Abstract 6714: AI-guided tailor-made anti-TROP2 T-cell engagers for T-cell mediated cancer immunotherapy with enhanced therapeutic index

Abstract Bispecific T-cell engagers (TCEs) have shown significant therapeutic advances in the treatment of hematologic cancers. However, the clinical efficacy of TCEs in treating solid tumors remains to be demonstrated. Accumulating evidence suggests novel TCE modalities that simultaneously engage both CD3 (signal 1) and CD28 (signal 2) co-stimulatory signals may offer potential advantage to enhance clinical efficacy of TCEs with improved therapeutic index. To explore the full potential of TCEs as a powerful approach of immunotherapy for solid tumors, we developed an integrated AI-guided TCE platform to streamline the discovery, optimization and high-throughput function screening and characterization of TCE molecules. Here we report the construction and characterization of a novel panel of TROP2-targeting TCEs by leveraging our AI-guided optimization technology, plus a high-throughput in vitro screening platform. These tailor-made TCE molecules exhibit favorable developability and functional properties. Our data show that a novel TROP2 × CD3 x CD28 trispecific TCE that contains a CD3-targeting arm in concomitant with a CD28-targeting arm can induce potent T-cell co-stimulation and promising synergistic T cell-mediated tumor cell killing in vitro, compared to its counterparts with a single CD3-targeting arm. We further generate a trivalent TROP2 x CD3 bispecific TCE constructed as an asymmetric ‘2+1’ format with bivalent binding to TROP2 but a monovalent CD3-targeting arm. This molecule stimulates very low levels of cytokine release, but drives robust antigen-specific killing in in vitro assessment. Anti-tumor activity of the various TROP2 x CD3 TCEs is currently being investigated in multiple tumor xenograft mouse models. Citation Format: Chuan Chen, Liang Tian, Chenpeng Su, Dandan Liu, Xiaoqian Chen, Yifei Zhou, Suze Jiang, Guifang Wang, Jiyuan Tian, Yuan Yuan, Bing Yang, Jian Peng. AI-guided tailor-made anti-TROP2 T-cell engagers for T-cell mediated cancer immunotherapy with enhanced therapeutic index abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 6714.