[Form 4] Mereo BioPharma Group plc Insider Trading Activity

Rhea-AI Filing Summary

Shames Daniel reported acquisition or exercise transactions in this Form 4 filing.

Mereo BioPharma Group plc director Daniel Shames reported receiving new equity awards. On February 26, 2026, he was granted 66,000 share options and 96,163 deferred restricted stock units as compensation. The options vest in substantially equal monthly installments over one year from the grant date.

The deferred restricted stock units are granted in the form of American Depositary Shares instead of annual cash compensation for non-executive directors and also vest in substantially equal monthly installments over the plan year. Each ADS represents five ordinary shares of Mereo BioPharma Group plc.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Shames Daniel

Role Director

Type	Security	Shares	Price	Value
Grant/Award	Share Options (Right to buy)	66,000	$0.00	--
Grant/Award	Deferred Restricted Stock Units	96,163	$0.00	--

Holdings After Transaction: Share Options (Right to buy) — 66,000 shares (Direct); Deferred Restricted Stock Units — 96,163 shares (Direct)

Footnotes (1)

1. Vests in substantially equal monthly installments over a one year period from the February 26, 2026 grant date. Each American Depositary Share ("ADS") represents five ordinary shares, nominal value GBP 0.003 per ordinary share, of the Issuer. Deferred restricted stock units ("DRSU") are granted to non-executive directors who elected to receive DRSUs in the form of ADSs in lieu of annual cash compensation. DRSUs vest in substantially equal monthly installments over the plan year following the grant date. Payment of DRSUs in ADSs will generally be made 180 days following separation of service.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Shames Daniel

(Last) (First) (Middle)

C/O MEREO BIOPHARMA GROUP PLC

4TH FLOOR, ONE CAVENDISH PLACE

(Street)

LONDON X0 W1G 0QF

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Mereo BioPharma Group plc [ MREO ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
02/26/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Share Options (Right to buy)	$0.39	02/26/2026		A		66,000		(1)	02/26/2036	American Depositary Shares(2)	66,000	$0	66,000	D
Deferred Restricted Stock Units	(3)	02/26/2026		A		96,163		(3)	(3)	American Depository Shares(2)	96,163	(3)	96,163	D

Explanation of Responses:

1. Vests in substantially equal monthly installments over a one year period from the February 26, 2026 grant date.

2. Each American Depositary Share ("ADS") represents five ordinary shares, nominal value GBP 0.003 per ordinary share, of the Issuer.

3. Deferred restricted stock units ("DRSU") are granted to non-executive directors who elected to receive DRSUs in the form of ADSs in lieu of annual cash compensation. DRSUs vest in substantially equal monthly installments over the plan year following the grant date. Payment of DRSUs in ADSs will generally be made 180 days following separation of service.

	/s/ Christine Fox, by power of attorney	02/27/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Mereo BioPharma (MREO) director Daniel Shames report?

Daniel Shames reported receiving equity awards from Mereo BioPharma Group plc. He was granted 66,000 share options and 96,163 deferred restricted stock units on February 26, 2026, as part of his non-executive director compensation structure, rather than through open-market share purchases or sales.

How many share options and deferred stock units did Mereo BioPharma (MREO) grant?

Mereo BioPharma granted 66,000 share options and 96,163 deferred restricted stock units to director Daniel Shames. These awards are reported as grants or other acquisitions, reflecting compensation rather than trading activity, and are structured to vest gradually over time according to the company’s equity plans.

How do the Mereo BioPharma (MREO) director’s new awards vest over time?

The 66,000 share options vest in substantially equal monthly installments over one year from the February 26, 2026 grant date. The deferred restricted stock units vest in substantially equal monthly installments over the plan year following the grant date, aligning compensation with ongoing board service.

What are Mereo BioPharma (MREO) deferred restricted stock units for non-executive directors?

Deferred restricted stock units are equity awards granted to non-executive directors who choose ADS-based compensation instead of annual cash payments. These units vest monthly over the following plan year, and payment in American Depositary Shares is generally made 180 days after the director’s separation from service.

How do Mereo BioPharma (MREO) American Depositary Shares relate to ordinary shares?

Each American Depositary Share represents five ordinary shares of Mereo BioPharma Group plc. Deferred restricted stock units granted to the director are structured in the form of these ADSs, linking director equity compensation directly to the underlying ordinary share capital of the company.