De-escalation of Medications After Initiation of Elexacaftor-Tezacaftor-Ivacaftor in Children 6 to 11 Years of Age With Cystic Fibrosis.

OBJECTIVE: The management of cystic fibrosis (CF) requires intensive, chronic medication regimens that can have a high treatment burden and cost. De-escalation of chronic medications for patients with CF aged 12 years and older on elexacaftor-tezacaftor-ivacaftor (ETI) has been evaluated; however, data are lacking for patients aged 6 to 11 years. METHODS: This single-center, retrospective study evaluated the non-inferiority of chronic medication de-escalation following an institutional algorithm in children 6 to 11 years with CF by comparing the difference in percent predicted FEV1 (ppFEV1) at 3 to 12 months after ETI initiation. Children with CF who had at least 1 copy of F508del and were started on ETI between January 1, 2021, and December 31, 2022, were included. Secondary outcomes included changes in the number of chronic inhaled CF medications, presence of Pseudomonas on a sputum culture, CF-related hospitalizations, and body mass index (BMI) z-score. RESULTS: Forty-one patients were included. The sample's baseline mean ppFEV1 was 95%. The mean difference in ppFEV1 between month 3 and month 12 on ETI was -1.37% (95% CI, -5.33 to 2.6). The lower bound of the 95% CI was less than the pre-defined non-inferiority margin (NIM) of -3.0%. Half of the patients had zero chronic inhaled medications by month 12 on ETI. Any Psuedomonas decreased from 27.5% to 7.5% (p = 0.037) 1 year post-ETI initiation. CONCLUSIONS: Following the initiation of an institutional medication de-escalation algorithm, the number of chronic medications in children aged 6 to 11 years with CF on ETI was decreased. However, this study was unable to confirm the non-inferiority of chronic medication de-escalation in this younger population with CF.