How does it work?
Mabthera infusion contains the active ingredient rituximab, which is a type of medicine known as a monoclonal antibody. It works by attacking white blood cells called B lymphocytes. This action means it can be used to treat three different diseases: cancers of the lymphatic system known as non-Hodgkins lymphomas, chronic lymphocytic leukaemia, and the inflammatory disease of the joints known as rheumatoid arthritis.
Lymphomas are cancers involving white blood cells called lymphocytes. Cancer occurs when these lymphocytes, for some reason, begin to multiply in an uncontrolled way. This can cause a lump or tumour in the lymph nodes. Lymphocytes are normally involved in fighting infection and they travel around the lymphatic system and the bloodstream to do this. If abnormal cancerous lymphocytes travel, the cancer can spread to other lymph nodes and other areas of the body. Rituximab is used to treat non-Hodgkins lymphomas that involve a sub-group of lymphocytes called B lymphocytes.
Leukaemias are also cancers involving white blood cells. In leukaemia the bone marrow produces too many immature white blood cells. These abnormal cells take up space in the bone marrow and result in less room for production of normal healthy blood cells. Rituxumab is used to treat a type of leukaemia called chronic lymphocytic leukaemia, in which too many abnormal B lymphocytes are produced.
In both these conditions rituximab works by attacking the abnormal B lymphocytes.
Rituximab works in a similar way to the natural antibodies produced by our immune system. Our natural antibodies recognise foreign invadors and bind to them, helping our immune systems to attack them and protect us from infections. Monoclonal antibodies like rituximab are made in laboratories. They are designed to attack particular body cells.
Rituximab specifically recognises and binds to a protein called CD20, which is found on the surface of cancerous B lymphocyte cells. This triggers the immune system to attack the cancerous cells, and can also sometimes cause the cells to destroy themselves. This is how how rituximab works in treating lymphoma and leukaemia.
Rituximab can also be used to treat severe forms of rheumatoid arthritis. This disease is known as an autoimmune disease, because the inflammation and damage to the joints results from overactivity in the immune system. B lymphocytes seem to play a key role in this process. Rituximab works in rheumatoid arthritis by attacking the B lymphoctyes in the same way as described above. This interrupts the process of inflammation and damage in the joints. It has been shown to slow down joint damage and improve physical functioning.
What is it used for?
- A type of cancer of the lymphatic system called follicular non-Hodgkins lymphoma (as a first-line treatment in combination with chemotherapy).
- Follicular non-Hodgkins lymphoma that is resistant to chemotherapy or has relapsed following chemotherapy.
- A type of cancer of the lymphatic system called CD20 positive diffuse large B cell non-Hodgkin's lymphoma (in combination with CHOP chemotherapy).
- Chronic lymphocytic leukaemia (in combination with chemotherapy, for people who have not yet had any treatment, or whose disease has relapsed after previous treatment).
- Severe active rheumatoid arthritis, in combination with another medicine called methotrexate, in adults whose arthritis has not responded well enough to treatment with disease modifiying antirheumatic drugs (DMARDs, including infliximab, etanercept or adalimumab), or who cannot take these medicines due to side effects.
How is this treatment given?
- Rituximab is given by a drip into a vein (intravenous infusion). Some people can have a severe allergic reaction to rituximab, so to reduce the chance of this the first drip will usually be given over a period of a few hours. You will also usually be given some painkillers, antihistamine and possibly steroids before the drip to help prevent a reaction. If you don't have a reaction to the medicine, subsequent doses may be given over a shorter time as an outpatient.
- To treat lymphoma, this medicine will either be given on its own, or in combination with other chemotherapy medicines. If used on its own, it will usually be given once a week for four weeks. If used in combination with other chemotherapy, it will be given on the same day as the other medicines, which are usually given eight times at three week intervals. Courses may be repeated. If the cancer responds to the intial treatment, maintenance treatment may be given once every two or three months for up to two years.
- To treat leukaemia, this medicine will usually be given on the first day of each cycle of chemotherapy.
- To treat rheumatoid arthritis, two doses of rituximab will be given, two weeks apart. This course may be repeated after six months if your doctor feels it is necessary to control your symptoms.
- Molecules called cytokines may be released into the body when the B lymphocytes are destroyed by this medicine. This can lead to severe infusion-related reactions such as fever, chills, breathing difficulties, itching, blisters, throat or tongue swelling, nausea and vomiting, headache, flushing or palpitations. People whose lung function is compromised or who have cancer that has invaded the lungs, or who have a high number of cancer cells circulating in the blood or a high tumour burden are at greater risk of this syndrome. All patients must be very closely monitored, particularly those with a history of heart disease or a history of breathing problems. Your doctor may need to interrupt your infusion if you develop these symptoms. These reactions are less likely to happen after your second infusion.
- You will need to have regular blood tests to check the levels of your blood cells while you are having treatment with this medicine, particularly if you are also receiving chemotherapy treatment.
- This medicine can increase your risk of infections. You should tell your doctor immediately if you get any signs of infection following any of your infusions, for example, a high temperature (fever), sore throat, mouth ulcers or swollen glands.
- Very rarely, some people treated with this medicine have had a serious brain infection called Progressive Multifocal Leukoencephalopathy (PML). This usually causes severe disability and can be fatal. As a result, you should tell your doctor immediately if you experience possible symptoms of this disorder, which include memory loss, trouble thinking, changes in behaviour, difficulty with walking, trouble moving one side of your body, pins and needles sensations or loss of vision.
- It is not known if rituximab can affect reproductive ability, or if it can harm a developing baby when given during pregnancy. However, because it could potentially cross the placenta and attack the B cells of a developing foetus, women who could get pregnant must use an effective method of contraception to avoid pregnancy both during treatment and for 12 months after stopping treatment with this medicine.
Use with caution in
- People who have a high number of cancer cells circulating in the blood or a high tumour burden.
- People with cancer that has invaded the lungs.
- People with a history of lung disease.
- People with a history of heart disease.
- People who have previously been treated with chemotherapy that can have side effects on the heart.
- People with low numbers of blood cells called neutrophils and platelets in their blood.
- People whose immune systems have a decreased ability to fight infection and disease.
- People with a history of recurrent or chronic infections.
- People with a history of hepatitis B.
Not to be used in
- People with active severe infections.
- People with a very poorly functioning immune system, for example due to previous courses of chemotherapy or radiotherapy.
- People who are allergic to mouse protein.
- When treating rheumatoid arthritis, this medicine should not be given to people with severe heart failure, or other severe uncontrolled heart disease.
- The safety and efficacy of MabThera in children have not been established by the manufactuer. It is not recommended for children.
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.
- It is not known if rituximab can affect reproductive ability, or if it can harm a foetus when given during pregnancy. However, because it could potentially cross the placenta and attack the B cells of a developing baby, it should not be given to pregnant women unless the potential benefit outweighs the possible risk.
- Women who could get pregnant must use an effective method of contraception to prevent pregnancy, both during treatment with this medicine and for 12 months after their last drip. Seek further medical advice from your doctor.
- It is not known if this medicine passes into breast milk. However, because it may pass into breast milk and harm a nursing infant, it should not be given to women who are breastfeeding. Women who have been treated with Mabthera should not breastfeed for 12 months after their last drip. Seek medical advice from your doctor.
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. Side effects are less likely if you are being treated with this medicine for rheumatoid arthritis.
- Fever (pyrexia) or chills.
- Weakness or loss of strength (asthenia).
- Decreased numer of white blood cells, platelets or red blood cells in the blood.
- Increased susceptibility to infections - see warning section above.
- Rash or itching.
- Hair loss.
- Disturbances of the gut such as nausea and vomiting, diarrhoea, constipation, abdominal pain or swelling, indigestion.
- Runny or itchy nose.
- Severe swelling of lips, face or tongue (angioedema).
- Decrease or increase in blood pressure.
- Pins and needles or numb sensations.
- Difficulty sleeping (insomnia).
- Anxiety, agitation, nervousness or depression.
- Sensation of ringing or other noise in the ears (tinnitus).
- Breathing difficulties due to a narrowing of the airways (bronchospasm) or other lung problems.
- Throat irritation.
- Pain in the muscles, joints, back or neck.
- Increased blood sugar level (hyperglycaemia).
- Swollen ankles due to fluid retention.
- Tumour pain.
- Heart problems, such as abnormal heart beats (arrhythmias), heart failure, chest pain or heart attack.
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?
Always tell your doctor if you are taking any other medicines, including over-the-counter and herbal medicines, before starting treatment with rituximab. Similarly, always seek advice from your doctor or pharmacist before taking any new medicines while you are receiving treatment with rituximab, so they can check that the combination is safe.
Rituximab may cause low blood pressure and enhance the effect of blood pressure lowering medicines. For this reason, if you are taking medicines for high blood pressure your doctor may want you to stop taking them 12 hours before your Mabthera drip.
If you are having this medicine for rheumatoid arthritis, you should tell your doctor if you are likely to need any vaccinations, for example travel vaccinations, before you have your drip. As this medicine attacks your B cells, which are part of your immune system, it can make it hard for your body to produce antibodies. This means that vaccines may potentially be less effective if given during treatment, and live vaccines may cause serious infections. For this reason, if you need to have any vaccinations, these should be completed at least four weeks before your first MabThera drip. Live vaccines are not recommended while your B cells are depleted (for a few months after your drip). Live vaccines include measles, mumps, rubella, MMR, oral polio, oral typhoid and yellow fever.
The use of this medicine in combination with other medicines for rheumatoid arthritis has not been studied (with the exception of methotrexate). If you are prescribed any other disease modifiying antirheumatic drugs (DMARDs, eg infliximab, etanercept, adalimumab, gold, penicillamine, chloroquine, sulfasalazine) after your Mabthera drip, you should let your doctor know if you experience any side effects, particularly any signs of infection such as fever.
Other medicines containing the same active ingredient
There are currently no other medicines available in the UK that contain rituximab as the active ingredient.