08:39 AM EST, 12/19/2024 (MT Newswires) -- Regeneron Pharmaceuticals ( REGN ) said Thursday that its two investigational Factor XI antibodies showed "robust" antithrombotic effects with no clinically relevant bleeding observed in a phase 2 proof-of-concept study.

Monoclonal antibodies REGN7508 and REGN9933, which are being evaluated for potential to control thrombosis, were compared with standards of care and given 12 to 24 hours after total knee replacement in the study, the company said.

The company said it will test REGN7508 and REGN9933 in a phase 3 trial, expected to begin in 2025.