VOLUNTARY ANNOUNCEMENT - PHASE II CLINICAL TRIAL OF SYS6026 INJECTION FOR THE TREATMENT OF HPV TYPE 16- OR 18-RELATED CERVICAL HIGH-GRADE SQUAMOUS INTRAEPITHELIAL LESION OFFICIALLY INITIATED IN CHINA

Hong Kong Exchanges and Clearing Limited and The Stock Excha nge of Hong Kong Limited take no responsibility for the contents of this announcement, make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoe ver for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this ann ouncement. CSPC PHARMACEUTICAL GROUP LIMITED (Incorporated in Hong Kong with limited liability) (Stock Code: 1093) ʮ ̡ VOLUNTARY ANNOUNCEMENT PHASE II CLINICAL TRIAL OF SYS6026 INJECTION FOR THE TREATMENT OF HPV TYPE 16- OR 18-RELATED CERVICAL HIGH-GRADE SQUAMOUS INTRAEPITHELIAL LESION OFFICIALLY INITIATED IN CHINA The Board of Directors (the ‘‘Board ’’) of CSPC Pharmaceutical Group Limited (the ‘‘Company ’’, together with its subsidiaries, the ‘‘Group ’’) is pleased to announce that the Phase II clinical trial of SYS6026 Injection (the ‘‘Product ’’) developed by the Group for the treatment of human papilloma virus (‘‘HPV’’) type 16- or 18-related cervical high-grade squamous intra epithelial lesion ( ‘‘HSIL ’’) has been officially initiated in China. The Product is a therapeutic mRNA vaccine, classified as a Cl ass 1 therapeutic biological product, targeting the E6 and E7 protein antigens of HPV subtypes 16 an d 18. Following delivery into cells via lipid nanoparticles (LNP), the Product translates and expr esses E6 and E7 proteins intracellularly. These are subsequently presented on the cell surface by huma n leukocyte antigen (HLA) molecules, inducing the body to produce E6- and E7-specific T cells to er adicate HPV-infected cells or tumour cells expressing the target antigen genes. HPV types 16 and 18 are the most highly pathogenic HPV subtype s known to date. Approximately 10% of women infected with HPV type 16 or 18 will develop high-gra de cervical precancerous lesions within 3 years of infection, and more than 70% of high-grade c ervical lesions and cervical cancers are associated with HPV type 16 or 18 infection. As a novel non-su rgical therapeutic approach, the Product is expected to provide a new treatment option for patients wi th HPV type 16- or 18-related HSIL. – 1 – Previously, the Group received the Notice of Approval for Cl inical Trial issued by the National Medical Products Administration of the People ’s Republic of China in November 2024, and subsequently initiated a Phase I clinical trial to evaluate the safety and tolerability of the Product in patients with HPV type 16- or 18-related HSIL. The Phase II cl inical trial initiated this time is a multicentre, randomised, double-blind, placebo-control led study designed to evaluate the efficacy and safety of the Product compared with placebo in participants with HPV type 16- or 18-related HSIL. Currently, recruitment and screening of project participa nts for the study are actively underway. By Order of the Board CSPC Pharmaceutical Group Limited CAI Dong Chen Chairman Hong Kong, 22 July 2026 As at the date of this announcement, the Board comprises Mr. C AI Dong Chen, Dr. CAI Lei, Mr. WEI Qingjie, Mr. ZHANG Cuilong, Mr. WANG Zhenguo, Dr. LI Chunlei , Dr. YAO Bing, Mr. CAI Xin, Mr. CHEN Weiping, Mr. QU Zhiyong and Mr. ZHANG Yiwei as Executive Directors; and Mr. WANG Bo, Mr. CHEN Chuan, Prof. WANG Hongguang, Mr. AU Chun Kwok Alan, M r. LAW Cheuk Kin Stephen and Ms. LI Quan as Independent Non-executive Directors. – 2 –

The release as fetched from its publisher. irasia.com ↗