Stock-based compensation - Activity Under Stock Option Plan (Details)	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Number of Shares
Outstanding at beginning of period (in shares) | shares	10,051,283
Granted (in shares) | shares	2,530,740
Exercised (in shares) | shares	(8,826)
Cancelled (in shares) | shares	(273,670)
Outstanding at end of period (in shares) | shares	12,299,527
Options exercisable, at end of period (in shares) | shares	5,902,352
Weighted- Average Exercise Price
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 9.84
Granted (in dollars per share) | $ / shares	6.07
Exercised (in dollars per share) | $ / shares	3.80
Cancelled (in dollars per share) | $ / shares	10.08
Outstanding at end of period (in dollars per share) | $ / shares	9.07
Options exercisable, at end of period (in dollars per share) | $ / shares	$ 9.51