National Cohort of Compassionate Use of Meropenem-Vaborbactam: No Benefit over Meropenem for .

BACKGROUND

Meropenem-vaborbactam (MEM-VAB) is a novel carbapenem-beta-lactamase-inhibitor combination that demonstrates activity against carbapenem-resistant (CR) Gram-negative bacteria, and more specifically KPC-producers, since vaborbactam is an effective inhibitor of KPC enzymes in vitro. This study aimed to describe the initial uses and efficacy of MEM-VAB for compassionate treatment during the first 21 months following its early access in France.

METHOD

A national multicenter retrospective study was conducted, including all patients who received at least one dose of MEM-VAB between 20 July 2020, and 5 April 2022. Clinical characteristics and outcomes were collected using a standardized questionnaire. The minimum inhibitory concentration (MIC) of antimicrobials, and complete genome sequencing of bacteria were performed when bacterial isolates were available.

RESULTS

Ultimately, 21 patients from 15 French hospitals were included in the study. The main indication for MEM-VAB treatment was respiratory tract infections ( = 9). The targeted bacteria included ( = 12), ( = 3), ( = 3), ( = 1), ( = 1), and ( = 1). Overall, no significant advantage of vaborbactam over meropenem alone was observed across all strains of in terms of in vitro susceptibility. However, MEM-VAB demonstrated a notable impact, compared to carbapenem alone, on the MIC for the two KPC-3-producing and .

CONCLUSIONS

MEM-VAB seems effective as a salvage treatment in compassionate use, but vaborbactam was shown to lack benefits compared to meropenem in treating -related infections. Therefore, it is crucial to compare meropenem to MEM-VAB MICs, particularly for , before prescribing MEM-VAB.