Ivacaftor Treatment in 4 Month to 2 Year Old CF Subjects

Ivacaftor (Kalydeco®, Vertex Pharmaceuticals Inc.) was the first of a new class of drugs that improved CFTR gating dysfunction (2, 3, 4). For such mutations (G551D, G178R, S549N, S549R, G551S, G970R, G1244E, S1251N, S1255P, G1349D) that permit CFTR expression at the cell membrane but compromise its activity.