Inotuzumab ozogamicin (Besponsa)

Inotuzumab ozogamicin is a type of targeted cancer drug.

You pronounce inotuzumab ozogamicin as in-oh-too-zoo-mab oh-zoh-ga-my-sin. It's often called inotuzumab for short.

It is a treatment for a type of acute lymphoblastic leukaemia (ALL) called B cell precursor ALL. You might have it if the leukaemia has come back (relapsed) or not responded to treatment (refractory).

How does inotuzumab work?

Inotuzumab is a type of targeted cancer drug called a monoclonal antibody (MAB). It finds the leukaemia cells by targeting a certain protein on them. This protein is called CD22. It then delivers the drug directly into the leukaemia cells and kills them. 

How you have inotuzumab?

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

You might have 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

If you don't have a central line

You might have treatment through a thin short tube (a cannula) that goes into a vein in your arm. You have a new cannula each time you have treatment.

How often do you have inotuzumab?

You have inotuzumab in cycles of treatment Open a glossary item. This means that you have the drug and then a rest to allow your body to recover. Each cycle of treatment usually lasts 3 weeks. Some people might have it over 4 weeks.

You have it once every 3 or 4 weeks. It takes about an hour each time. You may be at the hospital for longer. You have up to 6 cycles of inotuzumab. This takes about 5 months in total. If you have inotuzumab before a stem cell transplant you have 2 or 3 cycles.


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.

Side effects

Side effects can vary from person to person. They also depend on what other treatment you are having. 

This treatment affects the immune system. This may cause inflammation in different parts of the body which can cause serious side effects. They could happen during treatment, or some months after treatment has finished. In some people, these side effects could be life threatening.

When to contact your team

Your doctor, pharmacist or nurse will go through the possible side effects. They will monitor you closely 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. 

Contact your healthcare team immediately if you have signs of infection, including a temperature above 37.5C or below 36C.

We haven't listed all the side effects here. 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:

Increased risk of infection 

Increased risk of getting an infection is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. You might have other symptoms depending on where the infection is.

Infections can sometimes be life threatening. You could develop a serious reaction to an infection (sepsis Open a glossary item). You should contact your advice line urgently if you think you have an infection. 

Bruising and bleeding 

You may have bruising and bleeding. This is due to a drop in the number of platelets Open a glossary item in your blood. These blood cells help the blood to clot when we cut ourselves.

You may have nosebleeds or blood in your poo. You may have heavy bleeding, or bleeding that you can’t stop from an injury. Call your advice line if you have any unusual bleeding. If you are losing a lot of blood call 999 or go straight to Accident and Emergency (A&E).

Your healthcare team will regularly check the level of platelets with blood tests. They will go through which symptoms to look out for and when to contact someone.

Breathlessness and looking pale

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

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.


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

Tummy (abdominal) pain 

Tell your doctor or nurse if you have this. They can check for the cause of the pain and give you medicine to help. 

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.

Diarrhoea or constipation 

Tell your healthcare team if you have diarrhoea or constipation. They can give you medicine to help. 

Sore mouth 

Mouth sores and ulcers can be painful. It helps to keep your mouth and teeth clean, drink plenty of fluids and avoid acidic foods such as lemons. Chewing gum can help to keep your mouth moist. Tell your doctor or nurse if you have ulcers.

Liver changes

You might have high levels of a substance called bilirubin in the blood or changes to the levels of liver enzymes. This can cause jaundice. You might have yellowing of the skin or whites of the eyes.

Less commonly you might also have small blockages in the blood vessels going into and inside the liver. Symptoms of this include loss of appetite, feeling or being sick, diarrhoea, dark coloured urine, light coloured poo, tummy pain, yellowing skin or eyes, feeling generally unwell, rapid weight gain or fluid build up causing swelling.

You have regular blood tests to check for any changes in the way your liver is working.

High temperature

If you get a high temperature, let your healthcare team know straight away. Ask them if you can take paracetamol to help lower your temperature.


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.

Allergic reaction 

A reaction may happen during the infusion, causing a skin rash, itching, swelling of the lips, face or throat, breathing difficulties, fever and chills. Tell your nurse or doctor immediately if at any time you feel unwell. They can give you medicine to help.

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:

  • high levels of chemicals in your blood due to the breakdown of tumour cells - you will have regular blood tests to check for this

  • high levels of uric acid in the blood that might cause kidney changes and swollen joints (gout)

  • a build up of fluid in your tummy (ascites) or swelling of your tummy

  • changes to your heart rhythm usually picked up on an electrocardiogram (ECG) – tell your nurse or doctor if you feel lightheaded or dizzy

  • high levels of enzymes called amylase and lipase in the blood. They help to digest food. You have regular blood tests to check this

Coping with side effects

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

What else do I 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.

Pregnancy and contraception

This treatment might harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you are having treatment.

Women must not become pregnant for at least 8 months after the end of treatment. Men should not get someone pregnant for at least 5 months after treatment. 

Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner become pregnant while having treatment.

Loss of fertility 

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


Don’t breastfeed during this treatment and for 2 months afterwards. The drug may come through in the breast milk.

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.


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, yellow fever and one of the shingles vaccines called Zostavax.

You can 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 it in relation to your cancer treatment

Members of your household who are aged 5 years or over are also able to have the COVID-19 vaccine. This is to help lower your risk of getting COVID-19 while having cancer treatment and until your immune system Open a glossary item recovers from treatment.

Contact with others who have had immunisations - You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine. Sometimes people who have had the live shingles vaccine can get a shingles type rash. If this happens they should keep the area covered.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray as this is a live vaccine. This is for 2 weeks following their vaccination.

Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.

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.

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