CONSOLIDATED STATEMENT OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2024	Dec. 31, 2025
Income Statement [Abstract]
License revenue		$ 0	$ 10,844
Operating Expenses [Abstract]
Research and development	[1]	14,034	138,086
General and administrative	[2]	3,157	25,390
Total operating expenses		17,191	163,476
Loss from operations		(17,191)	(152,632)
Other income (expense):
Interest income		176	2,875
Interest expense	[3]	(852)	(2,185)
Loss before provision for income taxes		(17,867)	(151,942)
Provision for income taxes		0	(2,000)
Net loss and comprehensive loss		(17,867)	(153,942)
Net loss and comprehensive loss		$ (17,867)	$ (153,942)
Net loss per share attributable to ordinary shareholders, basic (in dollars per share)		$ (23.28)	$ (12.81)
Net loss per share attributable to ordinary shareholders, diluted (in dollars per share)		(23.28)	(12.81)
Net loss per share attributable to Series A non-voting convertible preferred shareholders, basic (in dollars per share)		0	(12,818.01)
Net loss per share attributable to Series A non-voting convertible preferred shareholders, diluted (in dollars per share)		$ 0	$ (12,818.01)
Weighted-average ordinary shares outstanding used in computing net loss per share to ordinary shareholders, basic (in shares)		767,580	10,413,649
Weighted-average ordinary shares outstanding used in computing net loss per share to ordinary shareholders, diluted (in shares)		767,580	10,413,649
Weighted-average Series A non-voting convertible preferred shares outstanding used in computing net loss per share to Series A non-voting convertible preferred shareholders, basic (in shares)		0	1,599
Weighted-average Series A non-voting convertible preferred shares outstanding used in computing net loss per share to Series A non-voting convertible preferred shareholders, diluted (in shares)		0	1,599

[1] Includes related party amount of $23,653 for the twelve months ended months ended December 31, 2025 and $13,185 for the period from September 19, 2024 (inception) through December 31, 2024.

[2] Includes related party amount of $720 for the twelve months ended months ended December 31, 2025 and $571 for the period from September 19, 2024 (inception) through December 31, 2024.

[3] Includes related party amount of $865 for the twelve months ended December 31, 2025 and $341 for the period from September 19, 2024 (inception) through December 31, 2024.