Efficacy of Bezlotoxumab Against Clostridioides difficile Infection: A Case-Series Study at a University Hospital in Japan and Literature Review.

Background infection (CDI) recurrence is a public health concern as well as a health economic burden. Bezlotoxumab treatment is one way to prevent recurrence; however, its clinical results have not been reported in Japan. Therefore, we investigated the efficacy and safety of bezlotoxumab in patients with CDI at a university hospital in Japan and compared them with previously reported findings. Methodology We retrospectively examined all patients with some risk factors for recurrent CDI who received bezlotoxumab at the discretion of physicians at the Aichi Medical University Hospital, Aichi, Japan, between July 2018 and July 2022. The primary outcome was the three-month CDI recurrence rate. The secondary outcomes were an initial clinical cure and the six-month CDI recurrence rate. The safety of the administration was also assessed. Results A total of nine patients who received bezlotoxumab were included during the study period. The rate of CDI recurrence within three months was 28.5% (2/9). Two patients died due to other causes before their diarrhea improved. None of the patients experienced CDI recurrence between three and six months after the initial clinical cure of the baseline episode. Patients showed good tolerability to bezlotoxumab with no adverse effects. Two patients with a single episode of CDI recurrence before bezlotoxumab administration showed no recurrence. Conclusions In this Japanese case-series study, the efficacy of bezlotoxumab in preventing CDI recurrence in elderly patients with CDI and multiple underlying diseases was inferior to that reported in previous studies that analyzed real-world data. It is possible that bezlotoxumab may not be fully effective in elderly patients with CDI.