Abstract 6020: Quantitative measurement of Fc-mediated ADCC & ADCP activity of therapeutic antibodies using a robust, universal cell-based assay platform

Abstract The clinical success of a broad range of biologics has driven the development of diverse immunomodulatory agents with unique mechanisms of action (MOA) targeting novel antigens. Regulatory guidelines now require evaluation of antibody effector functions, such as antibody-dependent cell-mediated cytotoxicity (ADCC), particularly for lot-release assays that measure immune cell-mediated killing directly rather than surrogate endpoints. Additionally, antibody-dependent cellular phagocytosis (ADCP) has become a key MOA, especially for IND-enabling studies involving antibodies with modified Fc regions. To address these needs, Eurofins DiscoverX® developed the KILR® cytotoxicity assay platform that accurately measures the killing of antigen-expressing target cells in co-culture with immune effector cells. This dye-free, radioactivity-free platform leverages the validated Enzyme Fragment Complementation (EFC) technology and supports various immune-mediated killing mechanisms, including ADCC, CDC, ADCP, and T-cell redirection. Here, we showcase the KILR platform’s versatility across multiple antigens (e.g., HER2, CD20, CD19) and effector cell types. Combined with engineered KILR CD16 Effector Cells, the KILR platform provides robust, reproducible assay performance necessary for testing in the quality-controlled environment for commercial lot release. This platform also quantifies ADCP cost-effectively, simplifying traditional FACS or imaging-based workflows. To ensure assay reproducibility, many KILR target cell models are now available in an assay-ready format, with phase-appropriate qualification data supporting their suitability for potency and screening applications. Citation Format: Alpana Prasad, Surekha Bonasu, Gaurav Agrawal, Jane E. Lamerdin. Quantitative measurement of Fc-mediated ADCC & ADCP activity of therapeutic antibodies using a robust, universal cell-based assay platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6020.