Monoclonal antibodies are drugs that can recognise specific cells in the body. These drugs are designed to find a particular type of cancer cell, attach themselves to them and destroy them.

A monoclonal antibody treatment called rituximab (Mabthera®) is used in the treatment of some types of non-Hodgkin lymphoma. It may be used on its own or in combination with chemotherapy.

Rituximab attaches to a protein called CD20 that is found on the surface of B lymphocytes, both normal and cancerous. Rituximab stimulates the body’s natural defences to attack and destroy the lymphocytes. It attacks some healthy B lymphocytes (white blood cells) as well as the lymphoma cells, but the body can replace the healthy ones and the level of these cells in the blood returns to normal within a few months once the treatment has ended.

Rituximab is given as a drip (infusion) into a vein, and can be used in different ways. It is sometimes given in combination with CVP chemotherapy, as the first treatment for some types of low-grade NHL. It may also be given on its own as four, weekly sessions if low-grade NHL comes back after previous treatment. If rituximab works well to treat low-grade NHL it is sometimes used, on its own, as maintenance therapy, for up to two years.

As treatment for high-grade NHL, rituximab is usually given alongside CHOP chemotherapy.

Some monoclonal antibodies have radioactive molecules attached to them, which give a dose of radiation directly to the cancer cells. Radioactive monoclonal antibodies that may be used to treat NHL include ibritumomab tixuetan (Zevalin®) and tositumomab (BEXXAR®).

Other monoclonal antibodies are being developed and you may be offered these as part of research trials. Some research trials use monoclonal antibodies in combination with chemotherapy.

Some people can have an allergic reaction to monoclonal antibodies, particularly with the first dose. This can cause a flu-like reaction, a drop in blood pressure or feelings of sickness. Because of this, the first dose is given slowly, over a number of hours. You may be given some other medicines first to make a reaction less likely. You are less likely to react to further doses.