Stock-based compensation - Summary of stock option activity (Details) - 2020 Stock Option and Incentive Plan - $ / shares	6 Months Ended
	Jun. 30, 2022
Number of Stock Options
Outstanding, beginning balance (in shares)	5,983,425
Granted (in shares)	1,962,600
Exercised (in shares)	(123,288)
Cancelled or forfeited (in shares)	(766,824)
Outstanding, ending balance (in shares)	7,055,913
Options exercisable (in shares)	2,152,611
Vested and expected to vest (in shares)	7,055,913
Weighted-Average Exercise Price
Outstanding, beginning balance (in dollars per share)	$ 22.33
Granted (in dollars per share)	20.58
Exercised (in dollars per share)	4.78
Cancelled or forfeited (in dollars per share)	21.77
Outstanding, ending balance (in dollars per share)	22.21
Options exercisable (in dollars per share)	20.92
Vested and expected to vest (in dollars per share)	$ 22.21