Zejing Pharmaceutical (688266.SH): Injection ZGGS34 Obtained Approval for Clinical Drug Trials

Zejing Pharmaceuticals (688266.SH) announced that the company recently received the "Notice of Approval for Drug Clinical Trial" issued by the National Medical Products Administration (hereinafter referred to as the "NMPA"). The clinical trial of ZGGS34 for injection, used for MUC17-positive advanced solid tumors, has been approved. ZGGS34 is a three-specificity antibody drug developed by the company, belonging to the category of three-specific T cell engagers (TriTE). ZGGS34 (MUC17/CD3/CD28) is a three-specificity antibody targeting CD3 and CD28 on T cells, as well as the tumor-associated antigen (TAA) MUC17. MUC17 (Mucin-17) is a transmembrane mucin protein that is highly expressed in gastric cancer, gastroesophageal junction cancer, pancreatic cancer, and colorectal cancer, making it a hot target for the diagnosis and treatment of digestive system tumors in recent years. One end of the ZGGS34 molecule binds to the surface of tumor cells expressing MUC17, while the anti-CD3 end and anti-CD28 end bind to T cells. ZGGS34 bridges tumor cells and T cells, bringing T cells closer to tumor cells, leading to the activation of T cells, which produce immune synapses and release perforins, granulysins, cytokines, etc., to kill tumor cells. Compared to typical T cell engagers (BiTEs), ZGGS34 introduces a CD28 stimulatory antibody, as CD28 is a crucial second signal for T cell activation, mainly expressed on the surface of T cells, playing an essential role in the activation, proliferation, and survival of T cells. After binding to CD80/CD86 on antigen-presenting cells (APC), CD28 reduces the T cell activation threshold, enhancing T cell proliferation, metabolism, and anti-apoptotic abilities. Thus, ZGGS34 has a stronger ability to activate T cells and sustain T cell-mediated tumor killing compared to typical BiTEs, enhancing the anti-tumor immune response. Preclinical study results show that ZGGS34 has significant tumor inhibition effects in various tumor models, leading to tumor regression, indicating its potent tumor-killing effects. Completed toxicology studies in non-human primates have shown that ZGGS34 has good safety characteristics.