PegBio Co., Ltd. — Share Issue/Capital Change 2026

Mar 10, 2026

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.

PegBio Co., Ltd.

派格生物醫藥(杭州)股份有限公司

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

(Stock Code: 2565)

CHANGE IN BOARD LOT SIZE

The board of directors (the "Board") of PegBio Co., Ltd. (the "Company") announces that the board lot size of the H shares of RMB1.00 each in the capital of the Company (the "H Shares") for trading on the Main Board of The Stock Exchange of Hong Kong Limited (the "Stock Exchange") will be changed from 500 H Shares to 50 H Shares with effect from 9:00 a.m. on Tuesday, March 31, 2026.

The H Shares are currently traded in board lots of 500 H Shares each. The Board expects that the reduction in board lot size will lower the threshold for investors to purchase the H Shares, thus facilitating the trading and improving the liquidity of the H Shares. Upon the change in board lot size becoming effective, the H Shares shall be traded in board lots of 50 H Shares each. Upon the change in board lot size becoming effective, the market value of the then board lot of 50 H Shares each will be HK$2,590 (based on the closing price of HK$51.8 per Share as quoted on the Stock Exchange as at the date of this announcement).

The change in board lot size will not result in any change in the relative rights of the shareholders of the Company. As no odd lot of the H Shares will result from the aforesaid change in board lot size, no odd lot arrangement is required to be made to match the sales and purchases of odd lots. The Board considers that the change in board lot size to be in the interest of the Company and its shareholders as a whole.

EXPECTED TIMETABLE

Event

First day of free exchange of existing share certificates in board lots of 500 H Shares each for new share certificates in board lots of 50 H Shares each

Last day for trading of the H Shares in board lots of 500 H Shares each in the original counter

Hong Kong Date and Time

Tuesday, March 17, 2026

Monday, March 30, 2026

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Event	Hong Kong Date and Time
Effective date of the change in board lot size from 500 H Shares to 50 H Shares each	Tuesday, March 31, 2026
Original counter for trading in the H Shares in board lots of 500 H Shares each becomes a counter for trading in the H Shares in board lots of 50 H Shares each	9:00 a.m., Tuesday, March 31, 2026
Temporary counter for trading in the H Shares in board lots of 500 H Shares each opens	9:00 a.m., Tuesday, March 31, 2026
First day of parallel trading in the H Shares (in board lots of 50 H Shares each and board lots of 500 H Shares each)	9:00 a.m., Tuesday, March 31, 2026
Last day of parallel trading in the H Shares (in board lots of 500 H Shares each and board lots of 50 H Shares each)	4:10 p.m., Thursday, April 23, 2026
Temporary counter for trading in the H Shares in board lots of 500 H Shares each closes	4:10 p.m., Thursday, April 23, 2026
Last day for submission of H Share certificates in board lots of 500 H Shares each for new H Share certificates in board lots of 50 H Shares each	4:30 p.m., Monday, April 27, 2026

EXCHANGE OF NEW H SHARE CERTIFICATES

Shareholders of the Company may submit their existing H Share certificates in board lots of 500 H Shares each to the Company's branch registrar in Hong Kong, Computershare Hong Kong Investor Services Limited (the "H Share Registrar") at Shops 1712-1716, 17/F, Hopewell Centre, 183 Queen's Road East, Wanchai, Hong Kong, in exchange for new H Share certificates in board lots of 50 H Shares each free of charge during business hours from 9:00 a.m., Tuesday, March 17, 2026 to 4:30 p.m., Monday, April 27, 2026 (both days inclusive). After the expiry of such period, existing H Share certificates will be accepted for exchange only on payment of a fee of HK$2.50 (or such higher amount as may from time to time be specified by the Stock Exchange) for each new H Share certificate in board lots of 50 H Shares each issued or each existing H Share certificate submitted, whichever number of H Share certificate involved is higher. It is expected that the new H Share certificates will be available for collection from the Share Registrar by the shareholders of the Company within 10 business days after delivery of the existing H Share certificates to the Share Registrar for the purpose of exchange.

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With effect from March 31, 2026, all new H Share certificates will be issued in board lots of 50 H Shares each (except for odd lots or where the Share Registrar is otherwise instructed). All existing H Share certificates in board lots of 500 H Shares each will continue to be good evidence of title to such H Shares and be valid for transfer, delivery and settlement purposes. Save and except for the change in the number of H Shares for each board lot, the new H Share certificates (for H Shares in board lots of 50 H Shares each) will have the same design and colour as the existing H Share certificates (for H Shares in board lots of 500 H Shares each).

By order of the Board

PegBio Co., Ltd.

Michael Min XU

Chairman of the Board, Executive Director

and General Manager

Hong Kong, March 10, 2026

As of the date of this announcement, the board of directors of the Company comprises: (i) Dr. Michael Min XU and Ms. Xiaojun WANG as executive directors; (ii) Dr. Xiangjun ZHOU, Dr. Yuhong XU, Ms. Ting ZHAI and Mr. Hongkai LI as non-executive directors; and (iii) Dr. Jiancun ZHANG, Dr. Yangyang CHEN and Ms. Xinpeng FAN as independent non-executive directors.

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