Cabozantinib (Cometriq) | Cancer Research UK
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What cabozantinib is

Cabozantinib is a treatment for a rare type of thyroid cancer called medullary thyroid cancer. It is for people who can’t have surgery or whose cancer has spread to another part of the body.

You may have cabozantinib as part of clinical trials for other types of cancer.

Cabozantinib is also called by its brand name Cometriq.


How cabozantinib works

Cabozantinib is a cancer growth blocker. It works by blocking particular proteins called protein kinases on cancer cells. The protein kinases encourage the cancer to grow. Cabozantinib blocks a number of these proteins and is called a multi kinase inhibitor. It also stops the cancer cells growing blood vessels, which the cells need to be able to grow.

Cabozantinib may shrink the cancer or stop it growing for a time.


How you have cabozantinib

Cabozantinib comes as capsules. You take them once a day. Swallow them whole and don’t open them. The capsules come in different colours – orange and grey. How many you take depends on your needs. Your doctor may change the dose during the treatment.

You should take the capsules at the same time each day. Don’t eat for at least 2 hours before you take them and for an hour after taking them.

If you forgot to take a dose and it is more than 12 hours until your next dose then take the missed dose and the next dose as normal.

If you forgot to take a dose and it is less than 12 hours until your next dose then miss that dose and take your next dose as normal.

It is very important that you take the tablets according to the instructions your doctor or pharmacist gives you. For example, whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream. So check the pack leaflet and follow the instructions it gives. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

You usually carry on taking cabozantinib for as long as it is working, or until the side effects get too bad.


Common side effects

More than 10 in every 100 people have one or more of these side effects.

  • Bruising more easily due to a drop in platelets – you may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechia)
  • An increased risk of getting an infection from a drop in white blood cells – it is harder to fight infections and you can become very ill. You may have headaches, aching muscles, a cough, a sore throat, pain passing urine, or you may feel cold and shivery. If you have a severe infection this can be life threatening. Contact your treatment centre straight away if you have any of these effects or if your temperature goes above 38°C. You will have regular blood tests to check your blood cell levels
  • Diarrhoea affects just over 6 out of 10 people (60%). Drink plenty of fluids and tell your doctor or nurse if you are worried about how bad it is, or if it continues for more than 3 days
  • Soreness, redness and peeling on the palms of the hands and soles of the feet (palmar–plantar syndrome) happens in around half of people (50%). This may cause tingling, numbness, pain and dryness. If it is severe tell your doctor as you may need to take a lower dose
  • Loss of appetite affects around 5 out of 10 people (50%)
  • Weight loss occurs in about 5 out of 10 people (50%)
  • Tiredness and weakness (fatigue) happens in about 4 out of 10 people (40%)
  • Feeling or being sick occurs in just over 4 out of every 10 people (40%). This is usually well controlled with anti sickness medicines
  • Taste changes or loss of taste happen in 3 out of 10 people (30%)
  • Hair colour changes (lightening) and thinning affect 3 out of 10 people (30%)
  • Changes to blood pressure happen in about 3 in 10 people (30%) – it may be higher than normal but more rarely is lower than usual
  • Constipation happens in 3 out 10 people (30%)
  • A sore mouth and throat occur in 2 out of 10 people (20%)
  • Indigestion or heartburn (dyspepsia)
  • A hoarse voice or changes to your voice happen in about 2 in 10 people (20%)
  • Low levels of potassium in your blood (hypokalaemia) – you will have blood tests to check the levels of potassium and other minerals, such as calcium and phosphate
  • Tummy (abdominal) pain
  • Dizziness – don’t drive or operate machinery if you have this
  • Headaches
  • Joint pain and muscle spasms
  • Swollen lymph glands
  • Women may stop having periods (amenorrhoea) but this can be temporary
  • Loss of fertility – you may not be able to become pregnant or father a child after treatment with this drug. Talk to your doctor before starting treatment if you think you may want to have a baby in the future. Men may be able to store sperm before starting treatment

Occasional side effects

Between 1 and 10 in every 100 people have one or more of these side effects.

  • Feeling sad or depressed
  • Skin changes – you may have blistering, redness, or acne, and more rarely the skin can become paler and flaky
  • Confusion
  • Earache and ringing in the ears (tinnitus) and more rarely hearing loss
  • Weakness, tingling and numbness in your hands and feet
  • Chills
  • Pain
  • Stomach pain caused by inflammation of your pancreas (pancreatitis) – let your doctor know if you have sudden strong abdominal pains
  • Dehydration – drink plenty of fluids (around 2 litres a day)
  • Blood clots – let your doctor or nurse know straight away if you suddenly become breathless or have leg pain and redness or swelling of the legs
  • A collection of pus with swelling and inflammation (abscesses). These could develop in any part of the body including the mouth and tummy (abdomen)
  • Swelling can occur in any part of the body including the face, lips and tongue
  • Increased hair growth
  • Piles (haemorrhoids), causing pain in the back passage (rectum)
  • An abnormal join between 2 body cavities or from a body cavity on to the skin (fistula)
  • A drop in the level of thyroid hormones (hypothyroidism). You may feel tired or cold, or your voice may deepen. You will have regular blood tests to check your thyroid hormone levels
  • Yellow skin and eyes (jaundice) – let your doctor or nurse know straight away if you have this
  • Blurred vision
  • Fungal infections such as thrush
  • Blood and protein in your urine and pain passing urine
  • Gallstones
  • A fast heart beat

Rare side effects

Fewer than 1 in 100 people have these side effects.

  • Mild effects on the liver and kidneys which are unlikely to cause any symptoms. The effects usually go back to normal after the treatment ends. You will have regular blood tests to check how your liver and kidneys are working
  • Inflammation of the food pipe (oesophagus) – causing a combination of symptoms including feeling sick, taste changes, chest pain, bloating, burping, and heartburn. Let your doctor or nurse know if you suddenly have these effects
  • Inflammation of the lungs causing breathlessness
  • Heart problems that can cause chest pain or a heart attack
  • Damage to the jawbone (osteonecrosis) causing pain in your mouth or jaw. Have a dental check up before you start treatment and tell your dentist that you are having cabozantinib
  • Difficulty concentrating
  • Loss of consciousness
  • Strange dreams
  • Eye inflammation and clouding of the eye
  • Changes in the brain causing headaches, confusion, fits (seizures), and loss of eyesight – let your doctor or nurse know straight away if you have these
  • An increased risk of stroke, heart attack or short term loss of the blood supply to the brain. Let your doctor or nurse know straight away if you have sudden headaches, dizziness, or faintness
  • Abnormal vaginal bleeding in women
  • Pain in the face

Important points to remember

You may have some of the side effects listed above. They may be mild or more severe. A side effect may get better or worse through your course of treatment. Or you may have more side effects as the course goes on. This depends on

  • How many times you've had a drug before
  • Your general health
  • How much of the drug you have (the dose)
  • Other drugs you are having

Tell your doctor or nurse straight away if you are worried about any of the side effects or how bad they are.

Coping with side effects

It is very important to tell your doctor, pharmacist or nurse about all your side effects so that they can help you manage them. They can give you advice or reassure you. Your nurse will give you a contact number to ring if you have any questions or problems. If in doubt, call them.

Other medicines and foods

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies. Many medicines can react with cabozantinib.

Don’t eat grapefruit or drink grapefruit juice while having treatment with cabozantinib. It can change the amount of cabozantinib you absorb and make the side effects worse.

Pregnancy and contraception

This drug may harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment with this drug and for a few months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.


Do not breastfeed during this treatment because the drug may come through in the breast milk.

Slow wound healing

Cabozantinib can make wounds heal more slowly. If you need to have an operation you may need to stop taking cabozantinib for a while beforehand. Your treatment team will let you know when you can start taking it again.

Possible long term effects

Cabozantinib is a fairly new drug in cancer treatment. So there is limited information available at the moment about possible longer term effects that it may cause. Tell your doctor or nurse if you notice anything that is not normal for you.



You should not have immunisations with live vaccines while you are having this treatment or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG, yellow fever and Zostavax (shingles vaccine).

You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered from your treatment. It is safe to have the flu vaccine.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with vaccines you take by mouth (oral vaccines), but not many people in the UK have these now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.


Related information

You can read our information about

Medullary thyroid cancer

Cancer growth blockers

Anti angiogenesis treatments (blood vessel growth blockers)

Taking medicines safely


More information about cabozantinib

We don’t list all the very rare side effects of this treatment that are very unlikely to affect you. For further information look at the Electronic Medicines Compendium website at

If you have a side effect we don’t list here and you think it may be due to this treatment, you can report it to the Medicines Health and Regulatory Authority (MHRA). Go to

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Updated: 2 March 2015