VOLUNTARY ANNOUNCEMENT - DOCETAXEL FOR INJECTION (ALBUMIN-BOUND) (HB1801) AND ANBENITAMAB (KN026) GRANTED BREAKTHROUGH THERAPY DESIGNATION IN CHINA FOR THE FIRST-LINE TREATMENT OF ADVANCED HER2-POSITIVE BREAST CANCER

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 DOCETAXEL FOR INJECTION (ALBUMIN-BOUND) (HB1801) AND ANBENITAMAB (KN026) GRANTED BREAKTHROUGH THERAPY DESIGNATION IN CHINA FOR THE FIRST-LINE TREATMENT OF ADVANCED HER2-POSITIVE BREAST CANCER The Board of Directors (the ‘‘Board ’’) of CSPC Pharmaceutical Group Limited (the ‘‘Company ’’, together with its subsidiaries, the ‘‘Group ’’) is pleased to announce that Docetaxel for Injection (Albumin-bound) (HB1801), independently developed by the Group, and Anbenitamab (KN026), a human epidermal growth factor receptor 2 ( ‘‘HER2 ’’) bispecific antibody drug co-developed by Shanghai JMT-BIO Technology Co., Ltd., a subsidiary of the C ompany, and Jiangsu Alphamab Biopharmaceuticals Co., Ltd., have been granted Breakthro ugh Therapy Designation by the National Medical Products Administration (the ‘‘NMPA ’’) of the People ’s Republic of China for the intended indication of Docetaxel (Albumin-bound) in combination wi th Anbenitamab for the first-line treatment of unresectable or metastatic HER2-positive breast cancer in adults (the ‘‘Indication ’’). Previously, Anbenitamab has been granted Breakthrough Therapy Designa tion by the NMPA for the treatment of HER2-positive advanced gastric cancer following the failu re of first-line treatment. Breast cancer is the second most common malignancy among wom en in China, of which the HER2- positive subtype accounts for approximately 20% to 30%. In C hina, approximately 20% of patients with breast cancer are already at an advanced stage upon initial d iagnosis, and approximately 10% of patients with HER2-positive early breast cancer experienc e disease recurrence within 3 years after radical surgery. Trastuzumab in combination with pertuzum ab and docetaxel (the ‘‘THP regimen ’’) currently remains the preferred first-line treatment for H ER2-positive advanced breast cancer both domestically and overseas. Although this treatment regime n has significantly prolonged the progression-free survival ( ‘‘PFS’’) of these patients, approximately 50% of patients still exp erience disease progression within 2 years, representing an urgent unmet clinical need. – 1 – As announced on 10 June 2026, the Phase III clinical study (He aler, KN026 –003) for the Indication had successfully achieved its primary endpoint of PFS, as asses sed by the Independent Data Monitoring Committee (IDMC). The study results demonstrated that the c ombination therapy of Docetaxel for Injection (Albumin-bound) and Anbenitamab exhibited sign ificantly superior PFS compared to the current standard-of-care THP regimen, with differences th at are both statistically significant and clinically meaningful, while maintaining a favourable ove rall safety profile. Detailed clinical data from this study will be presented at an upcoming international ac ademic conference, and the Group plans to submit a New Drug Application (NDA) for the Indication in the near future. The combination therapy of Docetaxel for Injection (Albumi n-bound) and Anbenitamab has now completed the comprehensive clinical layout across the ent ire disease course for HER2-positive breast cancer, encompassing neoadjuvant, adjuvant, and first-li ne advanced settings. The research and development (R&D) of Docetaxel for Injection (Albumin-bou nd) for indications such as breast cancer and gastric cancer have also entered Phase III clinical tria ls. The Breakthrough Therapy Designation granted to Docetaxel for Injection (Albumin-bound) and Anb enitamab will further accelerate their R&D and regulatory review processes for HER2-positive advance d breast cancer, and is expected to reshape the first-line treatment landscape of such disease. By Order of the Board CSPC Pharmaceutical Group Limited CAI Dong Chen Chairman Hong Kong, 14 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 –

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