The French Compassionate Program of elexacaftor-tezacaftor-ivacaftor in people with cystic fibrosis with advanced lung disease and no F508delCFTRvariant

Background The European Medicines Agency has approved the cystic fibrosis transmembrane conductance regulator (CFTR) modulator combination elexacaftor-tezacaftor-ivacaftor (ETI) for people with cystic fibrosis (pwCF) carrying at least one F508del variant. The United States Food and Drug Administration (FDA) also approved ETI for pwCF carrying one of 177 rare variants. Methods An observational study was conducted to evaluate the effectiveness of ETI in pwCF with advanced lung disease that were not eligible to ETI in Europe. All patients with no F508del variant and advanced lung disease (defined as having a percent predicted forced expiratory volume (ppFEV 1 )<40 and/or being under evaluation for lung transplantation) and enrolled in the French Compassionate Program initiated ETI at recommended doses. Effectiveness was evaluated by a centralized adjudication committee at 4–6 weeks in terms of clinical manifestations, sweat chloride concentration and ppFEV 1 . Results Among the first 84 pwCF included in the program, ETI was effective in 45 (54%) and 39 (46%) were considered to be non-responders. Among the responders 22/45 (49%) carried a CFTR variant that is not currently approved by FDA for ETI eligibility. Important clinical benefits, including suspending the indication for lung transplantation, a significant decrease in sweat chloride concentration by a median IQR −30 -14;-43mmol·l −1 (n=42; p <0.0001) and an improvement in ppFEV 1 by+10.0 6.0; 20.5 (n=44, p <0.0001), were observed in those for whom treatment was effective. Conclusion Clinical benefits were observed in a large subset of pwCF with advanced lung disease and CFTR variants not currently approved for ETI.