CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2024	Dec. 31, 2025
Cash flows from operating activities:
Net loss		$ (17,867)	$ (153,942)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	[1]	1,134	13,300
Research and development license expense		0	80,000
Depreciation expense		0	84
Non-cash interest expense	[2]	2	2,185
Non-cash research and development expense related to Paragon option agreement		1,000	0
Non-cash lease expense		0	212
Changes in operating assets and liabilities
Accrued expenses and other current liabilities	[3]	2,172	5,363
Deferred revenue		0	4,156
Deposit liability		0	5,000
Operating lease liability		0	(37)
Accounts receivable		0	(18,000)
Prepaid expenses and other current assets		(38)	(5,015)
Other assets		0	162
Net cash used in operating activities		(6,269)	(71,532)
Cash flows from investing activities:
Purchase of research and development license		0	(72,000)
Purchases of property and equipment		0	(919)
Net cash used in investing activities		0	(72,919)
Cash flows from financing activities:
Proceeds from the Pre-Closing Financing, net		0	143,007
Proceeds from the private placement financing, net		0	178,880
Cash acquired in connection with the reverse recapitalization		0	1,269
Proceeds from early exercise of options		0	5
Proceeds from issuance of common stock		315	0
Proceeds from issuance of Series Seed convertible preferred stock		4,000	0
Proceeds from the issuance of notes payable, net of issuance costs	[4]	37,480	0
Payment of deferred offering costs		(760)	0
Repurchase of equity awards		0	(177)
Net cash provided by financing activities		41,035	322,984
Net increase in cash, cash equivalents, and restricted cash		34,766	178,533
Cash at beginning of period		0	34,766
Cash, cash equivalents, and restricted cash at end of period		34,766	213,299
Supplemental disclosure of non-cash operating and financing activities:
Operating lease liability arising from obtaining operating right-of-use asset		0	1,681
Assets acquired in connection with the reverse recapitalization		0	1,710
Other liabilities assumed in connection with the reverse recapitalization		0	(2,454)
Purchases of property and equipment included in accounts payable and accrued expenses		0	11
Deferred financing costs included in accounts payable and accrued expenses		53	6,945
Convertible note principal and non-cash accrued interest converted to ordinary shares		0	40,515
Non-cash exchange of Pre-Merger Crescent Series Seed Preferred Stock for Series A Non-Voting Convertible Preferred Shares		0	4,000
Nonrelated Party
Changes in operating assets and liabilities
Accounts payable		107	2,081
Related Party
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense		61	4,297
Non-cash interest expense		0	865
Changes in operating assets and liabilities
Accrued expenses and other current liabilities		341	0
Related party accounts payable and other current liabilities		7,221	(7,081)
Cash flows from financing activities:
Proceeds from the issuance of notes payable, net of issuance costs		$ 14,993	$ 0

[1] Includes related party amounts of $4,297 for the twelve months ended December 31, 2025 and $61 for the period from September 19, 2024 (inception) through December 31, 2024.

[2] Includes related party amounts of $865 for the twelve months ended December 31, 2025 and $0 for the period from September 19, 2024 (inception) through December 31, 2024.

[3] Includes related party amounts of $0 for the twelve months ended December 31, 2025 and $341 for the period from September 19, 2024 (inception) through December 31, 2024.

[4] Includes related party amounts of $0 for the twelve months ended December 31, 2025 and $14,993 for the period from September 19, 2024 (inception) through December 31, 2024