SinoMab BioScience Limited — Capital/Financing Update 2019

Dec 6, 2019

Hong Kong Exchanges and Clearing Limited, The Stock Exchange of Hong Kong Limited (the “ Stock Exchange ”) and Hong Kong Securities Clearing Company Limited (“ HKSCC ”) 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.

Unless otherwise defined in this announcement, capitalized terms used herein shall have the same meanings as those defined in the prospectus dated 31 October, 2019 (the “ Prospectus ”) issued by SinoMab BioScience Limited (the “ Company ”).

This announcement is made pursuant to section 9(2) of the Securities and Futures (Price Stabilizing) Rules (Chapter 571W of the Laws of Hong Kong). This announcement is for information purposes only and does not constitute an offer or an invitation to induce offer by any person to acquire, purchase or subscribe for securities. Potential investors should read the Prospectus for detailed information about the Global Offering described below before deciding whether or not to invest in the Shares.

This announcement is not for release, publication, distribution, directly or indirectly, in or into the United States (including its territories, its possessions and all areas subject to its jurisdiction) or any other jurisdiction where such distribution is prohibited by law. This announcement does not constitute or form a part of any offer to sell or solicitation to purchase or subscribe for securities in Hong Kong, the United States or elsewhere. The securities mentioned herein have not been, and will not be, registered under the United States Securities Act of 1933 (the “ U.S. Securities Act ”) or with any securities regulatory authority of any state or other jurisdiction of the United States. The securities may not be offered or sold in the United States except pursuant to an exemption from, or in a transaction not subject to the registration requirements of the U.S. Securities Act and in compliance with any applicable state securities laws. There will be no public offer of securities in the United States.

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SinoMab BioScience Limited 中國抗體製藥有限公司 (Incorporated in Hong Kong with limited liability) Stock Code: 3681

LAPSE OF OVER-ALLOTMENT OPTION, STABILIZING ACTIONS AND END OF STABILIZATION PERIOD

LAPSE OF OVER-ALLOTMENT OPTION

The Company announces that the Over-allotment Option had not been exercised by the Joint Global Coordinators (on behalf of the International Underwriters) during the stabilization period and lapsed on 5 December 2019. Accordingly, no Shares were or will be issued under the Over-allotment Option.

The Company continues to comply with the public float requirements under Rule 8.08(1)(a) and Rule 18A.07 of the Listing Rules.

STABILIZING ACTIONS AND END OF STABILIZATION PERIOD

The Company further announces that the stabilization period in connection with the Global Offering ended on 5 December 2019, being the 30th day after the last day for the lodging of applications under the Hong Kong Public Offering. Stabilizing actions were undertaken by China International Capital Corporation Hong Kong Securities Limited, as the Stabilizing Manager, or any person acting for it, during the stabilization period, further information in relation to which is set out below.

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LAPSE OF OVER-ALLOTMENT OPTION

The Company announces that the Over-allotment Option had not been exercised by the Joint Global Coordinators (on behalf of the International Underwriters) during the stabilization period and lapsed on 5 December 2019. Accordingly, no Shares were or will be issued under the Over-allotment Option.

The Company continues to comply with the public float requirements under Rule 8.08(1)(a) and Rule 18A.07 of the Listing Rules.

STABILIZING ACTIONS AND END OF STABILIZATION PERIOD

The Company further announces that the stabilization period in connection with the Global Offering ended on 5 December 2019, being the 30th day after the last day for the lodging of applications under the Hong Kong Public Offering.

The Company has been informed by China International Capital Corporation Hong Kong Securities Limited, the Stabilizing Manager, that the stabilizing actions undertaken by it or any person acting for it during the stabilization period involved:

• (1) over-allocations of an aggregate of 27,319,200 Shares in the International Offering, representing approximately 15.0% of the Offer Shares initially available under the Global Offering before any exercise of the Over-allotment Option;

• (2) the borrowing of an aggregate of 27,319,200 Shares by the Stabilizing Manager from Skytech Technology pursuant to the Stock Borrowing Agreement to cover over-allocation of Shares in the International Offering. Such Shares will be returned and redelivered to Skytech Technology in accordance with the terms of the Stock Borrowing Agreement; and

• (3) the purchase of an aggregate of 27,319,200 Shares in the price range of HK$4.72 to HK$7.30 per Share (exclusive of brokerage fee of 1%, SFC transaction levy of 0.0027% and Hong Kong Stock Exchange trading fee of 0.005%, if any) on the market during the stabilization period, representing approximately 15.0% of the Offer Shares initially available under the Global Offering before any exercise of the Over-allotment Option.

The last purchase made by the Stabilizing Manager or its agent on the market during the course of the stabilization period was on 15 November 2019 at the price of HK$4.80 per Share (excluding brokerage of 1%, SFC transaction levy of 0.0027% and Hong Kong Stock Exchange trading fee of 0.005%).

By order of the Board SinoMab BioScience Limited Dr. Shui On LEUNG Executive Director, Chairman and Chief Executive Officer

Hong Kong, 6 December 2019

As at the date of this announcement, the executive Director is Dr. Shui On LEUNG, the non-executive Directors are Ms. Wenyi LIU, Dr. Haigang CHEN, Mr. Senlin LIU, Mr. Chang LIU and Mr. Huiyuan MA, and the independent non-executive Directors are Mr. Dylan Carlo TINKER, Mr. Michael James Connolly HOGAN and Mr. Ping Cho Terence HON.

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