Obinutuzumab (Gazyvaro)

Obinutuzumab is a type of targeted cancer drug. This is pronounced OH-bi-nue-TOOZ-ue-mab. It is a treatment for chronic lymphocytic leukaemia and follicular lymphoma. It is also known by its brand name Gazyvaro.

How obinutuzumab works

Obinutuzumab is a type of targeted cancer drug called a monoclonal antibody.

Monoclonal antibodies work by recognising and finding specific proteins on cells.

Obinutuzumab targets a protein called CD20 on the surface of the lymphoma and leukaemia cells. Obinutuzumab sticks to all the CD20 proteins it finds. This makes it easier for the cells of the immune system to pick out the marked cells and kill them. 

How you have obinutuzumab

You have obinutuzumab as a drip into your bloodstream (intravenously). 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 each time you have treatment.

Into your bloodstream

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.

When you have obinutuzumab

You have obinutuzumab as cycles of treatment. Each cycle of treatment last 28 days (4 weeks). You usually have up to 6 cycles of treatment in total.

Cycle 1

You have obinutuzumab on day 1, 8, and 15. People with chronic lymphocytic leukaemia might also have obinutuzumab on day 2.

Cycle 2 to 6

You have obinutuzumab on day 1.

You usually have obinutuzumab with a chemotherapy drug or a combination of chemotherapy drugs.

If you have follicular lymphoma, you might then have obinutuzumab on its own every 2 months for up to 2 years. This is called maintenance therapy and aims to stop the lymphoma coming back for as long as possible.


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

How often and how severe the side effects are 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. 

Contact your advice line 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:

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 should contact your advice line urgently if you think you have an infection. 

Bruising and bleeding

This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechiae).

Breathlessness and looking pale

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

Lung problems

You might develop a cough or breathing problems. This could be due to infection, such as pneumonia or inflammation of the lungs. 

Let your doctor or nurse know straight away if you suddenly become breathless or develop a cough.

Inflammation of the sinuses

You might have a runny nose and a sore throat.


You might have to take an anti viral drug to prevent shingles (herpes zoster virus).

Urinary tract infections (UTIs)

Tell your doctor or nurse if you think you might have a urinary tract infection. You might find it difficult to pass urine, want to go with some urgency or are going more often. There may be pain or burning when you go. You may see blood in your urine, or your urine might smell bad or look cloudy.

Difficulty sleeping

It can help to change a few things about how you try to sleep. Try to go to bed and get up at the same time each day and spend some time relaxing before you go to bed. Some light exercise each day may also help. 


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

Diarrhoea or constipation

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

Hair loss (alopecia)

You could lose all your hair. This includes your eyelashes, eyebrows, underarm, leg and sometimes pubic hair. Your hair will usually grow back once treatment has finished but it is likely to be softer. It may grow back a different colour or be curlier than before. 


You might have itching (pruritus). Let your doctor or nurse know if you have this.  

Joint or muscle pain

You might feel some pain from your muscles and joints. Speak to your doctor or nurse about what painkillers you can take to help with this.

Lack of energy and strength

This is usually mild. You can do things to help yourself, including some gentle exercise. It’s important not to push yourself too hard and eat a well balanced diet.

Talk to your doctor or nurse if this effect is stopping you from doing your usual daily activities.

High temperature (fever)

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.

Allergic reaction

A reaction may happen during the infusion. Symptoms can include a skin rash, itching, swelling of the lips, face or throat, breathing difficulties, fever and chills. Your nurse will give you medicines beforehand to try to prevent a reaction. 

Tell your doctor or nurse immediately if at any time you feel unwell. They will slow or stop your drip for a while and give you medicine to help relieve your symptoms.

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:

  • a runny or blocked nose
  • getting a type of skin cancer called squamous cell carcinoma
  • pain in the small glands in your body called lymph nodes
  • high uric acid levels in the blood due to the breakdown of tumour cells (tumour lysis syndrome)
  • changes in potassium levels in the blood
  • feeling anxious and depressed
  • heart problems such as cardiac failure and an irregular and fast heart beat causing shortness of breath and light headedness
  • high blood pressure which can cause headaches, nose bleeds, blurred or double vision or shortness of breath
  • weight gain
  • pain or difficulty passing urine and loss of control when passing urine
  • night sweats
  • patches of skin becoming inflamed, itchy, red, cracked, and rough
  • problems with digestion such as heartburn
  • inflammation of the intestine which can cause pain, diarrhoea, tiredness and weight loss
  • swollen veins in the anus which can be painful and get irritated when you empty your bowels (haemorrhoids)
  • pain in different parts of the body such as your bones, mouth and throat, chest, arms and legs

Rare side effects

This side effects happens in fewer than 1 in 100 people (fewer than 1%) have a hole in their bowels or stomach which can cause severe tummy (abdominal) pain.

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 drinks

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.

Loss of fertility

You may not be able to become pregnant or father a child after treatment with this drug. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Men might be able to store sperm before starting treatment. And women might be able to store eggs or ovarian tissue. But these services are not available in every hospital, so you would need to ask your doctor about this. 

Contraception and pregnancy

This treatment might harm a baby developing in the womb. It is important not to become pregnant or father a child while you're having treatment and for at least 18 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.

Continue to use effective contraception for 18 months after stopping treatment with obinutuzumab.


Don’t breastfeed during this treatment and for 18 months afterwards. The drug may come through in the breast milk.

Treatment for other conditions

Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.


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 go to the electronic Medicines Compendium (eMC) website.

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

  • Electronic medicines compendium 

    Accessed March 2020

  • Obinutuzumab for untreated advanced follicular lymphoma Technology appraisal guidance (TA513)

    National Institute for Health and Care Excellence 2018

  • Obinutuzumab with bendamustine for treating follicular lymphoma refractory to rituximab Technology appraisl guidance (TA472)

    National Institute for Health and Care Excellence 2017 

  • Obinutuzumab in combinaion with chlorambucil for untreated chronic lymphocytic leukaemia Technology appraisal (TA343) 

    National Institute for Health and Care Excellence 2015 

  • Immunisation against infectious disease : chapter 6: General contraindications to vaccination

    Public Health England 

    First published: March 2013 and regularly updated on the Gov.UK website

Last reviewed: 
09 Jun 2020
Next review due: 
09 Jun 2020

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