Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities
Net loss	$ (53,298)	$ (30,079)
Adjustments to reconcile net loss to net cash used for operating activities:
Share-based compensation expense	10,804	9,330
Third party share-based compensation expense	167	1,013
Depreciation expense	510	209
Loss on disposal of equipment	75	0
Changes in operating assets and liabilities:
Restricted cash	37	(200)
Prepaid clinical expenses	118	1,168
Prepaid expenses and other current assets	(778)	(347)
Other assets	(149)	(57)
Accounts payable	(508)	1,837
Accrued expenses	2,693	219
Accrued payroll and related expenses	231	205
Net cash used for operating activities	(40,098)	(16,702)
Investing activities
Purchase of property and equipment	(1,419)	(1,681)
Net cash used for investing activities	(1,419)	(1,681)
Financing activities
Net proceeds from the issuance of common stock	0	104,596
Net proceeds from the exercise of stock options for common stock	85	287
Net cash provided by financing activities	85	104,883
Net decrease in cash and cash equivalents	(41,432)	86,500
Cash and cash equivalents at beginning of period	126,467	48,555
Cash and cash equivalents at end of period	85,035	135,055
Series C-1 Convertible Preferred Stock [Member]
Non-cash investing and financing activity:
Conversion of stock	0	11
Series F Convertible Preferred Stock [Member]
Non-cash investing and financing activity:
Conversion of stock	$ 0	$ 61