VX17-659-103 Efficacy and Safety of VX-659/TEZ/IVA in CF Homozygous


Therapeutic category
Restore CFTR Function
Trial status
closed Participating Centres
Phase III

Full title

A Phase 3, Randomised, Double-blind, Controlled Study Evaluating the Efficacy and Safety of VX-659 Combination Therapy in Subjects With Cystic Fibrosis Who Are Homozygous for the F508del Mutation (F/F)

CF is caused by decreased quantity and/or function of the Cystic Fibrosis transmembrane conductance protein regulator (CFTR) protein due to mutations in the gene that codes for the CFTR protein. The CFTR protein regulates salt and water absorption and secretion and pH balance in sweat glands and multiple organs, including the lungs, pancreas, and other gastrointestinal organs. The most common disease-causing CFTR mutation is F508del and subjects can either have two copies of the gene, known as homozygous, or one copy, known as heterozygous.
Therapies targeted at improving the function of the protein which is formed as a result of the F508del mutation have shown some positive effects if patients carry two copies of this gene mutation (homozygous).
This study will evaluate the efficacy of VX-659 in triple combination with tezacaftor (TEZ) and ivacaftor (IVA) in subjects with Cystic Fibrosis. Preliminary results from a previous trial with VX-659 indicated a clinical benefit supporting the development of this triple combination. The study population includes male and female subjects with Cystic Fibrosis who are 12 years of age or older, and who are homozygous for the F508del mutation. The study plans to include 100 participants globally, who will be randomised (1:1) to the triple combination arm or triple placebo arm. The study duration is 16 weeks; 4 weeks screening period, 4 weeks for the TEZ/IVA Run-in period, 4 weeks of treatment and 4
weeks for the safety follow-up. The study consists of 8 clinic visits. Study drugs will be taken as a tablet, two in the morning (VX-659/TEZ/IVA) and one in the evening (IVA).
Trial Reference Number
Trial type
Length of participation
24 weeks
Recruitment target
Last edited date
CF sponsor
Vertex Pharmaceuticals Incorporated
CF sponsor type

Who can take part?

Top inclusion criteria
  • 12 Years and older
  • Forced expiratory volume in 1 second (FEV1) value ≥40% and ≤90% of predicted mean for age, sex, and height
Top exclusion criteria
  • Clinically significant cirrhosis with or without portal hypertension.
  • Glucose-6-phosphate dehydrogenase (G6PD) deficiency.
  • Lung infection with organisms associated with a more rapid decline in pulmonary status.

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