STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Research contract revenue	$ 272	$ 200	$ 544	$ 400
Operating expenses:
Research and development, including costs of research contracts	7,424	8,346	81,673	14,888
General and administrative	7,073	3,031	11,323	6,473
Total operating expenses	14,497	11,377	92,996	21,361
Loss from operations	(14,225)	(11,177)	(92,452)	(20,961)
Other income (expense), net	14	1	10	(8)
Change in fair value of warrants		5,600		5,682
Net loss	$ (14,211)	$ (5,576)	$ (92,442)	$ (15,287)
Net loss per share-basic and diluted	$ (0.11)	$ (0.06)	$ (0.76)	$ (0.15)
Weighted average common shares outstanding used to compute net loss per share-basic and diluted	128,413,417	100,422,564	120,953,279	100,326,416