Shanghai Junshi Biosciences : VOLUNTARY ANNOUNCEMENT - UPDATE ON JUPITER-02 STUDY

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SHANGHAI JUNSHI BIOSCIENCES CO., LTD.*

上海君實生物醫藥科技股份有限公司

(a joint stock company incorporated in the People's Republic of China with limited liability)

(Stock code: 1877)

VOLUNTARY ANNOUNCEMENT-UPDATE ON JUPITER-02 STUDY

This announcement is made by Shanghai Junshi Biosciences Co., Ltd.* (上海君實生物醫藥科技股 份有限公司) (the "Company") on a voluntary basis.

The board (the "Board") of directors (the "Directors") of the Company is pleased to announce that a Phase III clinical study (JUPITER-02 study) of Tuoyi* (generic name: Toripalimab injection) combined with chemotherapy as a first-line treatment in patients with recurrent or metastatic nasopharyngeal cancer has completed the enrollment of 280 patients of the study design.

The JUPITER-02 (NCT03581786) is a randomized, placebo-controlled,double-blind and multi-center Phase III clinical study conducted in the Asia-Pacific region to evaluate the efficacy and safety of Toripalimab injection combined with Gemcitabine/cisplatin as a first-line treatment in patients with recurrent or metastatic nasopharyngeal cancer. It is also the first randomized controlled pivotal registrational clinical trial of anti-PD-1 monoclonal antibody for the treatment of nasopharyngeal cancer that has been established and has achieved the enrollment goal of the study design globally. As of the date of this announcement, the enrollment of 280 patients of the study design was completed.

ABOUT TUOYI* (TORIPALIMAB INJECTION)

Tuoyi*, as the first domestic anti-PD-1 monoclonal antibody that has obtained marketing approval, received support from the National Science and Technology Major Project. The clinical investigation and research of Toripalimab injection has commenced since the beginning of 2016. So far, more than 30 clinical studies covering more than ten indications have been carried out in the PRC, the United States and other countries. In March 2018, the National Medical Products Administration of the PRC officially accepted the application for marketing approval of Toripalimab injection, and included it in the priority review and approval category to speed up the review and approval. The results of the pivotal registrational clinical trials for which Toripalimab injection has been approved for marketing indications show that the objective response rate (ORR) for patients with unresectable or metastatic melanoma after failure of systemic treatment is 17.3%, the disease control rate (DCR) is 57.5%, and the one-year survival rate is up to 69.3%. The Company considers that the marketing approval of Toripalimab injection has positive effect in solving the clinical drug selection problem of cancer patients in the PRC.

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ABOUT JUPITER-02

The JUPITER-02 is a randomized, placebo-controlled,double-blind and multi-center Phase III clinical study with an aim to compare the efficacy and safety of Toripalimab injection combined with Gemcitabine/cisplatin with that of a placebo combined with Gemcitabine/cisplatin, as a first- line treament in patients with recurrent or metastatic nasopharyngeal cancer. JUPITER-02 is the world's first randomized controlled pivotal registrational clinical trial of anti-PD-1 monoclonal antibody for the treatment of nasopharyngeal cancer that has been established and has achieved the enrollment goal of the study design. As of the date of this announcement, the enrollment of 280 patients of the study design was completed. Such trial is studied with a primary endpoint of progression-free survival (PFS), and secondary endpoints including overall survival (OS), ORR, duration of response (DOR) and DCR.

At the time of this announcement, in view of the fact that the above research is still at the clinical trial stage, shareholders and potential investors are advised to be cautious of the investment risks. The Company will pay close attention and make disclosure (if required) in a timely manner according to the subsequent progress of such clinical research.

By order of the Board

Shanghai Junshi Biosciences Co., Ltd.*

Mr. Xiong Jun

Chairman

Shanghai, the PRC, 20 November 2019

As at the date of this announcement, the board of directors of the Company comprises Mr. Xiong Jun, Dr. Li Ning, Dr. Feng Hui, Mr. Zhang Zhuobing, Dr. Wu Hai and Dr. Yao Sheng as executive Directors; Mr. Tang Yi, Mr. Li Cong, Mr. Yi Qingqing and Mr. Lin Lijun as non-executive Directors; and Dr. Chen Lieping, Dr. He Jia, Mr. Chen Xinjun, Mr. Qian Zhi and Dr. Roy Steven Herbst as independent non-executive Directors.

Cautionary Statement required by Rule 18A.05 of the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited: The Company may not be able to ultimately develop and market JUPITER-02successfully. Investors are reminded to exercise caution.

• For identification purpose only

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