Head-to-head: meropenem/vaborbactam versus ceftazidime/avibactam in ICUs patients with KPC-producing K. pneumoniae infections– results from a retrospective multicentre study

Purpose: Meropenem/vaborbactam (M/V) and ceftazidime/avibactam (C/A) are considered key agents in treating KPC-producing Klebsiella pneumoniae (Kp) infections. We compared these two drugs in ICUs patients with BSI and/or pneumoniae due to KPC- Kp. Methods: This retrospective multicentre study analysed ICU patients with bloodstream infections (BSI) and/or pneumonia caused by KPC-Kp across five Italian ICUs from January 2021 to December 2023. Propensity-score matching (PSM) was applied to mitigate the impact of confounding factors. The primary outcome was 30-day all-cause mortality. Secondary outcomes included early clinical improvement at 72 h, computing the odds ratio (OR) as effect size, and infection-related events. Subgroup analyses were performed based on relevant prognostic factors. Results: The study included 177 patients, with 88 subjects paired after-matching (52 treated with C/A and 36 with M/V). As for primary outcome, after PSM, no statistically significant differences in 30-day mortality were observed between the two groups: in the Kaplan-Meier survival log-rank test was p = 0.38, and PSM-adjusted HR of M/V on mortality was 0.65 (95% CI 0.55–1.68). As for secondary outcomes, M/V significantly improved early clinical response post-PSM (OR: 2.19, 95% CI: 1.35–3.55). Conclusions: M/V showed no statistically significant difference in 30-day mortality compared to C/A but demonstrated significantly improved in early clinical response for patients with KPC-Kp. These findings were consistent between unmatched and matched patients. Further prospective studies are warranted to validate these observations.