How does it work?

Vectibix infusion contains the active ingredient panitumumab, which is a type of medicine called a humanised monoclonal antibody. It is used to treat cancers of the bowel and rectum (colorectal cancers).

Many cancer cells have structures called epidermal growth factor receptors (EGFRs) on their surfaces. These receptors allow a protein called epidermal growth factor (EGF) to attach to the cells. When the epidermal growth factor attaches to the receptor, this stimulates the growth and multiplication of the cancer cells.

Panitumumab works by specifically recognising, binding to and blocking the EGFRs on cancer cells. This stops the cancer cells receiving the messages they need to grow, multiply and spread, and causes the cancer cells to die.

Your doctor may do various tests to check the level of EGFR on your cancer cells, as this can predict if your cancer is likely to respond to the treatment. The response to treatment with panitimumab has also been shown to be dependent on the presence of a non-mutated form of the K-RAS oncogene in the cancer cells. Therefore, before treatment with Vectibix is started, tests to identify the presence of non-mutated K-RAS should be carried out.

Panitumumab is given as a drip into a vein (intravenous infusion) once every two weeks. It is not used in combination with other chemotherapy treatments. The recommended infusion time is about 60 minutes, but this may be increased to 90 minutes if higher amounts of panitumumab are administered.

What is it used for?

• Cancer of the bowel or rectum (colorectal cancer).

Vectibix is licensed to treat advanced colorectal cancer that has spread to other areas of the body and has not responded to treatment with other chemotherapy treatments, such as 5FU (fluorouracil), irinotecan or oxaliplatin.

Warning!

• Skin reactions such as rash, itching, scaling and redness of skin are the most common side effects of this medicine. You should tell your doctor immediately if these get worse, because they may lead to complications such as infections or abscesses. You should avoid exposing your skin to sunlight or sunlamps if you are experiencing skin reactions while having treatment with this medicine, as sunlight can make the reaction worse. If exposure to sunlight cannot be avoided, use protective measures such as sun-creams and protective clothing, including a hat. Your doctor can prescribe you a high factor sun-cream.
• If you get a sudden new or worsening cough, high temperature (fever), wheezing or shortness of breath while taking this medicine, you should let your doctor know, as these could be symptoms of a rare form of lung irritation called interstitial lung disease, which can be a side effect of this medicine.
• This medicine may be harmful to an unborn baby. For this reason, women receiving this medicine should use an effective method of contraception to prevent pregnancy, both during treatment and for at least six months after treatment is finished. Women should consult their doctor immediately if they think they could be pregnant.
• This medicine may affect the ability of a woman to get pregnant. You should discuss fertility with your doctor before treatment with this medicine is started.
• You will need to have a blood test to monitor the level of magnesium and calcium in your blood every two weeks during treatment with this medicine. If this level is too low, magnesium or calcium supplements may be required. The level of magnesium and calcium in your blood will also need to be checked eight weeks after treatment is stopped.

Use with caution in

• People on a low salt (sodium) diet.
• The safety and efficacy of this medicine have not been studied in people with decreased liver or kidney function.

Not to be used in

• People with thickening and stiffening of the lungs (pulmonary fibrosis).
• People with inflammation of the lungs (interstitial pneumonitis).
• Pregnancy.
• Breastfeeding.
• The safety and efficacy of this medicine have not been established in children and adolescents less than 18 years of age. It is not recommended for this age group.

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

• The safety of this medicine in pregnancy has not been established. It is likely to be harmful to a developing baby. For this reason, it should not be used during pregnancy. Women who could get pregnant should use a reliable method of contraception to avoid getting pregnant while being treated with this medicine and for at least six months after treatment is finished. Seek further medical advice from your doctor.
• It is not known if this medicine passes into breast milk, however it is likely that it will do. Mothers who are having treatment with this medicine should not breastfeed during treatment and for three months after their last treatment. Seek further medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

• Skin reactions such as rash, itching, dry flaky skin, redness of skin, and cracks in the skin (see warning above).
• Inflammation of the nail bed (paronychia).
• Diarrhoea.
• Fatigue.
• Nausea and vomiting.
• Low blood potassium level (hypokalaemia).
• Low blood sodium level (hyponatraemia).
• Low blood magnesium level (hypomagnesaemia).
• Shortness of breath (dyspnoea).
• Cough.
• Fever/high temperature.
• Headache.
• Dehydration.
• Inflammation of the eye (conjunctivitis).
• Eye problems such as dry eye, itchy eyes, redness of the eye, and increased tear flow.
• Sore, inflamed mouth.
• Dry nose or mouth.
• Loosening of the nails (onycholysis).
• Excess hair growth (hypertrichosis).
• Excessive hair loss (alopecia).

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while being treated with this one, to ensure that the combination is safe.

It is recommended that Vectibix is not used in combination with bevacizumab and chemotherapy treatments, because combined use has been shown to carry an increased risk of severe side effects and death.

Other medicines containing the same active ingredient

There are currently no other medicines available in the UK that contain panitumumab as the active ingredient.