Novel Method Development Issues Observed for an IgG4-Based Therapeutic

WRIB 2020 -- IgG4-based therapeutics are a small but growing class of monoclonal antibodies employed for various patient treatments. The unique structure of the IgG4 molecule minimizes antibody and complement-dependent cytotoxicity, making it ideal for specific therapeutic purposes where 'silencing' of a target protein is required. The structure of IgG4 also presents challenges for the development of ligand binding assays. We present some of the novel issues observed in developing an assay for an IgG4-based therapeutic likely caused by its unique structural characteristics, and the practical solutions utilized to develop a functional fit-for-purpose assay.