DEED OF CONSENT AND AMENDMENT TO NOTE INSTRUMENT

Exhibit 4.30

DEED OF CONSENT AND AMENDMENT TO NOTE INSTRUMENT

THIS DEED is dated 24 November 2020 (such date being the “Effective Date”)

BETWEEN:

WHEREAS

IT IS AGREED AS FOLLOWS:

Terms defined in the Note Instrument shall have the same meanings as given therein when used in this Deed unless otherwise defined herein.

(a) the principal amount of Notes to be converted;

(b) whether any accrued but unpaid interest on such principal amount is to be converted

(c) the Conversion Date; and

(d) whether the Ordinary Shares resulting from conversion are to be delivered as ADSs,

(a) the Noteholder; or

(b) in the event that the Noteholder has required pursuant to paragraph 3.1 that the Ordinary Shares to be issued upon conversion are to be delivered as ADSs and delivered a duly completed Issuance and Delivery Instruction, and there is an effective registration statement covering the Ordinary Shares to be issued on such exercise, issued to, deposited with (and otherwise registered in the name of) the custodian (or its nominee) of the Depositary, and following such issuance and deposit the Company will direct the Depositary to issue an amount of ADSs via DTC (with such ADSs being eligible for listing on Nasdaq) in accordance with the corresponding Issuance and Delivery Instruction;

and in each case the certificates for such Ordinary Shares shall be dispatched to the persons entitled to them at their own risk.

Appendix 1

Note Instrument

Appendix 2

ADS Issuance and Delivery Instruction

[DATE]

Citibank, N.A., as Depositary

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Attn.: ▇▇. ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇▇ (▇▇▇▇▇.▇.▇▇▇▇▇▇▇▇▇▇@▇▇▇▇.▇▇▇)

With a copy simultaneously delivered to:

Citibank, N.A., London Branch

25 Canada Square

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Attn.: UK Custody Settlements

Custody Team (▇▇▇▇▇▇▇▇▇▇▇▇▇@▇▇▇▇.▇▇▇)

Re: Issuance and Delivery Instruction - Mereo BioPharma Group plc (CUSIP No.: ▇▇▇▇▇▇▇▇▇) – Deposit & Hold

Dear Sirs:

Reference is made to the Deposit Agreement, dated as of April 23, 2018, as amended and supplemented from time to time (the “Deposit Agreement”), by and among Mereo BioPharma Group plc, a public limited company incorporated under the laws of England and Wales and its successors (the “Company”), Citibank, N.A., a national banking association organized and existing under the laws of the United States of America, as Depositary (the “Depositary”), and all Holders and Beneficial Owners of American Depositary Shares (the “ADSs”) issued thereunder. All capitalized terms used, but not otherwise defined herein, shall have the meaning assigned thereto in the Deposit Agreement.

In accordance with the terms and subject to the limitations set forth in the Deposit Agreement, promptly following the Depositary’s receipt of confirmation from the Custodian that the Custodian has received a deposit of the number of Shares specified below made by the Company for the benefit of the undersigned holder thereof (the “Holder” and together with the Company, the “Undersigned”), the Undersigned hereby jointly instruct the Depositary, and the Depositary hereby agrees:

(i) to promptly accept for deposit the number of Shares and issue the number of ADSs as specified below:

and (ii) to promptly deliver such Program ADSs, as follows:

The Company hereby confirms and certifies that (i) the registration statement on Form F-3 (File No. 333-239708) (the “Registration Statement”), filed with the U.S. Securities and Exchange Commission (the “Commission”) on July 6, 2020, registers the resale of the above Shares represented by ADSs, such ADSs will be freely transferable following the issuance thereof by the Depositary, and there are no legal restrictions on subsequent transfers of the ADSs to be issued hereunder under the laws of England and Wales or the United States, (ii) the Registration Statement is effective under the Securities Act of 1933, as amended (the “Securities Act”), and (iii) no stop order suspending the effectiveness of the Registration Statement has been issued and no proceedings for such purpose have been instituted or are pending or, to the best knowledge of the Company, are contemplated or threatened by the Commission.

The Holder hereby represents and covenants to, and for the benefit of, the Depositary and Citibank, N.A.—London Branch (the “Custodian”), that (i) the Holder is not an “affiliate” of the Company as that term is defined in Rule 144 promulgated by the Commission under the Securities Act and has not been an affiliate at any time during the 90 days immediately preceding the date hereof, and (ii) all stamp duty taxes, including, without limitation, the U.K. Stamp Duty Reserve Tax (“SDRT”), will be paid in full and on a timely basis to the extent such taxes are payable in respect of the deposit of the Shares and the issuance and delivery of the ADSs as contemplated herein.

Each of the Holder and, to the extent it is not unlawful for the Company to do so under the applicable laws of England and Wales, the Company agrees to indemnify the Depositary and the Custodian for, and to hold the Depositary and the Custodian harmless against, all losses, liabilities, taxes, charges, penalties or expenses (including reasonable legal fees and disbursements), incurred by the Depositary and/or by the Custodian or to which the Depositary and/or the Custodian may become subject to and arising directly or indirectly from the failure by any person to pay (or discharge) any applicable stamp duty taxes, including, without limitation, SDRT, or any other similar duty or tax in connection with the deposit of the Shares and the issuance and delivery of the ADSs as contemplated herein, save to the extent that such losses, liabilities, taxes, charges, penalties or expenses are due to the negligence or bad faith of the Custodian or the Depositary.

IN WITNESS WHEREOF this agreement has been executed as a deed and delivered by the parties on the date first above written.