ABSTRACT

The concept of using antibodies as ‘magic bullets’ in the treatment of disease was first proposed by Ehrlich in 1901. The specificity of an antibody for its target is only one of the factors to be considered before an antibody can be approved for human therapy. Before an antibody preparation can be approved for therapy, it is a requirement that it should be thoroughly tested in vitro for cross-reactions with a wide range of human and animal tissue, including blood cells and cell lines, in different assay formats. However, cross-reactivity need not necessarily be a barrier to therapeutic application. Most patients will develop anti-antibodies following administration of rodent monoclonal antibodies, since they are only about 60-70% homologous with their human counterparts. Humanized antibodies have the effect of reducing or delaying the immunogenicity of the foreign antibody by replacing the constant regions of the rodent antibody with the human equivalent.