Efficacy and safety of switching within one international non-proprietary name (elexacaftor/tezacaftor/ivacaftor) in children with cystic fibrosis: clinical experience of transition from Trikafta to Trilexa

Abstract

Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane regulator gene and is accompanied by chronic damage to the respiratory and gastrointestinal systems. Triple therapy with elexacaftor, tezacaftor, and ivacaftor significantly improves lung function and nutritional status. However, the high cost of the original drugs limits long-term use, making the use of bioequivalent generics such as Trilexa® relevant. Objective: To evaluate the efficacy and safety of switching from the original triple therapy (Tricafta®) to the generic drug Trilexa® in children with cystic fibrosis in a real-world clinical setting. Materials and methods: Data from 28 children aged 6–18 years (14 boys, 14 girls; median age 13.0 years (11.8–15.0)) with confirmed cystic fibrosis, treated with Trikafta® for 2–36 months and transferred to Trilexa® with a subsequent 180-day observation were analyzed. Body mass index, forced expiratory volume in the first second, forced vital capacity (% of predicted), and sweat chloride concentration were assessed; statistical processing was performed using the Wilcoxon test ( p < 0.05). Results: the median body mass index increased from 17.6 to 17.7 kg/m² ( p = 0.077), with 75.0 % of patients showing an improvement or stabilization of the indicator. Forced expiratory volume in the first second increased from 93.5 to 95.0 % of the predicted value ( p = 0.220), forced vital capacity – from 95.5 to 99.5 % ( p = 0.025), the proportion of children with forced vital capacity ≥ 100 % increased from 50.0 to 64.3 %. Sweat chloride concentration remained stable (47.5 and 50.5 mmol/L; p = 0.875); no serious adverse reactions were recorded, all patients continued therapy at the full dose. Conclusion: the switch from Trikafta® to Trilexa® in children with cystic fibrosis does not lead to the loss of the achieved clinical effects, is accompanied by the preservation of nutritional status, stability of external respiratory function and sweat test parameters, and is characterized by a favorable safety profile.