Consolidated statements of operations and comprehensive loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue from collaborations	$ 13,907	$ 4,359
Operating expenses:
Research and development	85,077	104,153
General and administrative	26,410	28,527
Total operating expenses	111,487	132,680
Loss from operations	(97,580)	(128,321)
Interest and other income, net	1,640	132
Loss before income tax expense	(95,940)	(128,189)
Income tax expense	(106)	(143)
Net loss	(96,046)	(128,332)
Other comprehensive (loss) and income:
Gains on pension plans	6	749
Losses on available for sale investments	(57)	(109)
Comprehensive loss	$ (96,097)	$ (127,692)
Net loss per share, basic and diluted	$ (2.25)	$ (3.22)
Weighted average shares of common stock, basic and diluted	42,695,227	39,855,403