Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Revenue:
Grant revenue	$ 449
Total revenue	$ 21,478	$ 27,098
Revenue, Product and Service [Extensible Enumeration]	Collaboration Revenue [Member]	Collaboration Revenue [Member]
Operating expenses:
Research and development	$ 70,984	$ 70,148
General and administrative	26,319	25,719
Restructuring charges	4,859
Total operating expenses	102,162	95,867
Loss from operations	(80,684)	(68,769)
Other income (expense):
Interest income	1,223	36
Other expense, net	(3)	(8)
Total other income, net	1,220	28
Net loss and comprehensive loss	$ (79,464)	$ (68,741)
Net loss per share, basic	$ (2.76)	$ (2.49)
Net loss per share, diluted	$ (2.76)	$ (2.49)
Weighted-average common shares outstanding, basic	28,812,904	27,578,844
Weighted-average common shares outstanding, diluted	28,812,904	27,578,844
Collaboration Revenue [Member]
Revenue:
Revenue	$ 21,029	$ 27,098