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Shenyang Sunshine Pharmaceutical Co., Ltd. (“Shenyang Sunshine”), a subsidiary of 3SBio Inc. (the “Company”), and its subsidiaries entered into a cooperation agreement with Duality Biologics (Shanghai) Co., Ltd. (“Duality Biologics”), a clinical-stage innovative biopharmaceutical company focusing on the research and development of next-generation ADC therapeutic agents for patients suffering from cancers and autoimmune diseases, in respect of a HER2 ADC drug DB-1303. Pursuant to the agreement, Shenyang Sunshine will obtain the commercialization right of the HER2 ADC drug DB-1303 developed by Duality Biologics for various indications in Mainland China, Hong Kong and Macau. Shenyang Sunshine will pay Duality Biologics an initial payment as well as research and development and sales milestone payments in accordance with the agreement. Meanwhile, Duality Biologics will continue to be responsible for the clinical development, registration and other works of the relevant indications in the cooperation regions.