668. Quality of Life Changes in Patients with Clostridium difficile Infection (CDI): A Randomized, Double-Blind Trial of Ridinilazole (RDZ) Compared with Vancomycin (VAN)

BACKGROUND: C. difficile is the most frequent hospital-acquired bacteria in the United States. CDI is associated with significant morbidity and mortality, and a 46% lower mean EQ-5D index of Health-Related Quality of Life (HRQoL) compared with the general population. However, data on the impact of antibiotic treatment for CDI on HRQoL are lacking. METHODS: RDZ is a novel, narrow-spectrum antibiotic with targeted activity against C. difficile, under development for the treatment of CDI and prevention of recurrence. We evaluated HRQoL prospectively with the EQ-5D-3L in 69 patients enrolled in a Phase 2 randomized, double-blind trial comparing RDZ (n = 36) with VAN (n = 33). EQ-5D-3L was obtained at five time points (baseline, days 5, 10, 12, and 40) with summary index values calculated using US weights (Shaw 2005) evaluating raw scores for mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, and visual analog scale (VAS) scores. RESULTS: As early as Day 5, CDI patients on RDZ had significant improvements in mean change from baseline in index scores (P = 0.008) and VAS scores (P = 0.01) but no significant improvements were seen in patients on VAN. Time to resolution of diarrhea also occurred sooner with RDZ with a hazard ratio 1.19 in favor of RDZ (90% CI: 0.76, 1.87). Mean changes in index scores in the VAN group took longer to improve significantly compared with baseline and became higher on VAN on Day 12 and Day 40. Treatment-related improvements in pain/discomfort and anxiety/depression are shown in Figures 1 and 2. The mean change from baseline in EQ-5D-3L domains showed the highest (significant) improvements in the pain/discomfort domain for both treatment groups across all time points. However, by Day 40, anxiety/depression improved significantly more with RDZ than with VAN (P = 0.039). CONCLUSION: We believe this is the first study to document improvements in HRQoL after antimicrobial treatment for CDI. Patients receiving ridinilazole experienced greater improvements in HRQoL sooner than those on VAN. Anxiety/depression and pain/discomfort improved significantly with treatment. HRQoL should be evaluated in Phase 3 interventional studies for CDI. These results will need to be validated in the ongoing Phase 3 randomized, double-blind, global trials comparing RDZ to VAN for the treatment of CDI. [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.