CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Product revenue, net	$ 1,151	$ 0
Cost of goods sold	424	0
Gross profit	727	0
Operating expenses:
Research and development	56,070	41,003
Selling, general and administrative	95,601	13,458
Total operating expenses	151,671	54,461
Loss from operations	(150,944)	(54,461)
Other income (expense):
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	(152)	(17)
Total other expense, net	(21,299)	(7,734)
Loss before provision for income taxes	(172,243)	(62,195)
Provision for income taxes	694	109
Net loss and comprehensive loss	$ (172,937)	$ (62,304)
Net loss per share - basic and diluted (in dollars per share)	$ (3.07)	$ (1.41)
Weighted average common shares outstanding - basic and diluted (shares)	56,412,439	44,242,070