A cancer immunotherapy (anti-CTLA-4)
Ipilimumab
A cancer immunotherapy given as a drip that strongly helps the immune system attack cancer, often combined with nivolumab.
What is Ipilimumab?
Ipilimumab (Yervoy) is a cancer immunotherapy given as a drip into a vein by an oncology team. It works by taking the 'brakes' off your immune system, blocking a protein called CTLA-4, so your own immune cells can attack cancer. It is often combined with nivolumab. Importantly, ipilimumab — especially in combination — causes more frequent and more severe immune-related side effects than the PD-1 and PD-L1 immunotherapies on their own. The immune system can attack healthy organs such as the bowel, liver, lungs, skin and hormone glands, and these reactions can be serious. Report new symptoms promptly, have blood tests before each cycle, and carry an alert card.
Education and reference only. This is a plain-language guide to Ipilimumab — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Ipilimumab is a type of cancer immunotherapy known as an immune checkpoint inhibitor. It is a man-made antibody that blocks a protein called CTLA-4, which acts as an early 'brake' on the immune system. It is used by oncology specialists to treat certain cancers, and it is frequently given together with nivolumab to produce a stronger immune effect. It is given slowly into a vein as an infusion (a drip), usually as a course of cycles in a hospital or chemotherapy day unit.
How it works
Ipilimumab blocks CTLA-4, a 'brake' that normally holds back immune cells early on. Releasing this brake helps your immune cells (T-cells) become active against the cancer. Because it acts on an early and powerful checkpoint, and because it is often combined with nivolumab, the immune system can become very active — which is effective against some cancers but also more likely to attack healthy organs. This is why ipilimumab, particularly in combination, causes more frequent and stronger immune-related side effects than the PD-1 and PD-L1 medicines used on their own.
Company & origin
Originated / developed by: Bristol Myers Squibb.
A modern cancer immunotherapy given by specialist oncology teams in the UK as a drip, often combined with another immunotherapy.
Practical use
How to take Ipilimumab
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by your oncology team as a drip into a vein; you do not take it yourself at home.
- It is often combined with nivolumab, so be especially watchful for new symptoms, as immune reactions are more common and stronger with the combination.
- You will have blood tests before each cycle to check your organs and hormone levels.
- Report any new or worsening symptoms promptly — diarrhoea, breathlessness, cough, severe tiredness, yellowing skin or unusual thirst — even between appointments or after treatment ends, and do not wait to see if they pass.
- Carry the alert card you are given at all times and show it to any healthcare professional you see.
Weighing it up
Advantages & disadvantages of Ipilimumab
Advantages
- Can produce long-lasting responses in some cancers by strongly activating the immune system.
- Combined with nivolumab, it can work where single immunotherapy might not.
- Given as a planned drip in cycles, with intensive specialist monitoring.
Disadvantages
- Causes more frequent and more severe immune-related side effects than PD-1 or PD-L1 medicines alone, especially in combination.
- Bowel and other organ reactions can be serious and need prompt steroid treatment.
- These reactions can appear weeks or months after treatment stops, and it does not work for everyone.
Practical use
Good to know
The most important thing to understand is that ipilimumab can cause immune-related side effects, and these tend to be more frequent and more severe than with the other checkpoint inhibitors, especially when it is combined with nivolumab. The freed-up immune system can attack almost any part of the body: the bowel (diarrhoea or colitis, which can be serious), the liver (hepatitis), the lungs (pneumonitis, with cough or breathlessness), the skin (rash or itching) and the hormone glands such as the thyroid, pituitary and adrenal glands, and it can sometimes cause diabetes. These reactions can begin during treatment or weeks to months after it finishes. The key message is to report new symptoms promptly — new or worsening diarrhoea, breathlessness, a new cough, severe tiredness, yellowing of the skin or eyes, or unusual thirst — because early treatment, often with steroids, is very important. You will have blood tests (including thyroid and liver checks) before each cycle, and you should carry the alert card you are given.
Who should not take it / use with caution
- People with certain active autoimmune conditions may not be suitable, as this strong immunotherapy can worsen them; your team will weigh this up carefully.
- Those who have had a serious immune reaction to this type of medicine before may be advised against further treatment.
- It is used with great caution, and only after specialist assessment, in people who have had an organ transplant.
Monitoring
- Blood tests before each cycle, including liver function and thyroid and other hormone checks.
- Particularly close monitoring for immune-related reactions, especially in combination with nivolumab.
- Scans to assess how the cancer is responding to treatment.
Side effects
- Immune-related effects are more common and more severe than with other checkpoint inhibitors and can affect the bowel (diarrhoea, colitis), liver (hepatitis), lungs (pneumonitis), skin (rash) and hormone glands (thyroid, pituitary, adrenal, and sometimes diabetes).
- More general effects include tiredness, reduced appetite, nausea, joint or muscle aches and a reaction around the time of the drip.
- Rarely, serious reactions affecting the heart, nervous system, kidneys or eyes can occur and need urgent medical attention.
Key interactions
- Tell your team about all medicines, as long-term steroids or medicines that dampen the immune system may affect how it works.
- It is frequently combined with nivolumab on purpose, but only under close specialist guidance because reactions are stronger.
- Some herbal remedies and supplements that affect the immune system should be discussed with your team before use.
Available as: Given as an infusion (a drip) into a vein by an oncology team.
Answers
Ipilimumab: frequently asked questions
How is ipilimumab different from the other immunotherapies?
It blocks a different and earlier 'brake' on the immune system (CTLA-4) and is often combined with nivolumab. This makes it more effective for some cancers but also more likely to cause frequent and severe immune-related side effects.
Why does it cause more side effects?
Because it releases a powerful early immune brake, often alongside another immunotherapy, the immune system becomes very active and is more likely to attack healthy organs. This is why monitoring is especially close.
What symptoms should I report straight away?
Tell your team promptly about new or worsening diarrhoea, breathlessness, a new cough, severe tiredness, yellowing of the skin or eyes, or unusual thirst — early treatment, often with steroids, is very important.
Can side effects happen after treatment ends?
Yes. Immune-related reactions can appear weeks or even months after your last drip, so stay alert and report new symptoms even after treatment finishes.
Why do I need so many blood tests?
Blood tests before each cycle check your liver, thyroid and other hormone glands so any immune-related effect can be caught and treated early, which matters even more with this medicine.
Authoritative sources
- BNF
- NICE CKS
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