Real-world 12-months outcomes after initiation of triple modulators in Australian cystic fibrosis population

In Australia, elexacaftor/tezacaftor/ivacaftor (ETI) was approved in April 2022 for people with cystic fibrosis (pwCF) ≥ 12 years of age. We investigated the effect of ETI on Australian pwCF by comparing changes in lung function (FEV1pp), use of intravenous antibiotics, and adverse events over the 12 months before and after ETI treatment. PwCF were categorised into four groups: (1) those on a full ETI dose, (2) those on a partial dose; (3) those who ceased ETI, and (4) those who switched to another CF transmembrane conductance regulator modulator (CFTRm). Descriptive statistics were used to describe the population, health service use and adverse events. The change in FEV1pp was compared using t tests and linear regressions. Data from 2,073 pwCF were analysed (1,100 (53.1%) male, 1,145 (55.2%) F508del homozygous). 1,833 (88.4%) participants were on a full dose, 97 (4.7%) on partial, 117 (5.6%) ceased ETI and 26 (1.3%) switched to another CFTRm. The greatest improvement in FEV1pp was observed in those on full and partial doses, with a mean (SD) change of 8.1% (9.2) and 8.6% (9.0) respectively. Post-ETI healthcare utilisation differed across ETI treatment groups after adjustment for pre-ETI utilisation and baseline characteristics, with generally higher clinic visit, hospitalisation and hospital IVAB utilisation among participants who did not remain on full-dose ETI. While ETI was generally well tolerated, approximately 12% of pwCF did not maintain a full dose due to side effects.