CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue:
Grant and other	$ 10,773	$ 6,732	$ 20,426	$ 12,412
Total revenue	10,773	6,732	20,426	12,412
Expenses:
Research and development	44,542	39,263	89,056	76,916
General and administrative	8,224	8,940	16,876	17,793
Total expenses	52,766	48,203	105,932	94,709
Loss from operations	(41,993)	(41,471)	(85,506)	(82,297)
Other income (expense):
Investment income	807	523	1,338	997
Interest expense	(3,403)	(3,516)	(6,806)	(7,029)
Other income (expense)	97	(1)	130	10
Net loss	$ (44,492)	$ (44,465)	$ (90,844)	$ (88,319)
Basic and diluted net loss per share	$ (0.12)	$ (0.16)	$ (0.25)	$ (0.32)
Basic and diluted weighted average number of common shares outstanding	375,923	283,444	356,555	278,836