Abstract 2925: In vitro characterization of next generation therapeutic antibodies

Abstract Therapeutic antibodies are an established drug class. Checkpoint inhibitors, such as anti-PD-1/PD-L1 and anti-CTLA-4 antibodies for cancer indications, and anti-TNF-α monoclonal antibody against autoimmune disorders represent some of most successful therapeutics in the past decade. Over 100 therapeutic targets suitable for antibody therapy have been identified for various disease indications, with several currently in late-stage clinical trials. In addition, there has been an explosion in the various types of therapeutic antibody modalities due to the increasing number of antibody engineering platforms. The new emerging bi-specific T-cell engaging antibodies (BiTEs) along with antibody-drug conjugates (ADCs) have demonstrated superior therapeutic qualities over the traditional monoclonal antibodies. Here, we describe a pipeline to extensively characterize the various antibody therapeutics in vitro utilizing multiple innovative technologies. Assays to determine target expression and binding potency provide a thorough understanding of the target engagement. Furthermore, we present data from an innovative technology platform, the z-Movi, which measures cell avidity to predict invitro effector functions of T-cell engaging therapies, enabling more robust read-outs and could drive the lead selection of said therapies. Several mechanisms of action of different antibodies were investigated and relevant case studies describing the innate immune effector functions and the signaling pathway modulation are presented. Using a unique label-free approach, the xCELLigence, we report on the kinetics of target cell killing mediated by lymphocytes upon recognition of antigen-antibody complexes. Finally, safety assessment studies focusing on on-target/off-tumor effects of antibodies on primary cells were conducted. The cytokine profiling and cell viability assays to assess potential risk due to exaggerated levels of cytokine, reiterate the specificity and safety of the next generation of antibody therapeutics and support Investigational New Drug (IND) applications. In conclusion, we provide a comprehensive report on the in vitro characterization of the advanced antibody therapeutics, showcasing a pipeline for development and functional characterization of various antibody modalities, including bispecific T-cell engagers. This workflow can be used to progress a wide range of engineered antibodies from pre-clinical to the clinical phase of the drug discovery process. NJ and GM contributed equally to the work. Citation Format: Benita Quist, Hamed Janbazacyabar, David Cobeta Lopez, Namrata Jayanth, Gemma Moiset. In vitro characterization of next generation therapeutic antibodies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2925.