Prescribing Patterns and Clinical Outcomes of Ceftolozane/Tazobactam by Renal Function and Body Mass Index: A SPECTRA Real-World Multi-Country Analysis

<b>Background:</b> Antimicrobial resistance is a global health crisis associated with high mortality and economic burden. Patients with renal dysfunction and obesity have increased susceptibility to infections and may experience different real-world outcomes, including clinical success and mortality, but are often under-represented in clinical trials. Ceftolozane/tazobactam (C/T) is an innovative therapy used to treat resistant Gram-negative infections. We aimed to describe real-world clinical outcomes in hospitalized adults treated with C/T across categories of renal function and BMI in the SPECTRA study. <b>Methods:</b> SPECTRA was a multi-national observational study on 617 patients who received C/T for ≥48 h. Outcomes included clinical success, all-cause in-hospital mortality, readmission, and ICU admission and length of stay (LOS), with sub-analysis of patients across BMI and renal function strata. <b>Results:</b> Renal function and weight were reported in 597 and 469 patients, respectively, of which 51.9% had lower creatine clearance (<80 mL/min) and 50.7% were overweight. Clinical success and all-cause in-hospital mortality ranged at 59.1-77.8% and 11.1-29.2% across renal function strata and 64.6-68.6% and 18.6-21.4% across weight subgroups. Across renal function and weight subgroups, 38.9-54.2% and 45.9-53.5% of patients were admitted to ICU. Median ICU LOS was 8-21.5 and 14-20 days, respectively. Readmission (30-day all-cause) occurred in 4.5-11.8% and 8.2-11.9% of patients across renal function and weight strata. <b>Conclusions:</b> Results from this sub-analysis suggest real-world clinical effectiveness of C/T across patients with renal impairment and obesity, highlighting C/T as a component within treatment guidelines for resistant Gram-negative infections.