Durvalumab (Imfinzi)

Durvalumab is a type of immunotherapy. It may also be called an immune checkpoint inhibitor Open a glossary item. Durvalumab is also known by its brand name, Imfinzi.

You pronounce durvalumab as dur-val-yoo-mab.

It is treatment for non small cell lung cancer (NSCLC). You might also have durvalumab as part of a clinical trial for another type of cancer.

How does durvalumab work?

Durvalumab stimulates the body's immune system Open a glossary item to fight cancer cells.

Durvalumab seeks out cancer cells by looking for the PD-L1 protein and attaching to it. The immune system then recognises the marked cells and kills them.

How do you have durvalumab?

You have durvalumab 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 durvalumab?

You have durvalumab as cycles of treatment. This means that you have the drug and then a rest to allow your body to recover. Each cycle of treatment lasts either 14 days (2 weeks) or 28 days (4 weeks).

You have durvalumab over around an hour each time.

You have durvalumab for up to a year as long as it is working and the side effects are not too bad.


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.

What are the side effects of durvalumab?

We haven't listed all the side effects. It is very unlikely that you will have all of these side effects, but you might have some of them at the same time.

How often and how severe the side effects are can vary from person to person.

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 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 doctor or nurse immediately if you have signs of infection, including a temperature above 37.5C or below 36C.

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:

Lung problems

You might develop a cough or breathing problems. This could be due to:

  • infection - such as pneumonia
  • inflammation of the lungs (pneumonitis)
  • scarring of the lungs (interstitial lung disease) - this is rare

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

Infections of the sinus’ and throat (upper respiratory tract infections)

You might have an infection of your upper airways or throat. You might:

  • be sneezing
  • have a stuffy or runny nose
  • have a sore throat
  • have a croaky voice

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.

Changes to thyroid hormone levels

You will have regular blood tests to check your thyroid hormone levels. The levels may go up or down. You might see them go up before they go down.

Symptoms of dropping thyroid levels (hypothyroidism) include feeling tired or cold, gaining weight, feeling sad or depressed, or your voice may deepen.


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

Tell your treatment team if you have this. They can check the cause and give you medicine to help. 

Skin rash

You might develop a skin rash on your face and body. It may appear like blisters on the skin. It may be itchy but not always. 

If you notice a rash on your skin let your doctor know straight away.

Itchy skin

Your skin might feel itchy after having this drug. Let your doctor or nurse know if you have this.

Joint stiffness

Your joints might feel stiff. Let your healthcare team know if you have this.

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:

  • tooth or mouth infections including thrush (this looks like white patches in your mouth)
  • the flu (influenza), symptoms include a sudden fever, feeling achy and very tired
  • night sweats
  • muscle pain
  • hoarse voice
  • changes to how your liver works - you have regular blood tests to check this
  • changes to how your kidneys work - you have regular blood tests to check this
  • swelling of your hands or lower legs
  • finding it difficult or painful to wee
  • a reaction to durvulumab that happens on the day of the infusion or the day after – this might include a red, itchy rash (hives)

Rare side effects

These side effects happen in fewer than 1 in 100 people (fewer than 1%). You might have one or more of them. They include:

  • severe muscle weakness
  • high levels of glucose in your body (diabetes) – you might have regular blood sugar tests
  • damage to the adrenal gland which can cause a drop in the level of certain hormones such as cortisol
  • inflammation of the liver (hepatitis), bowel, pancreas, kidneys or heart muscle
  • inflammation or problems with hormone production in the brain
  • psoriasis - flaky patches of skin which form scales
  • bladder irritation
  • infection of the tissues covering the brain and spinal cord (meningitis) - symptoms might include fever, headaches, neck pain or stiffness, feeling or being sick or sensitivity to light
  • bruising or bleeding because there are fewer platelets in the blood than usual – this can be life threatening

Other side effects

There isn't enough information to work out how often these side effects might happen. You might have one or more of them. They include:

  • inflammation of the brain
  • inflammation of the spinal cord – this can be life threatening
  • the immune system attacking the nervous system (Guillain-Barre syndrome) - causing numbness, weakness and pain in the body

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 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. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Pregnancy and contraception

Durvalumab may harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you are having treatment with this drug and for at least 3 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner falls pregnant while having treatment.


It is not known whether this drug comes through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment.

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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