Clover Biopharmaceuticals, Ltd. — Capital/Financing Update 2024

Oct 28, 2024

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.

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Clover Biopharmaceuticals, Ltd. 三葉草生物製藥有限公司

(Incorporated in the Cayman Islands with limited liability) (Stock Code: 2197)

VOLUNTARY ANNOUNCEMENT

CLOVER ANNOUNCES POSITIVE CLINICAL DATA FOR RSV VACCINE CANDIDATE SCB-1019 COMPARED HEAD-TO-HEAD VERSUS GSK’S AREXVY

This announcement is made by the board (the “ Board ”) of directors (the “ Directors ”) of Clover Biopharmaceuticals, Ltd. (the “ Company ” or “ Clover ”, together with its subsidiaries, the “ Group ”) on a voluntary basis to inform the shareholders of the Company and potential investors on the latest business development of the Group.

The Company is pleased to announce the positive additional immunogenicity and safety data in older adult & elderly subjects from its Phase I trial evaluating SCB-1019 – the Company’s nonadjuvanted bivalent RSV prefusion-stabilized F (PreF)-Trimer subunit vaccine candidate based on Clover’s Trimer-Tag vaccine technology platform – compared head-to-head with GSK’s AS01E-adjuvanted RSV vaccine (AREXVY).

In the ongoing Phase I trial, 70 older adult & elderly subjects were enrolled and received either Clover’s SCB-1019, GSK’s AREXVY or saline placebo. Preliminary results for immunogenicity and safety for SCB-1019 are summarized below:

Immunogenicity Results

• RSV Neutralizing Antibodies (nAbs): Non-adjuvanted SCB-1019 induced geometric mean titers (GMTs) in RSV-A and RSV-B nAbs that were comparable to AS01E- adjuvanted AREXVY at Day 28, with no statistically significant differences observed.

• RSV-A nAbs: SCB-1019 induced GMTs in RSV-A nAbs of approximately 30,500 IU/mL, compared to approximately 26,700 IU/mL for AREXVY and approximately 3,300 IU/mL for placebo at Day 28.

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• RSV-B nAbs: SCB-1019 induced GMTs in RSV-B nAbs of approximately 32,000 IU/mL, compared to approximately 37,700 IU/mL for AREXVY and approximately 2,900 IU/mL for placebo at Day 28.

• RSV-B Specific Antibodies: SCB-1019 (bivalent RSV-A/B) included an approximately 1.5fold higher trend in antibodies (Geometric Mean Ratio, GMR) against a potent RSV-B specific neutralization epitope in Site V compared to AREXVY (monovalent RSV-A), based on an exploratory competitive-ELISA assay, indicating the potential for greater and more sustained immunological breadth upon re-vaccination if confirmed in subsequent studies.

Safety & Reactogenicity Results

• Significantly lower rates of local adverse events (AEs) were observed for non-adjuvanted SCB1019 (16.7%) compared to AS01E-adjuvanted AREXVY (76.7%).

• SCB-1019 was generally well-tolerated. Local and systemic AEs were generally mild for SCB1019 and were comparable to saline placebo.

• No vaccine related serious adverse events (SAEs), adverse events of special interest (AESIs), or AEs leading to discontinuation were observed.

Based on these positive Phase I trial results, the Company plans to initiate clinical trials in 2025 evaluating SCB-1019 (non-adjuvanted bivalent RSV-A/B vaccine candidate) utilized in an RSV re-vaccination setting and as part of a respiratory combination vaccine.

Shareholders of the Company and potential investors are advised to exercise caution when dealing in the shares of the Company.

By order of the Board Clover Biopharmaceuticals, Ltd. Dr. Peng LIANG Chairman of the Board

Shanghai, PRC, October 29, 2024

As of the date of this announcement, the Board comprises Dr. Peng LIANG and Mr. Joshua G LIANG as executive Directors; Dr. Xiaodong WANG, Dr. Donna Marie AMBROSINO and Dr. Ralf Leo CLEMENS as non-executive Directors; and Dr. Xiaobin WU, Mr. Xiang LIAO, Mr. Jeffrey FARROW and Mr. Thomas LEGGETT as independent non-executive Directors.

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