STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Research contract revenue	$ 1,869	$ 633	$ 2,413	$ 1,033
Operating expenses:
Research and development, including costs of research contracts	16,970	9,733	98,643	24,621
General and administrative	3,065	2,842	14,388	9,315
Total operating expenses	20,035	12,575	113,031	33,936
Loss from operations	(18,166)	(11,942)	(110,618)	(32,903)
Other income (expense), net	(4)	2	6	(6)
Change in fair value of warrants		5,847		11,529
Net loss	$ (18,170)	$ (6,093)	$ (110,612)	$ (21,380)
Net loss per share - basic and diluted	$ (0.14)	$ (0.06)	$ (0.89)	$ (0.21)
Weighted average common shares outstanding used to compute net loss per share - basic and diluted	129,732,356	100,428,520	123,911,796	100,360,825