Also known as durvalumab

Key points about Imfinzi

  • Imfinzi is a medicine used to treat certain cancers.
  • Find out how it's given and possible side effects.
blue unaunahi tile generic
Print this page

Imfinzi is a medicine that's used to treat certain cancers by working with your body's immune system to detect and destroy cancer cells (called immunotherapy). Imfinzi belongs to a group of medicines called immune checkpoint inhibitors. Read more about immune checkpoint inhibitors and how they work.

In Aotearoa New Zealand, Imfinzi is funded for the treatment of locally advanced non-small cell lung cancer (NSCLC) for people who meet the eligibility criteria.

Imfinzi is given by a drip into your vein (called an intravenous infusion or ‘IV’) over about 1 hour, every 2, 3 or 4 weeks. Your doctor will work out your dose and schedule.

During the infusion

Most people have few side effects during the infusion. Very rarely, Imfinzi can cause a reaction while it's being given or up to one day after the infusion. You may experience fever, chills, flushing, dizziness, back or neck pain or have trouble breathing. Tell the nurse immediately if any of these occur. This reaction is usually mild and sometimes it can be controlled by giving Imfinzi more slowly.

Before starting Imfinzi, tell your doctor about any other medicines you are taking including prescription, over-the-counter, vitamins, or herbal remedies.

Tell your doctor if you're pregnant (hapū) or may be pregnant before starting Imfinzi. Imfinzi isn't recommended for use during pregnancy, so you should avoid becoming pregnant while you are on it. Use effective birth control during treatment and for at least 3 months after your final dose of Imfinzi. Ask your doctor when you may safely become pregnant after therapy.

Tell your doctor if you're breastfeeding or plan to breastfeed. It's not advisable to breastfeed during treatment with Imfinzi and for 3 months after your final dose.

Here are some things to know when you're taking Imfinzi. Other things may be important as well, so ask your healthcare provider what you should know about.


  • Since Imfinzi affects your immune system, you're at increased risk of infection. It's strongly advised that you're up-to-date with the annual flu vaccination and the Covid-19 vaccinations. These are non-live vaccines and are safe to have while you're receiving immune checkpoint inhibitor treatment.
  • Live vaccines such as MMR (measles, mumps and rubella) and varicella (chickenpox vaccine) should NOT be given while you are receiving immune checkpoint inhibitor treatment and for 6 months after treatment has stopped.

Treatment delays

There may be times when your treatment is delayed. This can happen:

  • if your doctor thinks you may have severe side effects
  • if you get severe side effects
  • if your blood counts are affected
  • if you're finding it hard to cope with the treatment.

Your doctor will tell you if you need any delays to your treatment and the reason why.

Like all medicines, Imfinzi can cause side effects, although not everyone gets them. Because Imfinzi affects the immune system, it may cause immune cells to attack healthy cells, triggering a variety of side effects.

You may experience side effects at any time during your treatment or even months after treatment has finished. Some side effects go away within a few days or weeks and some may be longer lasting. 

Note: To monitor your side effects, you will need regular reviews and blood tests. These will be done to check your thyroid, liver, kidneys and blood before you start treatment and while you are receiving treatment. 

Common side effects

Report any side effects to your healthcare provider straight away even if they appear mild. Don't try to manage these side effects on your own:

  • feeling very tired and weak (fatigue)
  • feeling sick (nausea)
  • runny poo (diarrhoea)
  • decreased appetite
  • cough
  • fever
  • rash.

Rare, serious side effects

For some people, these side effects could be life threatening. If you have any of the side effects mentioned below OR any new or worsening symptoms, contact your healthcare team or Healthline on 0800 611 116 straight away:

  • Dark urine, and pale poo with yellowing of the eyes or skin (signs of inflamed liver).
  • New or worsening cough, shortness of breath, and chest pain (possible signs of an inflamed lung or heart).
  • Weight loss, weight gain, changes in mood, changes in eyesight and vision, increased sensitivity to cold or heat, slow or rapid heart rate, hair loss (possible signs of thyroid problems).
  • Blood in your poo, severe pain in your tummy or back (possible signs of an inflamed gut or pancreas).
  • Neck stiffness, headache, vomiting, eye sensitivity to light, confusion and sleepiness (signs of inflammation of the brain or spinal cord). 
  • Muscle weakness, numbness or tingling in hands and feet (signs of problems with your nerves).
  • Swelling or burning feeling on your skin, ulcers in your mouth or lips, genital or anal areas, purple spots on the skin, blisters or peeling (signs of a severe skin reaction).

Note: This is not a full list of side effects and side effects can vary in different people. If you are unsure whether your symptoms are side effects, contact your healthcare team straight away.

Free helplines

Healthline logo

Text 1737 Helpline logo

Logo with link to Māori Pharmacists website

Credits: Healthify He Puna Waiora editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist; Joanna Buchanan, Oncology Pharmacist

Last reviewed: