Abstract 1867: Pre-clinical characterization of anti-CEACAM1 antibody

Abstract Targeting checkpoint molecules cytotoxic T lymphocyte antigen-4 (CTLA-4) or programmed death receptor-1 (PD-1) expressed on immune cells has shown promising results in the treatment of cancer patients. Nevertheless only a small portion of population benefited from current ICI treatments, so there should be other mechanisms for immune evasion potentially. The carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1) is an activation-induced inhibitory molecule on T and NK cells. In a wide range of cancers, it’s also expressed on tumor cells and other immune cells including macrophages and neutrophils. Homophilic interaction between CEACAM1 expressed on tumor cells and immune cells dampens NK and T cell function, mediates tumor migration, and promotes tumor angiogenesis, which implies that this homophilic interaction is an important mechanism for tumor progression. Here, we describe the identification and characterization of a novel humanized anti-human CEACAM1 therapeutic antibody developed via Neologics’ novel target validation and antibody screening Tier-A platform. This anti-CEACAM1 antibody specifically binds to recombinant human CEACAM1 with nM level affinity and significantly enhances T cell activities and NK killing on CEACAM1 expressing tumor cells, inhibits tumor cell migration in vitro as well. In humanized mouse models, this antibody evidently reduces tumor growth alone or combined with other immune checkpoint blockers. Taken together, we have demonstrated this anti-CEACAM1 antibody specifically enhance NK cell activity, modulate T cell immune activation and inhibit tumor migration supporting further clinical investigation for various indications. Citation Format: Jinyu Dong, Yu Zhang, Baiyang Wang, Tingting Pu, Liegang Shao, Binbin Wang, Dong Wang, Jie Ni, Sunan Li, Xin Dong. Pre-clinical characterization of anti-CEACAM1 antibody [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 1867.