0001470831-26-000174.txt : 20260218 0001470831-26-000174.hdr.sgml : 20260218 20260218170438 ACCESSION NUMBER: 0001470831-26-000174 CONFORMED SUBMISSION TYPE: 4 PUBLIC DOCUMENT COUNT: 1 CONFORMED PERIOD OF REPORT: 20260213 FILED AS OF DATE: 20260218 DATE AS OF CHANGE: 20260218 REPORTING-OWNER: OWNER DATA: COMPANY CONFORMED NAME: Mossler Mark CENTRAL INDEX KEY: 0001992219 ORGANIZATION NAME: FILING VALUES: FORM TYPE: 4 SEC ACT: 1934 Act SEC FILE NUMBER: 001-39567 FILM NUMBER: 26649867 MAIL ADDRESS: STREET 1: C4 THERAPEUTICS, INC. STREET 2: 490 ARSENAL WAY, SUITE 120 CITY: WATERTOWN STATE: MA ZIP: 02472 ISSUER: COMPANY DATA: COMPANY CONFORMED NAME: C4 Therapeutics, Inc. CENTRAL INDEX KEY: 0001662579 STANDARD INDUSTRIAL CLASSIFICATION: BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836] ORGANIZATION NAME: 03 Life Sciences EIN: 475617627 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 BUSINESS ADDRESS: STREET 1: 490 ARSENAL WAY STREET 2: SUITE 120 CITY: WATERTOWN STATE: MA ZIP: 02472 BUSINESS PHONE: (617) 231-0700 MAIL ADDRESS: STREET 1: 490 ARSENAL WAY STREET 2: SUITE 120 CITY: WATERTOWN STATE: MA ZIP: 02472 4 1 wk-form4_1771452272.xml FORM 4 X0508 4 2026-02-13 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 2026-02-13 4 A 0 56980 0 A 75184 D Common Stock 2026-02-14 5 M 0 E 9420 0 A 75184 D Common Stock 2026-02-14 4 F 0 3268 1.89 D 71916 D Represents restricted stock units ("RSUs"). Each RSU represents the contingent right to receive one share of the Issuer's Common Stock upon vesting and settlement. The RSUs shall vest as follows: (i) 28,490 RSUs shall vest in three equal annual installments following the grant date, with the first installment vesting on February 13, 2027, and (ii) 28,490 RSUs shall vest in full on February 13, 2029, subject to potential acceleration upon achievement of certain performance milestones. Reflects the acquisition of shares of Common Stock upon vesting of previously disclosed grants of RSUs. The grants of RSUs were initially reported in Table I of the Forms 4 filed by the Reporting Person on April 10, 2024 and February 18, 2025. Represents shares withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs and does not represent a sale by the Reporting Person. /s/ Shagha Russell, Attorney-in-Fact 2026-02-18