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.