Regeneron to advance two Factor XI antibodies into broad Phase 3 program

Regeneron (REGN) Pharmaceuticals announced positive Phase 2 results for two novel monoclonal antibodies targeting distinct domains of Factor XI. REGN7508 is designed to maximize anticoagulant activity while minimizing bleeding risk, and REGN9933 is designed to provide an additional option for patients with the highest bleeding risk who would otherwise not be candidates for currently available anticoagulants. Per the Phase 2 results, there was a robust antithrombotic effect for each antibody, and no clinically relevant bleeding was observed in any treatment arm. There were no treatment-related serious AEs in any arm. Phase 3 program to be initiated in 2025