Adherence to lumacaftor-ivacaftor therapy in patients with cystic fibrosis in France

Background Lumacaftor-ivacaftor combination is a promising treatment for cystic fibrosis (CF) patients homozygous for the F508del-CFTR mutation. Optimal adherence is essential to achieve full health outcomes benefits. Methods This retrospective study used pharmacy refills data to calculate proportion of days covered (PDC). Adherence was defined as a PDC ≥80%. A logistic regression analysis was conducted to examine factors associated with medication adherence. Results Ninety-six patients were included in the final cohort for analysis. The mean PDC was 96%  ± 14 at 6 months, and 91% ± 17 at 12 months. The proportion of adherent patients was 89% and 83% at 6 and 12 months respectively. Age and ppFEV1 were found to affect medication adherence. Conclusions Considering the medico-economic impact of CFTR modulator therapy, high adherence rates to lumacaftor-ivacaftor found in this study are encouraging.