DEF 14A

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of

the Securities Exchange Act of 1934

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:


☐	Preliminary Proxy Statement


☐	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))


☒	Definitive Proxy Statement


☐	Definitive Additional Materials


☐	Soliciting Material under §240.14a-12

MEREO BIOPHARMA GROUP PLC

(Name of Registrant as Specified In Its Charter)

N/A

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):


☒	No fee required.


☐	Fee paid previously with preliminary materials.

      ☐

      Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

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MEREO BIOPHARMA GROUP PLC

Registered office: 4th Floor, One Cavendish Place, London, W1G 0QF, United Kingdom

Incorporated in England and Wales with registered no. 09481161

April 9, 2026

Dear Shareholder,

2026 Annual General Meeting of Mereo BioPharma Group plc (the “AGM” or the “Meeting”)

This letter, the notice of the AGM set out in this document (the “Notice”) and associated materials for the AGM are being sent or supplied to you because, as of 6:00 p.m. (British Summer Time) (1:00 p.m. Eastern Time) on Tuesday, April 7, 2026, you are registered in the register of members of Mereo BioPharma Group plc (the “Company”) as a holder of ordinary shares in the capital of the Company. However, this letter, the Notice and associated materials will also be available to holders of American Depositary Shares (“ADS”) representing ordinary shares and contains information relevant to holders of ADSs.

I am pleased to confirm that our AGM will take place at 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Thursday, May 14, 2026 at 5th Floor, One Cavendish Place, London W1G 0QF, United Kingdom. The Notice is set out in this document and it contains the resolutions to be proposed at the AGM (the “Resolutions”).

Action to be taken by holders of ordinary shares

If you are a holder of ADSs, please ignore this section and refer instead to the section below — “Action to be taken by holders of American Depositary Shares.”

If you are a holder of ordinary shares and are planning to attend the AGM in person (or by way of corporate representative) it would be helpful if you could inform the Company’s registrar, MUFG Corporate Markets, in advance via the Investor Centre app or at https://uk.investorcentre.mpms.mufg.com/.

Holders of ordinary shares are entitled to appoint a proxy to exercise all or any of their rights to attend and to speak and vote on their behalf at the AGM. Proxy appointment instructions may be submitted online using the Investor Centre app or at https://uk.investorcentre.mpms.mufg.com/. Alternatively, you may simply complete, sign and return the enclosed form of proxy in accordance with the instructions printed thereon. CREST members may appoint a proxy by using the CREST electronic proxy appointment service. If you are an institutional investor you may also be able to appoint a proxy electronically via the Proxymity platform. All proxies, however submitted, must be received by MUFG Corporate Markets by no later than 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Tuesday, May 12, 2026 or 48 hours before any adjourned meeting.

If you require additional forms of proxy or assistance with how to complete, sign and return your form of proxy or assistance in submitting your proxy appointment online, please email shareholderenquiries@cm.mpms.mufg.com or call MUFG Corporate Markets' portal team on

+44 (0) 371 664 0391. Calls are charged at the standard geographic rate and will vary by provider. Calls from outside the U.K. will be charged at the applicable international rate. Lines are open 9:00 a.m. to 5:30 p.m. (British Summer Time), Monday to Friday, excluding public holidays in England and Wales.

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In order to attend and vote at the AGM as an ordinary shareholder or for your proxy appointment instructions to remain valid, you must continue to be registered as a holder of ordinary shares in the Company’s register of members as of 6:00 p.m. (British Summer Time) (1:00 p.m. Eastern Time) on Tuesday, May 12, 2026 (or, if the AGM is adjourned, of 6:00 p.m. (British Summer Time) (1:00 p.m. Eastern Time) on the date which is two business days prior to the adjourned meeting). If you sell or transfer your ordinary shares on or prior to such time, any proxy appointment instructions that you submit (whether before or after you sell or transfer your ordinary shares) will be treated as invalid. Please pass this document to the person who arranged the sale or transfer for delivery to the purchaser or transferee.

The appointment of a proxy will not preclude you from attending, speaking and voting at the AGM should you wish and be entitled to do so. Please refer to the notes to the Notice for further information relating to your entitlement to attend and vote at the AGM and to appoint a proxy to attend and to speak and vote on your behalf at the AGM.

Should you elect to convert your holding of ordinary shares into an interest in the capital of the Company represented by ADSs before the AGM, you will cease to be a holder of ordinary shares in your own name and will not be entitled to vote, whether in person or by proxy, at the AGM as an ordinary shareholder. However, you may be able to exercise your vote as a holder of an interest in the capital of the Company represented by ADSs — please refer to the next section — “Action to be taken by holders of American Depositary Shares.”

Action to be taken by holders of American Depositary Shares

In order to exercise your vote as a holder of an interest in ordinary shares represented by ADSs, you or your bank, broker or nominee must be registered as a holder of ADSs in the ADS register as of 5:00 p.m. Eastern Time (10:00 p.m. British Summer Time) on Thursday, April 9, 2026 (the “ADS Record Date”).

If you hold ADSs through a bank, broker or nominee as of 5:00 p.m. Eastern Time on the ADS Record Date, the materials for ADS holders, including this proxy statement, the Annual Report on Form 10-K and an ADS proxy card, will be sent to such bank, broker or nominee who should forward the materials to you – you should contact them to provide your voting instructions.

Please note that ADS proxy cards submitted by ADS holders must be received by Citibank, N.A. no later than 10:00 a.m. Eastern Time (3:00 p.m. British Summer Time) on Friday, May 8, 2026.

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Contact for holders of American Depositary Shares

If you have queries about how you can deliver voting instructions, please contact Citibank, N.A. — ADR Shareholder Services by telephone on +1-877-248-4237 (toll free within the United States) or +1-781-575-4555 (for international callers) or by emailing citibank@shareholders-online.com or by mail to Citibank Shareholder Services, P.O. Box 43077, Providence, RI 02940-3077.

Contact at Mereo BioPharma

If at any point you require guidance, please contact Charles Sermon, Mereo BioPharma Group plc Company Secretary, by emailing legal@mereobiopharma.com.

Recommendation

You will find an explanatory note in relation to each of the Resolutions in the attached proxy statement. Your Board of Directors consider that each Resolution is in the best interests of the Company and is likely to promote the success of the Company for the benefit of its members as a whole. Accordingly, your directors unanimously recommend that you vote FOR the Resolutions as each of the directors with personal holdings of ordinary shares or ADSs intends to do.

Thank you for your ongoing support of Mereo BioPharma Group plc.

Yours faithfully,

      /s/ Michael Wyzga

     

Michael Wyzga

Chairman

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Mereo BioPharma Group plc

4th Floor, One Cavendish Place, London, W1G 0QF,

United Kingdom

Registered Company No. 09481161

NOTICE OF 2026 ANNUAL GENERAL MEETING OF SHAREHOLDERS TO BE HELD ON THURSDAY, MAY 14, 2026

NOTICE IS HEREBY GIVEN that the Annual General Meeting of Mereo BioPharma Group plc, a public limited company incorporated under the laws of England and Wales (the “Company,” “we,” “us” and “our”), will be held at 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Thursday, May 14, 2026 at 5th Floor, One Cavendish Place, London W1G 0QF, United Kingdom to consider and, if thought fit, to pass Resolutions 1 to 10 below, as ordinary resolutions and Resolution 11 below as a special resolution.

Ordinary resolutions

That the annual report and accounts for the year ended December 31, 2025, together with the directors’ report and independent auditor’s report thereon, be received and adopted.

That PricewaterhouseCoopers LLP (“PwC”) be re-appointed as auditors to hold office from the conclusion of the annual general meeting until the conclusion of the next annual general meeting at which the Company’s annual report and accounts are presented.

That the Audit and Risk Committee be authorized to determine PwC’s remuneration for the fiscal year ending December 31, 2026.

That the directors’ remuneration report (excluding the directors’ remuneration policy), as set out in the Company’s annual report and accounts for the year ended December 31, 2025, be approved.

That the directors’ remuneration policy as set out in the Company’s annual report and accounts for
the year ended December 31, 2025, which takes effect from the end of the annual general meeting, be approved.

That the compensation of the Company's named executive officers be approved, on an advisory (non-binding) basis.

That Justin Roberts be re-appointed as a director of the Company.

That Dr. Daniel Shames be re-appointed as a director of the Company.

That Marc Yoskowitz be re-appointed as a director of the Company.

10.

That the Directors be generally and unconditionally authorized in accordance with section 551 of the Companies Act 2006 (the “Act”) to exercise all the powers of the Company to allot shares in the Company or to grant rights to subscribe for, or to convert securities into, shares in the Company up to a maximum aggregate nominal amount of £3,591,354.73, such authority to expire on June 30, 2029, save that the Company may, before such expiry, make offers or agreements which would, or might, require shares to be allotted or rights to subscribe for or to convert any securities into shares to be granted after such expiry and the Directors may allot shares or grant such rights under any such offer or agreement as if the authority conferred by this Resolution had not expired. Such authority shall replace the authority granted pursuant to section 551 of the Act at the annual general meeting of the Company held on May 22, 2023 to the extent not utilized at the date this Resolution is passed.

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Special resolution

11.

That, subject to Resolution 10 being passed, the Directors be generally empowered pursuant to section 570 and section 573 of the Act to allot equity securities for cash pursuant to the authority given by Resolution 10 and to sell equity securities held as treasury shares for cash pursuant to section 727 of the Act, in each case as if section 561(1) of the Act did not apply to any such allotment or sale, provided that this power shall be limited to the allotment or sale of equity securities up to an aggregate nominal value of £3,591,354.73, such power to expire on June 30, 2029, save that the Company may, before such expiry, make offers or agreements which would or might require equity securities to be allotted and equity securities held as treasury shares to be sold after such expiry, and the Directors may allot equity securities and sell equity securities held as treasury shares in pursuance of any such offer or agreement as if the power conferred hereby had not expired. Such power shall replace the power granted pursuant to section 570 and section 573 of the Act at the annual general meeting of the Company held on May 22, 2023 to the extent not utilized at the date this Resolution is passed.


BY ORDER OF THE BOARD		Registered Office
		4th Floor, One Cavendish Place,
/s/ Charles Sermon		London, W1G 0QF, United Kingdom
Charles Sermon		Registered in England & Wales
April 9, 2026		No. 09481161

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Notes:

The following notes apply to ordinary shareholders. Holders of ADSs should review the information in the section of the letter accompanying this Notice titled “Action to be taken by holders of American Depositary Shares” for voting and other relevant information for the Meeting.

Entitlement to Attend and Vote

To be entitled to attend and vote at the Meeting (and for the purposes of the determination by the Company of the votes that may be cast in accordance with Regulation 41 of the Uncertificated Securities Regulations 2001), only those members registered in the Company’s register of members at 6:00 p.m. (British Summer Time) (1:00 p.m. Eastern Time) on Tuesday, May 12, 2026 (or, if the Meeting is adjourned at 6:00 p.m. (British Summer Time) (1:00 p.m. Eastern Time) on the date which is two business days prior to the adjourned meeting) shall be entitled to attend and vote at the Meeting. Changes to the register of members of the Company after the relevant deadline shall be disregarded in determining the rights of any person to attend and vote at the Meeting.

Appointment of Proxies

If you are a member of the Company at the time set out in note 1 above, you are entitled to appoint a proxy to exercise all or any of your rights to attend, speak and vote at the Meeting. You can appoint a proxy only using the procedures set out in these notes and the notes to the form of proxy for use at the Meeting. In order to be valid, proxy appointment instructions must be received by the Company’s registrar, MUFG Corporate Markets, by no later than 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Tuesday, May 12, 2026 or 48 hours before any adjourned meeting.

A proxy does not need to be a member of the Company but must attend the Meeting to represent you. If you wish your proxy to speak on your behalf at the Meeting you will need to appoint your own choice of proxy (not the Chair of the Meeting) and give your instructions directly to them.

You may appoint more than one proxy provided each proxy is appointed to exercise rights attached to different ordinary shares. You may not appoint more than one proxy to exercise rights attached to any one ordinary share. To appoint more than one proxy, please indicate on your proxy submission how many ordinary shares it relates to.

A vote withheld is not a vote in law, which means that the vote will not be counted in the calculation of votes for or against the Resolution. If no voting indication is given, your proxy will vote or abstain from voting at their discretion. Your proxy will vote (or abstain from voting) as they think fit in relation to any other matter which is put before the Meeting.

Appointment of Proxy Using Hard Copy Proxy Form

A form of proxy for use at the Meeting has been provided. Instructions for its use are set out in the form. If you require additional forms of proxy or assistance with how to complete, sign and return a form of proxy or assistance in submitting your proxy appointment online, please call MUFG Corporate Markets’ general helpline team on +44 (0) 371 664 0391. Calls are charged at the standard geographic rate and will vary by provider. Calls from outside the U.K. will be charged at the applicable international rate. Lines are open 9:00 a.m. to 5:30 p.m. (British Summer Time), Monday to Friday, excluding public holidays in England and Wales. Alternatively, you can request additional forms of proxy via email at shareholderenquiries@cm.mpms.mufg.com or via postal address to MUFG Corporate Markets, PXS 1, Central Square, 29 Wellington Street, Leeds LS1 4DL, United Kingdom. In the case of a member which is a company, the form of proxy must be executed under its common seal or signed on its behalf by an officer of the company or an attorney for the company. Any power of attorney or any other authority under which the proxy form is signed (or a duly certified copy of such power or authority) must be included with the form of proxy.

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Appointment of a Proxy Online

Shareholders can vote online via the Investor Centre, a free app for smartphone and tablet provided by MUFG Corporate Markets (the Company's registrar). It allows you to securely manage and monitor your shareholdings in real time, take part in online voting, keep your details up to date, access a range of information including payment history and much more. The app is available to download on both the Apple App Store and Google Play, or by scanning the relevant QR code below. Alternatively, you may access the Investor Centre via a web browser at: https://uk.investorcentre.mpms.mufg.com/. Shareholders can use this service to vote or appoint a proxy online. Such instructions must be received by no later than 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Tuesday, May 12, 2026 or 48 hours before any adjourned meeting. Shareholders will need to use the unique personal identification Investor Code (“IVC”) printed on your share certificate. If you need help with voting online, please contact MUFG Corporate Markets’ portal team on +44 (0) 371 664 0391 or via email at shareholderenquiries@cm.mpms.mufg.com. Calls are charged at the standard geographic rate and will vary by provider. Calls from outside the U.K. will be charged at the applicable international rate. Lines are open 9:00 a.m. to 5:30 p.m. (British Summer Time), Monday to Friday, excluding public holidays in England and Wales.

Appointment of Proxies Through CREST

CREST members who wish to appoint a proxy or proxies by utilizing the CREST electronic proxy appointment service may do so for the Meeting and any adjournment(s) of it by using the procedures described in the CREST Manual (available from www.euroclear.com). CREST Personal Members or other CREST sponsored members, and those CREST members who have appointed a voting service provider(s), should refer to their CREST sponsor or voting service provider(s), who will be able to take the appropriate action on their behalf.

In order for a proxy appointment made by means of CREST to be valid, the appropriate CREST message (a CREST Proxy Instruction) must be properly authenticated in accordance with Euroclear UK & International Limited’s (EUI) specifications and must contain the information required for such instructions, as described in the CREST Manual. The message must be transmitted so as to be received by the issuer’s agent (ID: RA10) by no later than 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Tuesday, May 12, 2026 or 48 hours before any adjourned meeting. For this purpose, the time of receipt will be taken to be the time (as determined by the time stamp applied to the message by the CREST Applications Host) from which the issuer’s agent is able to retrieve the message by enquiry to CREST in the manner prescribed by CREST. After this time, any change of instructions to proxies appointed through CREST should be communicated to the appointee through other means. CREST members and, where applicable, their CREST sponsors or voting service providers should note that EUI does not make available special procedures in CREST for any particular messages. Normal system timings and limitations will therefore apply in relation to the input of CREST Proxy Instructions. It is the responsibility of the CREST member concerned to take (or, if the CREST member is a CREST personal member or sponsored member or has appointed a voting service provider(s), to procure that their CREST sponsor or voting service provider(s) take(s)) such action as shall be necessary to ensure that a message is transmitted by means of the CREST system by any particular time.

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10.

In this connection, CREST members and, where applicable, their CREST sponsors or voting service providers are referred, in particular, to those sections of the CREST Manual concerning practical limitations of the CREST system and timings. The Company may treat as invalid a CREST Proxy Instruction in the circumstances set out in Regulation 35(5)(a) of the Uncertificated Securities Regulations 2001.

Appointment of Proxies via Proxymity

11.

If you are an institutional investor you may also be able to appoint a proxy electronically via the Proxymity platform, a process which has been agreed by the Company and approved by the registrar. For further information regarding Proxymity, please go to www.proxymity.io. Your proxy must be received by no later than 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Tuesday, May 12, 2026 or 48 hours before any adjourned meeting. Before you can appoint a proxy via this process you will need to have agreed to Proxymity’s associated terms and conditions. It is important that you read these carefully as you will be bound by them and they will govern the electronic appointment of your proxy. An electronic proxy appointment via the Proxymity platform may be revoked completely by sending an authenticated message via the platform instructing the removal of your proxy vote.

Appointment of Proxy by Joint Members

12.

In the case of joint holders, where more than one of the joint holders purports to appoint a proxy, only the appointment submitted by the most senior holder will be accepted. Seniority is determined by the order in which the names of the joint holders appear in the Company’s register of members in respect of the joint holding, the first-named being the most senior.

Changing Proxy Instructions

13.

To change your proxy instructions simply submit a new proxy appointment using the methods set out above. Note that the cutoff times for receipt of proxy appointments (see above) also apply in relation to amended instructions; any amended proxy appointment received after the relevant cut-off time will be disregarded. Where you have appointed a proxy using a hard-copy form of proxy and would like to change the instructions using another form of proxy, please contact MUFG Corporate Markets as per the communication methods shown in note 6. If you submit more than one valid proxy appointment, the appointment received last before the latest time for the receipt of proxies will take precedence.

Termination of Proxy Appointments

14.

In order to revoke a proxy instruction, you will need to inform the Company by sending a signed hard copy notice clearly stating your intention to revoke your proxy appointment to MUFG Corporate Markets, at the address shown in note 6 above. In the case of a member which is a company, the revocation notice must be executed under its common seal or signed on its behalf by an officer of the company or an attorney for the company. Any power of attorney or any other authority under which the revocation notice is signed, or a duly certified copy of such power or authority, must be included with the revocation notice. The revocation notice must be received by MUFG Corporate Markets no later than 48 hours before the Meeting. If you attempt to revoke your proxy appointment but the revocation is received after the time specified then, subject to the paragraph directly below, your proxy appointment will remain valid. Completion of a proxy will not preclude you from attending the Meeting and voting in person if you so wish.

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Corporate Representatives

15.

A corporation which is a member can appoint one or more corporate representatives who may exercise, on its behalf, all its powers as a member provided that no more than one corporate representative exercises powers over the same ordinary share.

Issued Shares and Total Voting Rights

16.

As at close of business on the day immediately prior to the date of posting of this Notice, the Company’s issued share capital comprised 798,078,829 ordinary shares. Each ordinary share carries the right to one vote at a general meeting of the Company and, therefore, the total number of voting rights in the Company as at close of business on the day immediately prior to the date of posting of this Notice is 798,078,829.

Electronic Address

17.

You may not use any electronic address (within the meaning of section 333(4) of the Companies Act 2006 (the “Act”)) provided in this Notice (or in any related documents including any form of proxy) to communicate with the Company for any purposes other than those expressly stated.

Website Publication of Audit Concerns

18.

Under section 527 of the Act, members meeting the threshold requirement set out in that section have the right to require the Company to publish on a website a statement setting out any matter relating to: (a) the audit of the Company’s accounts (including the auditor’s report and the conduct of the audit) that are to be laid before the meeting; or (b) any circumstance connected with an auditor of the Company ceasing to hold office since the previous meeting at which annual reports and accounts were laid in accordance with section 437 of the Act. The Company may not require the shareholders requesting any such website publication to pay its expenses in compliance with sections 527 or 528 of the Act. Where the Company is required to place a statement on a website under section 527 of the Act, it must forward the statement to the Company’s auditor not later than the time when it makes the statement available on the website. The business which may be dealt with at the AGM includes any statement that the Company has been required, under section 527 of the Act, to publish on a website.

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	Page
INFORMATION CONCERNING PROXY SOLICITATION AND VOTING	1
QUESTIONS AND ANSWERS ABOUT VOTING AT THE ANNUAL GENERAL MEETING	1
PROPOSAL 1 — RESOLUTION TO ADOPT THE COMPANY’S U.K. STATUTORY ANNUAL REPORT AND ACCOUNTS	9
PROPOSAL 2 — RE-APPOINTMENT OF PRICEWATERHOUSECOOPERS LLP AS OUR AUDITORS, TO HOLD OFFICE UNTIL THE CONCLUSION OF THE NEXT ANNUAL GENERAL MEETING OF SHAREHOLDERS	10
PROPOSAL 3 — AUTHORIZATION FOR THE AUDIT AND RISK COMMITTEE TO DETERMINE THE AUDITORS’ REMUNERATION FOR THE FISCAL YEAR ENDING DECEMBER 31, 2026	12
PROPOSAL 4 — APPROVAL OF OUR U.K. STATUTORY DIRECTORS’ ANNUAL REPORT ON REMUNERATION ON AN ADVISORY (NON-BINDING) BASIS	13
PROPOSAL 5 — APPROVAL OF OUR U.K. STATUTORY DIRECTORS’ REMUNERATION POLICY.	14
PROPOSAL 6 — APPROVAL OF THE COMPENSATION OF THE COMPANY’S NAMED EXECUTIVE OFFICERS ON AN ADVISORY (NON-BINDING) BASIS	15
PROPOSAL 7 — RE-ELECTION OF JUSTIN ROBERTS TO THE BOARD OF DIRECTORS	17
PROPOSAL 8 — RE-ELECTION OF DR. DANIEL SHAMES TO THE BOARD OF DIRECTORS	18
PROPOSAL 9 — RE-ELECTION OF MARC YOSKOWITZ TO THE BOARD OF DIRECTORS	19
PROPOSAL 10 — APPROVAL OF GENERAL AUTHORITY TO ALLOT SHARES	22
PROPOSAL 11 — APPROVAL OF AUTHORITY TO DISAPPLY STATUTORY PRE-EMPTION RIGHTS	23
BOARD OF DIRECTORS AND CORPORATE GOVERNANCE	24
DIRECTORS' COMPENSATION	33
SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT	35
TRANSACTIONS WITH RELATED PERSONS	37
EXECUTIVE OFFICERS OF THE COMPANY	39
EXECUTIVE COMPENSATION	40
PAY VERSUS PERFORMANCE	46
AUDIT AND RISK COMMITTEE REPORT	49
DELIVERY OF PROXY MATERIALS	51
ADDITIONAL INFORMATION	52
FORM OF PROXY FOR ORDINARY SHAREHOLDERS	A-1

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Mereo BioPharma Group plc

4th Floor, One Cavendish Place, London, W1G 0QF, United Kingdom Registered Company No. 09481161

PROXY STATEMENT FOR THE 2026 ANNUAL GENERAL MEETING OF SHAREHOLDERS TO BE HELD ON THURSDAY, MAY 14, 2026

INFORMATION CONCERNING PROXY SOLICITATION AND VOTING

We have sent you this proxy statement and the enclosed form of proxy because the Board of Directors of Mereo BioPharma Group plc (referred to herein as the “Company”, “Mereo”, “we”, “us” or “our”) is soliciting your proxy to vote at our annual general meeting of shareholders (referred to herein as the “Meeting” or the “AGM”) to be held at 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Thursday, May 14, 2026, at 5th Floor, One Cavendish Place, London W1G 0QF, United Kingdom.

•

This proxy statement summarizes information about the proposals to be considered at the Meeting and other information you may find useful in determining how to vote.

•

The form of proxy is the means by which you actually authorize another person to vote your shares in accordance with your instructions.

In addition to solicitations by mail, our directors, officers and regular employees, without additional remuneration, may solicit proxies by telephone, e-mail, internet and personal solicitation. All costs of solicitation of proxies will be covered by us.

We are mailing the Notice, this proxy statement and the form of proxy to our ordinary shareholders of record as of 6:00 p.m. (British Summer Time) (1:00 p.m. Eastern Time) on Tuesday, April 7, 2026 for the first time on or about Thursday, April 9, 2026. We are also including our annual report on Form 10-K for the year ended December 31, 2025 (the “Annual Report on Form 10-K”). This includes mailing or supplying our proxy materials, including the Notice, this proxy statement and the accompanying form of proxy, and the Annual Report on Form 10-K, to relevant brokers, dealers, bankers and their nominees in their capacity as shareholders of record, so that they can supply these materials to the relevant beneficial owners of ordinary shares.

While this document is being sent or supplied to our ordinary shareholders of record, this document will also be made available to holders of American Depositary Shares (“ADSs”) and contains information relevant to holders of ADSs.

Important Notice Regarding the Availability of Proxy Materials for the Annual General Meeting to be Held on Thursday, May 14, 2026

Our Notice, this proxy statement and the accompanying form of proxy and the Annual Report on Form 10-K

are available in the Investors section of our website at: http://www.mereobiopharma.com/agm2026.

QUESTIONS AND ANSWERS ABOUT VOTING AT THE ANNUAL GENERAL MEETING Why am I receiving these materials?

We have sent you this proxy statement and the enclosed form of proxy because you are an ordinary shareholder of record and our Board of Directors (the “Board” or “Board of Directors”) is soliciting your vote at the Meeting, including at any adjournments or postponements of the Meeting. You are invited to attend the Meeting to vote on the proposals described in this proxy statement. However, you do not need to attend the Meeting in person to vote your shares. Instead, please submit your proxy online using the Investor Centre app or

-1-

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at https://uk.investorcentre.mpms.mufg.com/ (see instructions in the explanatory notes to the Notice). Alternatively, you may simply complete, sign and return the enclosed form of proxy in accordance with the instructions printed thereon. CREST members may appoint a proxy by using the CREST electronic proxy appointment service. If you are an institutional investor you may also be able to appoint a proxy electronically via the Proxymity platform. All proxies, however submitted, must be received by our registrar, MUFG Corporate Markets, by no later than 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Tuesday, May 12, 2026 or 48 hours before any adjourned meeting.

We intend to mail this proxy statement, the accompanying form of proxy and the Annual Report on Form

10-K on or about Thursday, April 9, 2026 to all ordinary shareholders of record as of 6:00 p.m. (British Summer Time) (1:00 p.m. Eastern Time) on Tuesday, April 7, 2026.

Materials for ADS holders of record, including this proxy statement, the Annual Report on Form 10-K and the ADS proxy card, will be mailed on or about Tuesday, April 14, 2026 to all ADS holders, including banks, brokers and nominees, who are registered as holders of ADSs in the ADS register by 5:00 p.m. Eastern Time (10:00 p.m. British Summer Time) on Thursday, April 9, 2026 (the "ADS Record Date").

Who can vote at the Meeting?

Ordinary shareholders

Only ordinary shareholders of record registered in the register of members at 6:00 p.m. (British Summer Time) (1:00 p.m. Eastern Time) on Tuesday, May 12, 2026 will be entitled to attend and vote in person at the Meeting. As of Tuesday, April 7, 2026 there were 798,078,829 ordinary shares issued and outstanding and entitled to vote.

All proxies must be received by our registrar, MUFG Corporate Markets, by no later than 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Tuesday, May 12, 2026 or 48 hours before any adjourned meeting.

If you sell or transfer your ordinary shares in the Company on or prior to Tuesday, May 12, 2026, your form of proxy can no longer be used and if submitted (whether before or after you sell or transfer your ordinary shares) will be treated as invalid. Please pass this document to the person who arranged the sale or transfer for delivery to the purchaser or transferee. The purchaser or transferee should contact the Company’s registrar, MUFG Corporate Markets, using the details set out in the Notice, to request a new form of proxy for its use.

Beneficial owners of ordinary shares which are registered in the name of a broker, bank or other agent

If, on Tuesday, April 7, 2026, your ordinary shares were held in an account at a brokerage firm, bank or other similar organization and you are the beneficial owner of shares, these proxy materials should be forwarded to you by that organization. The organization holding your account is considered the shareholder of record for purposes of voting at the Meeting by proxy. You are encouraged to provide voting instructions to your broker or other agent so that they may submit a proxy.

Holders of American Depositary Shares

You are entitled to exercise your vote as a holder of an interest in the capital of the Company represented by

ADSs if you or your brokerage firm, bank or nominee is registered as a holder of ADSs in the ADS register as of

the ADS Record Date.

If you hold ADSs through a brokerage firm, bank or nominee on the ADS Record Date, the materials for ADS holders, including this proxy statement, the Annual Report on Form 10-K and the ADS proxy card, will be sent to that organization. The organization holding your account is considered the ADS holder of record. Please reach out to that organization to provide your voting instructions.

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Please note that ADS proxy cards submitted by ADS holders must be received by Citibank, N.A. by no later than 10:00 a.m. Eastern Time (3:00 p.m. British Summer Time) on Friday, May 8, 2026.

Citibank, N.A. will collate all votes properly submitted by ADS holders and submit a vote on behalf of all ADS holders.

What are the differences between ADS holders and ordinary shareholders?

We are requesting Citibank, N.A., which holds the ordinary shares represented by the ADSs, to seek ADS holders’ instructions for voting at the Meeting. As a result, ADS holders may instruct Citibank, N.A., as Depositary, to vote the ordinary shares represented by their ADSs.

Because we have asked Citibank, N.A. to seek the instructions of ADS holders, Citibank, N.A. will notify ADS holders of the upcoming vote and arrange to deliver the proxy materials to them. Citibank, N.A., as Depositary, then tries, as far as practicable, to vote the ordinary shares as our ADS holders instruct. We cannot guarantee that ADS holders will receive this proxy statement and the other proxy materials from Citibank, N.A. in time to permit them to instruct Citibank, N.A., as Depositary, to vote their shares. In addition, there may be other circumstances in which ADS holders may not be able to exercise voting rights. Furthermore, ADS holders can exercise their right to vote the ordinary shares underlying their ADSs by exchanging their ADSs for ordinary shares. However, even though we are subject to U.S. domestic issuer proxy rules, ADS holders may not receive proxy materials about the AGM early enough to exchange their ADSs for ordinary shares. ADS holders are not required to be treated as holders of ordinary shares and do not have the rights of holders of ordinary shares.

What is the difference between a shareholder of record and a beneficial owner?

These terms describe how your ordinary shares are held. If your ordinary shares are registered directly in your name in our register of members, you are a shareholder of record and the proxy materials are being sent directly, or otherwise being made available, to you. If your ordinary shares are held in the name of a broker, bank, or other nominee, you are a beneficial owner of the shares held by your broker, bank or other nominee and the proxy materials are being made available or forwarded to you by your broker, bank, or other nominee, who is treated as the shareholder of record. As the beneficial owner, you have the right to direct your broker, bank, or other nominee on how to vote your ordinary shares by following the instructions on the voting instructions provided to you by such broker, bank or other nominee.

Who do I contact regarding my ADS holdings?

If you have queries about how you can deliver voting instructions, please contact Citibank, N.A. — ADR Shareholder Services at tel: +1-877-248-4237 (toll free within the United States) or +1-781-575-4555 (for international callers) or by email: citibank@shareholders-online.com or at Citibank Shareholder Services, P.O. Box 43077, Providence, RI 02940-3077.

What do I do if I have additional questions?

If at any point you require guidance, please contact Charles Sermon, Company Secretary, by email:

legal@mereobiopharma.com, or telephone: +44 (0) 333 023 7300.

What are the requirements to elect the directors and approve each of the proposals?

The proposed resolutions will be subject to vote on a poll. This results in a more accurate reflection of the views of shareholders ensuring that votes by proxy will be fully counted. On a poll, each shareholder has one vote for every share held.

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Proposals 1 through 10 will be proposed as ordinary resolutions and Proposal 11 will be proposed as a special resolution. On a poll, assuming that a quorum is present, an ordinary resolution is passed if it is approved by a simple majority (more than 50%) of the votes cast by shareholders present (in person or by proxy) at the Meeting and entitled to vote. On a poll, a special resolution is passed if it is approved by holders representing not less than 75% of the votes cast by shareholders present (in person or by proxy) at the Meeting and entitled to vote.

What are the voting recommendations of our Board regarding the election of directors and other proposals?

The following table summarizes the items that will be brought for a vote of our shareholders at the Meeting, along with the Board’s voting recommendations.


Proposal	Description of Proposal	Board’s Recommendation
1	To receive and adopt the U.K. statutory annual report and accounts for the year ended December 31, 2025.	FOR
2	Re-appointment of PricewaterhouseCoopers LLP (“PwC”) as the Company’s auditors, to hold office until the conclusion of the next annual general meeting of shareholders at which the Company’s annual report and accounts are presented.	FOR
3	Authorization of the Audit and Risk Committee to determine PwC’s remuneration for the fiscal year ending December 31, 2026.	FOR
4	Approval of our U.K. directors’ remuneration report (excluding the directors’ remuneration policy), as set out in the Company’s annual report and accounts for the year ended December 31, 2025, on an advisory (non-binding) basis.	FOR
5	Approval of the directors’ remuneration policy as set out in the Company’s annual report and accounts for the year ended December 31, 2025, which takes effect from the end of the AGM.	FOR
6	Approval of the compensation of the Company’s named executive officers, on an advisory (non-binding) basis.	FOR
7	Re-appointment of Justin Roberts as a director.	FOR
8	Re-appointment of Dr. Daniel Shames as a director.	FOR
9	Re-appointment of Marc Yoskowitz as a director.	FOR
10	That the Directors be generally and unconditionally authorized in accordance with section 551 of the Companies Act 2006 (the “Act”) to exercise all the powers of the Company to allot shares in the Company or to grant rights to subscribe for, or to convert securities into, shares in the Company up to a maximum aggregate nominal amount of £3,591,354.73, such authority to expire on June 30, 2029, save that the Company may, before such expiry, make offers or agreements which would or might require shares to be allotted or rights to subscribe for or to convert any securities into shares to be granted after such expiry and the Directors may allot shares or grant such rights under any such offer or agreement as if the authority conferred by this Resolution had not expired. Such authority shall replace the authority granted pursuant to section 551 of the Act at the annual general meeting of the Company held on May 22, 2023 to the extent not utilized at the date this Resolution is passed.	FOR

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11		That, subject to Resolution 10 being passed, the Directors be generally empowered pursuant to section 570 and section 573 of the Act to allot equity securities for cash pursuant to the authority given by Resolution 10 and to sell equity securities held as treasury shares for cash pursuant to section 727 of the Act, in each case as if section 561(1) of the Act did not apply to any such allotment or sale, provided that this power shall be limited to the allotment or sale of equity securities up to an aggregate nominal value of £3,591,354.73, such power to expire on June 30, 2029, save that the Company may, before such expiry, make offers or agreements which would or might require equity securities to be allotted and equity securities held as treasury shares to be sold after such expiry, and the Directors may allot equity securities and sell equity securities held as treasury shares in pursuance of any such offer or agreement as if the power conferred hereby had not expired. Such power shall replace the power granted pursuant to section 570 and section 573 of the Act at the annual general meeting of the Company held on May 22, 2023 to the extent not utilized at the date this Resolution is passed.		FOR

What constitutes a quorum?

For the purposes of the Meeting, the quorum requirement is a minimum of two shareholders entitled to vote at the meeting and present in person or by proxy or, in the case of a shareholder which is a corporation, represented by a duly authorized representative. In addition, in accordance with the applicable Nasdaq rules, under the Articles of Association for a shareholders’ meeting to be quorate at least 33 1/3 per cent. of the Company’s issued and outstanding ordinary shares must be present at such meeting, whether represented in person (including, in the case of a corporate member, by a duly authorized representative) or by a duly appointed proxy.

If you are an ordinary shareholder of record, your shares will be counted towards the quorum only if you are present in person or represented by proxy at the Meeting. If you are a beneficial owner of ordinary shares

held in an account at a brokerage firm, bank or other similar organization your shares will be counted towards the quorum if your broker or nominee submits a proxy for those shares and the proxy represents the holder at the Meeting. A member represented by a proxy at the Meeting will be counted towards the quorum requirement even where the proxy abstains from voting. If a form of proxy does not instruct the proxy how to vote, the proxy may vote as he or she sees fit or abstain in relation to any business of the Meeting, but the member represented by that proxy at the Meeting will be counted towards the quorum requirement.

Where Citibank N.A. submits votes on behalf of any ADS holders, the number of ordinary shares represented by the ADSs held by the relevant ADS holders will count towards the quorum.

How do I vote my shares?

You may vote “for” or “against” or abstain from voting on the applicable resolutions. The procedures for voting are as follows:

Ordinary shareholders

If you are an ordinary shareholder of record, you may appoint a proxy to vote on your behalf:

•

By submitting your proxy online using the Investor Centre app or at https://uk.investorcentre.mpms.mufg.com/ (see instructions in the explanatory notes to the Notice); or

•

By completing and signing the form of proxy and returning it in accordance with the instructions printed thereon;

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•

For CREST members, by appointing a proxy by using the CREST electronic proxy appointment service; or

•

If you are an institutional investor you may also be able to appoint a proxy electronically via the Proxymity platform.

All proxies (however submitted) must be received by our registrar (MUFG Corporate Markets) by no later than 2:00 p.m. (British Summer Time) (9:00 a.m. Eastern Time) on Tuesday, May 12, 2026.

If you properly give instructions as to your proxy appointment by executing and returning a form of proxy, or by submitting your proxy online, via CREST or via Proxymity, and your proxy appointment is not subsequently revoked, your shares will be voted by the attendance of your proxy at the Meeting and your proxy voting in accordance with your instructions.

If your ordinary shares are held in an account at a brokerage firm, bank or similar organization, you should follow directions provided by your broker, bank or other nominee.

Holders of American Depositary Shares

If you are a holder of record of ADSs, you can return your executed ADS proxy card to Citibank, N.A. for tabulation. If you hold your ADSs through a broker, bank or other organization, that organization can return the ADS proxy card to Citibank, N.A. following your instruction. Citibank, N.A. will submit your votes to MUFG Corporate Markets for tabulation.

Please note that ADS proxy cards submitted by ADS holders must be received by Citibank, N.A. no later than 10:00 a.m. Eastern Time (3:00 p.m. British Summer Time) on Friday, May 8, 2026.

How will my shares be voted if I do not specify how they should be voted?

If you are an ordinary shareholder and you sign and send your form of proxy but do not indicate how you want your shares to be voted, your shares may be voted by the person that you appoint as your proxy as he or she sees fit or such person may abstain in relation to any business of the Meeting.

If a holder of ADSs does not submit an ADS proxy card to Citibank, N.A. by the deadline specified, the ADS holder shall be deemed to have instructed Citibank, N.A. to give a discretionary proxy to a person designated by us to vote the ordinary shares represented by his or her ADSs (provided that no such discretionary proxy shall be given if we inform Citibank, N.A. that we do not want such proxy to be given, substantial opposition exists or the rights of ADS holders may be adversely affected). If the ADS proxy card is signed but is missing voting instructions with respect to any resolution, then Citibank, N.A. will deem the ADS holder to have instructed it to vote in favor of such unvoted resolution(s).

Can I change my vote or revoke a proxy?

To change your proxy instructions simply submit new proxy instructions using one of the methods set out above prior to the relevant deadline or attend the Meeting and vote in-person.

In order to revoke a proxy instruction, you will need to inform the Company by sending a signed hard copy notice clearly stating your intention to revoke your proxy appointment to MUFG Corporate Markets, at MUFG Corporate Markets, PXS 1, Central Square, 29 Wellington Street, Leeds LS1 4DL, United Kingdom. The revocation notice, together with the accompanying material set out in the notes to the Notice, must be received by MUFG Corporate Markets no later than 48 hours before the meeting.

If your ordinary shares are held in an account at a brokerage firm, bank or similar organization, you may change or revoke your voting instructions by contacting the broker, bank or other nominee holding the shares.

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If you hold ADSs, directly or through a broker, bank or other nominee, you must follow the instructions provided by Citibank, N.A. or such broker, bank or other nominee if you wish to change your vote. The last instructions you submit prior to the deadline indicated by Citibank, N.A. or the broker, bank or other nominee, as applicable, will be used to instruct Citibank, N.A. how to vote your ADSs.

Who counts the votes?

MUFG Corporate Markets has been engaged as our independent agent to tabulate shareholder votes. If you are an ordinary shareholder of record, you may submit your proxy to MUFG Corporate Markets online, via CREST, via Proxymity, or return the form of proxy to MUFG Corporate Markets prior to the relevant deadline above.

If you hold your ordinary shares through a broker, your broker can directly submit your proxy to MUFG Corporate Markets online, via CREST, via Proxymity, or return the form of proxy to MUFG Corporate Markets prior to the relevant deadline above.

If you are a holder of record of ADSs, you can return your executed ADS proxy card to Citibank, N.A. prior to the relevant deadline above for tabulation. If you hold your ADSs through a broker, bank or other organization, that organization can return the ADS proxy card to Citibank, N.A. prior to such deadline following your instruction. Citibank, N.A. will submit your votes to MUFG Corporate Markets for tabulation.

How are votes counted?

Votes will be counted by MUFG Corporate Markets, who will separately count “for” and “against” votes, and “votes withheld” or abstentions. A “vote withheld” or abstention is not a vote in law and will not be counted in the calculation of the votes “for” and “against” a resolution.

How many votes do I have?

On a poll, each shareholder present in person or by proxy or (being a corporation) by a duly authorized representative has one vote for each share held by the shareholder.

What about joint holders?

In the case of joint holders of record of an ordinary share, the vote of the senior holder who tenders the vote

(whether in person or by proxy) will be accepted to the exclusion of the votes of any other joint holders. For these purposes, seniority shall be determined by the order in which the names stand in the register of members of the company in respect of the joint holding (with the first named being the most senior).

What if I plan to attend the Meeting?

Attendance at the Meeting will be limited to ordinary shareholders of record as of 6:00 p.m. (British Summer Time) (1:00 p.m. Eastern Time) on Tuesday, May 12, 2026. In order to obtain admittance to the Meeting each shareholder may be asked to present valid picture identification, such as a driver’s license or passport.

How do you solicit proxies?

We will solicit proxies and will bear the entire cost of this solicitation. The initial solicitation of proxies may be supplemented by additional mail communications and by telephone, fax, e-mail, internet and personal solicitation by our directors, officers or other employees. No additional compensation for soliciting proxies will be paid to our directors, officers or other employees for their proxy solicitation efforts. We also reimburse Citibank, N.A. for their expenses in sending materials, including ADS proxy cards, to ADS holders of record.

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What do I do if I receive more than one Notice or form of proxy?

If you hold your ordinary shares in more than one account, you will receive a form of proxy for each

account. To ensure that all of your shares are voted, please sign, date and return all forms of proxy. Please be sure to vote all of your shares.

If you hold ADSs in your own name registered on the books of Citibank, N.A., as Depositary, you are considered the registered holder of the ADSs and will receive a form of proxy from Citibank, N.A. If you hold ADSs through a broker, bank or other nominee, you are considered the beneficial owner of the ADSs and you will receive a form of proxy from your broker, bank or other nominee.

Will there be any other business conducted at the Meeting?

No. In accordance with our Articles of Association, other than with respect to procedural matters in relation to the Meeting, no business other than proposals 1 through 11 may be presented at this Meeting. We have not been notified of, and our Board is not aware of, any other matters to be presented for action at the Meeting.

What is the role of PwC?

PwC is our auditor for the year ended December 31, 2025 and our Audit and Risk Committee has selected PwC as our independent registered public accounting firm for the fiscal year ending December 31, 2026, and has further directed that we submit the selection of PwC for approval by our shareholders at the Meeting. Proposal 2 seeks your approval of the re-appointment of PwC to serve as our auditor, to hold office until the conclusion of the next annual general meeting of shareholders at which our annual report and accounts are presented.

PwC is entitled to attend any general meeting of the Company and be heard on any part of the business of the meeting that concerns them as auditors.

What is MUFG Corporate Markets’ role?

MUFG Corporate Markets is our registrar. All communications concerning ordinary shareholder of record accounts, including address changes, name changes, ordinary share transfer requirements and similar issues can be handled by contacting MUFG Corporate Markets via email shareholderenquiries@cm.mpms.mufg.com or by telephone to the general helpline: +44 (0) 371 664 0391 (if calling from overseas, please ensure the country code is used) or by writing to MUFG Corporate Markets, PXS 1, Central Square, 29 Wellington Street, Leeds LS1 4DL, United Kingdom.

How can I find out the results of the voting at the Meeting?

Voting results will be announced by the filing of a current report on Form 8-K within four business days after the Meeting. If final voting results are unavailable at that time, we will file an amended current report on Form 8-K within four business days of the day the final results are available.

Directions to Meeting

Directions to our Meeting, which is to be held at 5th Floor, One Cavendish Place, London W1G 0QF, United Kingdom, are available in the Contact Us section of our website at: https://www.mereobiopharma.com.

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PROPOSAL 1 — RESOLUTION TO ADOPT THE COMPANY’S U.K. STATUTORY ANNUAL REPORT AND ACCOUNTS

At the Meeting, our Board of Directors will present our U.K. statutory annual report and accounts for the period January 1, 2025 through December 31, 2025, which includes the directors’ report and independent auditor’s report thereon. We will provide our shareholders with an opportunity to review the U.K. statutory annual report and accounts and to adopt them.