The ECFS-CTN cannot guarantee that the information provided here is comprehensive. Please go to the ClinicalTrials.gov link for detailed and up-to-date information on study background, eligibility criteria, study design, outcome measures, study status, participating sites, sponsor contact information and timelines.

You can also contact the CTN coordinating centre for additional information: ECFS-CTN@uzleuven.be (link sends e-mail)

Study Name on
ClinicalTrials.gov (link is external)
A Phase 3 Study of VX-661 in Combination With Ivacaftor in Subjects Aged 12 Years and Older With Cystic Fibrosis, 
Who Have One F508del-CFTR Mutation and a Second Mutation That Has Been Demonstrated to be Clinically Responsive to Ivacaftor
Study DrugVX-661/ ivacaftor
Type of Study DrugCFTR Modulation
Study TitleA Phase 3, Randomized, Double-Blind, Ivacaftor-Controlled, Parallel-Group Study to Evaluate the Efficacy and Safety 
of VX-661 in Combination With Ivacaftor in Subjects Aged 12 Years and Older With Cystic Fibrosis, 
Heterozygous for the F508del-CFTR Mutation and a Second CFTR Allele With a Gating Defect That Is Clinically Demonstrated to be Ivacaftor Responsive
Study Phase3
Study SponsorVertex

Link on
clinicaltrials.gov (link is external)

https://clinicaltrials.gov/ct2/show/NCT02412111 (link is external)

Participating ECFS-CTN sitesBelgium : Leuven
Italy: Milan, Rome
UK: Belfast, Birmingham, Leeds, London
Age12 Years and Older