Real-world data on the efficacy and safety of tezacaftor-ivacaftor in adults living with cystic fibrosis homozygous for F508del and heterozygous for F508del and a residual function mutation

Background: To examine safety and efficacy of tezacaftor-ivacaftor (TEZ/IVA) in a real-life setting in adults living with cystic fibrosis. Methods: A multicentre retrospective observational study, including adults living with cystic fibrosis (pwCF) eligible for TEZ/IVA, with assessments at baseline, 3 months (visit _3mo) and 6 months (visit _6mo) after start of treatment. Outcomes included change in FEV ₁, LCI, FeNO, CFQ-R, estimated number of annual acute exacerbations, BMI, dosage of pancreatic enzyme replacement therapy (PERT) and airway microbiology. We also assessed safety. Results: Forty-eight adult pwCF (mean (±SD) age 33 (±12) years; mean FEV ₁ 65 (±19) %P) were included. Three subgroups were identified: pwCF F/F CFTR modulator-naive (n = 28; 58%), pwCF F/F previously treated with lumacaftor-ivacaftor (n = 11; 23%) and pwCF F/RF (n = 9; 19%). Adverse events were described in 3 pwCF (6%) during the 6-month observation period (in one leading to treatment interruption). At visit _3mo, FEV ₁ had improved in all subgroups. In the entire group, mean FEV ₁ had increased from 66 (±2.9) %P to 72 (±2.9) %P (p < 0.0001). Similarly, LCI improved by approximately one unit at visit _3mo (p = 0.02). At visit _6mo mean annual acute exacerbation rate decreased significantly (p = 0.02). Only in the CFQ-R social functioning domain score, a significant improvement was observed at visit _6mo (p < 0.01). Conclusions: We showed that TEZ/IVA is safe, well tolerated and effective in terms of improvement of lung function, ventilation inhomogeneity, health-related social functioning, and reduction of estimated annual acute exacerbation rate, in adult pwCF F/F and F/RF. Results in this real-life study reflect those observed in RCTs.