Arzerra (Ofatumumab)

How does it work?

Arzerra infusion contains the active ingredient ofatumumab, which is a type of medicine known as a monoclonal antibody. It is used to treat a type of cancer of the white blood cells called chronic lymphocytic leukaemia (CLL).

CLL is the commonest form of leukaemia. It occurs when the bone marrow, for some reason, begins to produce excessive numbers of white blood cells called lymphocytes.

Ofatumumab works in a similar way to the natural antibodies produced by our immune system. Our natural antibodies recognise foreign invaders and bind to them, helping our immune systems to attack them and protect us from infections. Monoclonal antibodies like ofatumumab are made in laboratories and are designed to recognise particular proteins in a similar way.

Ofatumumab specifically recognises and binds to a protein called CD20, which is found on the surface of cancerous B lymphocytes. This triggers the immune system to attack and kill the cancerous cells. Unfortunately it also causes the immune system to attack the healthy B lymphocyte cells, which can leave people susceptible to infection. However, the body quickly replaces any healthy cells that are damaged by the treatment.

Ofatumumab is given by a drip into a vein (intravenous infusion). Some people can have a severe allergic reaction to the medicine, so to reduce the chance of this each drip will usually be given over several hours. You will also usually be given some painkillers, antihistamine and steroids before the drip to help prevent a reaction. If you do have a reaction, your next drip will be given over a longer period of time.

Arzerra infusion is given once weekly for eight weeks, followed by a four to five week break. Treatment is then started again once a month for four months.

What is it used for?

  • Chronic lymphocytic leukaemia.

Ofatumumab is used to treat CLL that has not responded adequately to treatment with fludarabine or alemtuzumab.

Warning!

  • You may experience infusion-related reactions during treatment with this medicine. These are usually mild to moderate but can be more severe. Symptoms may include fever, chills, excessive sweating, cough, nausea, diarrhoea, throat irritation, rash, difficulty breathing, shortness of breath, rapid heart beat, flushing, low or high blood pressure, dizziness or back pain. Reactions usually occur during the first infusion or up to an hour after it has finished, but can also occur after several hours or after subsequent infusions. You will be monitored closely during your infusion and for about an hour afterwards, but it is very important to tell your nurse or doctor if you get these or any other symptoms either during or after each treatment.
  • You will need regular blood tests to monitor your blood cells during treatment with this medicine.
  • This medicine can lower the number of healthy white blood cells in your blood and so can increase your risk of getting infections. For this reason, you will be given preventative antibiotic and antiviral medicines during your treatment. They should be continued until your blood cells have recovered. You should tell your doctor immediately if you get any signs of infection during your treatment or after it has finished, for example a high temperature (fever), sore throat, mouth ulcers or swollen glands, so that your blood cells can be checked and treatment given if necessary. If your white blood cells fall too low or you get a severe infection your treatment may need to be stopped until this has resolved.
  • This medicine can also decrease the numbers of blood cells called platelets in your blood, which can cause problems with blood clotting. Tell your doctor if you experience any unexplained bruising or bleeding, or purple spots in your skin during your treatment.
  • You will need to have regular blood tests to monitor your liver function while you are taking this medicine. This is especially important if you already have any problems with your liver, in particular chronic hepatitis B. Symptoms that may suggest a liver problem include persistent nausea and vomiting, abdominal pain, or the development of jaundice (a yellow colouring to the skin and the whites of the eyes). Tell your doctor if you experience any of these symptoms.
  • It is not known if ofatumumab 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 blood cells of a developing foetus, women who could get pregnant must use an effective method of contraception to avoid pregnancy and men must use an effective method of contraception to avoid fathering a child, both during treatment and for 12 months after treatment with this medicine is finished.
  • This medicine may cause blockage of the large intestine (bowel). It is important to tell your doctor if you experience any persistent stomach pain whilst having treatment with this medicine.

Use with caution in

  • People who have a high number of cancer cells circulating in their blood.
  • Decreased kidney function.
  • History of lung disease.
  • History of heart disease.
  • History of hepatitis B.
  • People on a controlled sodium diet.

Not to be used in

  • This medicine is not recommended for children and adolescents under 18 years of age, as the manufacturer has not studied its safety and effectiveness in this age group.

This medicine should not be used if you are allergic to 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 ofatumumab 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 lymphocyte cells of a developing foetus, it should not be given to pregnant women unless considered essential by your doctor. Women who could get pregnant must use an effective method of contraception to prevent pregnancy and men must use an effective method of contraception to avoid fathering a child, both during treatment and for 12 months after the last infusion. Seek further medical advice from your doctor. If you think you could be pregnant you should inform your doctor immediately.
  • It is not known if this medicine passes into breast milk. However, because it may pass into breast milk and harm a nursing infant, women who need treatment with this medicine should not breastfeed. Women who have been treated with this medicine should not breastfeed for at least 12 months after their last infusion. Seek 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.

Very common (affect more than 1 in 10 people)

  • Lower respiratory tract infections such as pneumonia.
  • Upper respiratory tract infections such as cough and cold.
  • Decrease in the number of healthy white blood cells in the blood (neutropenia).
  • Decrease in the number of red blood cells in the blood (anaemia).
  • Rash (infusion-related reaction).

Common infusion reactions (affect between 1 in 10 and 1 in 100 people)

  • Increased heart rate (tachycardia).
  • Decrease or increase in blood pressure.
  • Shortness of breath, coughing.
  • Throat pain.
  • Narrowing of the airways (bronchospasm).
  • Low levels of oxygen in the tissues (hypoxia).
  • Blocked nose.
  • Back pain.
  • Diarrhoea.
  • Nausea.
  • Skin reactions, such as rash, hives, flushing or itching.
  • Fever.
  • Chills.
  • Excessive sweating.
  • Fatigue.
  • Hypersensitivity reaction to the infusion, eg anaphylaxis.

Other common side effects (affect between 1 in 10 and 1 in 100 people)

  • Decrease in the number of platelets in the blood (thrombocytopenia).
  • Bacterial infection of the blood (sepsis).
  • Herpes virus infections such as shingles or cold sores.
  • Urinary tract infections.
  • Obstruction of the bowel (see warning section above).

Uncommon side effects (affect between 1 in 100 and 1 in 1000 people)

  • Tumour lysis syndrome, where the body is unable to cope with all the waste products of the cancer cells killed by this medicine. This may lead to abnormal levels of salts in your blood and possibly kidney failure.
  • Sudden drop in red blood cell production (red cell aplasia).

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 taking this one, to ensure that the combination is safe.

As this medicine attacks your lymphocyte cells, which are part of your immune system, it may make it hard for your body to produce antibodies in response to vaccinations. 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 preferably be completed a few weeks before your treatment is started, or after your B cells have recovered.

Other medicines containing the same active ingredient

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