Erdafitinib (Balversa®)

Erdafitinib comes in tablets. This means you can take it at home.

During a course of treatment, you will meet someone from your cancer team, such as a:

• cancer doctor
• specialist nurse
• specialist pharmacist.

This is who we mean when we mention doctor, nurse or pharmacist in this information.

During your course of treatment, you will have regular blood tests. This is to check that it is safe for you to have treatment.

You will meet with a doctor, nurse or pharmacist before you have treatment. They will talk to you about your blood results and ask how you have been feeling. If your blood results are okay, the pharmacy team will prepare your targeted therapy.

You usually take erdafitinib once a day. Your cancer team will discuss your treatment plan with you. You usually take erdafitinib for as long as it is working well for you and side effects can be managed.

You may be given tablets of different strengths. Always take them exactly as explained. This is important to make sure the tablets work as well as possible for you.

Your cancer team may also give you anti-sickness drugs and other medicines to take home. Take all your capsules or tablets exactly as they tell you to.

Erdafitinib can be taken with or without food. Make sure you:

• swallow the tablets whole with a glass of water
• do not chew, break, dissolve or crush them
• take them at the same time every day.

If you forget to take the tablets, take the missed dose as soon as possible within the same day. If a full day has passed, take the next dose at the usual time. Do not take a double dose to make up for the missed dose. Contact the hospital on the 24-hour number you have been given for advice.

You should not have grapefruit or Seville oranges (bitter oranges) during your treatment. This includes eating them or drinking the juice. This can change how effective the drug is.

Other things to remember about your tablets:

• Keep them in the original package and at room temperature, away from moisture, heat and direct sunlight.
• Keep them safe, where children cannot see or reach them.
• If you are sick (vomit) just after taking them, do not take an extra dose. Take your next dose at the usual time.
• Do not throw away unused tablets. Return them to your cancer team at the hospital.

These side effects happen to 10 or more people in every 100 people (10% or more) who have this treatment.

This treatment can cause changes to the levels of phosphate in your blood. Phosphate is a mineral. Phosphates have different functions in the body, including keeping your bones and teeth healthy. Phosphates are in foods such as:

• meat
• eggs
• fish
• cheese.

You will have regular blood tests to check phosphate levels. Phosphate levels may be raised or lower than normal. A raised phosphate level is more common than a low level.

Symptoms of a raised phosphate can include:

• numbness
• tingling around the mouth
• muscle cramps
• confusion

Contact the hospital straight away on the 24-hour number if you have any of these symptoms.

If your phosphate levels are raised, your cancer team may suggest you make some changes to your diet. They may also prescribe medicine to reduce your blood phosphate levels.

This treatment can affect the eyes and eyesight (vision). You will have a detailed eye examination and tests before you start treatment. For the first 4 months of treatment, doctors will test your eyes every month. They will then do eye tests every 3 months.

This treatment can cause dry eyes. Your doctor, nurse or pharmacist will give you eye drops to use. They will tell you how and when to use them.

Contact the hospital straight away on the 24-hour number if you have any changes to your eyes or vision, including:

• flashes of light or seeing black spots (floaters)
• blurred vision or reduced vision
• having a ‘shadow’ in your vision or it appears like you are looking through a dark curtain
• sore, painful or swollen eyes.

You may need to see an eye specialist urgently for treatment.

Do not drive or operate machinery if your vision is affected.

This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is normal for you, or having watery or loose stools. You may also have stomach cramps. If you have a stoma, it may be more active than usual. 

If you are passing loose stools 3 or more times a day and this is not normal for you, contact the hospital as soon as possible on the 24-hour number. Follow the advice they give you about:

• taking anti-diarrhoea medicines 
• drinking enough fluids to keep you hydrated and to replace lost salts and minerals
• any changes to your diet that might help. 

They might also ask you for a specimen of your stool to check for infection.

This treatment can cause constipation. Constipation means that you are not able to pass stools (poo) as often as you normally do. It can become difficult or painful. Here are some tips that may help:

• Drink at least 2 litres (3½ pints) of fluids each day.
• Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
• Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital on the 24-hour number for advice. They can give you drugs called laxatives to help. 

If you have not been able to pass stools for over 2 days and are being sick, contact the 24-hour number straight away. 

This treatment may cause a sore mouth and throat. You may also get mouth ulcers. This can make you more likely to get a mouth or throat infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

Contact the hospital straight away on the 24-hour number, if:

• a sore mouth or throat affects how much you can drink or eat 
• your mouth, tongue, throat or lips have any blisters, ulcers or white patches. 

They can give you advice, and mouthwash or medicines to help with the pain or to treat any infection. Follow their advice and make sure you:

• drink plenty of fluids
• avoid alcohol and tobacco
• avoid food or drinks that irritate your mouth and throat.

This treatment can cause a dry mouth. Tell your doctor if this happens. The following tips may help:

• Add moisture to food to make it easier to swallow. For example, moisten foods with gravies and sauces.
• Take frequent sips of water or a sugar-free drink. Keep a glass of water by your bed and carry a drink with you when you go out
• Suck ice cubes or lollies. You can make lollies by freezing fresh fruit juice or squash in ice cube trays or lolly containers with sticks.

Your doctor, nurse or pharmacist will prescribe anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as they tell you to, even if you do not feel sick. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluid often and eat small amounts regularly. It is important to drink enough fluids. If you continue to feel sick, or if you are sick (vomit) 1 to 2 times in 24 hours, contact the hospital on the 24-hour number as soon as possible. They will give you advice. They may change your anti-sickness treatment. Let them know if you still feel sick.

You may get pain in your tummy (abdomen), or have indigestion. Your doctor, nurse or pharmacist can give you advice or treatment to help. Contact the hospital straight away on the 24-hour number if your symptoms do not go away, or get worse.

This treatment can affect your appetite. Don’t worry if you do not eat much for 1 or 2 days. But if your appetite does not come back after a few days, or if you are losing weight, tell your doctor, nurse or pharmacist. They can give you advice. They may give you food or drink supplements. Or they may suggest changes to your diet or eating habits to help.

Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. You may also get a bitter or metallic taste in your mouth. Your doctor, nurse or pharmacist can give you advice. It might help to try:

• sucking sugar-free sour or boiled sweets
• eating cold foods
• eating sharp-tasting fresh fruit.

Taste changes usually get better after treatment ends. We have more information about coping with changes to taste.

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may feel:

• very low in energy
• breathless 
• dizzy and light-headed. 

If you have these symptoms, contact the hospital straight away on the 24-hour number. You may need treatment for anaemia. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Feeling tired is a common side effect of this treatment. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can help you feel less tired.

If you feel sleepy, do not drive or use machinery.

This treatment can affect the palms of your hands and the soles of your feet. This is called palmar-plantar or hand-foot syndrome. 

If you have white skin these areas may become red. If you have black or brown skin, these areas might get darker. 

The skin on the palms of your hands and the soles of your feet may:

• be sore
• be painful, tingle, or swell
• peel, crack or blister. 

If you have any of these symptoms, contact the hospital straight away on the 24-hour number. They can give you advice. This is especially important if you have any broken skin or if walking is difficult. They can prescribe creams and painkillers to help.

You can care for your hands and feet by: 

• keeping your hands and feet cool by washing in cool water
• gently moisturising your hands and feet regularly
• wearing gloves to protect your hands and nails when working in the house or garden
• wearing loose cotton socks and avoiding tight-fitting shoes and gloves.

This treatment can affect your nails. They may break more easily or be a different colour. They may be painful or bleed. These changes usually disappear as the nails grow out after treatment. Sometimes nails can become loose or fall out.

If the skin around your nails becomes sore and swollen, contact the hospital straight away on the 24-hour number. These might be signs of an infection.

Tips to look after your nails:

• Keep your nails clipped short and clean.
• Avoid using very hot water when washing your hands or bathing.
• Moisturise your nails and cuticles regularly.
• Avoid false nails, gels or other acrylics during treatment.
• Wear gloves to protect your nails when working in the house or garden.
• If your toenails are affected, wear well-fitting shoes, or shoes with open toes to cushion them.

Tell your doctor or nurse about any changes to your nails.

This treatment can cause your skin to be dry. Try using soap-free cleansers and unperfumed moisturising cream every day.

This treatment may also cause:

a rash which may be itchy

abnormal growths on the skin

changes in the skin’s appearance.

It can make you more sensitive to the sun. Your skin may burn more easily during treatment and for several months after. Use a sun cream of at least SPF 30. SPF stands for sun protection factor. Cover up with clothing and wear a hat.

Always tell your doctor, nurse or pharmacist about any skin changes. They can give you advice or prescribe creams or medicines to help if needed. Changes to your skin are usually temporary and improve when treatment ends.

You might notice that your hair slowly gets thinner. But you are very unlikely to lose all the hair from your head. Your hair can also become more brittle. Your nurse can give you information about coping with hair loss. Your hair will usually go back to normal after treatment ends.

You may experience nosebleeds. Talk to your doctor, nurse or pharmacist about the best way to manage nosebleeds. If a nosebleed does not stop, call the NHS urgent advice number on 111.

This treatment can cause the inside of your nose to be very dry. Tell your doctor, nurse or pharmacist if this is a problem.

This treatment can affect how your kidneys or liver work. This is usually mild and goes back to normal after treatment ends. You will have blood tests to check how well your kidneys and liver are working. Contact the hospital on the 24-hour number if you:

• have blood in your urine (pee)
• are passing less urine or peeing less often than usual.

Drinking fluids also helps protect your kidneys. The advice is usually to try to drink at least 2 litres (3½ pints) of fluid each day. But follow any advice from your doctor, nurse or pharmacist about how much is right for you.

This treatment can cause low sodium levels in the blood. This can cause symptoms such as:

• headache
• feeling sick (nausea)
• poor balance
• confusion
• seizures

Contact the hospital straight away on the 24-hour number if you have any of these symptoms. You will have regular blood tests while taking this treatment to check your blood sodium levels.

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

• throbbing pain or swelling in a leg or arm
• reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
• suddenly feeling breathless or coughing.

Always call 999 if you have:

• chest pain
• difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

• medicines you have been prescribed
• medicines you buy in a shop, pharmacy or online
• vitamins or supplements 
• herbal drugs and complementary or homeopathic therapies
• recreational drugs – for example, cannabis.

Cancer doctors usually recommend that people with cancer have vaccinations for flu and coronavirus (covid). They may also recommend other vaccines, such as Shingrix^® for shingles. These all help reduce your risk of serious illness from these infections. Most people can have these vaccines, including people with weak immune systems.

You should not have live vaccines if your immune system is weak. This includes if you are having or recently had chemotherapy, radiotherapy or other cancer treatments that affect your immune system. Live vaccines can make you unwell because they contain a very weak version of the illness they protect you against. There are several live vaccines, including the yellow fever vaccine.

It is important to ask your doctor, nurse or pharmacist for advice about having vaccinations. They can explain what vaccines are right for you and when it is best to have them.

Your doctor, nurse or pharmacist will advise you not to get pregnant or make someone pregnant while having this treatment and for some time afterwards. The drugs may harm a developing baby. It is important to use contraception to prevent pregnancy. Follow their advice about:

• what types of contraception to use 
• how long after treatment you should continue to use contraception. 

You are advised not to breastfeed while having this treatment, or for some time after treatment ends. This is because the drugs could be passed to the baby through breast milk. 

Your doctor, nurse or pharmacist can give you more information.

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.