Determinants of early Elexacaftor-Tezacaftor-Ivacaftor use in adults with cystic fibrosis and preserved lung function: insights from a European multicenter survey

Background Limited evidence exists to guide Elexacaftor-Tezacaftor-Ivacaftor (ETI) use in adults with cystic fibrosis (awCF) and preserved lung function (ppFEV1 >90%). To address the resulting variability in prescribing practices, we conducted a European survey among a group of adult CF centres aiming at identifying factors influencing ETI initiation decisions in adults with preserved lung function. Methods Between April and June 2024, we invited 25 ECFS prescribers from 25 adult CF centres to participate in a web-based survey to explore factors influencing ETI initiation in adults with CF and ppFEV₁ >90%. The survey questionnaire collected data on centre characteristics, prescribing ETI attitudes, and the impact of specific clinical variables on ETI prescription decision in this subgroup. Results Twenty-three CF specialists (92%) responded. Most specialists (69.6%) favoured early treatment initiation in all eligible patients. A key factors influencing ETI initiation decisions was the presence of respiratory symptoms. In adults with preserved lung function, however, microbiological and imaging features emerged as the most influential factors driving treatment decision. While patient willingness and symptoms strongly encouraged ETI use, factors like age over 50, a history of mental health issues, and pregnancy desire resulted in conflicting prescribing attitudes among centers. Conclusions Although several disease markers more consistently support the decision to initiate ETI in individuals with preserved lung function, the absence of clear clinical guidance contributes to heterogeneous prescribing practices across centres. This highlights the need for longitudinal studies to clarify the long-term outcomes of ETI in this population.