v3.26.3
Research Collaboration and License Agreements - Schedule of Sources of Revenue (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
Jun. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Research Collaboration And License Agreements [Line Items]          
Revenue $ 0.5   $ 41.9 $ 265.8 $ 253.1
Vepdegestrant | Collaboration Agreement Revenue          
Research Collaboration And License Agreements [Line Items]          
Revenue 0.0   20.6 148.1 231.6
Vepdegestrant | Milestone Revenue          
Research Collaboration And License Agreements [Line Items]          
Revenue 0.0 $ 50.0 0.0 50.0 0.0
Pfizer, Inc. | Collaboration Agreement Revenue          
Research Collaboration And License Agreements [Line Items]          
Revenue 0.0   1.3 4.7 1.5
Novartis Pharma AG | License revenue          
Research Collaboration And License Agreements [Line Items]          
Revenue 0.0   20.0 0.0 20.0
Rigel Pharmaceuticals, Inc. | License revenue          
Research Collaboration And License Agreements [Line Items]          
Revenue $ 0.5   $ 0.0 $ 63.0 $ 0.0