Changes in anthropometric parameters in children with cystic fibrosis treated with ivacaftor/tezacaftor/ elexacaftor and ivacaftor, with transition within a single INN, in the Republic of Bashkortostan

Introduction. Highly effective CFTR modulators have substantially reshaped the clinical phenotype of cystic fibrosis, including nutritional status. However, real-world evidence on anthropometric changes in children receiving sequential originator-to-generic ivacaftor/tezacaftor/elexacaftor/ivacaftor therapy remains limited.
Aim. To assess nutritional and anthropometric outcomes in children with cystic fibrosis from the Republic of Bashkortostan treated with ivacaftor/tezacaftor/elexacaftor/ivacaftor, with particular attention to treatment duration and sequential switching from Trikafta® to Trilexa®.
Materials and methods. This retrospective cohort study included 38 pediatric patients with cystic fibrosis. Body weight, height, body mass index (BMI), and nutritional status categories were evaluated during Trikafta therapy at 6, 12, 18, and 24 months and after switching to Trilexa at 6 and 12 months.
Results. BMI increased progressively during Trikafta therapy, reaching +0.67 kg/m² at 6 months, +1.01 kg/m² at 12 months, +1.29 kg/m² at 18 months, and +1.62 kg/m² at 24 months relative to pretreatment baseline. The incremental BMI gain over consecutive 6-month intervals was 0.67, 0.34, 0.28, and 0.33 kg/m², respectively. Following the switch to Trilexa, BMI increased by a further 0.28 kg/m² at 6 months and 0.77 kg/m² at 12 months. The proportion of patients with protein-energy malnutrition declined from 28.9% at treatment initiation to 23.6% after 6 months, to 18.4% at the time of switching, and to 13.1% after 6 months of generic therapy. The proportion of patients with normal BMI increased from 50.0% at baseline to 63.0% after 6 months of originator therapy, then to 68.4% at switching and to 70.1% after 6 months of generic therapy.
Conclusion. Ivacaftor/tezacaftor/elexacaftor/ivacaftor therapy was associated with improved nutritional status and anthropometric outcomes in children with cystic fibrosis. Sequential switching from the originator to the generic formulation was not associated with loss of nutritional benefit, and favorable anthropometric trends were maintained over follow-up.

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