SCHEDULE 13G/A 0000902664-23-005480 0001910456 XXXXXXXX LIVE 3 Common Stock, $0.0001 par value per share 12/31/2025 0001662579 C4 Therapeutics, Inc. 12529R107 490 ARSENAL WAY SUITE 120 WATERTOWN MA 02472 Rule 13d-1(c) Lynx1 Capital Management LP DE 0.00 7098133.00 0.00 7098133.00 7098133.00 N 7.3 PN Weston Nichols X1 0.00 7098133.00 0.00 7098133.00 7098133.00 N 7.3 IN C4 Therapeutics, Inc. 490 Arsenal Way, Suite 120, Watertown, MA 02472 (i) Lynx1 Capital Management LP (the "Investment Manager"), a Delaware limited partnership, and the investment manager to Lynx1 Master Fund LP (the "Lynx1 Fund"), with respect to the shares of common stock, par value $0.0001 per share ("Common Stock"), of C4 Therapeutics, Inc., a Delaware corporation (the "Company"), directly held by the Lynx1 Fund; and (ii) Mr. Weston Nichols ("Mr. Nichols"), the sole member of Lynx1 Capital Management GP LLC, the general partner of the Investment Manager, with respect to the shares of Common Stock directly held by the Lynx1 Fund. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Securities Exchange Act of 1934, the beneficial owner of the securities reported herein. Lynx1 Capital Management LP D81 Calle C Suite 301, PMB 1202 Dorado, PR, 00646-2051 Weston Nichols c/o Lynx1 Capital Management LP D81 Calle C Suite 301, PMB 1202 Dorado, PR, 00646-2051 Investment Manager - Delaware Mr. Nichols - United States of America Y The information required by Item 4(a) is set forth in Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 96,914,418 shares of Common Stock outstanding as of October 29, 2025, as reported in the Company's Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2025, filed with the Securities and Exchange Commission on November 6, 2025. 7.3% The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference. Y N The Lynx1 Fund has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock reported herein. Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Lynx1 Capital Management LP /s/ Weston Nichols 02/17/2026 Weston Nichols /s/ Weston Nichols 02/17/2026