Shanghai Junshi Biosciences : VOLUNTARY ANNOUNCEMENT - ENTERING INTO THE DRUG DEVELOPMENT AND LICENSE CONTRACT WITH HANGZHOU DAC

Hong Kong Exchanges and Clearing Limited and The Stock Exchange 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 whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement.

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 -

ENTERING INTO THE DRUG DEVELOPMENT AND

LICENSE CONTRACT WITH HANGZHOU DAC

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 Company has entered into the Drug Development and License Contract (the "Agreement") with Hangzhou DAC Biotech Co., Ltd ("Hangzhou DAC").

According to the Agreement, the Company obtained a license to use DAC-002 (recombinant humanized anti-Trop2 monoclonal antibody - Tub196 conjugate for injection) from Hangzhou DAC by way of an exclusive license, responsible for subsequent clinical trials, drug registration, commercial production, sales and other commercial activities of DAC-002 in the licensed area (all Asian countries and regions excluding Japan and South Korea). According to the Agreement, Hangzhou DAC will receive a down payment of RMB30 million and a sample preparation fee of RMB2.268 million. From the approval for investigational new drug application to the approval for new drug application in respect of DAC-002 in the abovementioned licensed area, the Company will make Hangzhou DAC accumulative milestone payments of not more than RMB270 million based on the R&D progress, and pay 6% to 10% of its annual sales revenue to Hangzhou DAC after sales of DAC-002 is commercialized.

ABOUT DAC-002

DAC-002 is an anti-Trop2 monoclonal antibody conjugated with an antitubulin Tubulysin B analog through a smart linker. It is mainly used to treat solid tumors such as Trop2-positive triple negative breast cancer, small cell lung cancer, and pancreatic cancer. Currently, an application for clinical trials has been submitted to and has been accepted by National Medical Products Administration.

ABOUT HANGZHOU DAC

Hangzhou DAC is located in Hangzhou Economic and Technological Development Zone, Zhejiang Province, focusing on the research and development of antibody-drug conjugates targeting for cancer treatment.

The Company currently holds approximately 4.5479% in the shares of Hangzhou DAC. To the best knowledge, information and belief of the directors of the Company, Hangzhou DAC is not a connected person (as defined in the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited (the "Listing Rules")) of the Company.

1

IMPACT OF THE AGREEMENT ON THE COMPANY

The entering into of the Agreement is in line with the development need of the Company and will further enrich the research and development pipeline of the Company's drugs, and is expected to have a positive impact on the Company's continued operations.

RISK WARNING

DAC-002 , for which the Company has obtained an exclusive license, is still in the clinical trial application stage, and there are uncertainties in its final clinical trial and commercialization. The Company will perform corresponding procedures and information disclosure obligations based on the subsequent progress of the Agreement. Investors are advised to make decisions in a prudent manner and pay attention to investment risks.

Cautionary Statement required by Rule 18A.05 of the Listing Rules: The Company may not be able to ultimately develop and market DAC-002successfully. Investors are reminded to exercise caution.

By Order of the Board of Directors

Shanghai Junshi Biosciences Co., Ltd.*

Mr. Xiong Jun

Chairman

Shanghai, PRC, 3 December 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.

• For identification purposes only

2