CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net product sales	$ 21,398	$ 1,520	$ 51,269	$ 1,520
Collaboration revenue	1,212	1,340	3,813	3,621
Total revenues	22,610	2,860	55,082	5,141
Costs and expenses:
Cost of product sales (excluding amortization of intangible asset)	1,294	140	3,192	140
Research and development	33,255	34,425	100,868	102,038
Selling, general and administrative	39,559	24,583	104,713	70,332
Intangible asset amortization	1,972	1,971	5,914	1,971
Acquired in-process research and development costs	0	1,500	0	4,500
Change in fair value of contingent consideration	400	1,800	1,500	6,100
Total costs and expenses	76,480	64,419	216,187	185,081
Loss from operations	(53,870)	(61,559)	(161,105)	(179,940)
Other income (expense), net:
Interest income	85	934	579	2,504
Interest expense	(3,848)	0	(11,373)	0
Other, net	(371)	536	(631)	20,798
Total other (expense) income, net	(4,134)	1,470	(11,425)	23,302
Loss before income taxes	(58,004)	(60,089)	(172,530)	(156,638)
Income tax benefit	0	0	0	(17,425)
Net loss	$ (58,004)	$ (60,089)	$ (172,530)	$ (139,213)
Net loss per share, basic and diluted
Net loss per share, basic (in dollars per share)	$ (1.04)	$ (1.08)	$ (3.09)	$ (2.62)
Net loss per share, diluted (in dollars per share)	$ (1.04)	$ (1.08)	$ (3.09)	$ (2.62)
Weighted average number of shares used in the calculation of basic net loss per common share (in shares)	55,905	55,548	55,831	53,039
Weighted average number of shares used in the calculation of diluted net loss per common share (in shares)	55,905	55,548	55,831	53,039