Net loss per share - Basic and diluted net loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator:
Net loss	$ (42,603)	$ (26,828)	$ (81,667)	$ (54,392)
Denominator:
Weighted average ordinary shares outstanding, basic	30,191,693	29,648,564	30,097,234	29,626,974
Weighted average ordinary shares outstanding, diluted	30,191,693	29,648,564	30,097,234	29,626,974
Net loss per share, basic	$ (1.41)	$ (0.90)	$ (2.71)	$ (1.84)
Net loss per share, diluted	$ (1.41)	$ (0.90)	$ (2.71)	$ (1.84)