X0306 4 2022-01-04 0 0001662579 C4 Therapeutics, Inc. CCCC 0001308597 Dubin Glenn C/O C4 THERAPEUTICS, INC. 490 ARSENAL WAY #200 WATERTOWN MA 02472 1 0 0 0 Common Stock 2022-01-04 4 A 0 199 31.58 A 494 D Common Stock 770607 I By DF Investment Partners LLC Common Stock 20000 I By G&E Dubin Family Foundation These shares were issued in accordance with the Issuer's Non-Employee Director Compensation Policy, pursuant to which the Reporting Person elected to receive shares of the Issuer's common stock in lieu of cash compensation for services as a non-employee director of the Issuer. The price reported in Column 4 is based upon the closing market price of the Issuer's common stock on January 4, 2022. Shares held directly by DF Investment Partners LLC ("DFIP"). The Reporting Person serves as managing member of DFIP and may be deemed to exercise voting and investment power over the shares held by DFIP. The Reporting Person disclaims beneficial ownership of the shares held by DFIP except to the extent of his pecuniary interest therein. Shares held directly by G&E Dubin Family Foundation. The Reporting Person may be deemed to exercise voting and investment power over the shares held by G&E Dubin Family Foundation and disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. /s/ Jolie M. Siegel, Attorney-in-Fact 2022-01-18