Regeneron and Telix agreed to a multi-program radiopharmaceutical collaboration valued at up to $4.3 billion, pairing Regeneron’s VelocImmune antibody platforms with Telix’s radiopharmaceutical development and manufacturing capabilities. The partnership targets up to eight solid tumor indications through next-generation radiopharmaceutical therapies and companion diagnostics. The deal includes upfront payments for initial therapeutic programs and provisions for co-funding and profit-sharing on commercialization, with milestone structures and royalties depending on commercialization cost-sharing choices. Telix would lead commercialization efforts for diagnostic assets. For oncology developers, the collaboration reinforces the theranostics model: antibodies or biologics drive targeting biology, while radiopharmaceutical manufacturing and imaging support patient selection and response assessment. The companies plan to combine platform strengths rather than run independent programs. The radiopharma strategy also suggests how Regeneron intends to expand beyond its antibody portfolio by translating antigen-binding assets into radiolabeled formats, adding a modality with a distinct regulatory and CMC footprint. The alliance is positioned as a step toward building a pipeline of precision radiopharmaceuticals that can be matched to biomarker-defined patient subsets.