The trial posting for Vertex 108: A Phase 3, 2-Part, Open-Label Study to Evaluate the Safety, Pharmacokinetics, and Pharmacodynamics of Ivacaftor in Subjects with Cystic Fibrosis Who are 2 Through 5 Years of Age and Have a CFTR Gating Mutation is not listed as active in clinicaltrials.partners.org database. The trial may have stopped recruiting.