ABSTRACT
The breakthrough in recombinant DNA techniques in the 1970s that allowed for the overexpression of proteins in cell lines and the creation of the fi rst stable hybridoma for producing monoclonal antibodies by Kohler and Milstein in 1975, have collectively brought about entire new classes of therapeutic entities that have begun to enter the market as approved drugs. The fi rst monoclonal antibody to appear on the market occurred 20 years ago with the launch of Johnson and Johnson’s Orthoclone product for treating kidney transplant rejection episodes. This was followed by multiple classes of protein therapeutic agents: enzymes, interleukins, cytokines, hormones, etc., via three major pathways for the production of biologics, recombinant expression in cell lines, hybridomas, and transgenic animals. It is estimated that there are more than 400 biologics currently in various stages of drug development; approximately 40% of these are monoclonal antibodies (1).
