Real‐Life Experience With a Generic Formulation of Elexacaftor/Tezacaftor/Ivacaftor in Patients With Cystic Fibrosis With Responding Variants

Introduction Elexacaftor/Tezacaftor/Ivacaftor (ETI) has revolutionized cystic fibrosis (CF) care. In Argentina, the absence of patent restrictions allowed the production of a generic ETI formulation (ETIgf), significantly reducing costs. Objective This study evaluates the real‐world clinical impact of ETIgf in people with CF (pwCF). Methods This prospective, single‐center observational study in Buenos Aires, Argentina, included 71 pwCF (≥ 6 years) with responsive variants. Participants were categorized as: Group 1 (modulator‐naïve) or Group 2 (previously on lumacaftor/ivacaftor). Clinical outcomes, including ppFEV 1 , LCI 2.5 , BMI z ‐score, CFQ‐R, sweat chloride concentration (SCC), fecal elastase levels, liver enzymes and pulmonary exacerbations (PEx), were assessed over 12 months following the initiation of ETIgf. Results Group 1 included 43 patients, and Group 2 included 28 patients (median age: 10.9 and 10.6 years, respectively). The mean percentage change from baseline after 12 months of treatment for Group 1 and Group 2 was: ppFEV 1 +20.8 ( p < 0.01) and +18.5 ( p < 0.01); LCI 2.5 –13.3 ( p < 0.01) and –11.2 ( p < 0.05); CFQ‐R + 66.1 ( p < 0.01) and +30.4 ( p < 0.01); and SCC –53.1 ( p < 0.01) and –58.2 ( p < 0.01), respectively. BMI z ‐score increased by 0.5 in Group 1 ( p < 0.001), while Group 2 showed a non‐significant increase. Pulmonary exacerbations were reduced by 95% in both groups. No changes were observed in fecal elastase levels. Adverse events were mild: five patients experienced elevated transaminase levels and three presented with a rash. Conclusion ETIgf demonstrates robust clinical efficacy and safety, mirroring results reported for the originator. These findings highlight the viability of affordable generic modulators in expanding global access to life‐changing therapy.