REMEGEN - Overseas regulatory announcement - Announcement on the progress of the first centralized bidding transaction to repurchase the company's shares in 2026

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RemeGen Co., Ltd.*

Rongchang Biopharmaceutical (Yantai) Co., Ltd. (a joint stock limited company incorporated in the People's Republic of China) (Stock code: 9995)

Overseas regulatory announcement

This announcement is made by Rongchang Biopharmaceuticals in accordance with Rule 13.10B of the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited. (Yantai) Co., Ltd. (the "Company").

The announcement published by the Company on the website of the Shanghai Stock Exchange is set out below for reference only.

By order of the board of directors Rongchang Biopharmaceutical (Yantai) Co., Ltd.

Chairman and Executive Director Mr. Wang Weidong

Yantai, China August 3, 2026

As at the date of this announcement, members of the Board of Directors include executive directors Mr. Wang Weidong, Dr. Fang Jianmin, and Wen Qingkaixian. Sheng, Ms. Fang Yi and Mr. Wang Yuxiao; non-executive director Dr. Wang Liqiang; and independent non-executive director Song Xiliang

Mr. Huang Guobin and Mr. Chen Yunjin.

*For identification only

Securities code: 668888333311 Securities abbreviation: Rongrongchangchang Biotechnology Announcement No.: 22002266--003377

Rongrongchangchangsheng Biopharmaceutical ((Yantaitai)) Co., Ltd.

Regarding the repurchase of company shares for the first time in the year through a centralized bidding transaction. 2026

Announcement on the progress of

The board of directors and all directors of the company guarantee that the contents of this announcement do not contain any false records or misleading statements. or major omissions, and shall bear legal responsibility for the authenticity, accuracy and completeness of its content.

Important content reminder:

The first disclosure date of the repurchase plan is 2026/7/20 The implementation period of the buyback plan is July 19, 2026 ~ July 18, 2027 The estimated repurchase amount is 25 million yuan to 50 million yuan □Reduce registered capital √Used for employee stock ownership plans or equity incentives Repurchase purpose □Used to convert company convertible bonds □To protect the company’s value and shareholders’ rights and interests Cumulative number of shares repurchased: 13,000 shares The cumulative number of repurchased shares accounts for 0.0023% of the total share capital.

The cumulative repurchase amount is 1,428,220 yuan Actual repurchase price range: 109.00 yuan/share~109.99 yuan/share

11. Basic information on the repurchase of shares

Rongchang Biopharmaceutical (Yantai) Co., Ltd. (hereinafter referred to as the "Company") on July 19, 2026

The second meeting of the third session of the Board of Directors was held on July 1, and the "About the first centralized bidding transaction in 2026" was reviewed and approved

Proposal on the plan to repurchase the company's shares through an easy way. Agree that the company uses its own funds and/or self-raised funds to focus

Repurchase some of the company's issued RMB ordinary shares (A shares) through bidding transactions, with the total amount of funds planned to be repurchased The amount of the repurchased shares shall not be less than RMB 25 million (inclusive) and not exceed RMB 50 million (inclusive).

It will be used for employee stock ownership plans or equity incentives at an appropriate time in the future, and the repurchase price shall not exceed RMB 149/

shares (inclusive), the period for repurchasing shares is within 12 months from the date the company’s board of directors considers and approves the repurchase plan.

For details, please refer to the company’s website on the Shanghai Stock Exchange on July 20, 2026 (www.sse.com.cn)

The disclosed "Rongchang Biopharmaceutical (Yantai) Co., Ltd.'s first centralized bidding transaction in 2026"

Plan to repurchase the company's shares" (announcement number: 2026-033), "Rongchang Biopharmaceutical (Yantai) shares

Co., Ltd.’s repurchase report on the company’s first repurchase of the company’s shares through centralized bidding transactions in 2026 (public

Report No.: 2026-034).

22. Progress of the repurchase of shares

According to the "Share Repurchase Rules of Listed Companies" and "Self-Regulatory Supervision Guidelines for Listed Companies of the Shanghai Stock Exchange" No. 7

No.—Repurchase of Shares" and other relevant regulations, during the period of implementation of repurchase, the company shall make the first three transactions of each month.

Yiday announced the progress of the repurchase as of the end of last month. The company’s first share repurchase plan in 2026 is now The repurchase progress announcement is as follows:

As of July 31, 2026, the company traded through centralized bidding through the Shanghai Stock Exchange trading system

The company has repurchased a total of 13,000 shares of the company, accounting for 0.0023% of the company’s total share capital of 564,477,483 shares. The highest price of the repurchase transaction is 109.99 yuan/share, the lowest price is 109.00 yuan/share, and the total amount of funds paid is

RMB 1,428,220 (excluding transaction fees such as transaction commissions).

This share repurchase complies with relevant laws and regulations and the requirements of the company's share repurchase plan.

33. Other matters

The company will strictly follow the "Share Repurchase Rules of Listed Companies" and the "Self-Discipline Supervision of Listed Companies of the Shanghai Stock Exchange".

According to relevant regulations such as Management Guideline No. 7 - Repurchase of Shares, decisions should be made based on market conditions during the repurchase period.

Make repurchase decisions and implement them, and at the same time perform information disclosure obligations in a timely manner based on the progress of the share repurchase matter. Investors are advised to pay attention to investment risks.

Announcement is hereby made.

Board of Directors of Rongchang Biopharmaceutical (Yantai) Co., Ltd. August 4, 2026