,603)	$ (45,011)
Basic and diluted net loss per share	$ (0.29)	$ (0.08)	$ (0.58)	$ (0.18)
Basic and diluted weighted average number of common shares outstanding	270,760	268,083	270,469	254,727