Is Kalydeco affected by genetics?

Yes — the active ingredient is metabolized by a gene known to vary between individuals.

Relevant genes: CFTR

Kalydeco is affected by pharmacogenetics through the CFTR gene. Your genotype for this gene can change how your body processes Kalydeco, which can affect both how well it works and how well you tolerate it. The strongest evidence level on this page is Strong, based on CPIC or FDA guidelines.

What's in Kalydeco

ivacaftor affected by CFTR

Affected by CFTR · CPIC · Strong evidence

Read the full ivacaftor genetics guide →

Ivacaftor phenotype recommendations

Published guidance from CPIC on how ivacaftor should be dosed or substituted based on your CFTR phenotype.

Phenotype	What it means	Recommendation	Evidence
ivacaftor responsive CFTR	Your genetic variant is responsive to ivacaftor. This medication can help improve your lung function and other cystic fibrosis symptoms by helping the CFTR protein work better.	CPIC Use ivacaftor according to the product label	Strong
ivacaftor non-responsive CFTR	Your genetic variant is unlikely to respond to ivacaftor. This medication is not expected to improve your cystic fibrosis symptoms, and a different treatment approach is recommended.	CPIC Ivacaftor is not recommended	Moderate
ivacaftor irrelevant CFTR	The impact of your genotype on response to this drug is unknown	CPIC Initiate therapy with recommended starting dose.	—
Not available CFTR	The impact of your genotype on response to this drug is unknown	CPIC Initiate therapy with recommended starting dose.	—

Source: CPIC

The gene behind the guidance

CFTR Cystic Fibrosis Transmembrane Conductance Regulator

CFTR is the chloride channel that's broken in cystic fibrosis. Modern CF therapies (ivacaftor, tezacaftor, elexacaftor, and their combinations) restore partial channel function, but only for patients whose specific CFTR variant produces a protein the drugs can act on. The FDA labels each modulator with the exact list of responsive variants.

Patients with at least one gating variant like G551D respond dramatically to ivacaftor. Patients homozygous for F508del benefit from the triple combination (Trikafta), but not from ivacaftor alone.

See all drugs affected by CFTR →

Find out how your genetics affect Kalydeco

This page describes the general pharmacogenetics. A Gene2Rx report analyzes your own DNA to tell you which metabolizer group you fall into, across every medication.

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Informational only — not medical advice. Pharmacogenetic guidance describes population-level patterns; your individual response depends on many factors. Never start, stop, or change a medication without talking to your prescribing clinician.