Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue:
Total revenue	$ 2,785	$ 6,689	$ 152
Costs and expenses:
Cost of product revenue	265	790
Research and development:
Noncash compensation	13,224	24,047	13,962
Other research and development	112,128	198,532	151,934
Total research and development	125,352	222,579	165,896
Selling, general and administrative:
Noncash compensation	5,961	37,227	66,327
Other selling, general and administrative	64,046	90,863	41,523
Total selling, general and administrative	70,007	128,090	107,850
Total costs and expenses	195,624	351,459	273,746
Operating loss	(192,839)	(344,770)	(273,594)
Other expense (income):
Interest expense	10,191	5,638	6,329
Other income	(4,695)	(2,307)	(542)
Total other expense (income), net	5,496	3,331	5,787
Net loss	$ (198,335)	$ (348,101)	$ (279,381)
Basic net loss per common share (in dollars per share)	$ (1.46)	$ (2.63)	$ (2.42)
Diluted net loss per common share (in dollars per share)	$ (1.46)	$ (2.63)	$ (2.42)
Weighted-average shares used in computing basic net loss per common share (in shares)	135,411,258	132,222,753	115,333,693
Weighted-average shares used in computing diluted net loss per common share (in shares)	135,411,258	132,222,753	115,333,693
Product revenue, net [Member]
Revenue:
Total revenue	$ 2,633	$ 6,537
License revenue [Member]
Revenue:
Total revenue	$ 152	$ 152	$ 152