144 0001709024 XXXXXXXX LIVE 0000744218 Celldex Therapeutics, Inc. 000-15006 PERRYVILLE III, 53 FRONTAGE ROAD SUITE 220 HAMPTON NJ 08827 908-200-7500 Martin Samuel Bates Officer COMMON Morgan Stanley Smith Barney LLC Executive Services

200 W Civic Center Dr - 4th Floor SANDY UT 84070

17172 583848.00 65900000 06/14/2024 NASDAQ COMMON 06/14/2024 STOCK OPTION EXERCISE ISSUER N 6040 06/14/2024 COMPENSATION COMMON 08/10/2021 EXERCISED SHARES ISSUER N 11132 08/10/2021 COMPENSATION N SAMUEL MARTIN

PERRYVILLE III, 53 FRONTAGE RD STE 220 HAMPTON NJ 08827

STOCK OPTION EXERCISE 05/30/2024 25000 850639.98 SAMUEL MARTIN

PERRYVILLE III, 53 FRONTAGE RD STE 220, HAMPTON NJ 08827

ESPP 05/30/2024 985 33645.74 SAMUEL MARTIN

PERRYVILLE III, 53 FRONTAGE RD STE 220,, HAMPTON NJ 08827

EXERCISED SHARES 05/30/2024 4265 145415.13 06/14/2024 /s/ Samuel Bates Martin