Stock-based compensation - Stock Options - (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning balance (in shares) | shares	5,013,193
Granted (in shares) | shares	3,504,675
Exercised (in shares) | shares	(79,837)
Cancelled or forfeited (in shares) | shares	(2,358,960)
Outstanding, ending balance (in shares) | shares	6,079,071	5,013,193
Exercisable (in shares) | shares	2,581,363
Weighted Average Exercise Price
Outstanding (in dollars per share) | $ / shares	$ 12.69
Granted (in dollars per share) | $ / shares	5.14
Exercised (in dollars per share) | $ / shares	7.56
Cancelled or forfeited (in dollars per share) | $ / shares	13.22
Outstanding (in dollars per share) | $ / shares	8.20	$ 12.69
Exercisable (in dollars per share) | $ / shares	$ 10.85
Remaining Contractual Life
Outstanding	8 years 1 month 6 days	5 years 7 months 6 days
Exercisable	6 years 4 months 24 days
Aggregate Intrinsic Value
Outstanding | $	$ 5,693	$ 1,165
Exercisable | $	1,838
Stock options
Options disclosures
Unrecognized stock-based compensation expense | $	$ 13,500
Remaining weighted-average remaining vesting period	3 years 1 month 6 days