Mifamurtide (Mepact)

Mifamurtide is a type of targeted cancer drug. You pronounce it as mee-fam-ure-tide. It is also called Mepact.

It is a treatment for osteosarcoma in children and young people aged between 2 and 30 years. Osteosarcoma is a type of primary bone cancer.

You have mifamurtide with chemotherapy after surgery to help lower the risk of the cancer coming back. 

How does mifamurtide work?

Mifamurtide is a targeted cancer drug. It targets the immune system and boosts it to make white blood cells called monocytes and macrophages. These can kill cancer cells.

How do you have mifamurtide?

You have mifamurtide as a drip into your bloodstream (intravenously).

A nurse gives you the treatment through a long plastic tube that goes into a large vein in your chest. The tube stays in place throughout the course of treatment. This can be a:

• central line
• PICC line
• portacath

How often do you have mifamurtide?

You have mifamurtide as cycles of treatment. This means that you have the drug and then a rest to allow your body to recover.

Each cycle last 7 days (1 week). You have 36 cycles, taking around 9 months in total.

For the first 12 weeks you have treatment in the following way:

You then start a new cycle of treatment.

After 12 weeks, you have mifamurtide once a week for the next 24 weeks.

Tests

You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

Before treatment starts you may have a blood test to check for viruses such as hepatitis B, hepatitis C, and HIV . This is called a viral screen.

It’s important for your doctor to know if you have had any of these viruses. This is because this treatment can weaken your immune system and can cause the virus to become active again (reactivation). 

What are the side effects of mifamurtide?

Side effects can vary from person to person. They also depend on what other treatments you're having. 

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

• you have severe side effects 

• your side effects aren’t getting any better

• your side effects are getting worse

Early treatment can help manage side effects better. 

We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.

Remember it is very unlikely that you will have all of these side effects. But you might have some of them at the same time.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

Breathlessness and looking pale 

You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.

Chills

You might shake or shiver. Let your doctor or nurse know if this continues for more than 8 hours after you’ve had mifamurtide.

High temperature (fever)

You might get a high temperature fever for a few hours after having mifamurtide. A high temperature is also called a fever.

If the fever continues for more than 8 hours after your treatment then contact your doctor immediately.

Feeling or being sick

Feeling or being sick is usually well controlled with anti sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.

It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.

Tiredness and weakness (fatigue)

Tiredness and weakness (fatigue) can happen during and after treatment. Doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.

Fast heartbeat

You might have a fast heartbeat. Symptoms include feeling your heart pounding (palpitations), dizziness and feeling faint.

Tell your healthcare team if you have any of these symptoms.

Headaches

Tell your healthcare team if you keep getting headaches. They can give you painkillers to help.

Pain in different parts of the body

Mifamurtide might cause you to have pain. Talk to the team looking after you about this. 

This more commonly includes aches and pains in your muscles, joint stiffness, pain in your hands, feet, back or chest.

You may occasionally have pain in other areas of the body such as your liver, neck, groin, bones, shoulder and pain where the cancer is.

Mifamurtide can also cause pain at the drip site and pain after medical or surgical procedures.

Changes in blood pressure

During treatment, your blood pressure may be lower or higher than normal. Tell your nurse if you feel dizzy, faint, or if you have headaches, nosebleeds, blurred or double vision, or shortness of breath. Your blood pressure usually goes back to normal while you are on treatment or when treatment ends.

Hypothermia

Hypothermia is when there is a dangerous drop in body temperature. You may start shivering, become pale, have slurred speech and feel confused. Contact your doctor straight away if this happens.

Less often you may feel cold without having hypothermia.

Loss of appetite

You might lose your appetite for various reasons while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.

Coughing, fast breathing and breathlessness

You may have a cough, feel breathless or find you are breathing fast. Less commonly, your chest may sound wheezy or you may cough up blood.

Sometimes you can get a build-up of fluid in the lung (pleural effusion). But this is less common.

It is important to tell your doctor or nurse straight away if you have any of these symptoms. They can work out the cause and get you any medicine you need.

Dizziness

This drug might make you feel dizzy. Don’t drive or operate machinery if you have this.

Constipation

Constipation is easier to sort out if you treat it early. Drink plenty and eat as much fresh fruit and vegetables as you can. Try to take gentle exercise, such as walking. Tell your healthcare team if you think you are constipated. They can give you a laxative if needed.

Diarrhoea

Contact your advice line if you have diarrhoea. For example, in one day you have 2 or more loose bowel movements than usual. If you have a stoma , you might have more output than normal. Your doctor may give you anti diarrhoea medicine to take home with you after treatment.

Try to eat small meals and snacks regularly. It’s best to try to have a healthy balanced diet if you can. You don’t necessarily need to stop eating foods that contain fibre. But if your diet is normally very high in fibre, it might help to cut back on high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables. 

Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.

Tummy (abdominal) pain

Contact your advice line straight away if you get pain in your tummy so your doctor can find out what is causing it.

Sweating

You might sweat more than usual. Talk to your doctor if this becomes a problem for you.

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:

• sepsis - a serious reaction to an infection. Signs can include feeling very unwell, not passing urine, slurred speech or confusion, breathlessness, mottled or discoloured skin, extreme shivering or muscle pain. Call 999 or go to accident and emergency (A&E) immediately if you have any of these symptoms
• increased risk of getting an infection
• bruising, bleeding gums, or nosebleeds due to a drop in the level of platelets in your body
• skin looking a blue colour – this is more noticeable on the lips and finger nails. Contact your advice line if you have this as it can be due to a low amount of oxygen in your blood
• confusion
• sleeping problems including difficulty sleeping (insomnia), drowsiness or sleepiness
• depression and anxiety
• blurred vision
• ear problems including hearing loss and ringing in the ears (tinnitus)
• the feeling of the room spinning or moving around you (vertigo)
• indigestion - symptoms include heartburn, bloating and burping
• skin changes such as a rash, redness, itching and dry skin
• sudden reddening of the skin (flushing)
• hair thinning
• painful periods
• low levels of potassium in the blood which can cause cramps, weakness and palpitations
• skin sensation changes, such as tingling and numbness or reduced sensation when touching
• pain when having a wee, having blood in your wee or needing to wee more often during the day
• fluid build-up in different parts of the body
• shaking (tremor)
• inflammation or rash around the drip site
• muscle spasms
• loss of fluid in your body (dehydration)
• looking pale
• cold like symptoms such as a blocked nose or sinuses, runny nose and a sore throat
• swollen tummy

Coping with side effects

We have more information about side effects and tips on how to cope with them.

What else do you need to know?

Other medicines, foods and drink

Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.

Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.

Loss of fertility 

It is not known whether this treatment affects fertility in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Pregnancy and contraception

It is unknown whether treatment may or may not harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you are having treatment. Let your team know straight away if you or your partner become pregnant while having treatment.

Talk to your doctor or nurse about effective contraception you can use during treatment. Ask how long you should use it before starting treatment and after treatment has finished.

Breastfeeding

It is not known whether this drug comes through into the breast milk. Speak to your doctor if you wish to breast feed whilst you are having this drug.

Treatment for other conditions

If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.

Immunisations

Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having.

Ask your doctor or pharmacist how long you should avoid live vaccinations.

In the UK, live vaccines include rubella, mumps, measles, BCG, and yellow fever.

You can usually have:

• other vaccines, but they might not give you as much protection as usual
• the flu vaccine (as an injection)
• the coronavirus (COVID-19) vaccine

Talk to your doctor or pharmacist about the best time to have a vaccine in relation to your cancer treatment.

Contact with others who have had immunisations 

You can be in contact with other people who have had live vaccines as injections. If someone has had a live vaccine by mouth or nasal spray there may be a small risk the vaccine virus can be passed onto you if your immune system is weakened.

Your healthcare team will let you know if you need to take any precautions if you are in close contact with someone who has had a live vaccine.

More information about this treatment

For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.