An FGFR inhibitor for bladder and urinary-tract cancer
Erdafitinib
A targeted tablet used to treat advanced bladder and urinary-tract cancer that has particular FGFR gene changes.
What is Erdafitinib?
Erdafitinib is a specialist targeted treatment for advanced cancer of the bladder and urinary tract (urothelial cancer) in people whose cancer has certain FGFR gene changes. It is a tablet that blocks FGFR proteins, which drive the cancer's growth. Its most important risks are a rise in blood phosphate (hyperphosphataemia), which is monitored and used to guide the dose, and serious eye problems, particularly a retina condition called central serous retinopathy that can affect vision. It can also cause nail and skin changes and mouth soreness, so it is closely monitored.
Education and reference only. This is a plain-language guide to Erdafitinib — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Erdafitinib is a targeted cancer medicine used to treat advanced or spread cancer of the bladder and urinary tract, known as urothelial cancer, in people whose cancer carries specific changes in genes called FGFR. A test confirms these changes before it is used. It is taken by mouth as a tablet and is a more targeted treatment than standard chemotherapy. It is prescribed and supervised by a specialist cancer team, who monitor blood phosphate and the eyes closely and adjust the dose based on the results.
How it works
FGFR proteins are growth signals on the surface of cells. When the FGFR genes are altered, these signals can become stuck on, driving the cancer to grow. Erdafitinib blocks FGFR, switching off this faulty growth signal to slow or stop the cancer. Because FGFR also helps control phosphate balance in the body, blocking it tends to raise blood phosphate, which the team uses as a marker of how the medicine is working and to guide the dose. The same pathway is involved in the eyes, nails and skin, explaining several of its side effects.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist targeted treatment used for advanced bladder and urinary-tract cancer with certain FGFR gene changes.
Practical use
How to take Erdafitinib
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take the tablet by mouth as prescribed, swallowing it whole at about the same time each day, with or without food.
- Attend phosphate blood tests as arranged, as your dose may be increased or reduced depending on the results.
- Report any change in your eyesight straight away, such as blurring, dark spots or wavy lines, and attend all eye appointments.
- Use eye drops or other measures for dry eyes as advised, and look after your nails and skin as your team suggests.
- Use reliable contraception during treatment and for the time afterwards that your team advises, and report any possible pregnancy promptly.
Weighing it up
Advantages & disadvantages of Erdafitinib
Advantages
- A targeted treatment for advanced bladder and urinary-tract cancer with specific FGFR gene changes.
- Taken as a tablet at home rather than by infusion.
- Blood phosphate levels give the team a useful marker to fine-tune the dose.
Disadvantages
- Commonly raises blood phosphate, which needs monitoring and sometimes treatment.
- Can cause serious eye problems, including a retina condition that affects vision.
- Can cause nail and skin changes and mouth soreness, and can harm an unborn baby.
Practical use
Good to know
Two side effects stand out with erdafitinib. The first is a rise in blood phosphate, which is so consistent that the team uses phosphate levels to adjust the dose; very high levels need treatment, sometimes with a low-phosphate diet or phosphate-lowering medicines. The second is eye problems, especially a build-up of fluid under the retina called central serous retinopathy, which can blur or distort vision; any change in eyesight, such as blurring, dark spots or seeing wavy lines, must be reported promptly and regular eye checks are needed. Dry eyes are also common. Other effects include changes to the nails and skin, hand-foot reactions, mouth soreness, dry mouth, diarrhoea and taste changes. Because it can harm an unborn baby, reliable contraception is important during treatment and for a time afterwards for both women and men.
Who should not take it / use with caution
- People who have had a serious allergic reaction to erdafitinib should not take it.
- It is not used in pregnancy or while breastfeeding, as it can harm an unborn baby.
- It is used only where the right FGFR gene change has been confirmed and under close specialist supervision, with eye checks.
Monitoring
- Regular blood phosphate checks to guide the dose, especially early in treatment.
- Regular eye checks and prompt review of any change in vision.
- Watching for nail, skin and mouth side effects and reviewing response to treatment.
Side effects
- A rise in blood phosphate, which is monitored and may need a low-phosphate diet or medicine.
- Eye problems, including a retina condition (central serous retinopathy) and dry eyes, which can affect vision.
- Changes to the nails and skin, hand-foot reactions and mouth soreness.
- Dry mouth, taste changes, diarrhoea, reduced appetite and tiredness.
Key interactions
- Some medicines can raise or lower erdafitinib levels, so tell your team about all your medicines.
- Medicines or supplements affecting phosphate may need review, guided by your team.
- Avoid starting new medicines, including over-the-counter products, without checking with your team.
Available as: Tablets taken by mouth.
Answers
Erdafitinib: frequently asked questions
What is erdafitinib used for?
It is a targeted tablet for advanced bladder and urinary-tract cancer in people whose cancer has specific FGFR gene changes, confirmed by a test.
Why is my blood phosphate checked so often?
Erdafitinib reliably raises blood phosphate, so the team uses your phosphate level to fine-tune the dose, and treats it if it gets too high.
Why do I need eye checks?
It can cause eye problems, including a retina condition that affects vision, so regular eye checks are needed and any change in eyesight should be reported promptly.
How is it taken?
It is taken as a tablet by mouth, swallowed whole at about the same time each day, with or without food, exactly as your team prescribes.
Do I need contraception?
Yes. Because it can harm an unborn baby, reliable contraception is important during treatment and for a time afterwards for both women and men.
Authoritative sources
- BNF
- NICE CKS
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