Evaluating Bezlotoxumab-Fidaxomicin Combination Therapy in Clostridioides Infection: A Single-Center Retrospective Study from Aichi Prefecture, Japan

<b>Background/Objectives:</b><i>Clostridioides difficile</i> infection (CDI) poses a significant healthcare challenge, with recurrence rates reaching 30%, leading to substantial morbidity and costs. Fidaxomicin (FDX) and bezlotoxumab (BEZ) have shown potential in reducing recurrence; however, real-world data on the efficacy of their combination in high-risk CDI patients remain limited. This study aimed to evaluate the efficacy and safety of FDX + BEZ compared with FDX alone in CDI patients with recurrence risk factors. <b>Methods:</b> CDI patients with ≥two recurrence risk factors treated with FDX alone or FDX + BEZ were analyzed. Sixteen factors were evaluated as risk factors for recurrent CDI based on findings from previous studies. Patients with FDX treatment duration <10 days or other CDI treatment prior to FDX were excluded. Outcomes included recurrence within 2 months, global and clinical cure rates, and adverse events. Univariate and multivariate analyses were performed to evaluate efficacy. <b>Results:</b> Among 82 patients, the FDX + BEZ group (<i>n</i> = 30) demonstrated significantly higher global (86.7% vs. 65.4%; <i>p</i> < 0.05) and clinical cure rates (90.0% vs. 69.2%; <i>p</i> < 0.05) compared with the FDX-alone group (<i>n</i> = 52), despite more severe cases in the combination group. Recurrence rates were non-significantly lower in the FDX + BEZ group (3.3% vs. 11.5%). Combination therapy also accelerated diarrhea resolution without additional adverse events. Multivariate analysis identified FDX + BEZ as significantly associated with improved clinical cure (adjusted odds ratio 4.167; 95% CI: 1.029-16.885). <b>Conclusions:</b> FDX + BEZ therapy offers superior efficacy and safety in CDI patients with recurrence risk factors, presenting a promising strategy for optimizing CDI management.