Comparison of meropenem-vaborbactam with ceftazidime-avibactam in the treatment of carbapenem-resistant Enterobacterales infections

AIM: To compare the efficacy and safety of ceftazidime-avibactam (CAZ/AVI) and meropenem-vaborbactam (MER/VAB) in treating carbapenem-resistant Enterobacterales (CRE) infections. BACKGROUND: CRE infections pose significant clinical challenges due to limited treatment options. CAZ/AVI and MER/VAB are recommended therapies, yet robust data comparing these treatments are lacking. METHODS: Multicentric retrospective cohort study on patients treated with CAZ/AVI or MER/VAB for microbiologically documented CRE infections between 2018 and 2024, enrolled in the SUSANA (Surveillance of Safety and Outcome of New Antibiotics) cohort.Collected data included demographics, treatment regimens, infection sites, pathogens, clinical outcomes and adverse events (AE). RESULTS: One-hundred sixty-eight patients were enrolled (131 in CAZ/AVI, 37 in MER/VAB), with 62.6% and 62.2% males, respectively. Median age was 68 years in CAZ/AVI and 70 in MER/VAB. Median Charlson Comorbidity Index was 5 in both groups. [Fig.1]Most infections were respiratory, genitourinary, or abdominal. Klebsiella spp. was the predominant pathogen (CAZ/AVI: 98.5%, MER/VAB: 100%) with high prevalence of KPC-producing strains (82.2%; 73.0%, respectively). [Fig.2]Clinical success was comparable, with patients in CAZ/AVI achieving 67.9% clinical cure versus 64.9% in MER/VAB, while in-hospital mortality was 20.6% vs 29.7% and relapse 11.5% vs 5.4%, respectively (p-value=0.343). No differences were found after accounting for site of infection [Fig.3]. AE were similar between groups. Kaplan-Meier survival curves (Fig.4) showed no significant difference in overall 28-day survival (19.1% vs 27.0%, log-rank p=0.343) between the two groups. CONCLUSION: CAZ/AVI and MER/VAB are effective treatments for CRE infection, demonstrating similar clinical outcomes. Further prospective studies are needed to validate these findings.