Bezlotoxumab for the prevention of Clostridium difficile infection: a review of current evidence and safety profile Carolyn D Alonso,1,2 Monica V Mahoney3 1Department of Medicine, Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Boston, MA, USA; 2Harvard Medical School, Boston, MA, USA; 3Department of Pharmacy, Beth Israel Deaconess Medical Center, Boston, MA, USA Abstract: Clostridium difficile infection (CDI) is a leading nosocomial disease estimated to cause nearly half a million cases in the United States annually. Recurrent CDI (rCDI) affects ~25% of patients after completion of standard of care therapy and is associated with substantial health care costs and a negative impact on patient’s overall markers of quality of life. Bezlotoxumab is the first of its kind monoclonal antibody directed against C. difficile toxin B and indicated for prevention of rCDI in at-risk patients. For the present review, we assessed English-language studies evaluating the clinical efficacy, safety, and pharmacokinetics of bezlotoxumab in humans. Relevant studies were obtained through PubMed, Embase, Cochrane database library, Web of Science, and clinicaltrials.gov. Overall, bezlotoxumab demonstrated a 40% relative reduction rate (absolute rate reduction of ~10%) and a number needed to treat of 10 patients with a favorable safety profile. Special populations, including the elderly, immunocompromised, and patients with end-stage renal disease were evaluated in post hoc analyses with a similarly favorable reduction in rCDI. This review presents and interprets the most recent safety data and the clinical application of bezlotoxumab, highlighting specific high-risk patient populations. Keywords: MK-6072, MDX-1388, Clostridium difficile monoclonal antibody, Clostridioides difficile, bezlotoxumab, Zinplava