Targeted and immunotherapy drugs for advanced bowel cancer

You might have targeted or immunotherapy drugs as part of your treatment for advanced bowel cancer. 

Advanced bowel cancer is cancer: 

  • that started in either the back passage (rectum) or large bowel (colon), and
  • has spread to another part of the body

What are targeted and immunotherapy drugs for advanced bowel cancer?

Targeted cancer drugs work by targeting the differences in cancer cells that help them to grow and survive. Other drugs help the immune system attack cancer. They are called immunotherapies.

Some drugs work in more than one way. So they are targeted as well as working with the immune system.

When do you have targeted and immunotherapy drugs for advanced bowel cancer?

The aim of these treatments for advanced bowel cancer is to shrink the cancer or slow its growth. Unfortunately, they can't usually cure the cancer.

Whether you have targeted therapy or immunotherapy depends on:

  • the type of cancer you have
  • how far the cancer has grown (the stage)
  • other treatments you've already had

Tests on your bowel cancer cells

You might need to have a test using some of your cancer cells to find out whether the treatment is likely to work. These tests look for changes (mutations) in certain proteins or genes.

Your doctor usually tests a sample of your bowel cancer tissue from when you were first diagnosed. Or they may use a sample from your operation if you had one. The results will show whether a drug is suitable for you.

Your doctor can tell you if this applies to your treatment. This is not the case for all targeted and immunotherapy drugs, and you don’t always need this test.

Targeted drugs for advanced bowel cancer

Cetuximab (Erbitux), panitumumab (Vectibix) and bevacizumab (Avastin)

Cetuximab, panitumumab and bevacizumab are types of monoclonal antibodies. Monoclonal antibodies work by recognising and finding specific proteins on cancer cells. Different types of cancer have different proteins.  Monoclonal antibodies stop particular proteins from binding to cancer cells. Or they block the proteins from triggering the cancer cells to divide and grow.

Diagram showing a monoclonal antibody attached to a cancer cell

Cetuximab (Erbitux) and panitumumab (Vectibix) work by blocking proteins on cancer cells. These proteins are called epidermal growth factor receptors (EGFR).

A cancer needs a good blood supply to survive and grow. Bevacizumab (Avastin) stops the growth of blood vessels by cancer cells. Drugs that interfere with this blood supply are called anti angiogenesis drugs.

You might have these drugs during or after chemotherapy.

Aflibercept​ (Zaltrap)

Aflibercept (Zaltrap) is also an anti angiogenesis drug. So it stops the growth of blood vessels by the cancer cells.  

Regorafenib (Stivarga) and encorafenib (Braftovi)

Regorafenib and encorafenib are cancer growth blockers. They work by blocking particular proteins on cancer cells that help cancer to grow. Regorafenib also stops cancer from growing blood vessels.

Immunotherapy for advanced bowel cancer

Pembrolizumab (Keytruda)

Pembrolizumab is a type of immunotherapy. It stimulates the body's immune system to fight cancer cells.

Pembrolizumab targets and blocks a protein called PD-1 on the surface of certain immune cells. These immune cells are called T-cells. Blocking PD-1 triggers the T-cells to find and kill cancer cells.

Are these drugs available in the UK?

New cancer drugs are licensed for use in a particular way.  For example, a drug might have a license to treat a particular stage or type of cancer.

Once a drug has a license, several independent organisations approve the new cancer drugs. Only then can doctors prescribe them on the NHS.

Cetuximab and panitumumab

Cetuximab and panitumumab are available on the NHS for advanced bowel cancer. You can have either of these drugs as your first treatment, in combination with chemotherapy.

You can have cetuximab and panitumumab if your bowel cancer cells have a normal RAS gene. This is also called a RAS wild type gene.

Bevacizumab​ and regorafenib

These drugs have been licensed to treat advanced bowel cancer. But they have not been approved by the:

  • National Institute for Health and Care Excellence (NICE)
  • the Scottish Medicines Consortium (SMC)

So they are not routinely available as treatments on the NHS in the UK.


Aflibercept has been licensed to treat advanced bowel cancer. But it has not been approved by NICE. So it isn’t routinely available on the NHS in England, Wales or Northern Ireland.

Aflibercept is available in Scotland. The SMC has recommended aflibercept for advanced bowel cancer:

  • together with irinotecan and 5FU chemotherapy (FOLIFIRI)
  • as your second treatment for advanced bowel cancer. This is in situations where your first treatment, which included oxaliplatin chemotherapy, is no longer working

Encorafenib and cetuximab

Encorafenib and cetuximab are approved as a treatment in the UK if:

  • your bowel cancer has a BRAF V600E mutation, and
  • you have already had a treatment that reaches the whole body (systemic treatment), such as chemotherapy

Pembrolizumab (Keytruda)

Pembrolizumab is available in the UK as a treatment on the NHS for advanced bowel cancer. It is for people who have not had any treatment. And it is only for people whose cancer has gene changes that mean it is called:

  • mismatch repair deficient Open a glossary item (MMRd)
  • high microsatellite instability Open a glossary item (MSI high)

You can have this drug for up to 2 years if there are no signs of your cancer growing.

Having targeted and immunotherapy drugs for advanced bowel cancer

You have your treatment as tablets or capsules, or through a tube into your bloodstream. This depends on the type of drug you have.

Tablets or capsules

You must take tablets and capsules according to the instructions your doctor or pharmacist gives you.

You should take the right dose, not more or less.

Talk to your specialist or advice line before you stop taking a cancer drug.

Into the bloodstream

You have some of these drugs through a tube into your bloodstream. A nurse puts a small tube into a vein in your hand or arm and connects the drip to it.

Or you might have a central line. This is a long plastic tube that gives the drug into a large vein, either in your chest or through a vein in your arm. It stays in while you’re having treatment.

Side effects

Targeted therapy drugs and immunotherapy drugs can cause different side effects. Some of these can be serious.

Your doctor or nurse will talk to you about this. Always tell them about any side effects you have and follow the advice they give you.

Choose a drug on our A to Z list to read about side effects and find out more about the drug. 

Research into bowel cancer

Researchers are looking at:

  • new targeted and immunotherapy drugs
  • different combinations of these drugs with other treatments

Related links