Ivacaftor is an oral bioavailable potentiator of the cystic fibrosis transmembrane conductance regulator protein. It is the first therapeutic agent that has been registered for clinical use which targets the basic defect in people with cystic fibrosis who carry a G551D mutation or other rarer specific gating mutations. Clinical trials have shown consistent and impressive clinical benefit that appears to be sustained over time in people with cystic fibrosis who carry a G551D mutation and similar benefits have been seen in those who carry rarer gating mutations. Ivacaftor is orally administered twice daily with a dose that does not vary between children aged 6 years through to adult life in patients with G551D. It appears to be well tolerated although there are potential interactions with drugs that are metabolised through CYPP450 CYP3A. Ivacaftor is also currently being trialled in combination with correctors for patients with the most common mutation of cystic fibrosis transmembrane conductance regulator the F508del mutation.
Keywords: CFTR modulator; cystic fibrosis; gating mutation; ivacaftor; potentiator therapy.