License Agreements - Expenses Related Development Costs (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2024	Dec. 31, 2025
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development expense	[1]	$ 14,034	$ 138,086
General and administrative expense	[2]	3,157	25,390
Paragon Therapeutics | License Agreement Terms | Paragon Option Agreements
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development expense		13,124	19,356
General and administrative expense		394	570
Operating costs and expenses, total		$ 13,518	$ 19,926

[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.