Overview

The study proposes a planned, double-blind, non-inferiority clinical trial involving patients with febrile neutropenia and risk of extended-spectrum beta-lactamase (ESBL) infection. The goal is:

• Analyze the efficacy and tolerability of Ceftolozane/tazobactam (CEF/TAZ) compared to the current standard of care (meropenem) in patients with febrile neutropenia and risk of ESBL infection.

Patients will be randomly assigned to receive CEF/TAZ or meropenem, with assessment of clinical response, toxicity and microbiological evolution. Stool samples will be collected before, during and after treatment for intestinal microbiota analysis and intestinal microbiome analysis to evaluate possible effects on GVHD. Analysis of the results will include the taxonomic classification of the organisms present. Data will be analyzed to assess non-inferiority in clinical response, incidence of GVHD, antimicrobial resistance and other outcomes.

Eligibility

Inclusion criteria:

• Individuals who present with the onset of febrile neutropenia and at the same time present colonization with an ESBL-producing pathogen (identified through positive routine rectal swabs and/or positive culture of clinical specimen) or risk of infection with an ESBL-producing pathogen (use of 3rd/4th gen cephalosporin or piperacillin/tazobactam for at least 48 hours in the last 30 days).

Exclusion Criteria:

• Patients known to be colonized with carbapenem-resistant or CEF/TAZ-resistant pathogens
• Patients with previous use of carbapenems for at least 48h in the past 30 days are also excluded due to risk of resistance to the study drugs.
• Growth of a pathogen resistant to either study drug in a relevant clinical specimen during the intervention phase will be followed by adjustment of therapy according to local protocol, unblinding, and exclusion from the study.
• Patients that have received less than 72h of either study drug will also be excluded from the final analyses.