Glycoforms of Human IgG in Health and Disease

More than twenty recombinant antibody molecules are now licensed for treatment of a variety of cancers and chronic diseases. In addition there are, literally, hundreds in development and early phase clinical trials. Initially, the attraction of antibodies was their specificity for target antigens; however, it is now appreciated that the immune complexes formed trigger downstream biological activities that are critical to clinical success. It has been demonstrated that, although accounting for only 2-3% of antibody mass, glycosylation of the IgG-Fc is essential to the activation of such biologic mechanisms (effector functions). Additionally the precise structure of the attached oligosaccharide can determine protein conformation and stability and hence downstream biologic efficacy. Cellular engineering has been embraced to generate cell lines that synthesise selected homogeneous antibody glycoforms that may be optimal for a given disease indication. The advantage of being able to formulate therapeutic antibody preparations at high concentration might be aided by additional glycosylation within the IgG-Fab region. Novel production vehicles are also being developed that offer the possibility of lower production costs, with consequent lower cost of goods.