Targeted (biological) therapies for colon cancer

Targeted therapies interfere with the way cancer cells grow. They are sometimes called biological therapies.

Targeted therapies are sometimes used to treat bowel cancers that have spread to other parts of the body. They may be given on their own or with chemotherapy.

Targeted therapies that may be used include:

All of these drugs are given into a vein as an infusion (intravenously) except for regorafenib, which is taken as tablets.

Cetuximab (Erbitux®) and panitumumab (Vectibix®) are both a type of targeted therapy called EFGR inhibitors. They stop cancer cells from getting messages that tell them to grow.

Not all bowel cancers respond to cetuximab or panitumumab. Your doctors will test the cancer cells for a cell change called a RAS gene mutation, which is called being tested to find out your RAS status. Knowing if these genes are normal or changed (mutated) can help the doctors decide whether cetuximab or panitumumab will be appropriate for you.

Cetuximab and panitumumab are often given with chemotherapy.

Bevacizumab (Avastin®), aflibercept (Zaltrap®), ramucirumab (Cyramza®) and regorafenib (Stivarga®) work by preventing the cancer from developing a blood supply. This deprives it of oxygen and nutrients. Drugs that interfere with blood vessel growth are called angiogenesis inhibitors or anti-angiogenics.

If your cancer specialist thinks that a targeted therapy may be helpful, they will discuss this with you. However these drugs are not widely available through the NHS. If a drug isn’t available on the NHS, there may be different ways you are still able to have it. Your doctor can give you advice. They may be able to apply for funding to get it.

We can send you information about targeted therapy drugs, the Cancer Drugs Fund and what you can do if a treatment is not available. Call us on 0808 808 00 00.

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 drop in blood pressure or feeling sick. An allergic reaction is most common with the first dose of the drug. To reduce this risk, the first dose is given slowly over a few hours. You may also be given drugs to make an allergic reaction less likely.

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 in the bowel (perforation), but this is rare.

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