A phase 3, randomized, double-blind, parallel-group study to evaluate tezacaftor/ivacaftor in people with cystic fibrosis heterozygous for F508del-CFTR and a gating mutation

•In participants with CF who have F/gating genotypes, TEZ/IVA:•Did not significantly improve lung function or CFQ-R respiratory domain scores versus IVA alone•Was generally safe and well tolerated and had a safety profile consistent with that in prior studies•The impact of TEZ/IVA on the F508del-CFTR–mutant protein is insufficient to produce clinical benefit over IVA alone in people with CF with F/gating genotypes.