5PSQ-087 Clinical experience with bezlotoxumab in a third-level hospital

<h3>Background and Importance</h3> Bezlotoxumab is a monoclonal antibody with high affinity for the toxin B produced by Clostridium difficile indicated for adults at high-risk of recurrent infection. <h3>Aim and Objectives</h3> To evaluate the real-world efficacy and safety of bezlotoxumab. <h3>Material and Methods</h3> A retrospective observational study was performed including all patients diagnosed with Clostridium difficile infection (CDI) who were treated with bezlotoxumab since its funding approved (May 2018 to February 2024). Different variables were studied, both prior to administration (sex, age, immunosuppression, CDI in the previous 6 months, prior treatments, infection recurrences) and subsequent (number of subsequent recurrences and mortality at 12 and 24 weeks which were used to measure efficacy and the recording of adverse events (AEs) used to measure safety). Data were obtained from the prescribing software and the digital medical record. <h3>Results</h3> Forty-five patients were included, 29 men and 16 women, with a median age of 72.5 years (15–88). The risk factor for recurrence due to immunosuppression was present in 29 (64.4%) patients (of which: 58.6% (17) oncological, 34.5% (10) transplanted and 6.9% (2) belonging to both groups), 40% (18) had suffered one or more recurrences previously and 55% (10) of these had CDI in the previous 6 months. On the other hand, prior treatments received, the majority (77.7% (35)) received oral vancomycin at standard doses or its combination with metronidazole. Regarding the treatment efficacy, 88.9% (40) of patients achieved resolution of the CDI after using bezlotoxumab without subsequent recurrences. All patients who experienced a recurrence (8.9% (4)) after bezlotoxumab were older than 65 years and had a history of one or more recurrences of the disease previously. Currently, 28.88% (13) of the patients have died, with a mortality rate of 15.55% (7) at 12 and 24 weeks after the start of treatment. Main reasons for death were not related to CDI (other infections and oncologic disease). No AEs to bezlotoxumab were documented. <h3>Conclusion and Relevance</h3> Bezlotoxumab was an effective and safe drug in patients with CDI in real clinical practice. No AEs were detected and it prevented recurrence in most cases, demonstrating that its use in high-risk patients can aid in complete recovery. No patient died as a result of CDI. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest