This is a randomized, parallel-group, double-blind, placebo controlled multicenter study to evaluate the safety and efficacy of CTP-656 in CF patients with CFTR gating mutations, compared to Kalydeco, for a total of 28 days. Subjects will be randomized to receive either double-blind CTP-656 or placebo, or open-label Kalydeco.
This study will evaluate the efficacy and safety of CTP-656 in patients with cystic fibrosis (CF) who have a cystic fibrosis transmembrane conductance regulator (CFTR) gating mutation.