Raw research findings for this medication. Mostly single studies, not curated or confirmed robust.
Tezacaftor/ivacaftor is a combination CFTR modulator for cystic fibrosis: tezacaftor helps faulty CFTR protein reach the cell surface, and ivacaftor holds its channel open. It is used for people with two copies of F508del or with one of several residual-function CFTR variants, and causes fewer interactions than lumacaftor/ivacaftor. It is sold as Symdeko and Symkevi.
Whether it works depends on CFTR, the gene behind cystic fibrosis: it is approved for people homozygous for F508del (rs113993960), a finding rated at PharmGKB's highest level, and for listed residual-function variants. Both parts are broken down by CYP3A4. There is no CPIC or DPWG guideline for the combination.
Every published finding on gene variants and Symdeko. Upload your DNA file to see which of these rows apply to you.
PharmGKB weighs all studies of a variant and rates how strong the evidence is, from 1A (strongest) to 4.
CFTR rs113993960: Level 1A · replicated. Efficacy: Cystic Fibrosis. 3.
Studies of how well it worked in people carrying a variant.
Study findings and evidence levels: PharmGKB (CC BY-SA 4.0). Guidelines: CPIC and DPWG, as bundled in PharmCAT. Most studies were done mainly in people of European ancestry.
More drugs from the same category
Not a prescribing recommendation. This page is educational information about pharmacogenomic research and clinical guidelines - it is not medical or dosing advice, and not a prediction of how any medication will work for you. Never start, stop, or change a medication or dose based on it; talk to your doctor or pharmacist, who can order clinical-grade testing if appropriate.
Content updated September 2026.
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