Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines for Ivacaftor Therapy in the context of CFTR genotype

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 G551D -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 (

Type Guideline
CME Available No

Date of Resource

Genomic Competencies

Experts from the disciplines listed below have tagged this resource as fulfulling genomic competencies.


  • Pharmacogenetics/Pharmacogenomics
    • P1:   To demonstrate an understanding of how genetic variation in a large number of proteins, including drug transporters, drug metabolizing enzymes, direct protein targets of drugs, and other proteins (e.g. signal transduction proteins) influence pharmacokinetics and pharmacodynamics related to pharmacologic effect and drug response
    • P2:   To understand the influence (or lack thereof) of ethnicity in genetic polymorphisms and associations of polymorphisms with drug response
    • P3:   Recognize the availability of evidence based guidelines that synthesize information relevant to genomic/pharmacogenomic tests and selection of drug therapy (e.g. Clinical Pharmacogenomics Implementation Consortium)