Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Revenue	$ 0	$ 9,417	$ 0	$ 14,068
Operating expenses:
Research and development	13,273	17,401	27,054	32,507
General and administrative	8,000	9,499	17,477	19,243
Total operating expenses	21,273	26,900	44,531	51,750
Loss from operations	(21,273)	(17,483)	(44,531)	(37,682)
Interest income	425	118	520	143
Interest expense	(208)	(182)	(386)	(400)
Realized gain (loss) on investments	2	(10)	2	(14)
Foreign exchange (loss) gain	(3)	(1)	(2)	20
Other expense, net	(226)	(88)	(260)	(88)
Loss before income taxes	(21,283)	(17,646)	(44,657)	(38,021)
Income taxes	(2)	(10)	(14)	(10)
Net loss	$ (21,285)	$ (17,656)	$ (44,671)	$ (38,031)
Net loss per share attributable to common stockholders-basic and diluted	$ (0.61)	$ (0.52)	$ (1.28)	$ (1.11)
Weighted-average shares of common stock outstanding-basic and diluted	34,976,409	34,238,394	34,894,001	34,177,262