VOLUNTARY ANNOUNCEMENT - PHASE III CLINICAL STUDY OF SYS6010 IN COMBINATION WITH ENLONSTOBART FOR THE TREATMENT OF DRIVER GENE-NEGATIVE NON-SMALL CELL LUNG CANCER 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 III CLINICAL STUDY OF SYS6010 IN COMBINATION WITH ENLONSTOBART FOR THE TREATMENT OF DRIVER GENE-NEGATIVE NON-SMALL CELL LUNG CANCER 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 III clinical study (Protocol No.: SYS6010 –022 (SYNSTAR-04)) of SYS6010 in combination with enlonstob art for the treatment of driver-gene negative non-small cell lung canc er (the ‘‘NSCLC ’’) developed by the Group officially initiated in China, with the enrolment of the fir st subject expected to be completed in July 2026. SYS6010 is an antibody-drug conjugate ( ‘‘ADC’’) targeting the epidermal growth factor receptor (‘‘EGFR ’’) developed by the Group. It is composed of a humanised anti-E GFR monoclonal antibody conjugated to a topoisomerase I inhibitor payload via a clea vable linker. This drug specifically binds to EGFR on the surface of tumour cells and releases the cytotoxi c payload intracellularly upon internalisation, thereby exerting anti-tumour effects. E nlonstobart Injection (recombinant fully human anti-PD-1 monoclonal antibody injection) is a humanised Ig G4 variant monoclonal antibody targeting programmed cell death protein 1 (PD-1), which is indicated f or the treatment of malignant tumors in various human organs and tissues. – 1 – SYS6010 –022 (SYNSTAR-04) is a randomised, open-label, multi-centr e, Phase III clinical study designed to evaluate the efficacy and safety of SYS6010 in co mbination with enlonstobart versus immunotherapy plus platinum-based chemotherapy in subjec ts with driver gene-negative and programmed cell death ligand-1 (PD-L1)-positive locally a dvanced or metastatic NSCLC. Previously, the Group received the opinion from the Center for Drug Evalu ation of the National Medical Products Administration of the People ’s Republic of China in May 2026, granting approval to conduct this clinical trial. Currently, the recruitment and screening o f subjects are actively underway. By order of the Board CSPC Pharmaceutical Group Limited CAI Dongchen Chairman Hong Kong, 26 June 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 ↗