SinoMab BioScience : PROPOSED ELECTION OF INDEPENDENT NON-EXECUTIVE DIRECTOR AND SUPPLEMENTAL NOTICE OF ANNUAL GENERAL MEETING

THIS CIRCULAR IS IMPORTANT AND REQUIRES YOUR IMMEDIATE ATTENTION

If you are in any doubt as to any aspect of this circular or as to the action to be taken, you should consult a stockbroker or other registered dealer in securities, a bank manager, solicitor, professional accountant or other professional adviser.

If you have sold or transferred all your shares in SinoMab BioScience Limited, you should at once hand this circular, together with the enclosed form of proxy, to the purchaser or transferee or to the bank, stockbroker or other agent through whom the sale or transfer was effected for transmission to the purchaser or transferee.

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

SinoMab BioScience Limited

中國 抗體製藥有 限公司

(Incorporated in Hong Kong with limited liability)

(Stock code: 3681)

PROPOSED ELECTION OF

INDEPENDENT NON-EXECUTIVE DIRECTOR

AND

SUPPLEMENTAL NOTICE OF ANNUAL GENERAL MEETING

This supplemental circular should be read together with the circular of the Company dated 29 April 2021 and the notice convening an annual general meeting of the Company to be held at 10:00 a.m. on Tuesday, 15 June 2021 at Theater R1, 10/F, United Centre, 95 Queensway, Admiralty, Hong Kong. A supplemental notice of the 2021 AGM is set out on pages 8 to 10 of this supplemental circular. A revised form of proxy (the "Revised Proxy Form") is also attached with this supplemental circular.

Whether or not you are able to attend the 2021 AGM, please complete and sign the enclosed form of proxy for use at the 2021 AGM in accordance with the instructions printed thereon and return it to the Company's share registrar in Hong Kong, Computershare Hong Kong Investor Services Limited, at 17M Floor, Hopewell Centre, 183 Queen's Road East, Wanchai, Hong Kong as soon as possible but in any event not less than 48 hours (excluding any part of a day that is a public holiday) before the time fixed for holding the 2021 AGM (i.e. not later than 10:00 a.m. on Friday, 11 June 2021 (Hong Kong time)) or the adjourned meeting (as the case may be). Completion and return of the form of proxy will not preclude Shareholders from attending and voting in person at the 2021 AGM if they so wish.

This supplemental circular and the accompanying Revised Proxy Form are also published on the websites of Hong Kong Exchanges and Clearing Limited (www.hkexnews.hk) and the Company (www.sinomab.com).

12 May 2021

	CONTENTS
		Page
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1
Letter from the Board
1.	Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	3
2.	Proposed Election of Independent Non-executive Director . . . . . . . . . . . .	4
3.	2021 AGM and Proxy Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
4.	Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
Supplemental Notice of 2021 AGM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8

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DEFINITIONS

In this supplemental circular, unless the context otherwise requires, the following expressions shall have the following meanings:

"2021 AGM"	the annual general meeting of the Company to be held at
	10:00 a.m. on Tuesday, 15 June 2021 at Theater R1, 10/F,
	United Centre, 95 Queensway, Admiralty, Hong Kong, or
	any adjournment thereof
"Articles of Association"	the articles of association of the Company currently in
	force
"Board"	the board of Directors
"Company"	SinoMab BioScience Limited (中國抗體製藥有限公司), a
	company incorporated in Hong Kong with limited
	liability, the Shares of which are listed on the Main Board
	of the Stock Exchange
"Director(s)"	the director(s) of the Company
"Group", "our Group", "we",	the Company and its subsidiaries at the relevant time
"our" or "us"
"Hong Kong"	the Hong Kong Special Administrative Region of the
	People's Republic of China
"Latest Practicable Date"	5 May 2021, being the latest practicable date prior to the
	printing of this supplemental circular for ascertaining
	certain information in this supplemental circular
"Listing Rules"	the Rules Governing the Listing of Securities on the
	Stock Exchange as amended, supplemented or otherwise
	modified from time to time
"Notice of 2021 AGM"	the notice convening the 2021 AGM of the Company
	dated 29 April 2021
"Original Proxy Form"	the proxy form of the Company dated 29 April 2021
"Revised Proxy Form"	the new proxy form applicable for the 2021 AGM, which
	contains the additional resolution to be proposed at the
	2021 AGM, and is enclosed with this supplemental
	circular and the Supplemental Notice of 2021 AGM

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	DEFINITIONS
"SFO"	the Securities and Futures Ordinance (Chapter 571 of the
	Laws of Hong Kong), as amended, supplemented or
	otherwise modified from time to time
"Share(s)"	ordinary share(s) in the issued capital of the Company or
	if there has been a subsequent sub-division,
	consolidation, reclassification or reconstruction of the
	share capital of the Company, share(s) forming part of the
	ordinary equity share capital of the Company
"Shareholder(s)"	holder(s) of the Share(s)
"Skytech Technology"	Skytech Technology Limited, a limited company
	incorporated in the British Virgin Islands on 2 January
	2001 and wholly owned by Dr. Shui On LEUNG, a
	substantial Shareholder of the Company
"Stock Exchange"	The Stock Exchange of Hong Kong Limited
"Supplemental Notice of 2021	the supplemental notice convening the 2021 AGM
AGM"	appended to this supplemental circular

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LETTER FROM THE BOARD

SinoMab BioScience Limited

中國 抗體製藥有 限公司

(Incorporated in Hong Kong with limited liability)

(Stock code: 3681)

Executive Director:	Registered Office:
Dr. Shui On LEUNG (Chairman and Chief Executive Officer)	Level 54, Hopewell Centre
	183 Queen's Road East
Non-executive Directors:	Hong Kong
Dr. Haigang CHEN
Mr. Xun DONG
Mr. Senlin LIU
Ms. Wenyi LIU
Mr. Huiyuan MA
Mr. Jing QIANG
Independent Non-executive Directors:
Mr. George William Hunter CAUTHERLEY
Mr. Michael James Connolly HOGAN
Mr. Ping Cho Terence HON
Mr. Dylan Carlo TINKER
	12 May 2021
To the Shareholders
Dear Sir/Madam,

PROPOSED ELECTION OF

INDEPENDENT NON-EXECUTIVE DIRECTOR

AND

SUPPLEMENTAL NOTICE OF ANNUAL GENERAL MEETING

1. INTRODUCTION

This supplemental circular should be read together with the circular of the Company dated 29 April 2021 (the "Circular"). Unless indicated otherwise, the terms used in this supplemental circular shall have the same meaning as those defined in the Circular.

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