Overview Study of VX-121 in Healthy Subjects and in Subjects With Cystic Fibrosis Status: Completed Trial end date: 2019-05-03 Target enrollment: Participant gender: Summary The purpose of this study is to evaluate safety and tolerability of VX-121 in healthy subjects and in subjects with cystic fibrosis (CF). Phase: Phase 1/Phase 2 Details Lead Sponsor: Vertex Pharmaceuticals IncorporatedTreatments: Ivacaftor