Abstract 4693: Fc effector bioassays enable faster and quantitative measurement of ADCC and ADCP mechanisms of action

Antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cell-mediated phagocytosis (ADCP) are recognized as important mechanisms of action (MOA) of therapeutic antibodies. Primary peripheral blood mononuclear cells (PBMCs) are routinely used in traditional bioassays to measure potency, stability of antibody drugs in ADCC and ADCP. However these methods are labor intensive and highly variable. Here we report the development of a luciferase-based reporter assay that measures activation of effector cells via cross-linking of Fc receptors with target cell-bound antibodies. We will discuss functional cell-based Fc effector reporter bioassays developed to measure Human FcgRIIIa (V158 and F158 variants), Human FcgRIIa (H131 and R131 variants), Human FcgRI as well as Mouse FcgRIV and FcgRIII. Compared to primary cell-based assays these reporter bioassays are less variable, easier to use and provide more consistent analysis of the important MOAs that are critical to for drug development programs. In qualification studies, performed in accordance with ICH guidelines for antibody screening and characterization, we tested the bioassays for specificity, accuracy, precision and linearity. Citation Format: Zhi-Jie Jey Cheng, Rich Moravec, Aileen Paguio, Denise Garvin, Gopal B. Krishnan, Frank Fan, Mei Cong. Fc effector bioassays enable faster and quantitative measurement of ADCC and ADCP mechanisms of action [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4693. doi:10.1158/1538-7445.AM2017-4693