Efficacy of extended infusion of β-lactam antibiotics for the treatment of febrile neutropenia in haematologic patients (BEATLE): a randomised, multicentre, open-label, superiority clinical trial.

Objectives: The efficacy of extended infusions (EI) of β-lactam antibiotics for optimising outcomes in febrile neutropenia is unclear. We assessed whether the administration of β-lactams was more effective in EI than in intermittent infusion (II) for the treatment of febrile neutropenia.

Methods: We performed a randomised, open-label, superiority clinical trial of patients with febrile neutropenia at four Spanish university hospitals. Patients undergoing haematopoietic stem cell transplantation or with acute leukaemia receiving chemotherapy who required empirical antibiotic treatment for febrile neutropenia were randomly assigned (1:1) to receive EI of β-lactam or II after a first dose in bolus. The choice of antipseudomonal β-lactam was left to the discretion of the attending physician. The primary endpoint was treatment success at day 5, defined as defervescence without modifying the antibiotic treatment. Secondary endpoints included adverse events, attainment of the pharmacokinetic/pharmacodynamic target of 50, 75 and 100%ƒ_uT_>MIC, and 30-day mortality.

Results: Between November 19, 2019 and June 22, 2022, 295 patients we screened for eligibility, of whom 150 were randomly assigned to receive EI (n=77) or II (n=73) of the antipseudomonal β-lactam of choice. In the intention-to-treat analysis, treatment success at day 5 was achieved in 39/77 patients (50.6%) receiving EI versus 46/73 patients (63.0%) receiving II (risk difference -12.4%; 95% confidence interval, -29.4 to 4.7, p=0.17). The pharmacokinetic/pharmacodynamic targets of 75 and 100% ƒ_uT_>MIC for empirical treatment were achieved more frequently in the EI group. No statistically-significant differences were found between groups in terms of adverse events or 30-day mortality.

Conclusions: Our findings do not support the routine use of empirical EI of β-lactams in febrile neutropenia. Further studies should consider the clinical heterogeneity of febrile neutropenia and focus on patients with sepsis/septic shock and microbiologically documented infections, particularly those with infections caused by microorganisms less susceptible to β-lactams.