Is Balversa affected by genetics?

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

Relevant genes: CYP2C9

Balversa is affected by pharmacogenetics through the CYP2C9 gene. Your genotype for this gene can change how your body processes Balversa, which can affect both how well it works and how well you tolerate it. The strongest evidence level on this page is Moderate, based on CPIC or FDA guidelines.

What's in Balversa

erdafitinib affected by CYP2C9

Affected by CYP2C9 · FDA · Moderate evidence

Read the full erdafitinib genetics guide →

Erdafitinib phenotype recommendations

Published guidance from FDA on how erdafitinib should be dosed or substituted based on your CYP2C9 phenotype.

Phenotype	What it means	Recommendation	Evidence
Normal Metabolizer CYP2C9	Your body processes erdafitinib at a normal rate. The standard dose should work as expected.	FDA Initiate therapy with recommended starting dose.	—
Intermediate Metabolizer CYP2C9	Your body processes erdafitinib at a normal rate. The standard dose should work as expected.	FDA Initiate therapy with recommended starting dose.	—
Poor Metabolizer CYP2C9	Your body breaks down erdafitinib more slowly than normal, causing higher levels of the drug in your system. This increases the risk of side effects and closer monitoring may be needed.	FDA Initiate therapy with standard dose and monitor closely for adverse reactions. Consider dose reduction if adverse reactions occur.	Moderate
Indeterminate CYP2C9	The impact of your genotype on response to this drug is unknown	FDA Initiate therapy with recommended starting dose.	—
Not available CYP2C9	The impact of your genotype on response to this drug is unknown	FDA Initiate therapy with recommended starting dose.	—

Source: FDA

The gene behind the guidance

CYP2C9 Cytochrome P450 2C9

CYP2C9 metabolizes warfarin, phenytoin, celecoxib, and some NSAIDs. Variants that reduce its activity are most consequential for warfarin, where even small changes in drug clearance translate into very different doses (and a real bleeding risk if missed).

Poor metabolizers need substantially lower warfarin doses to hit the same INR target.

See all drugs affected by CYP2C9 →

Browse the full drug-class: Chemotherapy agents.

Related medications

Find out how your genetics affect Balversa

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.