CS23546 is a highly potent small-molecule PD-L1 inhibitor exclusively discovered by the company with global patent protection. It blocks the immunosuppressive activity mediated by the PD-1/PD-L1 signaling pathway by binding to PD-L1 and inducing its endocytosis. In preclinical studies, CS23546 demonstrated favorable oral absorption and metabolic characteristics of local enrichment in tumor tissues. It exhibited significant antitumor efficacy as a monotherapy in various tumor xenograft models and showed marked synergistic antitumor activity when combined with chemotherapy or other proprietary products such as Chidamide and Chiauranib. With a stable manufacturing process and controllable quality, CS23546 is expected to offer differentiated advantages as a new-generation oral small-molecule immune checkpoint inhibitor in the clinical treatment of various malignant tumors. It also holds potential for application in other immune-related diseases mediated by PD-L1 signaling.

• The Phase I clinical trial of CS23546 is progressing smoothly, with the first patient enrolled in the seventh dose cohort as of June 30, 2025.
• Overseas clinical trial applications for this molecule, including combination therapies, will be advanced in due course.