Roll-Over Study of Ivacaftor in Cystic Fibrosis Pediatric Subjects With a CF Transmembrane Conductance Regulator Gene (CFTR) Gating Mutation

The purpose of this study is to provide information regarding the long-term safety and pharmacodynamics of ivacaftor treatment in the pediatric population younger than 6 years of age with Cystic Fibrosis (CF) who have a CFTR gating mutation in at least 1 allele and will further explore the efficacy of long-term ivacaftor treatment in this population of patients with CF.