Basic and diluted net loss per common share - Schedule of potential shares of common stock excluded from computation (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Basic and diluted net loss per common share
Securities excluded from the computation of diluted net loss per share	8,569,072	7,636,147
Stock options to purchase common stock
Basic and diluted net loss per common share
Securities excluded from the computation of diluted net loss per share	7,724,059	5,706,130
Early exercised stock options subject to future vesting
Basic and diluted net loss per common share
Securities excluded from the computation of diluted net loss per share	565,224	1,079,794
Restricted stock
Basic and diluted net loss per common share
Securities excluded from the computation of diluted net loss per share	247,780	818,214
Warrants
Basic and diluted net loss per common share
Securities excluded from the computation of diluted net loss per share	32,009	32,009