Registry-based study in people with cystic fibrosis and an R117H variant treated with ivacaftor

Abstract

Background Ivacaftor approval was extended to people with cystic fibrosis (CF) and an R117H variant in 2014 in the USA. This observational, real-world, postapproval study evaluated long-term outcomes among people with CF and an R117H variant on ivacaftor using data from the US Cystic Fibrosis Foundation Patient Registry.Methods Key outcomes were evaluated in ivacaftor-treated people with CF and an R117H variant for up to 36 months before and after treatment initiation using within-group comparisons. Analyses were descriptive in nature, focused on evaluation of observed outcome patterns over time and were performed both overall and for age groups ≥2 to <6 years, ≥6 to <18 years and ≥18 years. Key outcomes included lung function, body mass index (BMI), pulmonary exacerbations (PEx) and hospitalisations.Results The ivacaftor cohort included 369 people with CF and an R117H variant who initiated therapy between 1 January 2015 and 31 December 2016. During each of the 12-month intervals following treatment initiation, the mean observed percent predicted forced expiratory volume in 1 s (ppFEV1) and BMI values were higher and the mean annualised number of PEx and hospitalisation events were lower than pretreatment values. Mean change in ppFEV1 from pretreatment baseline was an increase of 1.5 (95% CI 0.8 to 2.3), 1.7 (95% CI 0.7 to 2.7) and 1.8 (95% CI 0.6 to 3.0) percentage points in the first, second and third years of treatment, respectively. Similar trends were observed in adult and paediatric subgroups.Conclusions The results support the clinical effectiveness of ivacaftor in people with CF and an R117H variant, including adult and paediatric subgroups.