This is a Phase 2, randomized, multicenter, double-blinded, placebo-controlled, study of VX-661 monotherapy, and VX-661/ivacaftor co-therapy in participants with CF who are homozygous or heterozygous for the F508del CFTR mutation.~This study is separated into seven groups: Group 1-7, respectively. Approximately 180 participants were randomized in a ratio of 4:1; active drug to matching placebo in each group.
The purpose of this study is to evaluate the safety, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) effects of VX-661 alone and when coadministered with ivacaftor in participants with cystic fibrosis (CF) who are homozygous or heterozygous for the F508del-CFTR mutation.