Targeted therapies and immunotherapies for bowel cancer

Targeted therapies are sometimes used to treat bowel cancers that have spread to other parts of the body (secondary bowel cancer). Immunotherapy drugs are only available as part of a clinical trial.

Targeted therapies for bowel cancer

Targeted therapy drugs target something in or around a cancer cell that is helping it grow and survive.

Targeted therapies are sometimes used to treat colorectal cancer (colon or rectal cancer) that has spread to other parts of the body. They may be given on their own or with chemotherapy.

Your doctor will tell you if they think a targeted therapy will be helpful in your situation. These drugs are not always available through the NHS. If a drug is not available on the NHS, there may be different ways you can still have it. Your doctor can give you advice. They may be able to apply for funding to get the treatment on the NHS.

We have more information about targeted therapy drugs and what you can do if a treatment is not available.

Cetuximab and panitumumab

Cetuximab (Erbitux®) and panitumumab (Vectibix®) are a type of targeted therapy drug called monoclonal antibodies. They are also called cancer growth inhibitors.

Some cancers have receptors on their surface called epidermal growth factor receptors (EGFRs). A protein called epidermal growth factor activates the receptors, causing the cancer cells to grow. Cetuximab and panitumumab lock onto the EGFRs and block signals that tell the cancer cells to grow and divide.

Before cetuximab or panitumumab are used, doctors test the cancer cells for cell changes (mutations) in the RAS and BRAF gene. This helps your doctor decide if cetuximab or panitumumab is appropriate for you.

Not all bowel cancers respond to cetuximab and panitumumab. They only work on bowel cancers that have a normal RAS gene and no changes to the BRAF gene. Cetuximab and panitumumab are given into a vein as an infusion (intravenously). You often have them with chemotherapy.

Other targeted therapy drugs

Other targeted therapy drugs that may be used include:

These are all a type of targeted therapy called angiogenesis inhibitors.

These block the chemical signals that cells use to make blood vessels grow. This makes it difficult for a tumour to develop the network of blood vessels it needs to get a blood supply. Without a good blood supply, the tumour does not get the oxygen and nutrients it needs. This may slow the tumour’s growth, or sometimes cause it to shrink.

Bevacizumab, aflibercept and ramucirumab are given into a vein as an infusion (intravenously). Regorafenib is taken as tablets.

Side effects

Some targeted therapies can cause an allergic reaction. This may happen when the drug is being given or shortly after.

Signs of an allergic reaction can include:

  • flu symptoms
  • a sudden drop in blood pressure
  • feeling sick.

An allergic reaction is most common with the first two of doses of the drug, but can happen later. To reduce this risk, you will have the first dose over a few hours. Your nurse will closely monitor you during the infusion.

Your doctor or nurse should tell you about possible side effects before you start treatment. They will also tell you who you should contact if you develop any.

The most common side effect of cetuximab and panitumumab is a skin rash. Other possible effects include diarrhoea, hair changes and sore eyes.

The most common side effect of bevacizumab, aflibercept, ramucirumab and regorafenib is high blood pressure. There is also a small risk they may cause a hole (perforation) in the bowel.

If you have any side effects during cancer treatment, you should always tell your cancer doctor or specialist nurse.

Immunotherapy for bowel cancer

Immunotherapy drugs encourage the immune system to recognise and help destroy cancer cells. Immunotherapy drugs for bowel cancer are not regularly used by, or available on, the NHS. They are only available as part of a clinical trial.

Talk to your cancer doctor or specialist nurse for more information about immunotherapy.

Your cancer doctor may consider immunotherapy if both of these things apply:

Your cancer doctor will talk with you if immunotherapy may be option for you.

About our information

  • Reviewers

    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. It has been approved by Chief Medical Editor, Professor Tim Iveson, Consultant Medical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.