Article
作者: Liu, Xuejun ; Zhang, Cheng ; Liao, Haiyan ; Chung, Hyejin ; Jia, Keren ; Zhang, Yanni ; Sheng, Zhen ; Meng, Zhen ; Gao, Jing ; Niu, Yanling ; Zhu, Andrew X ; Zhang, Jingwu Z ; Shen, Lin ; Liu, Chanjuan ; Sung, Eunsil ; Chen, Xi ; Jiang, Wenqing ; Chen, Chan ; Wang, Zhengyi ; Jung, Jaeho
Background:Claudin18.2 (CLDN18.2) is a tight junction protein that has been identified as a clinically proven target in gastric cancer. Stimulation of 4-1BB with agonistic antibodies is also a promising strategy for immunotherapy and 4-1BB+T cells were reported to be present within the tumor microenvironment of patients with gastric cancer. However, hepatotoxicity-mediated by 4-1BB activation was observed in clinical trials of agonistic anti-4-1BB monoclonal antibodies.
Methods:To specifically activate the 4-1BB+T cells in tumor and avoid the on-target liver toxicity, we developed a novel CLDN18.2×4-1BB bispecific antibody (termed ‘givastomig’ or ‘ABL111’; also known as TJ-CD4B or TJ033721) that was designed to activate 4-1BB signaling in a CLDN18.2 engagement-dependent manner.
Results:4-1BB+T cells were observed to be coexisted with CLDN18.2+tumor cells in proximity by multiplex immunohistochemical staining of tumor tissues from patients with gastric cancer (n=60). Givastomig/ABL111 could bind to cell lines expressing various levels of CLDN18.2 with a high affinity and induce 4-1BB activation in vitro only in the context of CLDN18.2 binding. The magnitude of T-cell activation by givastomig/ABL111 treatment was closely correlated with the CLDN18.2 expression level of tumor cells from gastric cancer patient-derived xenograft model. Mechanistically, givastomig/ABL111 treatment could upregulate the expression of a panel of pro-inflammatory and interferon-γ-responsive genes in human peripheral blood mononuclear cells when co-cultured with CLDN18.2+tumor cells. Furthermore, in humanized 4-1BB transgenic mice inoculated with human CLDN18.2-expressing tumor cells, givastomig/ABL111 induced a localized immune activation in tumor as evident by the increased ratio of CD8+/regulatory T cell, leading to the superior antitumor activity and long-lasting memory response against tumor rechallenge. Givastomig/ABL111 was well tolerated, with no systemic immune response and hepatotoxicity in monkeys.
Conclusions:Givastomig/ABL111 is a novel CLDN18.2×4-1BB bispecific antibody which has the potential to treat patients with gastric cancer with a wide range of CLDN18.2 expression level through the restricted activation of 4-1BB+T cells in tumor microenvironment to avoid the risk of liver toxicity and systemic immune response.