CNTA Form 4: Officer Exercises Options at $9.42 and Sells Shares at $24

Rhea-AI Filing Summary

Tia L. Bush, Chief Technology & Quality Officer of Centessa Pharmaceuticals plc (CNTA), reported insider transactions on 09/24/2025. The filing shows the exercise of a stock option to acquire 35,000 ordinary shares at an exercise price of $9.42 and a contemporaneous sale of 35,000 ordinary shares at $24.00 executed under a Rule 10b5-1 trading plan adopted on 09/14/2024. After the non-derivative transactions the filing lists 156,503 shares beneficially owned following the acquisition and 121,503 shares following the sale. The related option covers 35,000 underlying ordinary shares, is exercisable in accordance with the stated vesting schedule, has an exercise price of $9.42 and an expiration date of 05/07/2031. The Form 4 is signed by an attorney-in-fact, Raphael Deferiere, dated 09/24/2025.

Positive

• Transactions were executed under a Rule 10b5-1 trading plan, indicating pre-established, compliance-oriented execution.
• Full disclosure of option terms and vesting schedule including exercise price $9.42 and expiration 05/07/2031.

Negative

• Sale reduced direct beneficial ownership from 156,503 shares after the acquisition to 121,503 shares following the sale.
• Significant insider sale volume of 35,000 shares could be viewed as reducing insider-held shares, though executed under a plan.

Insights

Securities Analyst

TL;DR: Routine option exercise and planned sale, likely liquidity management rather than new strategic signal.

The filing documents a simultaneous exercise of an option for 35,000 shares at $9.42 and a sale of 35,000 shares at $24.00 executed under a pre-established Rule 10b5-1 plan. The use of a 10b5-1 plan and the contemporaneous exercise-and-sell pattern are common for officers seeking liquidity while adhering to insider-trading compliance. The filing discloses post-transaction beneficial ownership levels of 156,503 shares after the acquisition and 121,503 shares after the sale, and identifies an outstanding option expiring on 05/07/2031 with a vesting schedule noted in the explanation. These are routine insider activity items with limited direct implication for company fundamentals.

Corporate Governance Expert

TL;DR: Disclosure appears complete and compliant; transactions were executed under a documented 10b5-1 plan.

The Form 4 discloses the reporting person’s officer role and provides required details: transaction codes, prices, quantities, vesting terms for the option, and the statement that sales were effected pursuant to a Rule 10b5-1 trading plan adopted on 09/14/2024. The form is signed by an attorney-in-fact. From a governance perspective, the presence of a 10b5-1 plan and clear vesting information supports procedural compliance and transparency. No material governance concerns are evident from the disclosed entries alone.

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^*

Bush Tia L

(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)
	Chief Technology & Quality Ofc

3. Date of Earliest Transaction (Month/Day/Year)
09/24/2025

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)	09/24/2025		M		35,000	A	$9.42	156,503	D
Ordinary Shares(1)	09/24/2025		S(2)		35,000	D	$24	121,503	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
Share Option (right to buy)	$9.42	09/24/2025		M			35,000	(3)	05/07/2031	Ordinary Shares(1)	35,000	$0	440,338	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. 25% of the shares subject to such option shall vest and become exercisable on May 20, 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:

	/s/ Raphael Deferiere, attorney-in-fact	09/24/2025
	** 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 Tia L. Bush (CNTA) report on 09/24/2025?

The Form 4 reports the exercise of an option to acquire 35,000 ordinary shares at an exercise price of $9.42 and a sale of 35,000 ordinary shares at $24.00 on 09/24/2025.

Were the sales by the reporting person part of a pre-arranged plan (CNTA)?

Yes. The filing states the sales were effected pursuant to a Rule 10b5-1 trading plan adopted on 09/14/2024.

How many shares did the reporting person beneficially own after the transactions (CNTA)?

The Form 4 shows 156,503 shares beneficially owned following the acquisition entry and 121,503 shares following the sale entry as reported on the form.

What are the key terms of the option exercised by Tia L. Bush (CNTA)?

The option has an exercise price of $9.42, covers 35,000 shares, includes a vesting schedule (25% on 05/20/2022 and remaining 75% monthly thereafter), and expires on 05/07/2031.

Who signed the Form 4 for the reporting person (CNTA)?

The Form 4 is signed by attorney-in-fact Raphael Deferiere and dated 09/24/2025.