Retrospective observational study of French patients with cystic fibrosis and a Gly551Asp-CFTR mutation after 1 and 2years of treatment with ivacaftor in a real-world setting.

Background: Ivacaftor has been shown to improve lung function and body weight in patients with CF and a gating mutation. Real-world evaluation is warranted to examine its safety and effectiveness over the long term.

Methods: A retrospective observational multicentre study collected clinical data in the year before and the 2years after ivacaftor initiation in patients with CF and a Gly551Asp-CFTR mutation.

Results: Fifty-seven patients were included. Mean absolute change in FEV% predicted improved from baseline to Year 1 (8.4%; p<0.001) and Year 2 (7.2%; p=0.006). Statistically significant benefits were observed with increased body mass index, fewer Pseudomonas aeruginosa and Staphylococcus aureus positive cultures, and decreased IV antibiotics and maintenance treatment prescriptions (including azithromycin, Dornase alpha and nutritional supplements). No significant adverse events were reported.

Conclusion: The clinical benefits of ivacaftor reported in previous clinical trials were confirmed in a real-world setting two years post-initiation, also reducing treatment burden.