144 0002074392 XXXXXXXX LIVE 0001847903 Centessa Pharmaceuticals plc 001-40445 3RD FLOOR 1 ASHLEY ROAD ALTRINCHAM, CHESHIRE X0 WA14 2DT 44 7391 789784 Accardi Mario Alberto Officer Common UBS Financial Services, Inc

Eleven Madison Avenue 4th Floor New York NY 10010

10000 300000.00 134447836 12/08/2025 Nasdaq Common 01/02/2020 Founders Shares Issuer N 5000 01/02/2020 NA Common 12/08/2025 Exercise of stock options Issuer N 5000 12/08/2025 Cash N Mario Alberto Accardi

3RD FLOOR, 1 ASHLEY ROAD ALTRINCHAM, CHESHIRE X0 WA14 2DT

Common 09/09/2025 7000 140000.00 Mario Alberto Accardi

3RD FLOOR 1 ASHLEY ROAD ALTRINCHAM, CHESHIRE X0 WA14 2D

Common 09/16/2025 8172 174846.48 Mario Alberto Accardi

3RD FLOOR, 1 ASHLEY ROAD ALTRINCHAM, CHESHIRE X0 WA14 2D

Common 10/27/2025 8000 200000.00 The transactions reported herein were effected pursuant to a Rule 10b5-1 trading plan. 12/08/2025 02/14/2025 /s/ UBS Financial Services Inc, as attorney-in-fact for Mario Alberto Accardi