LONGITUDE: An observational study of the long-term effectiveness of elexacaftor/tezacaftor/ivacaftor in people aged ≥12 years with cystic fibrosis using data from the United Kingdom Cystic Fibrosis Registry - 2-year analysis
G. Vega-Hernández, Gordon MacGregor, Andrew Wilfin, Francis Adams, Ciarán Haugh, Carl A. Baxter, Heike Wöhling, Siân Clarke, Susan C. Charman, S.B. Carr
Abstract
Background The cystic fibrosis (CF) transmembrane conductance regulator modulator (CFTRm) elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) has demonstrated efficacy and safety in clinical trials and emerging observational studies in people with CF. This study evaluated the real-world impact of ELX/TEZ/IVA in a large cohort of people with CF in the UK. Methods LONGITUDE is an observational, registry-based cohort study using data from the UK CF Registry to evaluate outcomes of ELX/TEZ/IVA in people aged ≥6 years who initiated ELX/TEZ/IVA from August 2019. Key outcomes included percent predicted forced expiratory volume in 1 s (ppFEV 1 ), body mass index (BMI), pulmonary exacerbations (PEx), lung infections, transplants, deaths, and treatment discontinuation. We report results of people ≥12 years with data up to December 31, 2022. Results A total of 5187 people were included (mean follow-up 19.1 months). ppFEV 1 improvements were observed at 2 years (10.2; 95 % CI: 9.6, 10.8; n = 1448). A clinically meaningful difference in the annual change of ppFEV 1 between ELX/TEZ/IVA-treated people and historical CFTRm-naïve controls was observed, with those treated with ELX/TEZ/IVA having less of a decline in lung function over time by 1.1 percentage points (95 % CI: 0.9, 1.4). A 64.7 % reduction in the rate of PEx, increase in BMI by 1.7 kg/m 2 (SD: 2.3), reduced lung infections, and low number of lung transplants and deaths were also observed. Conclusions People with CF aged ≥12 years in the UK who initiated ELX/TEZ/IVA had sustained improvements in multiple CF-related health outcomes, consistent with results from clinical trials. These results support the positive impact of ELX/TEZ/IVA on the lives of people with CF.