P049 Effects of elexacaftor/tezacaftor/ivacaftor after 6 months in Dutch people with cystic fibrosis with at least 1 F508del mutation

Objectives: To evaluate the effect of elexacaftor/tezacaftor/ivacaftor in The Netherlands for people with CF (pwCF) 12 years and older at least 1 F508del mutation after 6 months use. Methods: Our study is a prospective observational cohort which we report real life data on use elexacaftor/tezacaftor/ivacaftor. primary endpoint change percent predicted FEV1 (ppFEV1) secondary SCC correlation between ppFEV1 SCC. Results: We enrolled 185,169 (82.8%) homozygous patients 35 (17.2%) heterozygous mutation. baseline mean was 72% 84.4 mmol/L. After there significant increase 13.8% decrease 50.1 There no In subanalysis, female had higher 4.7% compared to men. PwCF who did not another CFTR modulator before, showed 5.5% those that were modulators before. addition, an FEV1>90% FEV1<90%, (non-significant), probably due fact these already used modulator. analysis only significantly different male patients. pwCF decreased 11.8% more group pwCF. Conclusion: conclusion, our show substantial lung function Dutch than age need biomarkers monitor modulators.