Measurement of Fc-mediated ADCC and CDC of anti-TNFα and anti-VEGF Therapeutic Antibodies using Reporter-based Bioassays and Engineered TNFα+ and VEGF+ Target Cells

Part # PS335

Abstract

Denise Garvin, Rich Moravec, Jamison Grailer, Jim Hartnett, Chris Heid, Frank Fan, Mei Cong and Zhi-jie Jey Cheng
Promega Corporation, 2800 Woods Hollow Rd, Madison, WI 53711

To measure ADCC activity of anti-TNFα and anti-VEGF blocking antibodies, we developed engineered target cells that express either membrane-bound TNFα or VEGF. When used as target cells with reporter-based effector cells expressing a relevant FcgR, ADCC activity of adalimumab (anti-TNFα) and bevacizumab (anti-VEGF) was detected in a specific and dose-dependent manner. Similarly, when used in a luminescence-based CDC assay, the engineered target cells elicited an appropriate FcgR-mediated response. The assay signals demonstrated IgG isotype specificity as IgG4 variants showed minimal activity in both ADCC and CDC assays. Our results demonstrate that the combined use of cell-based reporter bioassays with target cells engineered to express membrane-bound soluble ligands can provide a simple, specific, and quantitative platform to measure Fc-mediated effector functions of therapeutic antibodies targeting soluble ligands.