What is obinutuzumab (Gazyvaro®)?

Obinutuzumab (Gazyvaro®) is used to treat:

It is sometimes used to treat other cancers.

It is best to read this information with our general information about the type of cancer you have.

Obinutuzumab belongs to a group of targeted therapy drugs known as monoclonal antibodies.

These drugs work by targeting specific proteins (receptors). Obinutuzumab targets a protein called CD20 on the surface of white blood cells called B-lymphocytes (B-cells). It then triggers the body’s immune system to attack the cells and destroy them. 

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

How obinutuzumab is given

You will be given obinutuzumab at a day unit or during a stay in hospital. It is usually given in combination with chemotherapy drugs. It can also be given on its own. Your doctor or nurse will explain how it will be given.

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

Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level to have the treatment. 

You will see a doctor or nurse before you have your treatment. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your treatment. Your nurse will tell you when your treatment is likely to be ready. 

The drug can be given through: 

  • a short, thin tube the nurse puts into a vein in your arm or hand (cannula)
  • a fine tube that goes under the skin of your chest and into a vein close by (central line)
  • a fine tube that is put into a vein in your arm and goes up into a vein in your chest (PICC line).

Your course of treatment

You usually have a course of several cycles of treatment over a few months. Your nurse, pharmacist or doctor will discuss your treatment plan with you

If you have follicular lymphoma, you might continue to have obinutuzumab on its own after you have finished chemotherapy. This is called maintenance therapy. This can continue for up to 2 years.

About 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 have not 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.

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.

Side effects while treatment is being given

Some people may have side effects while they are being given the treatment or shortly after they have it:

Allergic reaction

Some people have a reaction to obinutuzumab. This is more common the first time it is given. You will be given drugs to help reduce the chance of getting a reaction.

Your nurse will check you for signs of a reaction during your infusion. Tell the nurse straight away if you start to feel sick or have any signs of a reaction. They can slow down the infusion and give you drugs to treat it. 

Signs of a reaction can include: 

  • feeling hot or flushed
  • a skin rash
  • itching
  • shivering
  • feeling dizzy
  • a headache
  • feeling breathless 
  • swelling of your face or mouth
  • pain in your back, tummy, or chest

Sometimes a reaction can happen a few hours after treatment. If you get any signs or feel unwell after you get home, contact the hospital straight away.

Blood pressure

Some people's blood pressure falls while they are having obinutuzumab. If you usually take medicine to lower your blood pressure, your doctor may ask you not to take it for 12 hours before having obinutuzumab. Sometimes, obinutuzumab can make your blood pressure go up. Your nurse will check your blood pressure regularly.

Common side effects

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 shivery
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine often.

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 if you have any bruising or bleeding that you cannot explain. This includes:

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

Some people may need a drip to give them extra platelets. This is called a platelet transfusion.

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 red blood cells. This is called a blood transfusion.

Feeling sick

You may feel sick in the first few days after this treatment. Your doctor will give you anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluids and eat small amounts often. If you continue to feel sick, or if you vomit more than once in 24-hours, contact the hospital as soon as possible. They will give you advice and may change the anti-sickness drug to one that works better for you.

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.

Diarrhoea

This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.

If you have diarrhoea:

  • try to drink at least 2 litres (3½ pints) of fluids each day
  • avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods
  • contact the hospital for advice.

Hair loss

Your hair may get thinner but you are unlikely to lose all the hair from your head. Hair loss usually starts after your first or second treatment. It is almost always temporary and your hair will usually grow back after treatment ends. Your nurse can talk to you about ways to cope with hair loss.

Skin changes

Obinutuzumab may affect your skin and cause itching and eczema. Tell your doctor or nurse about any skin changes. They can give you advice and prescribe creams if needed. Any changes to your skin are usually temporary and improve when treatment finishes.

Nose irritation

This treatment may cause a blocked or runny nose. Tell your doctor or nurse if this happens. There may be medicines that may help.

Muscle, joint or back pain

You may get pain in your muscles, joints or back. If this happens, tell your doctor so they can give you painkillers. Tell them if the pain does not get better.

Headaches

This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.

Difficulty sleeping and mood changes

This treatment may cause difficulty sleeping. Some people may have depression or anxiety. If you notice these changes or any other changes to your mood, talk to your doctor or nurse.

Effects on the lungs

This treatment can cause changes to the lungs. Tell your doctor if you develop:

  • a cough
  • wheezing
  • a fever (high temperature)
  • breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

High blood pressure

Obinutuzumab may cause an increase in blood pressure during treatment. Your nurse will check it regularly.

Effects on the heart

This treatment can affect the way the heart works. You may notice your heart is beating too fast or is irregular. Tell your doctor if you notice this.

You may have tests to see how well your heart is working. These may be done before, during, and sometimes after treatment.

Contact a doctor straight away if you:

  • have pain or tightness in your chest
  • feel breathless or dizzy
  • feel your heart is beating too fast or too slowly.

Other conditions can cause these symptoms, but it is important to get them checked by a doctor.

Less common side effects

Effects on the nervous system

Rarely, this treatment can affect the nervous system. It can cause a condition called PML (progressive multifocal leukoencephalopathy). Symptoms include:

  • difficulty speaking
  • difficulty walking
  • memory loss
  • confusion
  • changes in your eyesight.

Contact the hospital straight away if you have any of these symptoms. Or if someone with you notices you have these symptoms.

It is important not to drive or operate machinery if you notice these effects.

Hepatitis B reactivation

If you have had a liver infection in the past called hepatitis B, obinutuzumab can sometimes make it active again. Your doctor or nurse will talk to you about this and test you for hepatitis B. You may be given treatment to reduce the risk of this happening.

Raised levels of uric acid (tumour lysis syndrome)

This drug may cause the cancer cells to break down quickly. This releases uric acid (a waste product) into the blood. The kidneys usually get rid of uric acid but may not be able to cope with large amounts. Too much uric acid can cause swelling and pain in the joints, which is called gout.

Your doctor may give you tablets called allopurinol to help prevent this. Drinking at least 2 litres (3½ pints) of fluid a day will also help. You will have regular blood tests to check the uric acid levels.

Second cancer

Obinutuzumab can increase the risk of developing types of skin cancer called squamous cell carcinoma and basal cell carcinoma. But the benefits of treatment usually far outweigh this risk. Your doctor can talk to you about this.

Other information

Other medicines

Some medicines can affect how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:

  • medicines you have been prescribed
  • medicines you buy in a shop or chemist
  • vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.

Vaccinations

Your doctor or nurse may talk to you about vaccinations. These help reduce your risk of getting infections.

Doctors usually recommend that you have a flu jab, which is an inactivated vaccination. People with weak immune systems can have this type of vaccination.

If your immune system is weak, you need to avoid live vaccinations such as shingles. Your cancer doctor or GP can tell you more about live vaccinations.

Contraception

Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.

Breastfeeding

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

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

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 cancer treatment.

How we can help

How to print a PDF from this website
Instructions on how you can make a PDF version of this page using the print function on your browser.
Macmillan Grants

If you have cancer, you may be able to get a Macmillan Grant to help with the extra costs of cancer. Find out who can apply and how to access our grants.

0808 808 00 00
7 days a week, 8am - 8pm
Email us
Get in touch via this form
Chat online
7 days a week, 8am - 8pm
Online Community
An anonymous network of people affected by cancer which is free to join. Share experiences, ask questions and talk to people who understand.
Help in your area
What's going on near you? Find out about support groups, where to get information and how to get involved with Macmillan where you live.