CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues:
Total revenues	$ 9,210	$ 18,189	$ 41,864	$ 46,501
Operating expenses:
Research and development	33,147	24,685	102,149	75,014
General and administrative	10,297	10,231	30,234	28,862
Restructuring charges				1,524
Total operating expenses	43,444	34,916	132,383	105,400
Loss from operations	(34,234)	(16,727)	(90,519)	(58,899)
Investment income, net	11	11	35	719
Non-cash interest expense on liability related to the sale of future royalties and convertible senior notes	(2,751)	(5,645)	(10,952)	(17,428)
Interest expense on convertible senior notes		(24)	(47)	(71)
Other (expense) income, net	(365)	11	(648)	(81)
Net loss	$ (37,339)	$ (22,374)	$ (102,131)	$ (75,760)
Basic and diluted net loss per common share	$ (0.18)	$ (0.13)	$ (0.51)	$ (0.44)
Basic and diluted weighted-average common shares outstanding	204,844	174,508	201,212	172,215
Total comprehensive loss	$ (37,339)	$ (22,374)	$ (102,131)	$ (75,760)
Non-cash royalty revenue related to the sale of future royalties
Revenues:
Total revenues	6,533	18,087	38,768	45,159
License and milestone fees
Revenues:
Total revenues	$ 2,677	97	3,086	1,325
Research and development support
Revenues:
Total revenues		$ 5	$ 10	$ 17