VOLUNTARY ANNOUNCEMENT - NEW DRUG APPLICATION FOR SIROLIMUS FOR INJECTION (ALBUMIN-BOUND) ACCEPTED BY THE NMPA

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 NEW DRUG APPLICATION FOR SIROLIMUS FOR INJECTION (ALBUMIN- BOUND) ACCEPTED BY THE NMPA 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 new drug application for Sirolimus for Injection (Albumin-Bound) (the ‘‘Product ’’) independently developed by the Group has been accepted by the National Medical Products Administrat ion (the ‘‘NMPA ’’) of the People ’s Republic of China. Following review by the Center for Drug Ev aluation of the NMPA, the Product has also been included in the Breakthrough Therapy Drug Program and granted Priority Review status. The Product is a macrolide antibiotic immunosuppressant an d a highly selective inhibitor of the mammalian target of rapamycin ( ‘‘mTOR ’’). Sirolimus binds to the immunophilin FKBP12 to form an immunosuppressive complex, blocking the activation of the mTOR pathway. On the one hand, it inhibits cytokine-mediated T-lymphocyte activation and p roliferation, and arrests cell cycle progression from the G1 phase to the S phase; on the other hand, it downregu lates antibody production, thereby exerting potent immunosuppressive effects. The new drug ap plication for the Product was submitted as a Class 2.2 modified new drug under chemical drug classifica tion, with a proposed indication for unresectable locally advanced or metastatic malignant per ivascular epithelioid cell tumour (‘‘PEComa ’’). The new drug application is primarily based on a pivotal Phas e Ib/III clinical study that enrolled patients with histologically confirmed, unresectable loc ally advanced or metastatic malignant PEComa who had not previously received mTOR inhibitor therapy. The pivotal Phase III clinical trial met its predefined primary endpoint. Compared with the investigat or’s choice of conventional therapies in the control group, the Product demonstrated significant effic acy advantages, with statistically significant and clinically meaningful results, enabling rapid and deep tumour responses. Given the current lack of a unified standard treatment regimen for malignant PEComa, the Product has the potential to establish a new treatment standard in this therapeutic area and support the development of a standardised treatment – 1 – framework for the benefit of patients with PEComa. The Produ ct has demonstrated a favourable overall safety profile, with generally manageable adverse reactio ns and a wide safety margin. Its favourable benefit-risk profile makes it a core therapeutic drug for th is rare and difficult-to-treat tumour type. Sirolimus for Injection (Albumin-Bound) is the first intra venous sirolimus formulation approved for clinical research in China. At present, the Group is advanci ng a pivotal Phase III clinical trial of the Product in combination with fulvestrant for the treatment o f HR+/HER2- breast cancer and continues to explore the efficacy and safety of the Product as a monothera py and in combination regimens across various solid tumours, with the aim of benefiting more cance r patients in the future. By Order of the Board CSPC Pharmaceutical Group Limited CAI Dong Chen Chairman Hong Kong, 27 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 ↗