Commitments and contingencies - Additional Information (Details) - Lonza - Manufacturing Services Agreement - USD ($)		9 Months Ended
	Nov. 15, 2021	Sep. 30, 2022
Commitments And Contingencies [Line Items]
Cancellation fees and other charges		$ 0
MinimumNonCancelablePurchaseObligation		0
Agreement termination advance notice period	12 months
Impairment of prepaid manufacturing services		4,500,000
Prepaid manufacturing services utilized		$ 500,000