Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revised Statement of Cash Flow
Net loss	$ (136,725)	$ (90,980)
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired in-process research and development		4,000
Depreciation and amortization expense	954	733
Stock-based compensation expense	18,401	9,461
Non-cash interest expense	2,757	2,472
Changes in operating assets and liabilities:
Accounts receivable	134	2,561
Inventories	(179)	(4,886)
Other assets	(3,462)	(656)
Accounts payable	5,119	4,293
Accrued expenses	(1,847)	3,923
Deferred revenues	(22)	(15)
Other liabilities	172	1,478
Net cash used in operating activities	(114,698)	(67,616)
Investing activities
Acquisition of product candidate and technology licenses and milestone payments		(4,000)
Purchase of property and equipment	(1,790)	(380)
Change in restricted cash	(510)
Net cash used in investing activities	(2,300)	(4,380)
Financing activities
Proceeds from sales of common stock, net of issuance costs		154,972
Payments for stock issuance costs	(8)
Proceeds from exercise of stock options	3,323	1,338
Net cash provided by financing activities	3,315	156,310
Effect of exchange rate changes on cash and cash equivalents	45
Increase (decrease) in cash and cash equivalents	(113,638)	84,314
Cash and cash equivalents at beginning of period	785,877	230,146
Cash and cash equivalents at end of period	672,239	314,460
Non-cash investing and financing activities
Stock option exercise proceeds receivable as of period end	103	$ 82
Leasehold improvement assets funded by lessor	585
Purchase of property and equipment - cash not paid as of period end	301
Supplemental cash flow information
Cash paid for interest	3,019
Milestone obligation not paid as of period end	$ 24,790