MAB’s (MAOB’s) are classified as Biological Response Modifiers. Since these antibodies affect the immune system, treatment with monoclonal antibodies is called immunotherapy, as opposed to the other treatments such as chemotherapy, which is therapy with drugs which tend to interfere in cancerous cell growth.
Researchers make MAOB’s by injecting human cancer cells into mice so that the mice’s immune systems will make antibodies against these cancer cells. Then, researchers remove the mouse cells that are producing these antibodies and fuse them with a laboratory grown cell (also known as an “immortal” cell) to create a "hybrid" cell called a hybridoma. Hybridomas are capable of producing, indefinitely, large quantities of these pure monoclonal antibodies for treatment against cancer. MAOB’s, by themselves, have the potential to enhance a patient's own natural immune response to the cancer. Some antitumor effects have been seen in the antibody treatment of certain cancers that include lymphoma, and some other cancers. But this monoclonal antibody treatment is not yet perfect. Sometimes the injected monoclonal antibodies produce no positive response or they may block a normal response in the patient. Cancer cells can also have an ability to hide their antigens, making themselves less likely to be destroyed my monoclonal antibodies. A way to increase the potential effectiveness of MAOB’s is to combine them with another form of therapy, such as radiation therapy or chemotherapy.For example, MAOB’s can be bound to a chemotherapy agent to enhance the effect of the chemotherapy. Through this combination of agents, two different mechanisms attack the cancer cell - the chemical from the chemotherapy and also the immune response from the MAOB. Chemotherapy can be more effective when the cancer cells are weakened by the monoclonal antibody (MAOB).Radiation therapy can also be combined with monoclonal antibody therapy. In this case, the monoclonal antibodies would be maid to contain a radioactive substance (such as radioactive iodine) that targets and destroys the cancer cells in the patient. With this form of combined therapy, the patient’s cancerous tumor cells receive a large amount of radiation while the patient’s normal healthy cell tissue is spared from damage. Radioisotope-labeled MAOB’s may also potentially prove useful in the process of diagnosing certain cancers.