Quantitating Binding Similarities In IgG Fcγ Receptor Analysis

Assessment and control of Fc functionality during biotherapeutic antibody development and manufacturing is essential as receptor binding is linked to the safety and efficacy of the final drug. Typically, cell-based assays (such as ADCC, ADCP, and CDC) and/or surrogate binding assays are used for routine monitoring or characterization of the Fc functionality. The use of Biacore ligand-binding assays for studies of Fc receptor–Fc binding is well-established in the area; there is, however, a lack of consensus regarding assay setup. Further, evaluation of the heterogeneous binding kinetics seen with some of the receptors is challenging and can prevent determination of reliable rate and affinity constants. In this application note, our experience with different assay formats is described as well as the use of Sensorgram Comparison, a statistical tool incorporated in Biacore T200 Software v3.0. This software functionality enables quantitative assessment of comparability of complex kinetic data directly from curve shapes without kinetic modeling.