Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities
Net loss	$ (49,969)	$ (32,047)
Adjustments to reconcile net loss to net cash used for operating activities:
Share-based compensation expense	9,330	6,960
Third party share-based compensation expense	364	86
Depreciation expense	581	310
Loss on disposal of equipment	0	75
Changes in operating assets and liabilities:
Restricted cash	(710)	37
Prepaid expenses and other current assets	(270)	(702)
Other assets	219	(147)
Accounts payable	(732)	(250)
Accrued clinical and other expenses	(541)	888
Accrued payroll and related expenses	(214)	(295)
Net cash used for operating activities	(41,942)	(25,085)
Investing activities
Purchase of property and equipment	(2,021)	(910)
Net cash used for investing activities	(2,021)	(910)
Financing activities
Net proceeds from the issuance of common stock	117,480	0
Proceeds from the exercise of stock options for common stock	2,074	85
Net cash provided by financing activities	119,554	85
Net increase (decrease) in cash and cash equivalents	75,591	(25,910)
Cash and cash equivalents at beginning of period	65,726	126,467
Cash and cash equivalents at end of period	$ 141,317	$ 100,557