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Summary of significant accounting policies - Additional Information (Details) - USD ($)
3 Months Ended
Mar. 31, 2023
Mar. 31, 2022
Dec. 31, 2022
Lessee, Lease, Description [Line Items]      
Impairment of property and equipment $ 3,418,000 $ 0  
Allowance for credit loss 0    
Fair value, investments, unrealized loss $ 4,000,000    
Expected dividends 0.00% 0.00%  
Minimum      
Lessee, Lease, Description [Line Items]      
Property and equipment, useful life 3 years    
Maximum      
Lessee, Lease, Description [Line Items]      
Property and equipment, useful life 7 years    
Fair Value, Recurring | U.S. treasury securities - due within 3 months      
Lessee, Lease, Description [Line Items]      
U.S. treasury securities $ 50,920,000   $ 61,970,000
Prefunded Warrants      
Lessee, Lease, Description [Line Items]      
Outstanding pre-funded warrants (in shares) 12,663,010 12,663,010  
Money market funds      
Lessee, Lease, Description [Line Items]      
Money market funds $ 32,084,000   33,767,000
Money market funds | Fair Value, Recurring      
Lessee, Lease, Description [Line Items]      
Money market funds $ 32,084,000   $ 33,767,000
Office space | Maximum      
Lessee, Lease, Description [Line Items]      
Lease term 12 months