CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net loss	$ (172,937)	$ (62,304)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash share-based compensation expense	16,879	7,330
Non-cash interest expense on mandatorily redeemable preferred shares	5,561	0
Non-cash interest expense on liability related to sale of future royalties	8,425	6,817
Change in fair value of derivative liability	5,781	0
Loss from equity method investment	1,380	900
Other non-cash items	476	133
Changes in operating assets and liabilities:
Trade receivables, net	(4,337)	0
Inventories	(3,609)	0
Prepaid expenses and other current assets	(25,733)	(1,876)
Other assets	20	(29)
Accounts payable	14,475	(2,542)
Accrued expenses and other current liabilities	2,860	6,701
Other long-term liabilities	37	(1,999)
Net cash used in operating activities	(150,722)	(46,869)
Cash flows from investing activities:
Purchases of property and equipment	(1,016)	(1,038)
Payments for leasehold improvements	(1,600)	0
Payments for intangible assets	(20,750)	0
Net cash used in investing activities	(23,366)	(1,038)
Cash flows from financing activities:
Proceeds from issuance of common shares	283,333	0
Payments of issuance costs	(340)	0
Proceeds from exercise of stock options	2,607	1,065
Net cash provided by financing activities	285,600	1,065
Net increase in cash and restricted cash	111,512	(46,842)
Cash and restricted cash at beginning of period	317,727	264,249
Cash and restricted cash at end of period	429,239	217,407
Supplemental disclosure of cash flow information:
Cash paid for interest	0	0
Cash paid for income taxes	0	408
Supplemental disclosure of non-cash investing and financing activities:
Deferred offering costs included in accounts payable	160	0
Intangible asset costs included in accounts payable	$ 20,750	$ 0