X0508 4 2025-02-14 0 0001662579 C4 Therapeutics, Inc. CCCC 0001992219 Mossler Mark C/O C4 THERAPEUTICS, INC. 490 ARSENAL WAY #120 WATERTOWN MA 02472 0 1 0 0 Chief Accounting Officer 0 Common Stock 2025-02-14 4 F 0 1586 3.18 D 18204 D Represents shares withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units ("RSUs") and does not represent a sale by the Reporting Person. /s/ Shagha Russell, Attorney-in-Fact 2025-02-18