Sunitinib (Sutent)

Sunitinib is pronounced sue-nit-i-nib. It is a type of biological therapy called a protein kinase inhibitor. Protein kinase is a type of chemical messenger (an enzyme) that plays a part in the growth of cancer cells. Sunitinib blocks the protein kinase to stop the cancer growing. It is also known by its brand name Sutent (pronounced sue-tent).

Sunitinib is a treatment for 

• Advanced kidney cancer
• A rare type of stomach cancer called GIST
• Pancreatic neuroendocrine tumours

Sunitinib comes as tablets. You can take them with or without food.

For kidney cancer and GIST stomach cancer you take sunitinib once a day for 4 weeks and then have a 2 week break, when you don’t take the tablets. This 6 week period is called a cycle of treatment and is repeated for as long as the sunitinib works.

For pancreatic neuroendocrine tumours you take sunitinib once a day without any breaks for as long as it works.

It is very important that you take tablets according to the instructions your doctor or pharmacist gave you. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

The side effects associated with sunitinib are listed below. Remember most people don’t have all of them. You may have 1 or 2 effects, or several.

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

• Fatigue (tiredness) in almost 8 out of 10 people (80%) during and after treatment but this is usually mild – most people find their energy levels are back to normal by 6 months to a year after treatment ends
• Diarrhoea in around 6 out of 10 people (60%) but this is usually mild – do tell your doctor or nurse as you can be given medicines to control it
• Skin changes – your skin may be drier, become red, or have a rash and 3 out of 10 people (30%) have yellowing of their skin, which goes back to normal once treatment finishes
• Hands and feet may become red and blistered in about 3 out of 10 people (30%)
• A sore mouth in about 1 out of 10 people (10%)
• Raised blood pressure in many people who take sunitinib – if your blood pressure goes up you may need to take tablets to control it
• A slower heart rate
• Loss of appetite
• A change in taste in about 1 in 4 people (25%)
• Feeling sick in about 1 in 3 people (36%)  – this is usually well controlled with anti sickness medicines
• Indigestion
• Dizziness
• Weakness
• A drop in the level of thyroid hormones (hypothyroidism) in more than 1 in 10 people (14%) – this may help to explain why sunitinib causes tiredness. You will have regular blood tests to check your hormone levels
• A mild effect on the liver and kidneys, which is unlikely cause any symptoms and will almost certainly go back to normal after the treatment finishes – you will have regular blood tests to keep an eye on how your liver and kidneys are working
• Loss of fertility – we don’t know exactly how this drug may affect fertility so talk to your doctor before starting treatment if having a baby is important to you
• May harm a developing baby – we don’t know how this drug may affect a pregnancy. Talk to your doctor about contraception before having this treatment, if there is any chance you could become pregnant
• You should not breastfeed while having this drug as it may come through in the breast milk

With this drug, people may have a temporary drop in the number of blood cells made by the bone marrow, leading to the following side effects

• 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, sore throat, pain passing urine or feel cold and shivery
• Tiredness and breathlessness due to a drop in red blood cells (anaemia) – you may need a blood transfusion
• Bruising more easily due to a drop in platelets – you may have nosebleeds, bleeding gums after brushing your teeth, or lots of tiny red spots or bruises on your arms or legs (known as petechia)

Some of these side effects can be life threatening, particularly infections. You should contact your doctor if you have any of these bone marrow effects. Your doctor will check your blood counts regularly to see how well your bone marrow is working.

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

• A change in hair colour – your hair may become grey while you are having treatment but during the 2 weeks off treatment some colour may come back
• Watery eyes from over production of tears
• Nose bleeds

Fewer than 1 in 100 people have these.

• Seizures (fits) – these are very rare, affecting fewer than 1 in 100 people (1%)
• Changes to how the heart works – if you have a heart problem you may not be able to have sunitinib
• Blood clots
• Osteonecrosis of the jaw – a few people taking sunitinib have this side effect. Most of the people who have had it were also having or had recently stopped having a bisphosphonate. Have a dental check up before you start treatment and tell your dentist that you are having sunitinib. It is important to clean your teeth regularly.

Not everyone will get these side effects. You may only have one or two. A side effect may get worse through your course of treatment, or more side effects may develop as the course goes on. This depends on

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

Talk to your doctor, pharmacist or nurse about all your side effects so that they can help you manage them. Your specialist, clinic or ward nurse should give you a contact number. You can ring if you have any questions or problems. They can give you advice or reassure you. If in doubt, call them.

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and other over the counter remedies – some drugs can react together. It is especially important to tell your doctor if you are taking a blood thinning drug called warfarin because it can interact with the sunitinib.

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 and yellow fever. You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with oral vaccines, but not many people in the UK have oral vaccines 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.