2748. Ceftolozane/tazobactam For the Treatment of Cystic Fibrosis Patients: Results from a French Prospective Cohort Study
Authors: Bourge Xavier , Akrich Brune , Boutoille David , Brassac Isabelle , Mackosso Carole , Tavares Linsay Monteiro , Mootien Joy , Ruiz Fabrice , Timsit Jean-François , Castan Bernard , Burgel Pierre-Regis 
Published: November 2023

Abstract

Background
The aim of this prospective multicentre, French observational study was to describe the conditions of Ceftolozane/Tazobactam (C/T) use in hospital settings, and outcomes. This sub-analysis focuses on the cystic fibrosis (CF) patients included in the overall cohort.

Methods
Adult patients suffering from CF having received at least one dose of C/T and followed up as per routine clinical practice until stop of C/T were included in this analysis. Additional data related to CF were collected.

Results
Between October 2018 and December 2019, 63 patients with CF were enrolled from 28 sites. Mean age was 33.6 years and 44.4% were males. 12 patients (19.0%) received a lung transplant, 46.0% had comorbidities with diabetes (34.9%) being the most frequent. Most patients (69.8%) had normal renal function, almost one-third (28.6%) were immunosuppressed. One-half of patients presented with class 2 mutation of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. None of the patients received CFTR modulators due to non-availability during the study period.
About one-half of patients (52.4%) experienced intolerance/allergy to antibiotics; of these, 78.1% was associated with Ceftazidime.
Microbiology results showed that Pseudomonas aeruginosa was the most predominant pathogen representing 89.9% (71/79) of the isolates. C/T showed a very high susceptibility rate of 91.5% across those strains (Table 1). C/T demonstrated higher susceptibility rates than other B-lactam agents (Table 2).
Treatment duration until complete cure had a median of 15 days and occurred in 44.4% of patients. Treatment duration until partial cure or end of treatment was a median of 15 days and occurred in 46% of patients (Table 3). Only 2 patients experienced an adverse event leading to a discontinuation of treatment.
Treatment with C/T had a positive impact on pulmonary function measured by FEV1 (Table 4) with a mean increase after treatment from 1.33L (range 0.5 - 4.1L) to 1.47L (range 0.6 - 4.6L).

Conclusion
These results suggest that C/T is an effective and safe option for the treatment of CF patients with a potential positive impact on FEV1 when treating bacterial infections mainly caused by Pseudomonas aeruginosa.

Disclosures
Xavier Bourge, PharmD, Merck: Employe Brune Akrich, MD, MSD: Employee David Boutoille, MSD France: Board Member Isabelle Brassac, Scientist, MSD France: salary Carole Mackosso, n/a, MSD France: MSD employee Jean-François Timsit, MD, merck: Advisor/Consultant Bernard Castan, MD, ADVANZ: SPEAKER MODERATOR|BIOMERIEUX: SPEAKER MODERATOR|GILEAD: Advisor/Consultant|MSD France: Board Member|MSD France: SPEAKER MODERATOR|SANOFI: Advisor/Consultant|SHIONOGI: Advisor/Consultant Pierre-Regis Burgel, MD,PHD, ASTRA-ZENECA: Honoraria|BOEHRINGER INGELHEIM: Honoraria|CHIESI: Honoraria|GSK: Honoraria|INSMED: Honoraria|NOVARTIS: Honoraria|PFIZER: Honoraria|VERTEX: Grant/Research Support|ZAMBON: Honoraria