X0306 4 2020-10-06 0 0001662579 C4 Therapeutics, Inc. CCCC 0001132945 COHEN MARC A C/O C4 THERAPEUTICS, INC. 490 ARSENAL WAY, SUITE 200 WATERTOWN MA 02472 1 0 1 0 Common Stock 2020-10-06 4 C 0 237149 A 370024 I See Footnote Common Stock 2020-10-06 4 C 0 1482183 A 1852207 I See Footnote Common Stock 2020-10-06 4 C 0 2484425 A 2484425 I By Cobro Ventures Opportunity Fund, L.P. Common Stock 2020-10-06 4 P 0 5030 19.00 A 5030 D Series Seed Preferred Stock 2020-10-06 4 C 0 2000000 0.00 D Common Stock 237149 0 I See Footnote Series A Preferred Stock 2020-10-06 4 C 0 12500000 0.00 D Common Stock 1482183 0 I See Footnote Series B Preferred Stock 2020-10-06 4 C 0 20952403 0.00 D Common Stock 2484425 0 I By Cobro Ventures Opportunity Fund, L.P. Each share of Series Seed Preferred Stock, Series A Preferred Stock, and Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 8.4335-to-one basis upon the closing of the Issuer's initial public offering on October 6, 2020 and had no expiration date. Shares held by Reporting Person as trustee of the Marc Andrew Cohen Revocable Trust. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. Shares held by Cobro Ventures Opportunity Fund, L.P. ("Cobro Ventures"). The Reporting Person serves as a manager of Cobro Opportunity Fund GP, LLC, the general partner of Cobro Ventures, and may be deemed to exercise voting and investment power over the shares held by Cobro Ventures. The Reporting Person disclaims beneficial ownership of the shares held by Cobro Ventures except to the extent of his pecuniary interest therein. /s/ Jolie M. Siegel, Attorney-in-Fact 2020-10-06