Ivosidenib (Tibsovo)

Ivosidenib is a type of targeted cancer drug. It is also known as Tibsovo. You pronounce it as i-voh-sih-deh-nib.

You might have ivosidenib if the cancer has a change (mutation) in the gene called IDH1. Your doctor will check for this change before you start treatment.

Ivosidenib 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 - unfortunately this means the cancer is advanced

Your doctor might ask you to have ivosidenib as part of a clinical trial.

Ivosedinib combined with the chemotherapy drug azacitidine is a treatment for acute myeloid leukaemia (AML).

How does ivosidenib work?

Ivosidenib is a type of targeted cancer drug called a cancer growth blocker. It works by targeting certain proteins made by the changed IDH1 gene. These proteins help cancer cells to grow. Ivosidenib blocks these proteins. This stops or slows down the growth of the cancer.

How do you take ivosidenib?

Ivosidenib comes as tablets. You take them on an empty stomach. This means you must not eat anything for:

• 2 hours before taking it
• 1 hour after taking it

You swallow the tablets whole with a glass of water. You shouldn’t crush or dissolve them.

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.

You also have a test of your heart called an ECG (electrocardiogram). This checks the electrical activity of your heart. It can show changes to your heart rate or rhythm and tells your doctor how well your heart is working. You normally have an ECG:

• before you start taking ivosidenib
• once a week for the next 3 weeks

Some people have an ECG every month after that. Your doctor will talk to you about this if you need them.

What are the side effects of ivosidenib?

Side effects can vary from person to person. They also depend on what other treatments you're having. 

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

• you have severe side effects 

• your side effects aren’t getting any better

• your side effects are getting worse

Early treatment can help manage side effects better. 

We haven't listed all the side effects here. 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.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

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.

Tummy (abdominal) pain

Contact your advice line if you have this. Depending on what is causing the pain, they might give you medicine to help. 

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 stoma , 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.

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.

A build up of fluid in the tummy (abdomen)

This is called ascites. It can make your abdomen feel tight and very uncomfortable. It puts pressure on the organs in your abdomen. It can also put pressure on your diaphragm which is at the top of your abdomen. This can affect your lungs.

Symptoms of ascites can include your clothes feeling tighter, bloating, abdominal pain and breathlessness.

Contact your advice line if you have symptoms of ascites.

Breathlessness and looking pale

You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.

Rash

You can get a rash whilst taking this cancer drug. This can include red patches of skin. In people with black or brown skin, the patches of skin may look darker than usual.

Or you can get a mix of discoloured areas of skin and small raised bumps

This drug can sometimes cause serious skin conditions. It’s important to contact your advice line urgently if you have any skin changes.

Headaches

Tell your healthcare team if you keep getting headaches. They can give you painkillers to help.

Liver changes

You might have liver changes that are usually mild and unlikely to cause symptoms. These changes usually go back to normal when treatment finishes. But as this is a new drug, doctors are still learning about how long side effects like this last.

You have regular blood tests to check for any changes in the way your liver is working.

Numbness in fingers and toes

Numbness or tingling in fingers or toes is often temporary and can improve after you finish treatment. Tell your healthcare team if you're finding it difficult to walk or complete fiddly tasks such as doing up buttons. 

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:

• an increased risk of getting an infection due to a drop in white blood cells . Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. You might have other symptoms depending on where the infection is. Infections can sometimes be life threatening. You should contact your advice line urgently if you think you have an infection 
• bruising, bleeding gums or nosebleeds due to a drop in the number of platelets . You may also have lots of tiny red spots or bruises on your arms or legs (petechiae)
• yellowing of the skin and eyes (jaundice) caused by bile not being able to flow from your liver properly
• falling over
• changes to your heart rhythm – you should contact your advice line if you feel dizzy or faint

Possible rare and long term side effects

This is a new drug in cancer treatment. So, there is currently limited information available about possible rare and longer term effects that it may cause. Tell your doctor if you notice anything that is not normal for you.

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 fertility in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Contraception and pregnancy

This drug may harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you are having treatment with this drug and for at least one month afterwards.

Ivosidenib may stop the contraceptive pill, injection or implant working properly. If you are using one of these, you should also use a barrier method of contraception like condoms during sex.

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.

Breastfeeding

Do not breastfeed during this treatment and for 1 month after your last dose. This is because the drug may come through in your breast milk.

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, yellow fever and one of the shingles vaccines called Zostavax.

You can 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 it in relation to your cancer treatment

Members of your household who are aged 5 years or over are also able to have the COVID-19 vaccine. This is to help lower your risk of getting COVID-19 while having cancer treatment and until your immune system recovers from treatment.

Contact with others who have had immunisations - You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine. Sometimes people who have had the live shingles vaccine can get a shingles type rash. If this happens they should keep the area covered.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray as this is a live vaccine. This is for 2 weeks following their vaccination.

Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.

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.