Karen M. Anderson - 13 Mar 2026 Form 4/A - Amendment Insider Report for Centessa Pharmaceuticals plc (CNTA)

Role: Chief People Officer
Signature: /s/ Raphael Deferiere, attorney-in-fact
Issuer symbol: CNTA
Transactions as of: 13 Mar 2026
Net transactions value: -$3,150,673
Form type: 4/A - Amendment
Filing time: 16 Mar 2026, 18:09:44 UTC
Date Of Original Report: 13 Mar 2026
Previous filing: 03 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Anderson Karen M.	Chief People Officer	C/O CENTESSA PHARMACEUTICALS PLC, 3RD FL., 1 ASHLEY RD, ALTRINCHAM, CHESHIRE, UNITED KINGDOM	/s/ Raphael Deferiere, attorney-in-fact	16 Mar 2026	0001762176

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CNTA	Ordinary Shares	Options Exercise		+94,224	+130%	$4.01^*	166,940	13 Mar 2026	Direct	F1
transaction	CNTA	Ordinary Shares	Options Exercise		+15,174	+9.1%	$3.85^*	182,114	13 Mar 2026	Direct	F1
transaction	CNTA	Ordinary Shares	Sale	$2,823,234	-107,961	-59%	$26.15	74,153	13 Mar 2026	Direct	F1, F2, F3
transaction	CNTA	Ordinary Shares	Sale	$327,439	-12,068	-16%	$27.13	62,085	13 Mar 2026	Direct	F1, F2, F4

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	CNTA	Share Option (right to buy)	Options Exercise		-94,224	-39%	$0.000000^*	149,811	13 Mar 2026	Ordinary Shares	94,224	$4.01	Direct	F1, F5
transaction	CNTA	Share Option (right to buy)	Options Exercise		-15,174	-35%	$0.000000^*	28,336	13 Mar 2026	Ordinary Shares	15,174	$3.85	Direct	F1, F6

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

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).

Explanation of Responses:

Id	Content
F1	The Ordinary Shares may be represented by American Depositary Shares, each of which currently represents one Ordinary Share.
F2	The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 12, 2025.
F3	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.75 to $26.705, 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.
F4	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.805 to $27.455, 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.
F5	25% of the shares subject to such option shall vest and become exercisable on December 1, 2023 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.
F6	1/48th of the shares subject to such option shall vest and become exercisable in equal monthly installments with the first installment vesting on March 1, 2023.

Remarks:

This Form 4/A amends and restates the Form 4 filed on March 13, 2026 to correct the reporting of stock option exercises. The exercises were previously reported as originating from a single option grant but were exercised from two separate option grants with different exercise prices. This amendment reports the exercises from each grant at the applicable exercise prices. Except for the corrected reporting of the option exercises, the transactions and amounts previously reported remain unchanged.