A Study to Evaluate GLPG2222 in Ivacaftor-treated Subjects With Cystic Fibrosis

This clinical study is a phase IIa, multi-center, randomized, double-blind, placebo-controlled, parallel group study to evaluate two doses of orally administered GLPG2222 in adult subjects with a confirmed diagnosis of CF harbouring one F508del CFTR mutation and a second gating (class III) mutation and on stable treatment with ivacaftor. Up to 35 evaluable subjects are planned to be included in the study. Eligible subjects must be on stable treatment with physician prescribed ivacaftor (Kalydeco®) for at least 28 days at the baseline visit. They will be randomized in a 2:2:1 ratio to receive one of two active doses of GLPG2222 (150 mg q.d. or 300 mg q.d.) or placebo q.d. administered for 29 days. Subjects will be in the study for a minimum of 6 weeks and a maximum of 10 weeks, from screening until the follow-up visit.