Fair value of financial instruments - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 36,300		$ 36,300			$ 58,100
Common stock shares issued	48,709,652		48,709,652			48,511,735
Issuance of common stock, value	$ 49		$ 49			$ 49
Other Income
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success Payment Liability, Payable	900	$ 10,000	2,600	$ 9,700
Harvard and Board
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, payable	10,000,000		10,000,000
Success payment liability					$ 300		$ 6,300
Success payment liability, current portion							$ 6,300
Harvard | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, payable	$ 31,300		$ 31,300
Broad License Agreement
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Common stock shares issued	276,075		276,075
Antidilution Rights Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Common stock shares issued		878,098		878,098
Issuance of common stock, value		$ 32,500		$ 32,500
Antidilution Rights Liability | Other Expense
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Increase in liabilities		$ 26,000		$ 25,600