The U.S. Food and Drug Administration's Experience with Ivacaftor in Cystic Fibrosis. Establishing Efficacy Using In Vitro Data in Lieu of a Clinical Trial.

On May 17, 2017, the U.S. Food and Drug Administration expanded the patient population for use of ivacaftor to include patients with cystic fibrosis with relatively rare mutations in the cystic fibrosis transmembrane conductance regulator gene.

Change in sweat chloride as a clinical end point in cystic fibrosis clinical trials: the ivacaftor experience.

Cystic fibrosis (CF) is a life-shortening inherited disease caused by mutations in the CF transmembrane conductance regulator gene (CFTR), which encodes for the CF transmembrane conductance regulator (CFTR) ion channel that regulates chloride and water transport across the surface of epithelial cells. Ivacaftor, a drug recently approved by the US Food and Drug Administration, represents the first mutation-specific therapy for CF. It is a CFTR channel modulator and improves CFTR function in patients with CF who have a G551D mutation.