A phase 3 study of tezacaftor in combination with ivacaftor in children aged 6 through 11 years with cystic fibrosis

•Tezacaftor/ivacaftor exposures were in target range of those in patients ≥12 years.•Tezacaftor/ivacaftor was generally safe and well tolerated at the evaluated doses.•Lung function was stable in normal range; normal growth was maintained for 24 weeks.•Tezacaftor/ivacaftor improved CFTR function based on sweat chloride levels.•Tezacaftor/ivacaftor improved CFQ-R respiratory domain child version scores.