Phase 2 Study Reports Cefepime–Zidebactam Outcomes in Carbapenem-Resistant Infections

Carbapenem-resistant Gram-negative infections, particularly those caused by metallo-β-lactamase (MBL)-producing organisms, have limited treatment options. This prospective, open-label, multicenter phase 2 trial enrolled adults with these infections to receive intravenous cefepime–zidebactam for 7–21 days, with renal dose adjustment. Of 72 treated participants, 68 were included in the microbiological intent-to-treat population and 60 met criteria for the primary efficacy analysis. MBL producers accounted for 56 of 68 qualifying isolates (82.4%).

In the evaluable population, investigator-assessed clinical cure at test of cure was 91.7% (95% CI, 81.6%–97.2%), and favorable microbiological outcome was 90.0%. Among evaluable participants with MBL-producing pathogens, clinical cure was 93.9% and favorable microbiological outcome was 91.8%. External adjudication yielded lower rates: 86.7% for clinical cure and 85.0% for favorable microbiological outcome. Twenty-eight-day mortality was 2.8%; treatment-related adverse events occurred in 15.3%, including serious events in 2.8%.

The findings provide early clinical data for an infection group with limited options, but the single-arm design does not establish comparative efficacy. Results are based on a small evaluable cohort, and investigator-assessed and adjudicated outcomes differed.