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Summary of significant accounting policies - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Short-term investments	$ 38,900,000		$ 38,900,000
Allowance for credit loss	$ 0		$ 0
Expected dividends	0.00%	0.00%	0.00%	0.00%
Prefunded Warrants
Lessee, Lease, Description [Line Items]
Outstanding pre-funded warrants (in shares)	12,663,010	12,663,010	12,663,010	12,663,010
Money market funds
Lessee, Lease, Description [Line Items]
Cash equivalents	$ 76,400,000		$ 76,400,000		$ 140,900,000
Maximum \| Office space
Lessee, Lease, Description [Line Items]
Lease term	12 months		12 months