Gemtuzumab ozogamicin (Mylotarg®)

Gemtuzumab ozogamicin (Mylotarg®) is a targeted therapy drug used to treat acute myeloid leukaemia (AML). It is best to read this information with our general information about the type of cancer you have.

Mylotarg is given into a vein. You may have it as an outpatient or during a hospital stay. Your cancer doctor or nurse will tell you how often you will have it.

Like all targeted therapy drugs, Mylotarg can cause side effects. Some of the side effects can be serious, so it’s important to read the detailed information below. How targeted therapy affects people varies from person to person. Your healthcare team can talk to you more about this and give you advice on how to manage any side effects.

Tell your doctor or nurse straight away if you:

  • have a temperature
  • feel unwell
  • have severe side effects, including any we don’t mention here

Rarely, side effects may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

If you need to seek medical attention for any reason other than cancer, always tell the healthcare staff that you are having this treatment.

How Mylotarg works

Mylotarg (gemtuzumab ozogamicin) is a type of targeted therapy drug called a monoclonal antibody. It works by ‘targeting’ specific proteins on the surface of cells.

Mylotarg targets a protein called CD33. CD33 is found on the surface of leukaemia cells and some types of developing white blood cells. Mylotarg has two parts:

  • gemtuzumab
  • a chemotherapy drug called ozogamicin.

Gemtuzumab locks on to the CD33 protein. It releases ozogamicin into the leukaemia cells to damage and kill them.

During treatment, you will see a cancer doctor and a cancer nurse. This is who we mean when we mention doctor or nurse in this information.

How targeted therapies work

This animation shows how targeted therapies work and what effect they have on the body.

About our cancer information videos

How targeted therapies work

This animation shows how targeted therapies work and what effect they have on the body.

About our cancer information videos


When Mylotarg is used


How Mylotarg is given

Before, or on the day of treatment, a nurse or a person trained to take blood (phlebotomist) will take a blood sample from you. This is to check it is okay for you to have Mylotarg.

You may have this treatment as an outpatient or during a hospital stay. A nurse gives you the drug into a vein as a drip (intravenous infusion). They will usually run the drip through a pump. This will give you the treatment over two hours.

Your doctor will tell you how often you need to have it.


Possible side effects

We explain the most common side effects of this treatment here. We also include some less common side effects.

You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we haven’t listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Side effects during treatment

Some people have an allergic reaction to Mylotarg. This can happen when it is given or for up to 24 hours after. Your nurse will give you drugs to help prevent or reduce this. They will check you for signs of a reaction. If you have a reaction, they will treat it quickly.

Signs of a reaction can include:

  • flu-like symptoms (headaches, a high temperature or chills)
  • feeling sick
  • a rash
  • feeling itchy
  • breathlessness
  • pain in your back, tummy or chest
  • feeling unwell.

Tell your nurse straight away if you have any of these symptoms.

Some people's blood pressure falls while they are having Mylotarg. If you usually take medicine to lower your blood pressure, your doctor may ask you not to take it for 12 hours before having Mylotarg. The nurse will check your blood pressure regularly.

Reactions can happen for up to 24 hours after treatment. If you develop any of these symptoms or feel unwell, contact the hospital straight away on the 24-hour contact number they give you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shaky
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine a lot.

It is important to follow any specific advice your cancer treatment team gives you.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. Tell your doctor or nurse if you have any bruising or bleeding that you can’t explain. This includes:

  • nosebleeds
  • bleeding gums
  • tiny red or purple spots on the skin that may look like a rash.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this.

If you are very anaemic, you may need a drip to give you extra blood cells. This is called a blood transfusion.

Tumour lysis syndrome (TLS)

Mylotarg may cause the leukaemia cells to break down very quickly. This releases a chemical called uric acid into the blood. The kidneys usually get rid of uric acid, but they may not be able cope with large amounts. This can cause chemical imbalances in the blood that affect the kidneys and the heart. This is called tumour lysis syndrome (TLS).

If your white blood cell count is very high before starting Mylotarg, you may have a higher risk of TLS. Your doctor may give you a drug called hydroxyurea to reduce your white blood cell count before you start treatment.

During treatment, your doctor may give you a drug called allopurinol or rasburicase. You will also be given fluid through your drip to help protect your kidneys.

Feeling sick

Your doctor can give you anti-sickness drugs to help prevent or control sickness. If you still feel sick, tell your doctor. They can prescribe other anti-sickness drugs that may work better for you.

Sore mouth

You may get a sore mouth or mouth ulcers. This can make you more likely to get a mouth infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth is sore:

  • tell your nurse or doctor – they can give you a mouthwash or medicines to help
  • try to drink plenty of fluids
  • avoid alcohol, tobacco, and foods that irritate your mouth.

Diarrhoea

If you have diarrhoea, contact the hospital for advice. Try to drink at least 2 litres (3½ pints) of fluids every day. It can help to avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods.

Constipation

This treatment can cause constipation. Here are some tips that may help:

  • Drink at least 2 litres (3½ pints) of fluids each day.
  • Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
  • Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital for advice. Your doctor can give you drugs called laxatives to help.

Effects on the liver

Mylotarg may cause changes in the way the liver works. You will have regular blood tests to check how well your liver is working.


Other information

Other drugs

Some medicines, including ones you buy in a shop or chemist, can be harmful while you are having this treatment. Tell your cancer doctor about any drugs you are taking, including vitamins, herbal drugs and complementary therapies.

Fertility

Doctors don’t yet know how this treatment may affect your fertility (the ability to become pregnant or father a child). If you are worried about this, talk to you doctor before treatment starts.

Contraception

Your doctor will advise you not to get pregnant or father a child while having this treatment and for some time afterwards. The drugs may harm the developing baby. It is important to use effective contraception.

Breastfeeding

Women are advised not to breastfeed while having this treatment and for some time afterwards. This is because the drugs could be passed to the baby through breast milk.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having this treatment.

Emergency contacts

It is a good idea to know who you should contact if you have any problems or troublesome side effects when you’re at home. During office hours you can contact the clinic or ward where you had your treatment. Your specialist nurse or doctor will tell you who to contact during the evening or at weekends.