[Form 4] Centessa Pharmaceuticals plc Insider Trading Activity

Rhea-AI Filing Summary

Mario Alberto Accardi, President, Orexin Program at Centessa Pharmaceuticals plc (CNTA), reported two sales of Ordinary Shares on 09/16/2025 executed under a Rule 10b5-1 trading plan adopted February 14, 2025. The Form 4 shows a disposition of 7,430 shares at a weighted-average price of $21.3333, leaving 198,136 shares beneficially owned, and a disposition of 742 shares at a weighted-average price of $22.0213, leaving 197,394 shares beneficially owned. The filing notes Ordinary Shares may be represented by American Depositary Shares on a one-for-one basis and provides price ranges for the multiple transactions comprising each weighted average.

Positive

• Sales executed under a Rule 10b5-1 trading plan, indicating pre-arranged, documented insider transactions
• Full disclosure of weighted-average prices and price ranges with an undertaking to provide per-price details upon request

Negative

• Beneficial ownership decreased—holdings reported as 198,136 shares after the first sale and 197,394 shares after the second sale
• Multiple transactions required weighted-average pricing, indicating sales occurred across a price range rather than a single price point

Insights

Financial Analyst

TL;DR Insider executed pre-arranged sales, modestly reducing holdings; transactions were priced in the low-$20 range.

The reporting person completed two sales under a Rule 10b5-1 plan, selling 7,430 and 742 Ordinary Shares on 09/16/2025 at weighted-average prices of $21.3333 and $22.0213 respectively. Holdings decreased from prior levels to 198,136 and then 197,394 shares. The disclosure includes price ranges for the component trades. For investors, these are routine insider liquidity transactions documented under a 10b5-1 plan rather than ad hoc market timing.

Compliance/Risk Analyst

TL;DR Sales were executed under a documented 10b5-1 plan, reducing beneficial ownership; disclosures include weighted-average prices and price ranges.

The Form 4 clearly states the sales were effected pursuant to a Rule 10b5-1 trading plan adopted February 14, 2025, which helps demonstrate compliance with insider trading rules. The report provides weighted-average prices and commits to furnish per-price sale details upon request. No derivatives or other transactions are reported on this filing.

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).

1. Name and Address of Reporting Person^*

Accardi Mario Alberto

(Last) (First) (Middle)

C/O CENTESSA PHARMACEUTICALS PLC

3RD FL., 1 ASHLEY RD, ALTRINCHAM

(Street)

CHESHIRE X0 WA14 2DT

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Centessa Pharmaceuticals plc [ CNTA ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President, Orexin Program

3. Date of Earliest Transaction (Month/Day/Year)
09/16/2025

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
Ordinary Shares(1)	09/16/2025		S(2)		7,430	D	$21.3333(3)	198,136	D
Ordinary Shares(1)	09/16/2025		S(2)		742	D	$22.0213(4)	197,394	D

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

Explanation of Responses:

1. The Ordinary Shares may be represented by American Depositary Shares, each of which currently represents one Ordinary Share.

2. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 14, 2025.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.97 to $21.95, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.01 to $22.06, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.

Remarks:

	/s/ Raphael Deferiere, attorney-in-fact	09/16/2025
	** 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 shares did Mario Accardi sell on the Form 4 for CNTA?

The Form 4 reports dispositions of 7,430 Ordinary Shares and 742 Ordinary Shares on 09/16/2025.

At what prices were the CNTA shares sold in the Form 4?

The filings show weighted-average prices of $21.3333 for the 7,430-share sale and $22.0213 for the 742-share sale; component trades ranged $20.97–$21.95 and $22.01–$22.06 respectively.

Were the CNTA sales part of a pre-arranged trading plan?

Yes. The sales were effected pursuant to a Rule 10b5-1 trading plan adopted on February 14, 2025.

How many Centessa shares does the reporting person beneficially own after the sales?

The Form 4 reports 198,136 shares following the first reported sale and 197,394 shares following the second reported sale.

Do the Ordinary Shares correspond to American Depositary Shares (ADS)?

The filing states the Ordinary Shares may be represented by American Depositary Shares, each of which currently represents one Ordinary Share.