Ivacaftor response

Ivacaftor is the first FDA-approved drug designed to target a specific defect of the CFTR protein found in a subset of Cystic fibrosis (CF) patients. Hundreds of different variants within the CFTR gene have been identified. The G551D variant (rs75527207 G>A) results in defective gating at the plasma membrane and, in combination with another disease-causing CFTR allele, can result in CF disease phenotypes. Ivacaftor is designed to potentiate G115D-CFTR to improve symptoms in CF patients who carry this variant. Therapeutic guidelines for ivacaftor based on CFTR genotype have been published in Clinical Pharmacology and Therapeutics by the Clinical Pharmacogenetics Implementation Consortium (CPIC) and are available on the PharmGKB website (http://www.pharmgkb.org/drug/PA165950341).

PharmGKB