Consolidated Statements of Operations and Comprehensive Loss (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Revenue	$ 4
Operating expenses:
Research and development	16,286	9,659
General and administrative	22,973	4,809
Total operating expenses	39,259	14,468
Loss from operations	(39,255)	(14,468)
Other income (expense):
Interest expense, net	(2,672)	(5,543)
Change in fair value of warrant liability	(222)	(789)
Other income (expense), net	262	5
Total other income (expense), net	(2,632)	(6,327)
Loss before income taxes	(41,887)	(20,795)
Benefit (loss) from income taxes	43
Net loss	(41,844)	(20,795)
Net loss per share - basic and diluted	$ (6.81)	$ (88.26)
Weighted average number of common shares used in net loss per share calculation--basic and diluted	6,141,605	235,603
Comprehensive loss	$ (41,844)	$ (20,795)