A chimeric antibody is an antibody made by combining genetic material from a nonhuman source, like a mouse, with genetic material from a human being. These antibodies are generally around two thirds human, reducing the risk of a reaction to foreign antibodies from a non-human animal when they are used in therapeutic treatments. A closely related concept is a humanized antibody, made in a similar way but containing closer to 90% human genetic material.
Work on the development of chimeric antibodies began in the 1980s, as scientists began exploring the possibilities of recombinant technology in genetic research. Using recombinant technology, people can cut and splice genetic material from multiple sources and fuse it together. A chimeric antibody contains antibodies developed with animal cells in culture, with sections of the genetic code replaced with human genes in order to address concerns about a potential reaction with the animal's genetic material.
Several drugs based on these antibodies have been approved for human use and numerous others are in development. These compounds take the form of monoclonal antibodies, antibodies produced by cloning a parent cell to achieve a steady and reliable source of antibodies for use in the treatment of diseases like cancer. Drugs made with a chimeric antibody all have the suffix -ximab. Humanized antibodies are identified with the -zumab suffix. This nomenclature is designed to make it easy to distinguish the origins of a drug.
In the production of monoclonal antibodies, animals are inoculated with a desired antigen, stimulating them to produce antibodies. Cells are harvested and grown in culture, where they are fused with multiple myeloma cells. The fused cells express a variety of antibodies and people can select the cells producing the desired antibody, purify them, and grow them in culture to produce monoclonal antibodies, purified antibodies produced by clones of a single parent cell. To create this type of antibody, recombinant technology is used during the process of growing the cells in culture and purifying the desired cells.
Monoclonal antibodies sometimes cause adverse reactions or are less effective because the body of the patient reacts to the foreign DNA from the animal used to produce the antibodies. A chimeric antibody addresses this problem by eliminating some of the animal DNA, reducing the chances of a reaction, and humanized antibodies contain an even lower risk of adverse reactions. Such medications have a number of potential applications in the treatment of disease, as they can be developed to target very specific antigens attached to diseased or infectious cells while leaving other cells in the body alone.