Stock-based compensation - Activity Under Stock Option Plan (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Number of Shares
Outstanding at beginning of period (in shares) | shares	10,902,845
Granted (in shares) | shares	2,289,529
Exercised (in shares) | shares	(12,117)
Cancelled/forfeited (in shares) | shares	(469,818)
Outstanding at end of period (in shares) | shares	12,710,439
Exercisable, at end of period (in shares) | shares	6,626,590
Weighted- Average Exercise Price
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 7.42
Granted (in dollars per share) | $ / shares	3.02
Exercised (in dollars per share) | $ / shares	3.21
Cancelled/forfeited (in dollars per share) | $ / shares	8.36
Outstanding at end of period (in dollars per share) | $ / shares	6.59
Exercisable, at end of period (in dollars per share) | $ / shares	$ 8.21