VOLUNTARY ANNOUNCEMENT - EXCLUSIVE LICENSE AGREEMENT FOR SYS6005 WITH RADIANCE BIOPHARMA

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 EXCLUSIVE LICENSE AGREEMENT FOR SYS6005 WITH RADIANCE BIOP HARMA The board of directors (the ‘‘Board ’’) of CSPC Pharmaceutical Group Limited (the ‘‘Company ’’, together with its subsidiaries, the ‘‘Group ’’) is pleased to announce that CSPC Megalith Biopharmaceutical Co., Ltd. ( ‘‘CSPC Megalith ’’), a subsidiary of the Company, has entered into an exclusive license agreement (the ‘‘Agreement ’’) with Radiance Biopharma, Inc. ( ‘‘Radiance Biopharma ’’) for the development and commercialization of the Group ’s SYS6005 (the ‘‘Product ’’), a recombinant anti-human receptor tyrosine kinase-like orp han receptor 1 (ROR1) antibody-drug conjugate, in the United States, the European Union, the Uni ted Kingdom, Switzerland, Norway, Iceland, Liechtenstein, Albania, Montenegro, North Maced onia, Serbia, Australia, and Canada (the ‘‘Territory ’’). Under the terms of the Agreement, CSPC Megalith agreed to gra nt an exclusive license to Radiance Biopharma to develop and commercialize the Product in the Te rritory. CSPC Megalith will receive upfront payments of US$15 million and is also eligible to rec eive potential development and regulatory milestone payments of up to US$150 million and potential sal es milestone payments of up to US$1,075 million, plus tiered royalties based on annual net sales of t he Product in the Territory. About SYS6005 Utilizing the Group ’s proprietary enzyme-catalyzed site-specific antibody co njugation technology, the Product is able to direct the potent mitotic inhibitor MMAE s pecifically to ROR1 expressing cancer cells. The stability of the linker can also facilitate the de livery of high concentration of MMAE into the tumor and reduce side effects with the decrease in undesirab le systemic exposure. Compared with normal tissues, ROR1 is highly expressed in a variety of hema tological malignancies and solid tumors, and its expression is closely related to disease progressio n and treatment response. The aberrant expression of ROR1 and associated pro-proliferative signa ling observed in many types of malignancies make ROR1 an attractive therapeutic target for anti-cancer drug development. The Product was – 1 – designed to have homogeneous DAR distribution, better stab ility of the proprietary linker and reduced drug to antibody ratio in order to improve blood stability an d tumor-specific drug release for better safety profile and efficacy. About Radiance Biopharma Radiance Biopharma, based in Boston, Massachusetts, the Un ited States, is focused on developing a pipeline of antibody-based cancer therapeutics including mono and bispecific Antibody Drug Conjugates (ADCs) for the treatment of cancer and to address other unmet medical needs. Marc Lippman, MD, a co- founder and Chairman of the Board of Radiance Biopharma, is a renowned oncologist and former founding board member of Seagen Inc., a leader in the field of ADCs, whi ch was acquired by Pfizer Inc. in December 2023. For more information, please visit www.radi ancebiopharma.com. By order of the Board CSPC Pharmaceutical Group Limited CAI Dongchen Chairman Hong Kong, 19 February 2025 As at the date of this announcement, the Board comprises Mr. C AI Dongchen, Mr. ZHANG Cuilong, Mr. WANG Zhenguo, Mr. PAN Weidong, Mr. WANG Huaiyu, Dr. LI Chu nlei, Dr. YAO Bing, Mr. CAI Xin and Mr. CHEN Weiping as executive directors; and Mr. WANG Bo, Mr. CHEN Chuan, Prof. WANG Hongguang, Mr. AU Chun Kwok Alan, Mr. LAW Cheuk Kin Steph en and Ms. LI Quan as independent non-executive directors. – 2 –

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