CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue:
Government contracts	$ 2,184	$ 33,344	$ 26,213
Research and development collaborations	13,169	2,906	4,446
Total revenue	15,353	36,250	30,659
Expenses:
Research and development	237,939	162,644	94,422
General and administrative	46,527	30,842	19,928
Total expenses	284,466	193,486	114,350
Loss from operations	(269,113)	(157,236)	(83,691)
Other income (expense):
Investment income	2,143	660	286
Interest expense	(12,965)	(241)	(157)
Other income	(31)	(120)	0
Realized gains on marketable securities	0	0	615
Net loss	$ (279,966)	$ (156,937)	$ (82,947)
Basic and diluted net loss per share	$ (1.03)	$ (0.60)	$ (0.37)
Basic and diluted weighted average number of common shares outstanding	270,802	262,248	225,848