Bezlotoxumab, sold under the brand name Zinplava, is a human monoclonal antibody designed for the prevention of recurrence of Clostridium difficile infections. This drug, along with actoxumab, was developed through Phase II efficacy trials by a partnership between Medarex Inc and MassBiologics of the University of Massachusetts Medical School. The project was then licensed to Merck Sharp & Dohme Corp for further development and commercialization. Actoxumab and bezlotoxumab are fully human monoclonal antibodies which bind C. difficile toxins A and B, respectively.