Real-world outcomes of cefepime/enmetazobactam for Enterobacterales infections: a retrospective descriptive study

Cefepime/enmetazobactam (FEP/META) is a novel β-lactam/β-lactamase inhibitor combination with activity against Enterobacterales, including extended-spectrum β-lactamase-producing isolates, but real-world clinical data outside randomized trials remain limited. We conducted a retrospective multicenter descriptive study across 13 Italian hospitals. Eligible patients had infections caused by Enterobacterales and received ≥72 h of cefepime/enmetazobactam therapy (alone or in combination with other antimicrobials) under a compassionate-use program. Thirty-two patients were included. The most frequently isolated pathogens were Escherichia coli (16/32, 50.0%) and Klebsiella pneumoniae (13/32, 40.6%). Extended-spectrum β-lactamase production was documented in 29/32 isolates (90.6%), while β-lactam/β-lactamase inhibitor resistance and fluoroquinolone resistance were each observed in 18/32 isolates (56.2%). Four isolates were ertapenem-resistant but remained susceptible to imipenem and meropenem; no carbapenemase production was confirmed. FEP/META was safely administered as targeted therapy in most cases and was used both as monotherapy and in combination regimens, according to clinical severity and source of infection. Clinical cure was achieved in all patients, and microbiological eradication was documented in 25/32 cases (78.1%). No in-hospital deaths were recorded. Despite the inherent limitations of retrospective real-world studies, our findings suggest that cefepime/enmetazobactam may be a well-tolerated component of carbapenem-sparing treatment strategies for selected documented Enterobacterales infections. In 32 real-world documented Enterobacterales infections, cefepime/enmetazobactam achieved 100% clinical cure and 78.1% microbiological eradication, with favorable tolerability.