Shanghai Junshi Biosciences Co., Ltd. — Proxy Solicitation & Information Statement 2025

Sep 15, 2025

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this notice, 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 notice.

君实生物 TopAlliance

SHANGHAI JUNSHI BIOSCIENCES CO., LTD.*

上海君寶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)

SUPPLEMENTAL NOTICE OF EXTRAORDINARY GENERAL MEETING

References are made to the circular (the "Circular") of Shanghai Junshi Biosciences Co., Ltd.* (the "Company") and the notice (the "Notice of EGM") convening the 2025 first extraordinary general meeting (the "EGM") dated 5 September 2025, and the announcement in relation to the adjournment of the EGM (the "Announcement") and the supplemental circular (the "Supplemental Circular") dated 15 September 2025. Unless otherwise defined, capitalized terms used in this supplemental notice shall have the same meanings as those defined in the Circular and the Supplemental Circular.

SUPPLEMENTAL NOTICE IS HEREBY GIVEN that the 2025 first extraordinary general meeting (the "EGM") of Shanghai Junshi Biosciences Co., Ltd.* (the "Company") will be adjourned to be held at 15th Floor, Building 7, No. 6, Lane 100, Pingjiaqiao Road, Pudong New Area, Shanghai, the People's Republic of China on Monday, 29 September 2025 at 2:40 p.m., for the following purpose of considering, if thought fit, passing the resolution set out below in addition to those contained in the Notice of EGM:

SPECIAL RESOLUTIONS

1. The proposal in relation to the proposed grant of H Share Options to Mr. Zhang Zhuobing conditional upon the adoption of the 2025 H Share Option Incentive Scheme of the Company.

2. The proposal in relation to the proposed grant of H Share Options to Dr. Yao Sheng conditional upon the adoption of the 2025 H Share Option Incentive Scheme of the Company.

By Order of the Board

Shanghai Junshi Biosciences Co., Ltd.*

Mr. Xiong Jun

Chairman

Shanghai, the PRC, 15 September 2025

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Notes:

1. Pursuant to the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited (the "Stock Exchange") (the "Listing Rules"), any vote of shareholders at a general meeting will be taken by poll. As such, each of the resolutions set out in the Notice of EGM and this supplemental notice of EGM will be voted by poll. Results of the poll will be published on the Company's website at www.junshipharma.com and the Stock Exchange's website at http://www.hkexnews.hk after the EGM in accordance with the Listing Rules.

2. The register of members of H shares of the Company will be closed from Monday, 22 September 2025 to Friday, 26 September 2025, both days inclusive, during which period no transfer of H shares of the Company will be registered, in order to determine the entitlements of the shareholders of the Company to attend and vote at the EGM. The record date for determining the eligibility of the Shareholders to attend and vote at the EGM will be Friday, 26 September 2025. In order to be eligible to attend and vote at the EGM, all transfers of H shares accompanied by the relevant share certificates and transfer forms must be lodged with the Company's H share registrar, Tricor Investor Services Limited at 17/F, Far East Finance Centre, 16 Harcourt Road, Hong Kong (for holders of H shares) before 4:30 p.m. on Friday, 19 September 2025, being the last share registration date. Any person who becomes a H Shareholder during the period from Friday, 26 September 2025 to Monday, 29 September 2025 (both days inclusive) is not entitled to attend or vote at the EGM.

3. A shareholder entitled to attend and vote at the meeting may appoint one or more persons as his/her proxy(ies) to attend and vote on his/her behalf. A proxy need not be a shareholder of the Company but must attend the meeting in person to represent the member.

4. The instrument appointing a proxy must be in writing and signed by the appointing shareholder or his duly authorized attorney in writing. Where the appointing shareholder is a legal entity, such instrument must be either under its common seal or duly signed by its legal representative, director(s) or duly authorized attorney(s).

5. Shareholders who intend to attend the meeting by proxy should complete the proxy form. For holders of H shares, the proxy form should be returned to the Company's H Share registrar, Tricor Investor Services Limited at 17/F, Far East Finance Centre, 16 Harcourt Road, Hong Kong, in person or by post as soon as possible not less than 24 hours before the time fixed for holding the meeting or any adjournment thereof. Completion and return of the proxy form will not preclude you from attending the meeting and any adjournment thereof and voting in person. In such event, the form of proxy shall be deemed to be revoked.

6. The EGM is expected to last for less than half a day. Shareholders (in person or by proxy) who attend the EGM should bear their own transportation and accommodation expenses. Shareholders or their proxies attending the EGM shall present their identification documents.

7. Where there are joint registered holders of any share, any one of such persons may vote at the meeting, either in person or by proxy, in respect of such share as if he/she were solely entitled thereto; but if more than one of such joint holders be present at the meeting, the vote of the senior holder who tenders a vote, whether in person or by proxy, shall be accepted to the exclusion of the votes of the other joint holders and, for this purpose, seniority shall be determined by the order in which the names stand in the register of members of the Company in respect of the joint holding.

8. Unless otherwise stated, capitalized terms used herein shall have the same meanings as that defined in the circular of the Company dated 5 September 2025 ("Circular") and the supplemental circular of the Company dated 15 September 2025 ("Supplemental Circular"). References to times and dates in this supplemental notice of EGM are to Hong Kong local times and dates.

9. Further details of the resolutions have been included in the Supplemental Circular.

10. This supplemental notice of EGM is for holders of H shares only. The supplemental notice of EGM for the holders of A Shares is separately published on the website of the Shanghai Stock Exchange (http://www.sse.com.cn/).

As at the date of this notice, the Board of Directors of the Company comprises Mr. Xiong Jun, Dr. Li Ning, Dr. Zou Jianjun, Mr. Li Cong, Mr. Zhang Zhuobing, Dr. Yao Sheng, Dr. Wang Gang and Dr. Li Xin as executive Directors; Mr. Tang Yi as a non-executive Director; and Mr. Zhang Chun, Dr. Feng Xiaoyuan, Dr. Yang Yue, Mr. Li Zhongxian and Ms. Lu Kun as independent non-executive Directors.

• For identification purpose only

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