What is Cetuximab
Cetuximab is a type of drug known as a monoclonal antibody. It is not currently licensed for use in the UK and is only available to a small number of people, usually those taking part in research trials. In certain circumstances it may be given to patients if their cancer specialist thinks that it may help them and the drug manufacturer agrees (this is called prescribing on a named patient basis).
Cetuximab is being used in the USA in early trials to treat many different types of cancer, including colon cancer, kidney (renal) and bladder cancers, cancer of the head and neck, breast cancers, pancreatic cancer, non-small cell lung cancer, and ovarian cancer. These studies are being carried out on cancers that have come back after initial treatment, or have spread to other parts of the body (advanced or metastatic cancer).
Cetuximab can be given as a treatment on its own or in combination with chemotherapy or radiotherapy.
What is a monoclonal antibody?
Monoclonal antibodies are used to try to destroy some types of cancer cells while causing little harm to normal cells. They are designed to recognise certain proteins (receptors) that are found on the surface of particular cancer cells. The monoclonal antibody recognises the protein and locks onto it. This may trigger the body’s immune system to attack the cancer cells and can sometimes make the cells destroy themselves.
On the surface of some cancer cells are receptors known as epidermal growth factor receptors or EGFR. When growth factors (such as transforming growth factor alpha and epidermal growth factor) bind to the receptor, the cancer cell is stimulated to grow, divide and spread. New blood vessels may grow to feed the cancer cells.
Cetuximab locks onto the EGFR, preventing the growth factors from stimulating the cancer cell to grow, divide and spread. It may do this by preventing the cancer cell from producing the network of new blood vessels that it needs to grow. It stops the cancer cells from growing and spreading to other parts of the body and can sometimes kill the cells.
Cetuximab may also make the cancer cells more sensitive to chemotherapy.
Tests may be done to find the level of EGFR in the body before cetuximab is given. This can help the doctors to know whether you are likely to benefit from this treatment. Testing can be done at the same time as diagnosis of the cancer, or samples of cancer cells from previous biopsies or surgery may be used.
What it looks like
Cetuximab is a colourless liquid.
How it is given
Cetuximab is given by a drip into the vein (intravenously) through a fine tube (cannula) inserted into a vein. The first dose is given slowly, usually over two hours. After this doses are given weekly and this normally takes about an hour. The first dose is usually larger than the weekly ‘maintenance’ treatments. You may be given other medicines before cetuximab to lessen the side effects during treatment.
Possible side effects
Each person’s reaction to a cancer drug is unique. Some people have very few side effects, while others may experience more. If you do notice any effects which you think may be due to the drug, but which are not listed here, please discuss these with your doctor.
The side effects of cetuximab are generally mild and some of these can be reduced with medicines. As it is still a new drug it is too early to know about all the possible side effects.
Skin changes Mild skin rashes are very common. They begin during the first two weeks of treatment and usually go away completely when the treatment stops. Some people have more severe skin changes, which can include reddening of the skin and red pimples and spots on the face. The skin of the face may also become flaky and scaly. Some people have dry skin eczema on their fingertips, elbows and extremities, which is sore and itchy. If you have any of these skin changes let your doctor know straight away. If you have very severe skin problems the length of time between the treatments may be extended or the dose may be lowered.
Treatment can be prescribed by your doctor to reduce the rash. To help reduce the reddening it is best to avoid foods that make the skin go red, such as chillies and alcohol.
To help reduce the dry skin eczema it is helpful to avoid things that make your skin dry, such as too much central heating, and soap. Your doctor can prescribe creams to moisturise your skin.
To reduce scaly or flaky skin it is helpful to moisturise the skin and also avoid things that make you go red.
Tiredness (fatigue) and a general feeling of weakness. It is important to allow yourself plenty of time to rest. CancerBACUP has a section on coping with fatigue.
Nausea (feeling sick) and less commonly vomiting. There are now very effective anti-sickness drugs to prevent or greatly reduce this effect. If the sickness is not controlled or continues tell your doctor, who can prescribe other anti-sickness drugs which may be more effective. CancerBACUP has information on managing nausea and vomiting.
Diarrhoea. This can usually be controlled with medicine but tell your doctor if it is severe or continues. It is important to drink plenty of fluids if you do have diarrhoea.
Fever may occur. If your temperature goes above 38°C (100.5°F), contact your doctor or the hospital straight away.
Less common side effects
Allergic reactions. Signs of a reaction include skin rashes and itching, a feeling of swelling in the tongue or throat, irritation of the nasal passages, wheezing, a cough and breathlessness. You will be monitored closely during your treatment, but tell your nurse or doctor if you have any of these symptoms. To reduce the chance of developing an allergic reaction, certain drugs (antihistamines) can be given before the infusion. The drip can also be slowed down or stopped until the reaction is over.
Headaches. If you have headaches, let you doctor know.
Sore mouth. Your mouth may become sore, or you may notice small ulcers during this treatment. 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 doctor if you do have any of these problems. Special mouthwashes and medicines can be prescribed to prevent or clear any mouth infection.
Constipation. Your doctor can prescribe laxatives if constipation occurs.
Lowered resistance to infection Cetuximab can reduce the production of white blood cells by the bone marrow, making you more prone to infection. This is rare if cetuximab is given on its own.
Contact your doctor or the hospital straightaway if:
- Your temperature goes above 38°C (100.5°F)
- You suddenly feel unwell (even with a normal temperature)
CancerBACUP has information on how to avoid infection when you have reduced immunity, which you may find helpful.
Anaemia (low number of red blood cells) While having treatment with cetuximab you may become anaemic. This may make you feel tired and breathless. Let your doctor know if you feel tired or breathless or are very pale.
Tiredness and weakness Some people feel weak and tired, and as though they have no strength while having treatment with cetuximab. This gradually disappears once the treatment is finished.
Aching or pain in the muscles or bones can usually be controlled with mild painkillers which your doctor can prescribe.
Your liver may be temporarily affected Cetuximab may cause changes in the way that your liver works, which go back to normal when the treatment is finished. This is very unlikely to cause you any harm, but your doctor will monitor this carefully. Samples of your blood will be taken from time to time to check your liver function.
Cetuximab is not given to people who are allergic to mice.
This section has been compiled using information from a number of reliable sources including;
- Website of the American Cancer Society – www.cancer.org
- BASELGA, J (2001) The EGFR as a target for anticancer therapy – focus on cetuximab. European Journal Of Cancer. 37, S16-S22.
- Robert F et al (2001) Phase I study of anti-epidermal growth factor receptor antibody cetuximab in combination with radiation therapy in patients with advanced head and neck cancer. Journal Of Clinical Oncology. 19 (13), p3234-3243.
- McCarthy M (2003) Anti-angiogenesis drug promising for metastatic colorectal cancer. The Lancet. 361 (June 7), p1959/
- Mendelson J and Baselga J (2003) Status of epidermal growth factor receptor antagonists in the biology and treatment of cancer. Journal Of Clinical Oncology. 21 (14), p2787-2799.
- Ransom M and Sliwkowski M X (2002). Perspectives on anti-HER monoclonal antibodies. Oncology. 63 (supplement 1), p17-24
For further references, please see the general bibliography.