What is panitumumab (Vectibix®)?

Panitumumab (Vectibix®) is used to treat bowel cancer that has spread to other parts of the body. It is best to read this information with our general information about the type of cancer you have.

Panitumumab is a type of targeted therapy drug called a monoclonal antibody. It is also called a cancer growth inhibitor.

Panitumumab only works on bowel cancers that have a normal RAS gene. The RAS gene helps control cell growth. Before panitumumab is used, doctors test the bowel cancer cells to check that there are no changes (mutations) in this gene.

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

How panitumumab is given

You have panitumumab at a hospital day unit as an outpatient. You usually have it in combination with other cancer drugs. But you may have it on its own if you have already had chemotherapy.

During treatment you usually see a cancer doctor, a cancer nurse or specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.

Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level to have treatment.

You will see a doctor or nurse before you have treatment. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your targeted therapy. Your nurse will tell you when your treatment is likely to be ready.

You usually have panitumumab as a drip into a vein. This is called having an intravenous infusion. You have the infusion through an infusion pump. You have the first infusion slowly, usually over about 60 minutes. If you do not have any problems, you can have your next treatment over 30 to 60 minutes.

Some people have higher doses of panitumumab. These infusions are given over about 90 minutes.

Your course of treatment

You usually have panitumumab once every 2 weeks. Your nurse, pharmacist or doctor will discuss your treatment plan with you.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects.

You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.

Side effects while treatment is being given

Allergic reaction

Some people have an allergic reaction while having this treatment. Before treatment, you will be given medicines to help prevent or reduce any reaction.

Signs of a reaction can include:

  • feeling hot or flushed
  • shivering
  • itching
  • a skin rash
  • feeling dizzy
  • a headache
  • feeling breathless or wheezy
  • swelling of your face or lips
  • pain in your back, tummy or chest. 

Your nurse will check you for signs of a reaction during your treatment. If you feel unwell or have any of these signs, tell them straight away. If you do have a reaction, it can be treated quickly. 

Sometimes a reaction can happen after treatment. If you develop any signs or feel unwell after you get home, contact the hospital straight away.

 

Common side effects of panitumumab

Skin and nail changes

Most people having panitumumab will notice changes to the skin during treatment.

The most common side effect is an acne-like rash on the face, neck and body. This usually begins during the first 2 or 3 weeks of treatment. For most people, it goes away a few weeks after treatment ends.

Your skin may also become dry, itchy or scaly, and it may feel tender. The skin around your nails may become red and sore. Your nails may become brittle and break.

Very rarely, panitumumab may cause a severe skin reaction. The symptoms can include large blisters, peeling skin and sores in the mouth. You may also have a fever (high temperature). Contact the hospital straight away if you have these symptoms.

Always tell your doctor or nurse about any changes to the skin. They can give you advice and prescribe creams or medicines to help. If you are out in the sun, remember to protect your skin. Use a suncream with a sun protection factor (SPF) of at least 30. Wear long-sleeved tops, trousers and a wide-brimmed hat.

If you have severe skin problems, your doctor may suggest waiting a longer time between treatments or a lower dose of panitumumab.

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is sometimes called neutropenia.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. Contact the hospital straight away on the 24-hour contact number you have been given if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection
  • your temperature goes below 36°C (96.8°F).

Symptoms of an infection include:

  • feeling shivery and shaking
  • a sore throat
  • a cough
  • breathlessness
  • diarrhoea
  • needing to pass urine (pee) a lot, or discomfort when you pass urine.

It is important to follow any specific advice your cancer treatment team gives you.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time, until your cell count increases.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may have symptoms such as:

  • pale skin
  • lack of energy
  • feeling breathless
  • feeling dizzy and light-headed.

Tell your doctor or nurse if you have these symptoms.

If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Feeling sick

Your doctor will give you anti-sickness drugs to help prevent or control sickness during your treatment. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluids often and eat small amounts regularly. It is important to drink enough fluids. If you continue to feel sick, or are sick (vomit) more than once in 24 hours, contact the hospital as soon as possible. They will give you advice. Your doctor or nurse may change the anti-sickness drug to one that works better for you.

Diarrhoea

This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.

If you have diarrhoea:

  • try to drink at least 2 litres (3½ pints) of fluids each day
  • avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods
  • contact the hospital for advice.

Constipation

This treatment can cause constipation. Constipation means that you are not able to pass stools (poo) as often as you normally do. It can become difficult or painful. Here are some tips that may help:

  • Drink at least 2 litres (3½ pints) of fluids each day.
  • Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
  • Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital for advice. Your doctor can give you drugs called laxatives to help.

Tummy pain

This treatment may cause tummy (abdomen) pain. Tell your doctor or nurse if this happens so they can help.

Feeling tired

Feeling tired is a common side effect of this treatment. It is often worse towards the end of treatment and for some weeks after it has finished. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy.

If you feel sleepy, do not drive or use machinery.

Sore mouth and throat

This treatment may cause a sore mouth and throat. You may also get mouth ulcers. This can make you more likely to get a mouth or throat infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth or throat is sore:

  • tell your nurse or doctor – they can give you a mouthwash or medicines to help
  • try to drink plenty of fluids
  • avoid alcohol, tobacco, and foods that irritate your mouth and throat.

Sucking ice chips may sometimes help relieve mouth or throat pain. 

Hair changes

Your eyelashes may grow longer and more curly than usual. Men may notice less beard growth. You may notice your head and body hair is finer, curlier or more brittle. Some people may lose their hair slowly over several months. These changes are usually temporary and gradually improve once treatment is over. 

Effects on the eyes

Your eyes may water and feel sore. They may become more sensitive to light. Your doctor can give you eye drops to help with this. You may get conjunctivitis. This is when the eyes become red and inflamed. If you get conjunctivitis, tell your doctor. You may need antibiotic eye drops. Panitumumab may also cause blurred vision. Always tell your doctor or nurse if your eyes are painful or if there is a change in your vision.

Effects on the lungs

This treatment can cause changes to the lungs. Tell your doctor if you develop:

  • a cough
  • wheezing
  • breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

Indigestion or loss of appetite

Some people have indigestion or acid reflux. Acid reflux is when acid comes up from the stomach into oesophagus (food pipe). Tell your doctor if this happens. They can give you treatment to help.

During treatment, you may lose your appetite. Try to eat small meals regularly. If your appetite does not improve after a few days, tell your nurse. You can also ask to be referred to a dietitian. They can give you advice on improving your appetite and keeping to a healthy weight.

Reduced levels of magnesium, potassium or calcium in the blood

You will have regular blood tests to check this. If the levels are too low, your doctor may prescribe supplements.

Back pain

You may have back pain while having treatment with panitumumab. If this becomes a problem, ask your doctor for advice about painkillers.

Difficulty sleeping and anxiety

Some people have problems sleeping or feel anxious during treatment. Tell your doctor or nurse if this happens.

Fluid build-up

You may gain weight, or your face, ankles and legs may swell. This improves slowly after your treatment has finished. Your doctor may give you drugs to help reduce the swelling.

Less common side effects of panitumumab

Bleeding

This treatment may increase your risk of bleeding. Tell your doctor if you have any unexplained bleeding such as nosebleeds or blood in your poo.

Sore and red palms of hands and soles of feet

You may get sore and red palms of hands and soles of feet. The skin may also begin to peel. This is called palmar-plantar or hand-foot syndrome. It usually gets better after treatment ends.

Tell your doctor or nurse about any changes to your hands or feet. They can give you advice and prescribe creams to improve any symptoms you have. It can help to:

  • keep your hands and feet cool
  • moisturise your hands and feet regularly
  • avoid tight-fitting socks, shoes and gloves.

Raised blood sugar levels

This treatment may raise your blood sugar levels. You will have regular blood tests to check this. Symptoms of raised blood sugar include:

  • feeling thirsty
  • needing to pass urine (pee) more often
  • feeling tired.

Tell your doctor or nurse if you have these symptoms during treatment or after it finishes.

If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this.

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:

  • throbbing pain, redness or swelling in a leg or arm
  • suddenly feeling breathless or coughing
  • sharp chest pain, which may be worse when you cough or take a deep breath.

If you have any of these symptoms, contact the hospital straight away on the 24-hour contact number you have been given. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

A blood clot is serious, but it can be treated with drugs that thin the blood (anticoagulants). Your doctor or nurse can give you more information.

You can help reduce the risk of developing a blood clot by:

  • staying active during treatment
  • drinking plenty of fluids, especially water.

You may be given anticoagulants to help prevent a clot.

Changes in blood pressure

Your blood pressure may become higher or lower than normal. Tell your nurse or doctor if you have headaches or feel dizzy. These can be signs of blood pressure changes.

Effects on the heart

Panitumumab can cause a fast heartbeat. Sometimes it can cause chest pain. These are not usually serious. But you should contact your doctor straight away on the 24-hour number the hospital has given you if you have any of these symptoms during or after treatment:

  • pain or tightness in your chest
  • breathlessness
  • dizziness
  • changes to your heartbeat.

Other conditions can cause these symptoms, and it is important to get them checked by a doctor. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

Other information

Other medicines

Some medicines can affect how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:

  • medicines you have been prescribed
  • medicines you buy in a shop or chemist
  • vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.

Vaccinations

Vaccinations can reduce your risk of getting certain infections. Your doctor or nurse may talk to you about having vaccinations.

Doctors usually recommend that people with cancer have a flu vaccination and a coronavirus vaccination. These are both inactivated vaccinations that can help reduce the risk of infection. People with weak immune systems can have these, as they are not live vaccinations.

If your immune system is weak, you need to avoid live vaccinations. This is because they can make you unwell. Live vaccines, such as shingles, contain a very weak version of the illness they are vaccinating you against. Your cancer doctor or GP can tell you more about live and inactivated vaccinations.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Contraception

Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.

Breastfeeding

You are advised not to breastfeed while having this treatment, or for some time after treatment finishes. This is because the drugs could be passed to the baby through breast milk.

Your doctor or nurse can give you more information.

Driving

If panitumumab affects your concentration or vision, do not drive during treatment.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.

About our information


  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

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