Humanising Antibodies by CDR Grafting

CDR grafting, or antibody reshaping, is the most clinically validated route to a successful therapeutic humanised monoclonal antibody, and is the process described in this chapter. Accurate determination of the rodent antibody variable region DNA sequences, amplified by RT-PCR, and homology modelling of their protein translation are key starting points. Human framework selection and the design of the DNA and protein sequences of the CDR-grafted humanised antibody, based on a thorough analysis of the rodent variable regions and comparison with existing human antibody sequences, are discussed. The central concept of the design and generation of a set of framework mutations, expressed as full-length human IgG-kappa in transiently transfected mammalian cells, for determining relative binding potency is described. This naturally leads to the objective of identifying the minimal set of framework mutations necessary to recapitulate the binding potency of the original rodent.