About monoclonal antibodies

This page is about monoclonal antibodies (MAB). You can find information on

What monoclonal antibodies (MABs) are
How monoclonal antibodies work
Types of monoclonal antibodies
How you have monoclonal antibodies
General side effects of monoclonal antibodies

MABs are a type of biological therapy. ‘Monoclonal’ just means all one type. So each MAB is a lot of copies of one type of antibody. Each is made in a laboratory from a single copy of a human antibody. There is information about antibodies and the immune system in the about your body section of CancerHelp UK .

Monoclonal antibodies are designed to recognise and find specific abnormal proteins on cancer cells. Each monoclonal antibody recognises one particular protein. Different types of cancer have different abnormal proteins. So different antibodies have to be made to target different types of cancer.

Several different monoclonal antibodies are already available to treat cancer. Some are licensed to treat particular types of cancer and some are still in clinical trials. This is exciting research because it may be possible to kill cancer cells without damaging other body cells. It takes a long time to develop this type of treatment because monoclonal antibodies are so complicated.

There are 3 main types of monoclonal antibodies that work in slightly different ways. They may

Trigger the immune system
Stop cancer cells from taking up proteins
Carry cancer drugs or radiation to cancer cells

Trigger the immune system

Some monoclonal antibodies trigger the immune system to attack and kill cancer cells. Although cancer cells are abnormal, they develop from normal cells so they can be difficult for the immune system to spot. Some monoclonal antibodies simply attach themselves to cancer cells, making them easier for the cells of the immune system to find them. These include

Rituximab (Mabthera) for non Hodgkin’s lymphoma (NHL) and some types of leukaemia
Alemtuzumab (Campath-1H) for chronic lymphocytic leukaemia (CLL)

Stop cancer cells from taking up proteins

Some monoclonal antibodies work by seeking out cells that produce too much of particular growth factors and then blocking the cancer cell’s receptors. So the cancer cell can’t receive the signal to grow. This type of MAB includes

Trastuzumab (Herceptin) for breast cancer
Bevacizumab (Avastin) for advanced bowel cancer
Cetuximab (Erbitux) for advanced bowel cancer or in trials for other cancers
Panitumumab (Vectibix) for advanced bowel cancer, mainly in clinical trials

Carry cancer drugs or radiation to cancer cells

Some monoclonal antibodies have drugs or radiation attached to them. The MAB finds the cancer cells and delivers the drug or radiation directly to them. These are called conjugated MABs.

MABs that have a radioactive substance attached are still in clinical trials. They include

Ibritumomab (Zevalin) - in trials for non Hodgkin’s lymphoma (NHL) and for other cancers
Tositumomab (Bexxar) - in trials for non Hodgkin’s lymphoma (NHL)

MABs that have a drug attached are still in clinical trials. They include

Gemtuzumab ozogamicin (Mylotarg) - for acute leukaemia
ADEPT - for bowel cancer

There is more information about individual monoclonal antibodies in the cancer drug section and in the treatment sections for each type of cancer. Because some of these treatments are very new, you may find this information in the specific research pages for each type of cancer.

You have monoclonal antibody treatment through a drip (infusion) into a vein. How often you have treatment and how many treatments you need will depend on

Which monoclonal antibody you have
The type of cancer you have

All treatments have side effects. Some side effects depend on the type of cell the MAB is targeting. And whether it has a drug or radioactive substance attached to it.

The most common side effect of all monoclonal antibodies is an allergic reaction to the drug. This reaction is most likely to happen when you first have the treatment. You will have paracetamol and an antihistamine drug before you have the treatment to prevent a reaction. If you have a reaction, your doctor or nurse can usually control it by slowing down or stopping the drip for a while.

An allergic reaction can include these symptoms, though you may not have all of them