A Study of CFTR modulator combinations in Subjects with Cystic Fibrosis (VX18-121-101)

A Phase 2, Randomized, Double-blind, Controlled Study to Evaluate the Safety and Efficacy of VX-121 Combination Therapy in Subjects Aged 18 Years and Older With Cystic Fibrosis

Cystic fibrosis (CF) is a lifelong disease resulting from changes (mutations) in the code for one gene called the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Changes in this gene can affect the amount of protein made from this gene, or how well the protein works. When there is not enough protein or it does not work properly, some fluids in the body become sticky and cause problems in the lungs and other organs.



This study will look at how well the medicine ‘VX-121’ works, in combination with other medicines. Early studies have suggested that taking these medicines may improve health in some patients with CF. The study will include men and women with CF who are 18 years of age or older, and who have certain mutations in their CF genes. The study will check if the combinations can improve lung function and other measures of health in people with CF.



In Part 1, VX-121 will be tested with tezacaftor and VX-561, in people with one copy of a CF gene with a mutation termed F508del and one copy of a CF gene termed a minimal function mutation. Part 1 will last for 9 to 11 weeks and plans to include 54 participants, 9 will receive placebo (inactive pills).



In Part 2, VX-121 will be tested with tezacaftor and ivacaftor, in people who have two copies of the F508del mutation. Part 2 will last for 15 to 17 weeks and plans to include 27 participants, 9 will receive placebo.



In Part 3, VX-121 will be tested with tezacaftor and ivacaftor, in people with one copy of F508del mutation and one copy of a minimal function mutation. Part 3 will last for 9 to 11 weeks and plans to include 27 participants, 9 will receive placebo.