Segment information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Number of Operating Segments | segment	1
Number of reportable segments | segment	1
Collaboration revenue	$ 9,041	$ 14,018
Less:
In-process research and development	(152,344)	(80,802)
General and administrative	(32,955)	(19,657)
Total operating expenses	(314,841)	(123,548)
Loss from operations	(305,800)	(109,530)
Interest income	12,837	2,724
Net loss	(292,963)	(106,806)
Single reportable segment
Segment Reporting Information [Line Items]
Collaboration revenue	9,041	14,018
Less:
In-process research and development	(152,344)	(80,802)
Other	(35,335)	(11,278)
Indirect research and development	(28,764)	(11,811)
General and administrative	(32,955)	(19,657)
Total operating expenses	(314,841)	(123,548)
Loss from operations	(305,800)	(109,530)
Interest income	12,837	2,724
Net loss	(292,963)	$ (106,806)
Single reportable segment | Varegacestat
Less:
Direct research and development expenses	(27,954)
Single reportable segment | IM-3050
Less:
In house research and development expenses	(24,130)
Single reportable segment | IM-3050
Less:
In house research and development expenses	$ (13,359)