CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues:
Revenues	$ 15,662	$ 18,253	$ 63,300	$ 52,192
Costs and expenses:
Cost of product sales	1,665	0	1,704	0
Research and development	49,823	44,656	158,724	150,901
Selling, general and administrative	17,161	9,732	47,431	30,181
Total costs and expenses	68,649	54,388	207,859	181,082
Loss from operations	(52,987)	(36,135)	(144,559)	(128,890)
Other income	101	92	466	1,238
Net loss	(52,886)	(36,043)	(144,093)	(127,652)
Other comprehensive income (loss):
Unrealized gain (loss) on investments	(4)	(15)	4	(14)
Comprehensive loss	$ (52,890)	$ (36,058)	$ (144,089)	$ (127,666)
Basic net loss per common share (in usd per share)	$ (0.86)	$ (0.66)	$ (2.42)	$ (2.49)
Diluted net loss per common share (in usd per share)	$ (0.86)	$ (0.66)	$ (2.42)	$ (2.49)
Basic weighted average common shares outstanding (in shares)	61,169,754	54,463,412	59,494,836	51,176,884
Diluted weighted average common shares outstanding (in shares)	61,169,754	54,463,412	59,494,836	51,176,884
Revenue from collaborative and other agreements
Revenues:
Revenues	$ 11,986	$ 17,415	$ 54,338	$ 46,018
Product revenue, net
Revenues:
Revenues	3,591	0	7,681	0
Revenue from government agreements
Revenues:
Revenues	$ 85	$ 838	$ 1,281	$ 6,174