Panitumumab (Vectibix ®)
Panitumumab (Vectibix ®) is a biological therapy that may be used to treat people with cancer of the large bowel (colon and rectum) that has spread to other parts of the body. Panitumumab may also be used to treat other types of cancer as part of a research trial.
This page describes panitumumab, how it's given and some of its possible side effects. It should ideally be read with our general information about your type of cancer.
You'll see your doctor regularly while you have this treatment so they can monitor its effects. This information should help you discuss any queries about your treatment and its side effects with your doctor or specialist nurse.
Panitumumab belongs to a group of cancer drugs known as monoclonal antibodies. Monoclonal antibodies are sometimes called targeted therapies, because they work by ‘targeting’ specific proteins (receptors) on the surface of cells.
Some types of cancer have large numbers of receptors on their surface, called epidermal growth factor receptors (EGFRs). When the receptors are activated, they trigger the cancer cells to divide and grow.
Panitumumab locks on to the EGFRs. This stops them stimulating the cancer cells to divide and grow. It is most likely to work for cancers with large numbers of EGFRs on their surface.
Panitumumab only works for bowel cancers that have a normal KRAS gene. So before it's used to treat bowel cancer, the cancer cells are tested for changes (mutations) in the KRAS gene. This helps the doctors decide whether the treatment is appropriate. Testing can be done on samples of the cancer cells at the same time as diagnosis of the cancer, or by using cells from previous biopsies or surgery.
When panitumumab is used
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Panitumumab is licensed to treat people with bowel cancer that has spread to other areas of the body (advanced or metastatic cancer). It can be used:
as the first treatment, in combination with the chemotherapy regimen FOLFOX
as the second-line treatment, in combination with the chemotherapy regimen FOLFIRI
on its own (known as monotherapy) after other chemotherapy treatments, such as 5FU (fluorouracil), irinotecan or oxaliplatin, have already been tried.
The National Institute for Health and Clinical Excellence (NICE) currently gives advice on which new drugs or treatments should be available on the NHS in England and Wales. The Scottish Medicines Consortium (SMC) makes recommendations on the use of new drugs within the NHS in Scotland. Neither NICE nor the SMC have recommended the use of panitumumab as a treatment for people with advanced colorectal cancer.
As a result, panitumumab may not be widely available on the NHS, although you may be given it as part of a clinical trial. We have more information about what you can do if a treatment isn't available.
What panitumumab looks like
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Panitumumab is a colourless liquid.
How panitumumab is given
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Panitumumab is given as a drip into a vein (called an intravenous infusion). It’s usually given once every two weeks. The first infusion is given slowly over about 60-90 minutes. If you don’t have a reaction to the infusion, further infusions will be given over 30-60 minutes.
Side effects of panitumumab
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Each person’s reaction to cancer treatment is different. Some people have very few side effects, while others may experience more. The side effects described here won't affect everyone being treated with panitumumab.
We have outlined the most common side effects, but haven't included those that are rare and therefore unlikely to affect you. If you notice any effects that aren't listed here, discuss them with your nurse or doctor.
The side effects of panitumumab are generally mild, and some can be reduced with medicines. Side effects of panitumumab fall into two groups:
Infusion-related reactions, which may occur during the infusion or for up to about 24 hours afterwards.
Other side effects that may occur days or weeks later.
These are uncommon and affect fewer than 5 in 100 people having an infusion. If a reaction occurs it is usually mild, but rarely it can be more severe. You may be given drugs before the infusion to reduce the chances of you having a reaction. If you have a reaction, it can usually be treated by slowing down or stopping the drip until you feel better. Any future infusions will then also be given at a slower rate.
You’ll be monitored closely during the infusion, but tell your nurse or doctor if you feel unwell or have any of the following symptoms:
flu-like symptoms, such as feeling flushed or having a fever, chills or dizziness
red, warm and itchy bumps on the skin (like nettle rash)
a feeling of swelling in the lips, tongue or throat
breathlessness, wheezing, a cough or sudden difficulty in breathing
pain in your back or stomach
a tight chest or chest pain.
Rarely, an infusion-related reaction can happen a few hours after treatment. If you develop these symptoms or feel unwell after you get home, contact the hospital straight away for advice.
Other possible side effects of panitumumab
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The most common side effect of panitumumab is an acne-like rash that mainly affects the head, chest and back. This usually begins during the first 2-3 weeks of treatment and goes away within a few weeks once treatment ends.
Your skin may also become dry and itchy or feel tender and peel. Some people find the nails on their hands or feet become red, sore and brittle.
Taking the following steps may help reduce the effects on your skin, although it can’t prevent them altogether:
Use tepid water and mild, non-scented soap for bathing and washing.
Avoid skincare products that contain alcohol.
Don’t use anti-acne products, as they can dry your skin and make your symptoms worse.
Sunlight can make skin symptoms worse. Apply sunscreen with high protection against UVA rays and with a sun protection factor (SPF) of at least 30 before going outdoors. If you're having radiotherapy, don't apply sunscreen to any skin in the area being treated. Ask your cancer specialist for advice before applying creams or lotions to this area.
Moisturise your skin regularly and after bathing. Your doctor or specialist nurse can advise you on which moisturisers are best.
If you want to wear make-up to disguise the rash, choose a hypoallergenic brand such as Dermablend®.
Wear rubber gloves for housework and gardening.
Let your doctor know as soon as possible if you develop skin or nail changes. They can prescribe treatment to help. If skin problems are severe, the length of time between treatments may be extended or the dose may be lowered.
Feeling sick (nauseated) and being sick (vomiting)
Your doctor can prescribe anti-sickness drugs to prevent or greatly reduce nausea and vomiting. If the sickness isn't controlled, or if it continues, tell your doctor. They can prescribe other anti-sickness drugs that may work better for you.
Some anti-sickness drugs can cause constipation. Let your doctor or nurse know if this is a problem.
Panitumumab can cause diarrhoea. This can usually be controlled with medicine, but let your doctor know if it is severe or continues. It's important to drink plenty of fluids if you have diarrhoea.
Feeling tired is a common side effect, especially towards the end of treatment and for some weeks after it’s over. It’s important to try to pace yourself and get as much rest as you need. Try to balance this with taking some gentle exercise, such as short walks, which will help. If tiredness is making you feel sleepy, don’t operate machinery or drive.
These occur less commonly than skin changes, but sometimes develop after three months or more.
Your eyelashes may grow longer and more curly than usual. Men may notice they have less beard growth. You may notice your head and body hair is finer, curlier or more brittle.
A few people have hair loss. If this happens, it usually develops gradually over several months.
These changes are usually temporary and gradually improve once treatment is over. We have more information about coping with hair loss.
Breathing problems or a cough
This is more likely if you have an existing lung problem. Let your doctor know if you notice any increase in breathlessness.
Sore mouth and ulcers
Your mouth may become sore or dry, or you may notice small ulcers during this treatment. Some people find sucking on ice soothing. Drinking plenty of fluids, and cleaning your teeth regularly and gently with a soft toothbrush, can help reduce the risk of this happening. Tell your nurse or doctor if you have any of these problems, as they can prescribe mouthwashes and medicine to prevent or clear mouth infections. We have more information about coping with a sore mouth.
Some people find that panitumumab causes headaches. Let your doctor or nurse know if you’re affected by this, as they can give you painkillers to help.
If you notice any change to your vision, or if your eyes become sore, red or itchy, let your doctor know. They can prescribe eyedrops to help.
It’s important to let your doctor know straight away if you feel unwell or have any severe side effects, even if they’re not mentioned above.
Additional information about panitumumab
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Some medicines, including those that you can buy from a shop or pharmacy, can be harmful to take when you’re taking panitumumab. Tell your doctor about any medicines you’re taking, including over-the-counter drugs, complementary therapies and herbal drugs.
It's not advisable to become pregnant or father a child while having panitumumab, as it may harm the developing baby. It’s important to use effective contraception while having this drug, and for at least a few months afterwards. You can discuss this with your doctor.
It’s not known whether biological therapies can be present in semen or vaginal fluids. To protect your partner, it’s safest to either avoid sex or use a barrier form of contraception for about 48 hours after treatment.
Your ability to become pregnant or father a child may be affected by having this treatment. It's important to discuss fertility with your doctor before starting treatment.
There is a potential risk that panitumumab may be present in breast milk, so women are advised not to breastfeed during treatment and for a few months afterwards.
If you’re admitted to hospital for a reason not related to the cancer, it’s important to tell the doctors and nurses looking after you that you’re having panitumumab treatment. You should tell them the name of your cancer specialist so they can ask for advice.
It’s a good idea to know who you should contact if you have any problems or troublesome side effects when you’re at home. During office hours you can contact the clinic or ward where you had your treatment. Your specialist nurse or doctor will tell you who to contact during the evening or at weekends.
This information has been compiled using a number of reliable sources, including:
Balagula Y, et al. Dermatologic Toxicities of Targeted Anticancer Therapies. Supportive Oncology. July/August 2010. 8 (4): 149–161.
Colorectal cancer (metastatic) 2nd line – cetuximab, bevacizumab and panitumumab (review) (TA242). National Institute for Health and Clinical Excellence (NICE). January 2012.
Colorectal cancer (metastatic) – panitumumab (terminated appraisal) (TA240). National Institute for Health and Clinical Excellence (NICE). December 2011.
electronic Medicines Compendium (eMC). www.medicines.org.uk (accessed October 2012).
486/08 – Panitumumab (Vectibix) Scottish Medicines Consortium (SMC). June 2008.
769/12 – Panitumumab (Vectibix) Scottish Medicines Consortium (SMC). February 2012.
With thanks to: Dermot Ball, Cancer Network Pharmacist; and the people affected by cancer who reviewed this information. Reviewing is just one of the ways you could help when you join our Cancer Voices network.