Futibatinib (Lytgobi)
Futibatinib is a type of targeted cancer drug. You pronounce it as fue-tih-ba-tih-nib. It is also known as Lytgobi.
It is a treatment for bile duct cancer that has spread to either:
- the
lymph nodes 
or organs near the bile ducts, such as the gallbladder or pancreas - this is called locally advanced bile duct cancer - another part of the body away from the bile ducts, such as the lungs – this is called metastatic bile duct cancer
Bile duct cancer is also called cholangiocarcinoma.
You have futibatinib if the cancer has a change (mutation) in the gene called fibroblast growth factor receptor 2 (FGFR2). Your doctor will check for this change before you start treatment.
How does futibatinib work?
Futibatinib is a type of cancer growth blocker called a tyrosine kinase inhibitor (TKI). Tyrosine kinases are proteins that cells use to signal to each other to grow.
Futibatinib works by targeting the tyrosine kinase proteins made by the changed FGFR2 gene. This stops or slows down the growth of the cancer.
How do you take futibatinib?
You take futibatinib as tablets. You can take it with or without food. You take it at the same time each day.
You should take the right dose, not more or less.
Talk to your healthcare team before you stop taking a cancer drug, or if you miss a dose.
How often do you take futibatinib?
You usually take futibatinib once a day.
You normally keep taking it for as long as it is working or until the side effects get too bad.
Tests
You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.
Before treatment starts you may have a blood test to check for viruses such as hepatitis B, hepatitis C, and . This is called a viral screen.
It’s important for your doctor to know if you have had any of these viruses. This is because this treatment can weaken your and can cause the virus to become active again (reactivation).
What are the side effects of futibatinib?
Side effects can vary from person to person. They also depend on what other treatment you are having.
When to contact your team
Your doctor, nurse, or pharmacist will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:
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you have severe side effects
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your side effects aren’t getting any better
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your side effects are getting worse
Early treatment can help manage side effects better.
We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.
Remember it is very unlikely that you will have all of these side effects, but you might have some of them at the same time.
High or low levels of phosphate in your blood
Blood tests may show that you have high or low levels of phosphate in your blood. This can cause muscle cramps, bone weakness and confusion.
Phosphate is a mineral. It is in many foods such as meat, fish, eggs and cheese. Your doctor might ask you to follow a low or high phosphate diet depending on your levels.
Nail changes
Your nails may become darker or lighter during treatment. They might also be painful, become loose and come off. Your nails may also become infected. Tell your doctor or nurse if this happens.
Constipation
is easier to sort out if you treat it early. Drink plenty and eat as much fresh fruit and vegetables as you can. Try to take gentle exercise, such as walking. Tell your healthcare team if you think you are constipated. They can give you a laxative if needed.
Hair thinning and hair loss
You may have some hair loss or hair thinning. This can be upsetting. Your hair might grow back once treatment has finished. But it may not come back in the same condition.
Diarrhoea
Contact your advice line if you have diarrhoea. For example, in one day you have 2 or more loose bowel movements than usual. If you have a , you might have more output than normal. Your doctor may give you anti diarrhoea medicine to take home with you after treatment.
Try to eat small meals and snacks regularly. It’s best to try to have a healthy balanced diet if you can. You don’t necessarily need to stop eating foods that contain fibre. But if your diet is normally very high in fibre, it might help to cut back on high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables.
Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.
Dry mouth
A dry mouth is also called xerostomia (pronounced zero-stow-mee-a). Talk to your healthcare team if you have this. They can give you artificial saliva to help with a dry mouth. It can also help to drink plenty of fluids.
Tiredness and weakness
You might feel very tired and as though you lack energy.
Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.
Feeling or being sick
Feeling or being sick is usually well controlled with anti sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.
It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.
Skin problems
The skin on your hands and feet may become sore, red, or may peel. You may also have tingling, numbness, pain and dryness. This is called hand-foot syndrome or palmar plantar syndrome.
The skin on the rest of your body may also become dry.
Moisturise your skin regularly. Your healthcare team will tell you what moisturiser to use.
Liver changes
You might have liver changes. But they usually go back to normal when treatment finishes. You have regular blood tests to check for any changes in the way your liver is working.
Tummy (abdominal) pain
Tell your doctor or nurse if you have this. They can check for the cause of the pain and give you medicine to help.
Occasionally abdominal pain can be due to a blockage in your bowel (bowel obstruction). This causes abdominal pain that comes and goes. Other symptoms include a swollen abdomen, feeling or being sick and difficulty having a poo.
Tell your doctor straight away if you have these symptoms.
Sore mouth and throat
It may be painful to swallow drinks or food. Painkillers and mouth washes can help to reduce the soreness and keep your mouth healthy.
Joint or muscle pain
You might feel some pain from your muscles and joints. Speak to your doctor or nurse about what painkillers you can take to help with this.
Loss of appetite
You might lose your appetite for various reasons while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.
Taste changes
Taste changes may make you go off certain foods and drinks. You may also find that some foods taste different from usual or that you prefer to eat spicier foods. Your taste gradually returns to normal a few weeks after your treatment finishes.
Low levels of sodium in your blood
You may have changes in levels of minerals and salts in your blood, such as low sodium. This will most likely go back to normal when you finish treatment. You have regular blood tests during treatment to check this.
Eye problems
This drug can cause dry eyes. Speak to your nurse or pharmacist about having eye drops to help with this.
Occasionally fluid can build up in the eye. This can cause the inner lining of the eye (retina) to come loose. The retina sends messages to the brain about the amount of light coming through the eye. If the retina comes loose, it is called a detached retina. This means the messages won’t be able to get from your eye to your brain.
Symptoms of a detached retina include changes to your eyesight, seeing things floating in your vision and pain in your eye. Call 111 if you have symptoms of a detached retina.
Occasional side effects
Migraine is a side effect that can happen in between 1 and 10 out of every 100 people (between 1 and 10%).
Possible rare and long term side effects
This is a new drug in cancer treatment. So there is limited information available at the moment about possible rare and longer term effects that it may cause. Tell your doctor if you notice anything that is not normal for you.
Coping with side effects
We have more information about side effects and tips on how to cope with them.
What else do you need to know?
Other medicines, food and drink
Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.
Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.
Loss of fertility
It is not known whether this treatment affects in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.
Pregnancy and contraception
This treatment might harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you're having treatment and for 1 week afterwards.
Doctors don’t know if futibatinib stops contraception such as the pill, injection or implant from working properly. If you are using these types of contraception, you should also use a barrier method such as condoms during treatment and for at least 1 week after.
Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner become pregnant while having treatment.
Breast feeding
Don’t breastfeed during this treatment and for 1 week after your last dose, because the drug may come through into your breast milk.
Treatment for other conditions
If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.
Immunisations
Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having.
Ask your doctor or pharmacist how long you should avoid live vaccinations.
In the UK, live vaccines include rubella, mumps, measles, BCG, and yellow fever.
You can usually have:
- other vaccines, but they might not give you as much protection as usual
- the flu vaccine (as an injection)
- the coronavirus (COVID-19) vaccine
Talk to your doctor or pharmacist about the best time to have a vaccine in relation to your cancer treatment.
Contact with others who have had immunisations
You can be in contact with other people who have had live vaccines as injections. If someone has had a live vaccine by mouth or nasal spray there may be a small risk the vaccine virus can be passed onto you if your is weakened.
Your healthcare team will let you know if you need to take any precautions if you are in close contact with someone who has had a live vaccine.
More information about this treatment
For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.
You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.
