Share-based compensation - Plans (Details) - $ / shares		3 Months Ended
	Jan. 01, 2024	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Oct. 02, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance		14,923,124		13,202,327
Exercise price		$ 10.00
Weighted average grant date fair value		$ 14.62	$ 4.18
2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in shares available for future issuance	1,730,071	4,398,174
MorphImmune Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance					929,702
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant		906,251		473,733
Increase in shares available for future issuance	432,518