Abstract 1788: A novel costimulatory signaling domain for chimeric antigen receptor-engineering

Abstract

Abstract Chimeric antigen receptor (CAR)-engineered adoptive cell therapy has demonstrated a feasible, attractive “off-the-shelf” approach against various malignancies. Success of CAR-engineered cell therapy depends primarily on providing optimized costimulatory signals capable of achieving robust cell proliferation, persistence, and antitumor reactivity. We describe here the capability of a novel CD30-derived costimulatory signaling domain to generate effective CAR-redirected cells capable of eradicating hematological and solid cancers. After establishing CD19-redirecting second-generation CARs incorporating the CD30-derived intracellular signaling domain and third-generation CARs combining CD30 with either CD28 or 4-1BB, the effector functionality of CAR-transduced T cells was assessed in vitro and in vivo. Further, we evaluated the efficacy of epithelial cell adhesion molecule (EpCAM)-targeting third-generation CD30-encompassing CAR constructs for targeting solid tumors. The CD30-signaling CAR-T cells exhibited similar levels of cell proliferation, cytolytic efficacies, and cytokine secretion in vitro, and demonstrated improved tumor regression and prolonged survival in vivo with increased persistence of the CAR-T cells as those of other CARs with CD28 or 4-1BB costimulatory domain, which are currently in clinical use. Also, third-generation CARs including the CD30 costimulatory domain retained potent antitumor efficacies in vitro and in vivo independent of their position or type of partner costimulatory domain. More significantly, EpCAM-targeting CAR-T cells containing CD30-signaling domain revealed effective cytolytic activities correlating with EpCAM expression levels in the target cells. Our results demonstrate that the CD30-derived costimulatory domain could be an alternative for developing CAR-engineered therapeutics which may be applicable for various designs of CAR constructs, with an emphasis on effectiveness against solid tumors. Citation Format: Hyun-Il Cho, Chung-Hyo Kang, Sang-Eun Lee, Mi-So Kim, Bo-Ra Lim, Jung-Min Ha, Hyun-Jung Sohn, Tai-Gyu Kim. A novel costimulatory signaling domain for chimeric antigen receptor-engineering [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 1788.