Biopharmaceuticals

Session Summary:
Biopharmaceuticals are a class of therapeutic drugs with high growth rate in development and commercialization. Among those, monoclonal antibodies (MAbs) represent the largest class. Today, protein engineering allows deviations from the classical Y-shaped immunoglobulin molecule. Currently, two recombinant formats attract increasing attention: (i) antibody fragments and (ii) bispecific versions thereof.

Stable antibody fragments, in particular Fab but also scFv or even single domains, provide benefits with regard to tissue penetration, absence of Fc effector functions, and lack of receptor crosslinking arising from the bivalent nature of natural MAbs. In addition, most of the small antibody fragments can be efficiently produced in microbial host systems. Their simpler molecular architecture allows the construction of bispecific fusion proteins, which have shown recent clinical success in the recruitment of T-cells for the immunotherapy of cancer, for example. Notably, such small bispecific antibody formats allow much easier manufacturing than classical bispecific MAbs. In this sense, such novel biologics bridge the gap between the large therapeutic proteins and small molecule pharmaceuticals.