Ivacaftor
Not a drug for cystic fibrosis — a drug for particular CFTR variants. Two people with the same diagnosis get opposite answers depending on which change they carry, which is the whole argument of this site in one prescription.
What this drug connects to
The genes involved
CFTR
Cystic Fibrosis →Ivacaftor is prescribed on the basis of which CFTR variant a person carries rather than on the diagnosis of cystic fibrosis, which makes it one of the clearest examples in medicine of genotype-directed treatment. It is a potentiator: it holds open a CFTR channel that has reached the cell surface but opens poorly. CPIC recommends it for people carrying at least one gating variant, of which G551D is the archetype, and specifically notes that it is not effective in people homozygous for F508del alone — that protein never reaches the surface, so there is nothing there for a potentiator to act on. The combination therapies developed since pair a corrector with the potentiator to address exactly that gap. Treatment is decided in a specialist clinic on confirmed clinical genotyping, and nothing here should be read as a reason to start, stop or change any medicine.
CPIC Guideline for Ivacaftor Therapy in the Context of CFTR Genotype (Clin Pharmacol Ther 2014, PMID 24598717).
In the news
2026-04-01 · Vertex Pharmaceuticals (FDA label expansion covering any CFTR variant shown to still produce CFTR protein, not just a fixed list of named mutations)
FDA expanded the approved-use labels for two CFTR modulators -- Alyftrek (ages 6+) and Trikafta, which contains ivacaftor (ages 2+) -- from a fixed list of named mutations to any CFTR variant shown, by clinical or lab data, to still let the gene make CFTR protein: 564 variants qualify for Alyftrek, 521 for Trikafta. About 800 more people with CF in the US are now eligible, bringing total eligibility to roughly 95% of the US CF population -- a real-world example of exactly the variant-by-variant pharmacogenomic matching this page profiles.
Whose work this rests on
Every guideline above was written by people. Named here because they are contributors to this page in the same sense anybody else on this site is.
Variants MyGeneLog™ reports for these genes
These are the positions in your own file that carry the genes above. Not every gene in a guideline is one we report — where that is the case the gene appears above without a variant here, and the note says so.
Infective connective tissue disorders (PheCode 712)
CFTR · rs548335381
Read more →Acute pancreatitis
CFTR · rs113812546
Read more →Barrett's esophagus or Esophageal adenocarcinoma
CFTR · rs17451754
Read more →Free Cholesterol to Cholesteryl Esters in Small HDL ratio
CFTR · rs145380885
Read more →Triglycerides to Total Lipids in Small HDL percentage
CFTR · rs6977665
Read more →Cystic fibrosis (F508del)
CFTR · rs113993960
Read more →Cystic fibrosis (G551D, a gating variant)
CFTR · rs75527207
Read more →Questions about Ivacaftor
What is ivacaftor?
Ivacaftor is a CFTR modulator prescribed for cystic fibrosis based on which CFTR variant a person carries, not the diagnosis alone. It’s one of the clearest examples in medicine of genotype-directed treatment.
Which CFTR variants does ivacaftor actually work for?
CPIC recommends ivacaftor for people carrying at least one gating variant, of which G551D is the archetype. It’s a potentiator that holds open a CFTR channel that reaches the cell surface but opens poorly.
Does ivacaftor work for the most common CFTR variant, F508del?
Not on its own. CPIC notes ivacaftor isn’t effective in people homozygous for F508del alone, because that protein never reaches the cell surface, leaving nothing for a potentiator to act on.
Who decides whether someone should take ivacaftor?
Treatment is decided in a specialist clinic based on confirmed clinical genotyping, and nothing here should be read as a reason to start, stop or change any medicine.
Quoting this page
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Ivacaftor. MyGeneLog™. https://www.mygenelog.com/drugs/ivacaftor