P-130-T - Binding to Bridging: Complete Suite of FcyR Assay Tools Accelerates Antibody Therapeutic Development

Therapeutic antibodies mediate efficacy through Fc effector functions like ADCC and ADCP that are driven by interactions between the antibody Fc domain and FcγRs on immune cells. Traditional methods for characterizing these interactions are variable and labor-intensive, creating bottlenecks across the development pipeline. We developed an integrated, bioluminescent assay suite comprising Lumit® FcγR Binding Immunoassays, Lumit® C1q Binding Assays, Fc Effector Reporter Bioassays, and HiBiT Target Cell Killing Assays. Using anti-CD20 antibodies as a model system, we demonstrate subtype-specific FcγR binding, IgG isotype rank-ordering, and potency measurements across allelic variants. Assays were validated against on-market biosimilars including rituximab, obinutuzumab, and ublituximab. This platform delivers concordant, cross-tier data from binding through cell killing, ICH-compliant performance, and streamlined workflows to enable accelerated decision-making from early discovery through lot release.