Mifamurtide (Mepact)

Mifamurtide (pronounced mee-fam-ure-tide) is a type of biological therapy. It is also called by its brand name, Mepact. It boosts the immune system to kill cancer cells by making it produce certain types of white blood cells called monocytes and macrophages.

Mifamurtide is a treatment for osteosarcoma, a type of bone cancer. It is for children and young people aged between 2 and 30 years. You have it with chemotherapy after surgery to help lower the risk of the cancer coming back.

You have mifamurtide through a drip into a vein (intravenously) over an hour. You may have it through a central line, a portacath or a PICC line. These are long plastic tubes that give the drugs directly into a large vein in your chest. You have the tube put in just before your course of treatment starts and it stays in place as long as you need it.

You have the treatment twice a week, at least 3 days apart. You have it for 12 weeks. Then you have it once a week for another 24 weeks. This makes 36 weeks in total.

The side effects associated with mifamurtide are listed below. Because mifamurtide is a relatively new drug we are still learning about the side effects, especially longer term ones. Always tell your doctor or specialist nurse if you have a new symptom or side effect. They can decide whether it is due to the drug or to something else. They can then work out how to help you.

The side effects may be different depending on the type of chemotherapy you are having and any other drugs you are taking.

More than 10 in every 100 people have one or more of these effects.

A temporary drop in the number of blood cells made by the bone marrow. This can lead to the following side effects

• Increased risk of getting an infection from a drop in white blood cells – it is harder to fight infections and you can become very ill. You may have headaches, aching muscles, a cough, sore throat, pain passing urine or feel cold and shivery
• Tiredness and breathlessness due to a drop in red blood cells (anaemia) – you may need a blood transfusion
• Bruising more easily due to a drop in platelets – you may have nosebleeds, bleeding gums after brushing your teeth, or lots of tiny red spots or bruises on your arms or legs (known as petechia)
  Some of these side effects can be life threatening, particularly infections. You should contact your treatment centre if you have any of these effects. Your doctor will check your blood counts regularly to see how well your bone marrow is working.

Other common side effects include

• Tiredness in 1 in 2 people (50%) during and after treatment – most people find their energy levels are back to normal within 6 months to a year  
• Feeling or being sick in 1 in 2 people (50%), but this is usually well controlled with anti sickness medicines
• Loss of appetite in about 1 in 2 people (50%)
• Headaches and dizziness
• Sweating
• A faster heart beat and a feeling that your heart is racing (palpitations)
• Changes to your blood pressure – it may be higher or lower than normal
• A cough and breathlessness
• Flu like symptoms including a high temperature (fever), chills, sweating, aching joints and headaches – these affect nearly everyone at first but usually get better as the course of treatment continues. Taking paracetamol before treatment helps to control this
• Constipation in just under 1 out of 5 people (20%) – your doctor or nurse may give you laxatives to help prevent this but do tell them if you are constipated for more than 3 days
• Diarrhoea – drink plenty of fluids and tell your doctor or nurse if diarrhoea becomes severe, or continues for more than 3 days
• Loss of fertility – we don’t know exactly how this drug affects fertility so do talk to your doctor before starting treatment if having a baby is important to you

Some people may have one or more of the following side effects

• Difficulty sleeping
• Changes in mood and confusion
• Blurred vision
• Hearing loss
• Ringing in your ears (tinnitus)
• Dizziness and loss of balance (vertigo)
• Indigestion
• Skin changes, including a rash, reddening, itching and dry skin
• Hair thinning
• Pain – this can be anywhere in the body including muscle, joint and abdominal pain
• Girls or women may stop having periods (amenorrhoea) but this may be temporary
• Low levels of potassium in your blood – you will have regular blood tests to check the levels
• Numbness or tingling in fingers and toes can cause difficulty with fiddly things such as doing up buttons

You may only have 1 or 2 or a few of these side effects and some may be very mild. A side effect may get worse through your course of treatment. Or you may have more side effects as the course goes on. This depends on

• How many times you've had a drug before
• Your general health
• How much of the drug you have (the dose)
• Other drugs you are having

Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them.

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies – some drugs can react together.

We don’t know exactly how this drug affects a developing baby and it may be harmful, so talk to your doctor or nurse about contraception before having treatment if there is any chance that you or your partner could become pregnant.

You should not have immunisations with live vaccines while you are having this treatment or for at least 6 months afterwards. In the UK, live vaccines include rubella, mumps, measles (usually given together as MMR), BCG and yellow fever. You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with oral vaccines, but not many people in the UK have oral vaccines now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.