Licensing Agreements (Details) - USD ($)				3 Months Ended		9 Months Ended		12 Months Ended
		Oct. 11, 2024	May 14, 2024	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025
Related Party Transaction [Line Items]
Research and development	[1]			$ 89,169,000	$ 45,247,000	$ 215,083,000	$ 127,015,000
Related Party
Related Party Transaction [Line Items]
Research and development				$ 100,000	7,000,000.0	$ 3,200,000	9,600,000
Paragon Agreement | Related Party
Related Party Transaction [Line Items]
Campaign timeline, minimum term (in years)						5 years
Royalty step-down (as percent)				33.00%		33.00%
Royalty term expiration period (in years)						12 years
Termination notice period (in days)						60 days
Sublicensing fee				$ 100,000	1,000,000.0	$ 100,000	1,000,000.0
Cash milestone payments				0	3,000,000.0	3,000,000.0	5,500,000
Milestone payments, outstanding and payable				0		0		$ 0
Payment for sublicensing fee				0	0	0	500,000
SPY001 License Agreement | Related Party
Related Party Transaction [Line Items]
First milestone payment			$ 5,000,000.0
SPY002 and SPY072 License Agreement | Related Party
Related Party Transaction [Line Items]
First milestone payment			5,000,000.0
SPY003 License Agreement | Related Party
Related Party Transaction [Line Items]
First milestone payment		$ 5,000,000.0
License Agreement | Related Party
Related Party Transaction [Line Items]
Research and development				$ 0	$ 6,000,000.0	3,000,000.0	$ 8,500,000
Sublicensing fee, outstanding and payable						100,000		$ 0
Maximum | SPY001 License Agreement | Related Party
Related Party Transaction [Line Items]
Contingent obligation based on milestones			22,000,000.0
Maximum | SPY002 and SPY072 License Agreement | Related Party
Related Party Transaction [Line Items]
Contingent obligation based on milestones			$ 22,000,000.0
Sublicensing fee						$ 20,000,000
Maximum | SPY003 License Agreement | Related Party
Related Party Transaction [Line Items]
Contingent obligation based on milestones		$ 22,000,000.0

[1] Includes related party expenses of $0.1 million and $7.0 million for the three months ended September 30, 2026 and 2025, respectively. Includes related party expenses of $3.2 million and $9.6 million for the nine months ended September 30, 2026 and 2025, respectively.