What is immunotherapy?

The immune system protects the body against illness and infection. Immunotherapies are treatments that use the immune system to recognise and kill cancer cells.

Your doctor may suggest having immunotherapy after surgery. They will only suggest it if the surgeon was able to remove the melanoma, and if the melanoma has only spread to the nearby area or lymph nodes.

This is to help reduce the risk of the melanoma coming back. This is called adjuvant treatment.

If the melanoma cannot be removed, your doctor may suggest immunotherapy treatment to help slow the growth and help you live longer.

There are different types of immunotherapy that work in different ways. They are sometimes known as checkpoint inhibitors. The main drugs used are:

  • Ipilimumab
  • Nivolumab and pembrolizumab
  • T-VEC


Ipilimumab (Yervoy®) works by attaching itself to normal T-cells. T-cells are part of the immune system. They fight infection and diseases.

In some people, T-cells can recognise and destroy melanoma cells. But a protein on the T-cells stops this happening. Ipilimumab blocks this protein, so the T-cells can destroy melanoma cells. It can help shrink or slow the growth of advanced melanoma.

You have ipilimumab as an infusion (drip) into a vein.

Nivolumab and pembrolizumab

Pembrolizumab (Keytruda ®) and Nivolumab (OPDIVO®) both target a protein called a PD-1 receptor, which switches off T-cells. T-cells are part of the immune system. They fight infection and disease. The drugs attach to the receptor, so the T-cells cannot be switched off. This keeps the T-cells active. It may help shrink a tumour or stop it growing.

Both drugs are given as a drip (infusion) into a vein.

Nivolumab may be given together with ipilimumab.


T-VEC (Imlygic®) is a newer immunotherapy drug sometimes used to treat melanoma. It may be used if the melanoma has spread to the skin or the lymph nodes further away. But it is not suitable if the melanoma has spread to areas such as the bones or the brain.

T-VEC is given by injection directly into the melanoma. Some common side effects include:

Important side effects of immunotherapy

Nivolumab, pembrolizumab and ipilimumab can cause inflammation in many different parts of the body. This can include the bowel, liver, kidneys, skin and eyes. They can also affect the endocrine system (which makes hormones), the heart, the lungs and the nervous system.

This can sometimes cause more serious side effects, including:

  • diarrhoea that does not get better
  • changes in the way the liver works
  • skin rashes and blisters
  • blurred or double vision
  • feeling very tired.

If you notice these side effects, or any new side effects we have not listed, it is important to tell your doctor or specialist nurse straight away. They will usually give you steroid drugs to help reduce the inflammation. If your side effects are severe, they may recommend delaying the treatment or sometimes stopping it.

Clinical trials

There may be clinical trials looking at new immunotherapy or targeted therapy drugs to treat melanoma. Some of these trials test different combinations of drugs. This is to see whether the combination works better than one drug given alone.

Research is also looking at cancer vaccines. If there are clinical trials testing these or other drugs, your team will give you more information about them.