Commitments and contingencies - Additional Information (Details) - USD ($)
1 Months Ended 9 Months Ended 12 Months Ended
Nov. 15, 2021
Jan. 31, 2020
Sep. 30, 2020
Dec. 31, 2021
Dec. 31, 2020
Commitments And Contingencies [Line Items]          
Issuance of common stock, net of issuance costs       $ 61,681,000 $ 74,352,000
License Agreement | Kayla Therapeutics S.A.S          
Commitments And Contingencies [Line Items]          
Nonrefundable payment in cash     $ 15,000,000.0    
Nonrefundable payment in shares of common stock     177,318    
Nonrefundable cash payment paid         $ 15,000,000.0
MD Anderson Cancer Center | Research Agreement | Series B Redeemable Convertible Preferred Stock          
Commitments And Contingencies [Line Items]          
Issuance of common stock, net of issuance costs   $ 1,200,000      
Lonza | Manufacturing Services Agreement          
Commitments And Contingencies [Line Items]          
Cancellation fees and other charges       0  
Minimum non-cancelable purchase obligation       $ 0  
Agreement termination advance notice period 12 months