What is immunotherapy?

The immune system protects the body against illness and infection. Cancer immunotherapies are treatments that use the immune system to find and attack cancer cells.

There are different types of immunotherapy, including:

Each type of immunotherapy uses the immune system in a different way. Some are given in combination with other cancer drugs, such as chemotherapy. This is called chemoimmunotherapy.

This page has general information about cancer immunotherapy. You can search for information about a specific immunotherapy drug or combination of drugs using our cancer treatments and drugs A to Z.

You can also learn more in our cancer drug treatments information. This includes how treatment is planned, and what to expect before and during a cancer drug treatment.

Your course of immunotherapy treatment

Your cancer team will talk to you about the treatment you need and the possible side effects before you agree (consent) to have treatment.

How often you have immunotherapy, how it is given and how long your course of treatment lasts depends on:

  • the type of cancer
  • the type of immunotherapy you are having
  • how the cancer responds to the treatment
  • any side effects you have.

Treatment cycles

Cancer drugs are often given as several sessions of treatment, with a rest period in between each session. The rest period allows your body to recover from the side effects. Many immunotherapies are given in this way.

The treatment session and the rest period make up 1 cycle of your treatment. Your cancer team can explain the number of cycles you may need.

How is immunotherapy given?

Many immunotherapy drugs are given as:

  • a drip into a vein (intravenous)
  • an injection under the skin (subcutaneous).

But others may be given in the following ways:

Immunotherapy given into a vein or as an injection

If you are having an immunotherapy drug given into a vein or under the skin, you usually have this at a day unit or clinic as an outpatient.

You may have immunotherapy into a vein through:

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

The nurse will explain how long your immunotherapy treatment will take. For drugs into a vein, they usually use a pump to give you a controlled amount of treatment over a fixed time. This can be from 10 minutes to several hours, depending on the drug.

Side effects of immunotherapy

Different types of immunotherapy can cause different side effects. Your cancer team will give you information about possible side effects before you start treatment. You may get some of the side effects they mention, but you are unlikely to get all of them.

Your cancer team can give you:

  • drugs to help control some side effects
  • advice about managing your side effects.

It is important to take any drugs exactly as explained. This means they will be more likely to work for you.

Contacting the hospital

Your cancer team will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Sometimes side effects can become serious very quickly. Always contact the hospital straight away for advice.

Your patient alert card

For some immunotherapy drugs, your cancer team will give you a card with information about your treatment. It is important to keep the card with you during treatment and after treatment ends. You should show it to any doctor or healthcare professional caring for you.

More information about side effects

If you need information about a specific immunotherapy, you can check our cancer treatments and drugs A to Z. We have detailed information about many types of cancer drugs and their possible side effects.

You can also talk to your cancer team if you want more detailed information about a treatment. Or visit the electronic medicines compendium (emc) website, which has patient information leaflets (PILs) for individual drugs.

Other useful resources

If you want to explore more information about checkpoint inhibitor treatment and side effects, these resources may help:

  • visit our cancer treatment forum – our Online Community is a place to talk with others having treatment, share your experience, and ask a cancer expert your questions.
  • listen to The Immunobuddies podcast - founded and co-hosted by Medical Oncologist, Dr Ricky Frazer, episodes 56 to 61 answers questions on immunotherapy from a patient perspective.

Immune system side effects

Immunotherapy makes the immune system more active. That means it is better at finding and attacking cancer cells. For checkpoint inhibitor immunotherapy drugs, this can also cause unwanted effects. These are called immune system side effects or immune-related side effects.

Immune system side effects are different from the side effects of other cancer treatments, such as chemotherapy or radiotherapy. They are caused by the immune system attacking normal cells in the body as well as the cancer cells.

Immune system side effects may:

  • be mild to start with
  • quickly become serious unless treated
  • start during treatment
  • start weeks, months or sometimes more than a year after you finish treatment.

Some immune system side effects are rare. But it is important to know about them and to get advice if you have any side effects during treatment or after treatment ends.

If you have any of the following symptoms or side effects, contact the hospital straight away on the 24-hour number. Do not try to treat this type of side effect yourself.

Immune system side effects can affect any part of the body. We have shared examples for the following side effects. But your cancer team will explain your treatment and any important side effects that you should know about.

  • Skin, rashes and itching

    Checkpoint inhibitors may cause inflammation in the skin. This is usually mild but can become serious without treatment. Symptoms may include:

    • a rash or bumps on the skin
    • dry skin and itching
    • patches of white or paler skin.

    You may need to take extra care of your skin. Or you may need creams, steroids or other medicines to manage any changes. To protect your skin from the sun, use a suncream with a high sun protection factor (SPF) of at least 30. Cover up with clothing.

    Contact the hospital straight away on the 24-hour number if you have any of these symptoms:

    • a rash that is spreading
    • blistering or peeling skin
    • flu-like symptoms, such as a high temperature and joint pain.

    These symptoms can be a sign of a serious skin reaction that needs to be treated immediately in hospital.

  • Bowels, tummy and diarrhoea

    Checkpoint inhibitors can cause diarrhoea or tummy (abdominal) pain. They can also cause inflammation of the bowel (colitis), which can be very serious.

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

    Contact the hospital straight away on the 24-hour number if you have any of the following symptoms during treatment or after treatment ends:

    • You have diarrhoea 4 or more times in a day.
    • You have a moderate increase in stoma activity.
    • You have uncomfortable tummy cramps.
    • You have diarrhoea at night.
    • Your temperature is over 37.5°C.
    • There is blood or mucus in your stool.

  • Lungs and breathing

    Checkpoint inhibitors can cause inflammation of the lungs. This is called pneumonitis. Contact the hospital straight away on the 24-hour number if you notice any of these changes during treatment or after treatment ends:

    • breathlessness
    • a cough that does not go away
    • wheezing
    • a fever, with a temperature over 37.5°C
    • an existing breathing problem gets worse.

  • Liver

    Checkpoint inhibitors can cause liver inflammation and may affect how your liver works. This is called hepatitis. You will have regular blood tests to check this.

    Sometimes liver changes can be serious. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during treatment or after treatment ends:

    • yellow skin or eyes
    • feeling very sleepy
    • dark urine (pee)
    • unexplained bleeding or bruising
    • pain in the right side of your tummy (abdomen)
    • loss of appetite.

  • Kidneys and passing urine

    Checkpoint inhibitors can cause kidney inflammation and may affect how the kidneys work. This is called nephritis. This is not common. But if it is not treated, it can become serious. You will have regular blood tests to check how well your kidneys are working.

    Contact the hospital straight away on the 24-hour number if you have any of these symptoms during treatment or after treatment ends:

    • blood in your urine (pee)
    • passing less urine or peeing less often than usual
    • feeling you need to pass urine often, or having discomfort when you pass urine.

  • Hormones and feeling tired

    Feeling tired is a common side effect of checkpoint inhibitor treatment. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can help you feel less tired.

    Sometimes tiredness is a sign that treatment is affecting glands that produce hormones. Hormones control many different processes in the body. You will have regular blood tests to check some of your hormone levels.

    Contact the hospital on the 24-hour number if you have any of these side effects during treatment or after treatment ends:

    • increased sweating
    • weight gain or weight loss
    • dizziness or fainting
    • feeling more hungry or thirsty than usual
    • loss of sex drive
    • passing urine (peeing) more often than usual
    • headaches that do not go away
    • feeling more tired than usual (fatigue)
    • mood changes.

  • Heart and chest

    Checkpoint inhibitors can affect how the heart works. This is not common, but it can be serious. You may have tests to check how well your heart is working. These may be done before, during and after treatment.

    Contact the hospital straight away on the 24-hour number if you have any of these symptoms during treatment or after treatment ends:

    • breathlessness
    • dizziness
    • changes to your heartbeat
    • swollen feet and ankles.

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

    Always call 999 if you have:

    • chest pain
    • pressure, heaviness, tightness or squeezing across the chest
    • difficulty breathing.

  • Muscles and joints

    Checkpoint inhibitors can cause sore or weak muscles. Or they can cause stiff, sore or swollen joints (arthritis). If you already have problems with joint pain, this may become worse.

    Contact the hospital on the 24-hour number if you have any of these symptoms during treatment or after treatment ends:

    • new or worsening aches or pains
    • new or worsening stiffness in a joint
    • swollen joints.

  • Head, brain and nerves

    Rarely, checkpoint inhibitor treatment can affect the brain and nerves. These effects may be mild at first. But they can become serious if they are not treated. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during treatment or after treatment ends:

    • any weakness, numbness or tingling in your arms, legs or face
    • a headache that does not get better
    • dizziness
    • drowsiness or confusion
    • problems with moving or speaking
    • any unexplained pain in other parts of your body.

Long-term and late effects of immunotherapy

Cancer treatments sometimes cause side effects that do not go away after cancer treatment. Or they may cause side effects that start months or years after treatment ends. These are called long-term or late effects.

Many immunotherapies are newer treatments, and their possible long-term effects are still being researched. The benefit of having the treatment usually outweighs the risk of developing serious long-term effects.

Your cancer doctor, nurse or pharmacist can explain what is known about your treatment. Always get advice from your cancer team about any new symptoms or side effects.

About our information

This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer.

Rajinder Nijjar

Reviewer

Lead Cancer Pharmacist

Date reviewed

Reviewed: 01 May 2024
|
Next review: 01 May 2026
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

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