Genscript Biotech Corporation — Proxy Solicitation & Information Statement 2026

Apr 13, 2026

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

Genscript Biotech Corporation

(Incorporated in the Cayman Islands with limited liability)

(Stock Code: 1548)

NOTICE OF ANNUAL GENERAL MEETING

NOTICE IS HEREBY GIVEN THAT the 2026 Annual General Meeting (the "AGM") of Genscript Biotech Corporation (the "Company") will be held at Conference Room, No.1688, Shuanglong Avenue, Jiangning District, at 9:30 a.m. on Friday, 5 June 2026 for the following purposes:

ORDINARY RESOLUTIONS

As ordinary business:

1. To receive, consider and adopt the audited consolidated financial statements of the Company and its subsidiaries and the reports of the directors of the Company (the "Director(s)") and auditor of the Company for the year ended 31 December 2025.

2. To re-elect the following persons as the Directors (each as a separate resolution):

(A) To re-elect Mr. Jiange Meng as an executive Director;

(B) To re-elect Dr. Fangliang Zhang as an executive Director;

(C) To re-elect Dr. Li Zhu as an executive Director;

(D) To re-elect Dr. Chenyang Shi as an independent non-executive Director; and

(E) To authorize the board of Directors (the "Board") to fix remuneration of the Directors.

1. To re-appoint Ernst & Young, Certified Public Accountants, as the auditor of the Company and to authorize the Board to fix remuneration of the auditor.

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As special business:

To consider and, if thought fit, pass, with or without amendments, the following resolutions as ordinary resolutions:

4(A) "THAT:

(i) subject to paragraph (iii) below, the exercise by the Directors during the Relevant Period (as defined in paragraph (iv) below) of all the powers of the Company to allot, issue or otherwise deal with additional shares of the Company (including any sale or transfer of treasury shares ("Treasury Shares", which shall have the meaning ascribed to it under the Listing Rules) out of treasury) in the capital of the Company or securities convertible into shares, or options, warrants or similar rights to subscribe for shares or such convertible securities of the Company and to make or grant offers, agreements and/or options (including bonds, warrants and debentures convertible into shares of the Company) which may require the exercise of such powers be and is hereby generally and unconditionally approved;

(ii) the approval in paragraph (i) above shall be in addition to any other authorization given to the Directors and shall authorize the Directors during the Relevant Period to make or grant offers, agreements and/or options which may require the exercise of such power after the end of the Relevant Period;

(iii) the aggregate number of shares allotted or agreed conditionally or unconditionally to be allotted (including Treasury Shares, if any, sold or transferred or agreed conditionally or unconditionally to be sold or transferred, whether pursuant to options or otherwise) by the Directors during the Relevant Period pursuant to the approval in paragraph (i) above, otherwise than pursuant to (a) a Rights Issue (as defined in paragraph (iv) below); or (b) the grant or exercise of any option under the option scheme of the Company or any other option scheme or similar arrangements for the time being adopted for the grant or issue to officers and/or employees of the Company and/or any of its subsidiaries of shares or rights to acquire shares of the Company; or (c) any scrip dividend or similar arrangements providing for the allotment of shares in lieu of the whole or part of a dividend on shares of the Company in accordance with the articles of association of the Company in force from time to time; or (d) any issue of shares in the Company upon the exercise of rights of subscription or conversion under the terms of any existing convertible notes issued by the Company or any existing securities of the Company which carry rights to subscribe for or are convertible into shares of the Company, shall not

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exceed 20 per cent of the number of the issued shares of the Company (excluding Treasury Shares, if any) as at the date of passing this resolution and the said approval shall be limited accordingly; and

(iv) for the purpose of this resolution:

(a) “Relevant Period” means the period from the passing of this resolution until whichever is the earliest of:

(1) the conclusion of the next annual general meeting of the Company; or
(2) the expiration of the period within which the next annual general meeting of the Company is required by any applicable laws or the articles of association of the Company to be held; or
(3) the revocation or variation of the authority given under this resolution by an ordinary resolution of the shareholders of the Company in general meeting; and

(b) “Rights Issue” means an offer of shares in the capital of the Company, or issue of warrants, options or other securities giving rights to subscribe for shares of the Company, open for a period fixed by the Directors to holders of shares in the capital of the Company whose name appear on the register of members on a fixed record date in proportion to their then holdings of such shares (subject to such exclusion or other arrangements as the Directors may deem necessary or expedient in relation to fractional entitlements or, having regard to any restrictions or obligations under the laws of, or the requirements of, or the expense or delay which may be involved in determining the exercise or extent of any restrictions or obligations under the laws of, or the requirements of, any jurisdiction applicable to the Company, any recognised regulatory body or any stock exchange applicable to the Company).

4(B) “THAT:

(i) subject to paragraph (iii) below, the exercise by the Directors during the Relevant Period (as defined in paragraph (v) below) of all the powers of the Company to purchase issued shares in the capital of the Company on The Stock Exchange of Hong Kong Limited (the “Stock Exchange”) or on any other stock exchange on which the shares of the Company may be listed and recognised for this purpose by the Securities and Futures Commission and the Stock Exchange and, subject to and in accordance with all applicable laws and the requirements of the Rules

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Governing the Listing of Securities on the Stock Exchange (the “Listing Rules”) as amended from time to time, be and is hereby generally and unconditionally approved;

(ii) the approval in paragraph (i) above shall be in addition to any other authorization given to the Directors and shall authorize the Directors on behalf of the Company during the Relevant Period to procure the Company to buy back its shares at a price determined by the Directors;

(iii) the aggregate number of shares of the Company which are authorized to be bought back by the Directors pursuant to the approval in paragraph (i) above shall not exceed 10 per cent of the number of the issued shares of the Company as at the date of passing this resolution and the said approval shall be limited accordingly;

(iv) subject to the passing of each of the paragraphs (i) to (iii) of this resolution, any prior approvals of the kind referred to in paragraphs (i) to (iii) of this resolution which had been granted to the Directors and which are still in effect be and are hereby revoked; and

(v) for the purpose of this resolution:

“Relevant Period” means the period from the passing of this resolution until whichever is the earliest of:

(a) the conclusion of the next annual general meeting of the Company; or

(b) the expiration of the period within which the next annual general meeting of the Company is required by any applicable law or the articles of association of the Company to be held; or

(c) the revocation or variation of the authority given under this resolution by an ordinary resolution of the shareholders of the Company in general meeting.”

4(C) “THAT conditional upon the resolutions numbered 4(A) and 4(B) set out in the notice convening this meeting being passed, the general mandate granted to the Directors to exercise the powers of the Company to allot, issue and otherwise deal with additional shares of the Company (including a sale or transfer of Treasury Shares, if any) and to make or grant offers, agreements and options which might require the exercise of such powers pursuant to the ordinary resolution numbered 4(A) set out in the notice convening this meeting be and is hereby extended by the addition to the number of the issued shares of the Company which may be allotted and issued or agreed conditionally or unconditionally to be allotted and issued (including Treasury Shares, if any, sold or transferred or agreed conditionally or unconditionally to be sold or transferred) by the Directors pursuant to such general mandate an amount representing

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the number of the issued shares of the Company bought back by the Company under the authority granted pursuant to ordinary resolution numbered 4(B) set out in the notice convening this meeting, provided that such amount shall not exceed 10 per cent of the number of the issued shares of the Company (excluding Treasury Shares, if any) as at the date of passing of this resolutions."

SPECIAL RESOLUTION

To consider and, if thought fit, pass, with or without amendments, the following resolution as special resolution:

1. "THAT the proposed amendments to the fourth amended and restated memorandum of association and articles of association of the Company currently in force (the "Existing Memorandum and Articles"), which is set out in Appendix III to the circular of the Company dated 13 April 2026 of which this notice forms part be and are hereby approved and the fifth amended and restated memorandum of association and articles of association (the "Amended Memorandum and Articles", a copy of which having been produced before the meeting and signed by the chairman of the meeting for the purpose of identification) be and are hereby approved and adopted in substitution for and to the exclusion of the Existing Memorandum and Articles; and any one director and/or the registered office provider of the Company be and is hereby authorized severally to do all things necessary or expedient to implement the adoption of the Amended Memorandum and Articles, including without limitation, attending to the necessary filings in accordance with the relevant requirements of the applicable laws, rules and regulations in the Cayman Islands and Hong Kong."

By Order of the Board

Genscript Biotech Corporation

Robin Meng

Chairman and Executive Director

Hong Kong, 13 April 2026

Registered office:

4th Floor, Harbour Place

103 South Church Street

George Town, P.O. Box 10240

Grand Cayman KY1-1002

Cayman Islands

Notes:

(i) The ordinary resolution numbered 4(C) above will be proposed to the shareholders of the Company (the "Shareholder(s)") for approval provided that the ordinary resolutions numbered 4(A) and 4(B) above are passed by the shareholders.

Principal place of business in Hong Kong:

40th Floor, Dah Sing Financial Centre

No. 248 Queen’s Road East

Hong Kong

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(ii) Any shareholder entitled to attend and vote at the AGM is entitled to appoint one or more proxies to attend and vote in his/her stead if he/she holds two or more shares of the Company (“Share(s)”). A proxy need not be a shareholder.

(iii) In order to be valid, a form of proxy together with the power of attorney or other authority (if any) under which it is signed, or a notarially certified copy thereof, shall be deposited at the Company’s branch share registrar in Hong Kong, Computershare Hong Kong Investor Services Limited, at 17M Floor, Hopewell Centre, 183 Queen’s Road East, Wanchai, Hong Kong not less than 48 hours before the time for holding the AGM or any adjournment thereof. Completion and return of a form of proxy will not preclude a shareholder from attending and voting in person if he/she is subsequently able to be present.

(iv) A form of proxy must be signed by a Shareholder or his/her attorney duly authorized in writing or, in the case of a corporation, must be either executed under seal or under the hand of an officer or attorney duly authorized to sign the same.

(v) In the case of joint Shareholders, any one of such joint Shareholders may vote at the AGM, either personally or by proxy, in respect of such shares as if he/she were solely entitled thereto. However, if more than one of such joint Shareholder is present at the meeting, either personally or by proxy, the joint Shareholder whose name stands first in the register of members of the Company shall alone be entitled to vote in respect of such shares.

(vi) On a poll, every shareholder present at the AGM shall be entitled to one vote for every fully paid-up share. The result of such poll shall be deemed to be the resolution of the AGM at which the poll was so required or demanded.

(vii) For determining the entitlement to attend and vote at the AGM, the transfer books and register of members of the Company will be closed from Tuesday, 2 June 2026 to Friday, 5 June 2026, both days inclusive, during which period no share transfers can be registered. In order to qualify for attending and voting at the AGM, the Shareholders should ensure that all share transfer documents accompanied by the relevant share certificates must be lodged with the Company’s branch share registrar in Hong Kong, Computershare Hong Kong Investor Services Limited, at Shops 1712-1716, 17th Floor, Hopewell Centre, 183 Queen’s Road East, Wanchai, Hong Kong for registration not later than 4:30 p.m. on Monday, 1 June 2026.

(viii) In respect of the ordinary resolution numbered 4(A) above, the Directors wish to state that they have no immediate plans to issue any new shares pursuant to such general mandate, other than shares which may fall to be allotted and issued upon the exercise of any options granted under the post-IPO share option scheme adopted by the Company on 7 December 2015 by written resolution of the then sole shareholder and amended on 21 June 2024, or the settlement of any restricted share units granted under the relevant share incentive scheme(s) of the Company. Approval is being sought from the shareholders as a general mandate for the purposes of the Listing Rules.

(ix) In respect of ordinary resolution numbered 4(B) above, the Directors wish to state that they will exercise the powers conferred by the general mandate to buy back shares in circumstances which they deem appropriate for the benefits of the Shareholders. An explanatory statement containing the information necessary to enable the Shareholders to make an informed decision on whether to vote for or against the resolution to approve the general mandate to buy back shares as required by the Listing Rules, is set out in Appendix II to the accompanied circular of the Company dated 13 April 2026.

(x) As at the date of this notice, the executive Directors are Mr. Jiange Meng (“Mr. Robin Meng”), Dr. Fangliang Zhang (“Dr. Frank Zhang”), Dr. Li Zhu and Ms. Ye Wang (“Ms. Sally Wang”); and the independent non-executive Directors are Dr. Alphonse Galdes, Mr. Yiu Leung Andy Cheung (“Mr. Andy Cheung”), Mr. Jiuan Pan (“Mr. Ethan Pan”), Dr. John Quelch, Dr. Ross Grossman and Dr. Chenyang Shi (“Dr. Victor Shi”).

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