Panitumumab (Vectibix) | Cancer Research UK
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What panitumumab is

Panitumumab is pronounced pan-ee-chew-moo-mab. It is also known by its brand name Vectibix. Panitumumab is a treatment for advanced bowel cancer. Advanced cancers have spread from where they started to another part of the body. It is sometimes combined with other treatments such as the chemotherapy combinations of FOLFIRI or FOLFOX.

Panitumumab is being used in trials for other types of cancer. 


How panitumumab works

Panitumumab is a type of drug called a monoclonal antibody. It works by attaching to specific proteins called epidermal growth factor receptors (EGFR) on the surface of cancer cells. This blocks a protein called epidermal growth factor (EGF) from attaching to the cancer cell and triggering it to divide and grow. Panitumumab works better if your cancer cells have a lot of epidermal growth factor receptors. Before you have panitumumab, you may have tests to check the amount of epidermal growth factor receptors.

Panitumumab only works on cancers that have a normal Kras gene. You will need to have tests to check if this gene is normal. Panitumumab also helps the immune system to recognise the cancer cells so that it can destroy them.


How you have panitumumab

You have panitumumab through a drip into a vein (infusion). A pump controls the rate of the drip. You can have panitumumab through a thin, short tube (a cannula) put into a vein in your arm each time you have treatment. Or you may have it through a central line, a portacath, or a PICC line. These are long, plastic tubes that give the drugs directly into a large vein in your chest. You have the tube put in before or during your course of treatment and it stays in place as long as you need it.

You can read our information about having chemotherapy into a vein.

The first treatment takes about 60 to 90 minutes. After that you have treatment every 2 weeks and it takes about 30 to 60 minutes. You usually have panitumumab for a few months or as long as it is controlling the cancer.


Tests during treatment

You have blood tests before starting treatment and regularly during your treatment. The tests check your levels of blood cells and minerals in the blood. They also check how well your liver and kidneys are working.


About side effects

We've listed the side effects associated with panitumumab below. You can use the links to find out more about each side effect. Where there is no link, please go to our cancer drug side effects section or use the search box at the top of the page.

You may have a few side effects. They may be mild or more severe. A side effect may get better or 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)

The side effects may be different if you are having panitumumab with other drugs.

Tell your doctor or nurse straight away if any of the side effects get severe.


Common side effects

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

  • A skin reaction occurs in 9 out of 10 people (90%) – you may have a rash similar to acne on your face, neck and trunk. Or your skin may be dry and itchy. This can be severe for some people and you may need moisturising creams, steroid creams and antibiotics. The reaction usually starts about 10 days after the start of treatment and gets better within a month of finishing treatment. You may need to have a lower dose of the drug or stop treatment for a short time
  • Sensitivity to sunlight – wear sun cream (at least SPF 50) and cover up when you are having treatment. Sunlight can make skin reactions worse
  • Tiredness and breathlessness (fatigue) due to low levels of red blood cells (anaemia) – you may need a blood transfusion
  • A sore mouth and throat – your nurse or doctor can give you mouthwashes and medicines to help
  • Nail infection
  • Diarrhoea affects 3 out of 10 people (30%) – drink plenty of fluids and tell your doctor or nurse if it becomes severe or continues for more than 3 days
  • Severe tiredness and weakness affects 1 in 2 people (50%) during and after treatment – most people find their energy levels are back to normal within 6 months to a year
  • Feeling or being sick happens in about 1 out of every 5 people (20%) but is usually well controlled with anti sickness medicines
  • Sore, watery, eyes (conjunctivitis) or dry, itchy eyes occur in around 1 in 5 people (20%) – very rarely this can be due to inflammation of the cornea and you may need to stop treatment
  • Loss of appetite and weight loss
  • Low levels of magnesium, potassium and calcium in your blood
  • Cold sores – you can have anti viral creams to reduce the effects of the sores
  • Temporary hair thinning
  • Blurred vision – tell your doctor or nurse if you have any eye symptoms
  • Tummy (abdominal) pain – tell your doctor or nurse if you have this
  • Constipation – drink plenty of fluids and tell your doctor or nurse if it becomes severe or continues for more than 3 days as you can have laxatives to help
  • Swollen hands and feet due to fluid build up
  • A high temperature (fever)
  • Back pain
  • Sleep problems
  • A cough and breathlessness – let your doctor or nurse know if you have this

Occasional side effects

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

  • Headaches, dizziness or anxiety
  • Dehydration in people who have severe diarrhoea – drink plenty of fluids
  • A cough and shortness of breath due to changes in lung tissue
  • An allergic reaction while you have the treatment, causing a high temperature, chills, shivering (rigors), a headache, and feeling sick. A few people have a more severe reaction, with wheezing, an itchy rash, and a drop in blood pressure. Your nurse will give you medicines before treatment to try to prevent a reaction. They will stop or slow your drip if it occurs. Let your doctor or nurse know if you have fever or chills the night after the drip
  • Your eyelashes may grow in a different direction to normal
  • Women may stop having periods (amenorrhoea) but this may be temporary
  • Loss of fertility – you may not be able to become pregnant or father a child after this treatment. 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
  • An increased risk of infection due to low numbers of 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
  • Soreness, redness and peeling on the palms of the hands and soles of the feet (palmar–plantar syndrome). This may cause tingling, numbness, pain and dryness
  • Broken nails
  • Sweating more than usual
  • Indigestion and heartburn
  • Raised level of sugar in the blood – you may feel thirsty or need to pass more urine than usual
  • Blood clot in the lung – let your doctor or nurse know straight away if you have a sudden cough or breathlessness
  • Blood clot in the leg – let your doctor or nurse know straight away if you have a red, hot sore area on your leg
  • Raised blood pressure
  • Bleeding from the back passage – let your doctor or nurse know straight away if you have this
  • Excessive hair growth
  • A build up of fibrous tissue in the lungs (pulmonary fibrosis) – let your doctor know if you have a cough or breathlessness that starts some time after your treatment has ended
  • A faster heart rate

Rare side effects

Fewer than 1 in 100 people have these.

  • Inflammation and swelling of the eyelids
  • Chapped lips
  • Loosening of the nails
  • A severe skin reaction with blistering of the skin, mouth eyes and genital areas – let your doctor or nurse know straight away if you have this

Important points to remember

Talk to your doctor, pharmacist or nurse about all your side effects so 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

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies. Some drugs can react together.

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 and for at least 2 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.


Do not breastfeed during this treatment or for 2 months afterwards because the drug may come through in the breast milk.



You should not have immunisations with live vaccines while you are having 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


More information about panitumumab

This page does not 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 not mentioned here that you think may be due to this treatment you can report it to the Medicines Health and Regulatory Authority (MHRA) at

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Updated: 28 April 2015