[Form 4] Centessa Pharmaceuticals plc American Insider Trading Activity

Rhea-AI Filing Summary

Centessa Pharmaceuticals plc director and General Counsel Hussain Iqbal J reported multiple transactions in ordinary shares and share options on 09/09/2025 and 09/10/2025. The Form 4 shows purchases of 20,000 ordinary shares on each date at $5.84 per share and contemporaneous sales of 20,000 shares on each date: a weighted average sale price of $20.0051 on 09/09/2025 (sales ranged $20.00–$20.03) and sales at $22.00 on 09/10/2025. After the reported transactions the reporter’s directly held ordinary shares are shown as 105,386. The filing discloses 20,000 share options exercisable at $5.84 (vesting schedule described) and indicates 5,500 shares held indirectly by the reporter’s spouse. The sales on 09/09/2025 were effected pursuant to a Rule 10b5-1 trading plan adopted on September 14, 2024.

Positive

• Use of a Rule 10b5-1 trading plan for the reported sales, which is disclosed in the filing
• Full disclosure of option vesting terms and indirect spouse ownership (5,500 shares) enhances transparency
• Form 4 filed and signed (including attorney-in-fact signature), meeting Section 16 reporting obligations

Negative

• Insider sold 40,000 shares across 09/09/2025 and 09/10/2025 at weighted prices of approximately $20.01 and $22.00, reducing direct holdings to 105,386 shares
• Large intraday sells could be perceived by some investors as liquidity-taking from an executive-level holder

Insights

Securities Analyst

TL;DR: Routine insider activity: matched purchases and sales plus option holdings; limited immediate market impact.

The Form 4 documents contemporaneous buys and sells by the reporting insider, including 40,000 ordinary shares acquired at $5.84 and 40,000 shares sold at weighted average prices around $20.01 and $22.00. The filing also discloses in-the-money options exercisable at $5.84 with a stated vesting schedule and 5,500 shares held indirectly by a spouse. The sales on 09/09/2025 were executed under a previously adopted Rule 10b5-1 plan, which is relevant for compliance and market signaling. Taken together, the transactions show active liquidity management of a significant personal position but do not, by themselves, provide new operational or financial information about the issuer.

Corporate Governance Expert

TL;DR: Disclosure is consistent with Section 16 obligations and documents use of a 10b5-1 plan; governance controls appear observed.

The Form 4 is complete in noting the reporter’s roles (Director and General Counsel), the adoption and use of a Rule 10b5-1 trading plan for sales, and the signature by an attorney-in-fact. It also provides vesting terms for share options and specifies indirect spouse ownership. These elements support transparency around potential conflicts and trading intent. There is no indication in the filing of transactions outside disclosed plans or atypical governance concerns; the activity appears consistent with standard insider reporting practices.

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).

X

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^*

HUSSAIN IQBAL J

(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)
	General Counsel

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

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)	09/09/2025		M		20,000	A	$5.84	125,386	D
Ordinary Shares(1)	09/09/2025		S(2)		20,000	D	$20.0051(3)	105,386	D
Ordinary Shares(1)	09/10/2025		M		20,000	A	$5.84	125,386	D
Ordinary Shares(1)	09/10/2025		S(2)		20,000	D	$22	105,386	D
Ordinary Shares(1)								5,500	I	By spouse

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 Option (right to buy)	$5.84	09/09/2025		M			20,000	(4)	02/19/2031	Ordinary Shares(1)	20,000	$0	259,559	D
Share Option (right to buy)	$5.84	09/10/2025		M			20,000	(4)	02/19/2031	Ordinary Shares(1)	20,000	$0	239,559	D

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 September 14, 2024.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.00 to $20.03, 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. 25% of the shares subject to such option shall vest and become exercisable on February 19, 2022 and the remaining 75% of the shares subject to such option shall vest and become exercisable in 36 monthly installments on the first day of each month thereafter.

Remarks:

Exhibit 24.2 - Substitute Power of Attorney

	/s/ Raphael Deferiere, attorney-in-fact	09/11/2025
	** 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 insider transactions did CNTA reporting person Hussain Iqbal J disclose in this Form 4?

Answer: The filing reports acquisitions of 20,000 ordinary shares on 09/09/2025 and 20,000 on 09/10/2025 at $5.84 each, and sales of 20,000 shares on 09/09/2025 at a weighted average of $20.0051 and 20,000 on 09/10/2025 at $22.00.

Were any of the sales executed under a 10b5-1 plan in the CNTA Form 4?

Answer: Yes, the sales reported were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 14, 2024.

How many shares does the reporting person beneficially own after these transactions?

Answer: The Form 4 shows the reporting person directly beneficially owning 105,386 ordinary shares following the reported transactions.

Does the filing disclose derivative holdings or option details for CNTA insider?

Answer: Yes, the filing discloses share options exercisable at $5.84 with vesting beginning February 19, 2022 and additional monthly vesting thereafter; the reported number of option shares exercised/underlying is 20,000 per option entry as shown.

Is there any indirect ownership reported for CNTA insider Hussain Iqbal J?

Answer: Yes, the filing discloses 5,500 ordinary shares held indirectly by the reporting person’s spouse.