But, many drugs being used and developed today, such as interferons and monoclonal antibodies, are engineered proteins, and when these agents are introduced into the body they are perceived as foreign and the body mounts an immune attack. This can result in the production of "neutralizing antibodies" against the very drug that is intended to treat the disease. These neutralizing antibodies can develop in people with multiple sclerosis receiving interferon; and they have also been seen in people receiving interferon to treat hepatitis C virus, in people with hemophilia receiving factor VIII, in people receiving epoeitin, to treat anemia as well as in people receiving monoclonal antibody therapy for a variety of diseases. The growing debate in the medical community concerns the role, if any, these neutralizing antibodies may play in disease progression or relapse. And many physicians are monitoring the development of neutralizing antibodies in their patients receiving engineered proteins in an effort to keep patients on course with their treatment to control their disease.
The importance of neutralizing antibodies was underscored this year on November 12, when the Food and Drug Administration (FDA) approved new labeling for Avonex, one of the interferon preparations used to treat multiple sclerosis, to reflect a lower occurrence of neutralizing antibodies in people treated with the drug for at least a year.
Below, Dr. Bill Stuart, Medical Director of the MS Center in Atlanta, discusses the role of neutralizing antibodies in multiple sclerosis and how they may affect treatment decisions.
