The plausibility of treating drug addiction with antibodies, an approach known as immunotherapy, was demonstrated in 1974 by former NIDA Director Dr. Charles R. Schuster, currently a professor and director of the Substance Abuse Clinical Research Program at Wayne State University in Detroit, Michigan. Dr. Schuster showed that antibodies to heroin could block its effects in addicted monkeys. This approach, however, only worked for very low doses of heroin since a heroin antibody can only bind to, and neutralize, a single heroin molecule. Administering the large doses of antibody that would be needed to neutralize large doses of heroin is impractical in a clinical setting. Catalytic antibodies improve on the earlier approach to immunotherapy because the antibodies are not bound permanently to their target molecule.
Turnover thus prevents the rapid depletion of the antibodies.
Scientists are trying to develop catalytic antibodies, synthetic molecules that will target and break down cocaine molecules more quickly than the body's natural cocaine-metabolizing enzymes. This simplified diagram shows how a typical catalytic antibody works. With the release of the breakdown byproducts, the antibody is recycled and is free, unlike naturally occurring antibodies, to repeat this process with another target molecule. Still, some researchers suggest that it is too early to attempt to develop catalytic antibody medications for cocaine abuse. They point to the formidable technical hurdles that must be overcome before these compounds can be clinically useful as evidence that more basic research is needed.