Advanced Assay Platform for Antibody Development: Precision Assays for ADCC, ADCP and CDC

Presented by: Caroline Grygar, SVAR Life Science Poster Number: P-101-W Poster Session: Antibody Products and Automation Wednesday, 24 Sept. at 15:00 ----- Grygar C, Ulrich M, Lallemand C, Frier Bovin L Svar Life Science AB, Malmö Sweden Early in therapeutic antibody development, it is crucial to characterize their mode of action (MoA). The Fc regions of antibodies significantly influence their therapeutic characteristics, including half-life and cytotoxic effects like ADCC, ADCP, and CDC. Traditional ADCC and ADCP bioassays rely on human primary cells, which suffer from donor variability, limited expansion capacity, and labor-intensive culturing. To streamline this evaluation, we've developed advanced assays to assess ADCC, ADCP, and also CDC activities. Our Fc Effector assay platform uses reporter gene effector cells in combination with engineered target cells. Furthermore, to assess CDC, we have engineered target cells based on a B-cell line expressing no or only low levels of membrane-bound complement inhibitors (CD46, CD55 and CD59). The readout is based on Svar luciferase (SL) constitutively expressed by the target cells, which has some unique features like a bright signal and enhanced stability allowing its accumulation in cell culture medium upon killing without loss of enzymatic activity. This cell line can be rapidly customized to express a target of interest and allows to measure cell killing via CDC but also by primary T- and NK cells or CAR-T cells. We showcase, the use of these target cells to assess ADCC and ADCP with the above-described surrogate reporter gene systems and also complement-dependent cytotoxicity induced by rituximab, daratumumab, alemtuzumab and other drug antibodies.