Shanghai Junshi Biosciences : VOLUNTARY ANNOUNCEMENT - JS103 INJECTION RECEIVED THE CLINICAL TRIAL APPROVAL

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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 -

JS103 INJECTION RECEIVED THE CLINICAL TRIAL APPROVAL

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. Reference is also made to the overseas

regulatory announcement of the Company dated 12 May 2021.

The board (the "Board") of directors (the "Directors") of the Company is pleased to announce that, the Company has received the Clinical Trial Approval 《( 藥物臨床試驗批准通知書》) issued

by the National Medical Products Administration. The investigational new drug application for the JS103 injection (product code: "JS103") has been approved. Relevant information is as follows:

ABOUT JS103 INJECTION

Drug name: JS103 injection

Application matter: Registration of Domestic Production of Pharmaceutical Product

Acceptance No.: CXSL2100083

Applicant: Shanghai Junshi Biosciences Co., Ltd.* (上海君實生物醫藥科技股份有限公司)

Review conclusion: According to the Drug Administration Law of the People's Republic of China and relevant regulations, upon review, the JS103 injection accepted on 4 March 2021 meets the relevant requirements for drug registration and is approved to conduct clinical trials for the treatment of gout.

JS103 is a pegylated uricase derivative developed independently by the Company that is mainly used for the treatment of hyperuricemia with or without gout. JS103 catalyses the oxidation of uric acid to form an allantoin with significantly higher solubility than that of uric acid, thereby achieving the effect of reducing blood uric acid. Hyperuricemia is a metabolic disorder syndrome caused by excessive production of uric acid or obstruction of uric acid excretion due to purine metabolic disorder, as a result of which uric acid exceeds the critical limits in blood. Gout is a crystal-associated arthropathy caused by the deposition of monosodium urate, which is

directly related to hyperuricemia. According to the Guidelines for the Diagnosis and Treatment of Hyperuricemia and Gout in China (2019) 《( 中國高尿酸血症與痛風診療指南(2019)》), the

overall prevalence of hyperuricemia and gout in China is 13.3% and 1.1%, respectively. Gout and associated diseases caused by hyperuricemia are among the most common chronic diseases in China. Therefore, the development of JS103 is expected to bring more treatment options to patients.

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RISK WARNING

Due to the high-tech,high-risk and high-value-added characteristics of pharmaceutical products, there are substantial risks and uncertainties in the process of drug research, development and commercialization. These many stages make it susceptible to uncertainties and therefore, investors are advised to make cautious decisions and pay careful attention to investment risks. The Company will actively pursue the above research and development projects and fulfill its information disclosure obligations in a timely manner for subsequent progress in strict accordance with relevant regulations.

By order of the Board

Shanghai Junshi Biosciences Co., Ltd.*

Mr. Xiong Jun

Chairman

Shanghai, the PRC, 12 May 2021

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 and Dr. Yao Sheng as executive Directors; Dr. Wu Hai, Mr. Tang Yi, Mr. Li Cong, Mr. Yi Qingqing and Mr. Lin Lijun as non-executive Directors; and Dr. Chen Lieping, Mr. Qian Zhi, Mr. Zhang Chun, Dr. Jiang Hualiang and Dr. Roy Steven Herbst as independent non-executive Directors.

• For identification purpose only

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