CCCC / C4 Therapeutics, Inc. - SEC-Einreichungen, Jahresbericht, Proxy Statement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2026 (May 12, 2026) C4 TH

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2026 (May 12, 2026) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

C4 Therapeutics Reports First Quarter 2026 Financial Results and Recent Business Highlights Progressed Plans to Establish Cemsidomide as a Potentially Foundational Treatment for Multiple Myeloma; Enrollment Ongoing in Phase 2 MOMENTUM Trial and Phase

Exhibit 99.1 C4 Therapeutics Reports First Quarter 2026 Financial Results and Recent Business Highlights Progressed Plans to Establish Cemsidomide as a Potentially Foundational Treatment for Multiple Myeloma; Enrollment Ongoing in Phase 2 MOMENTUM Trial and Phase 1b Trial in Combination with Elranatamab Additional Phase 1b Trial Evaluating Cemsidomide in Combination with Approved Multiple Myeloma

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 12, 2026 C4 THERAPEUTICS, INC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 12, 2026 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission File

Protein degraded. Disease targeted. Lives transformed. May 2026 Forward-looking Statements and Intellectual Property 2 FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of

maycorporatedeckfinalx5 Protein degraded. Disease targeted. Lives transformed. May 2026 Forward-looking Statements and Intellectual Property 2 FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “anticipate,” “believe,” “could,” “

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant o

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)(

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 _____________________________________ FORM 10-K _____________________________________ (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF

cccc-20251231x10kars2026 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

AMENDMENT NO. 1 TO THE   SECOND AMENDED AND RESTATED   BY-LAWS   OF   C4 THERAPEUTICS, INC.   (the “Corporation”)   Section 8 of Article VI of the Second Amended and Restated By-laws of the Corporation (the “By-laws”) is hereby amended and restated i

bylaws-amendmentno1tosec AMENDMENT NO. 1 TO THE   SECOND AMENDED AND RESTATED   BY-LAWS   OF   C4 THERAPEUTICS, INC.   (the “Corporation”)   Section 8 of Article VI of the Second Amended and Restated By-laws of the Corporation (the “By-laws”) is hereby amended and restated in its entirety as follows:   “SECTION 8. Exclusive Jurisdiction of Delaware Courts or the United States Federal District Cour

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 10, 2026 (April 9, 2026) C4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 10, 2026 (April 9, 2026) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 9, 2026 (April 8, 2026) C4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 9, 2026 (April 8, 2026) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation)

C4 Therapeutics Expands Long-Term Partnership with Roche Through New Collaboration Agreement Focused on Discovering and Developing Degrader-Antibody Conjugates (DACs) Agreement Focused on Developing DACs With Payloads For Two Oncology Targets, With a

Exhibit 99.1 C4 Therapeutics Expands Long-Term Partnership with Roche Through New Collaboration Agreement Focused on Discovering and Developing Degrader-Antibody Conjugates (DACs) Agreement Focused on Developing DACs With Payloads For Two Oncology Targets, With an Option for a Third Target C4T to Develop Degraders With Payload Properties; Roche to Conjugate Payloads to Targeted Antibodies C4T to R

Protein degraded. Disease targeted. Lives transformed. April 2026 Forward-looking Statements and Intellectual Property 2 FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements o

aprilcorporatedeckfinal Protein degraded. Disease targeted. Lives transformed. April 2026 Forward-looking Statements and Intellectual Property 2 FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “anticipate,” “believe,” “could,”

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT Under The Securities Act of 1933 C4 Therapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 47-5617627 (State or other

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT Under The Securities Act of 1933 C4 Therapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 47-5617627 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 490 Arsenal Way, Suite 120 Watertown, MA 02472 (Address of princip

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 26, 2026 C4 THERAPEUTICS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 26, 2026 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

C4 Therapeutics Reports Fourth Quarter and Full Year 2025 Financial Results and Recent Business Highlights Cemsidomide Advancing into Later-stage Development with Potential for Accelerated Approval; First Patient Dosed in the Phase 2 MOMENTUM Trial f

Exhibit 99.1 C4 Therapeutics Reports Fourth Quarter and Full Year 2025 Financial Results and Recent Business Highlights Cemsidomide Advancing into Later-stage Development with Potential for Accelerated Approval; First Patient Dosed in the Phase 2 MOMENTUM Trial for Multiple Myeloma in the Fourth Line or Later Phase 1b Trial of Cemsidomide in Combination with Elranatamab on Track to Initiate in Q2

ACTIVE/204083388.2 PERFORMANCE-ACCELERATED RESTRICTED STOCK UNIT AWARD AGREEMENT FOR COMPANY EMPLOYEES UNDER THE C4 THERAPEUTICS, INC. 2020 STOCK OPTION AND INCENTIVE PLAN (PERFORMANCE-BASED ACCELERATED VESTING) Name of Grantee: No. of Performance-Ac

parsuagreementfebruary20 ACTIVE/204083388.2 PERFORMANCE-ACCELERATED RESTRICTED STOCK UNIT AWARD AGREEMENT FOR COMPANY EMPLOYEES UNDER THE C4 THERAPEUTICS, INC. 2020 STOCK OPTION AND INCENTIVE PLAN (PERFORMANCE-BASED ACCELERATED VESTING) Name of Grantee: No. of Performance-Accelerated Restricted Stock Units Grant Date: February 13, 2026 Pursuant to the C4 Therapeutics, Inc. 2020 Stock Option and In

DESCRIPTION OF CAPITAL STOCK

Exhibit 4.5 DESCRIPTION OF CAPITAL STOCK The summary of the general terms and provision of the registered securities of C4 Therapeutics, Inc. (“C4T,” the "Company," “we,” or “our”) set forth below does not purport to be complete and is subject to and qualified in its entirety by reference to our Fifth Amended and Restated Certificate of Incorporation, as amended (our “certificate of incorporation”

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2025 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-395

Table 1: Newly Registered Securities

Calculation of Filing Fee Tables S-8 C4 Therapeutics, Inc. Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee 1 Equity Common Stock, par value $0.0001 per share Other 4,845,720 $ 2.00 $ 9,691,440.00 0.0001381 $ 1,338.39 2 Equity C

SUBSIDIARIES

Exhibit 21.1 SUBSIDIARIES Subsidiary Jurisdiction of Incorporation C4T Securities Corporation Massachusetts

C4 Therapeutics Outlines Strategic Milestones to Advance Cemsidomide as a Potential Best-in-Class IKZF1/3 Degrader and Discovery Strategy Focused on Novel Targets in Clinically Validated Pathways Cemsidomide Phase 2 MOMENTUM Trial On Track to Initiat

Exhibit 99.1 C4 Therapeutics Outlines Strategic Milestones to Advance Cemsidomide as a Potential Best-in-Class IKZF1/3 Degrader and Discovery Strategy Focused on Novel Targets in Clinically Validated Pathways Cemsidomide Phase 2 MOMENTUM Trial On Track to Initiate in Q1 2026; Recommended Phase 2 Dose is 100 µg Cemsidomide Phase 1b Trial in Combination With Elranatamab On Track to Initiate in Q2 20

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 14, 2026 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 14, 2026 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

$125,000,000 Common Stock

424B5 Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-291696 PROSPECTUS SUPPLEMENT (to Prospectus dated December 10, 2025) $125,000,000 Common Stock We have previously entered into a sales agreement, or the Sales Agreement, with TD Securities (USA) LLC, which we refer to as TD Cowen or the Sales Agent, relating to shares of our common stock, par value $0.0001 per share, off

December 8, 2025

December 8, 2025 VIA EDGAR Office of Life Sciences Division of Corporation Finance U.

ACTIVE/203151211.2 Exhibit 4.7 C4 THERAPEUTICS, INC., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [●], 202[●] Subordinated Debt Securities ACTIVE/203151211.2 TABLE OF CONTENTS1 ARTICLE 1 DEFINITIONS Section 1.01 Definitions of Terms ARTICLE 2

c4t-formofsubordinatedin ACTIVE/203151211.2 Exhibit 4.7 C4 THERAPEUTICS, INC., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [●], 202[●] Subordinated Debt Securities ACTIVE/203151211.2 TABLE OF CONTENTS1 ARTICLE 1 DEFINITIONS Section 1.01 Definitions of Terms ARTICLE 2 ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION AND EXCHANGE OF SECURITIES Section 2.0 Designation and Terms of Securitie

As filed with the Securities and Exchange Commission on November 21, 2025

As filed with the Securities and Exchange Commission on November 21, 2025 Registration No.

ACTIVE/203150830.2 Exhibit 4.5 C4 THERAPEUTICS, INC., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [●], 202[●] Senior Debt Securities ACTIVE/203150830.2 TABLE OF CONTENTS1 ARTICLE 1 DEFINITIONS Section 1.01 Definitions of Terms ARTICLE 2 ISSUE

formofseniorindentureex4 ACTIVE/203150830.2 Exhibit 4.5 C4 THERAPEUTICS, INC., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [●], 202[●] Senior Debt Securities ACTIVE/203150830.2 TABLE OF CONTENTS1 ARTICLE 1 DEFINITIONS Section 1.01 Definitions of Terms ARTICLE 2 ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION AND EXCHANGE OF SECURITIES Section 2.01 Designation and Terms of Securities Sec

Security Type

Calculation of Filing Fee Tables S-3 C4 Therapeutics, Inc. Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2025 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2025 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

C4 Therapeutics Reports Third Quarter 2025 Financial Results and Recent Business Highlights Completed Equity Offering Resulted in $125 Million in Gross Proceeds, Extending Runway to End of 2028, Beyond Key Value Inflection Points; Potential to Earn u

Exhibit 99.1 C4 Therapeutics Reports Third Quarter 2025 Financial Results and Recent Business Highlights Completed Equity Offering Resulted in $125 Million in Gross Proceeds, Extending Runway to End of 2028, Beyond Key Value Inflection Points; Potential to Earn up to an Additional $225 Million in Proceeds Cemsidomide Phase 1 Multiple Myeloma Data Support Potential Best-in-Class Profile With a 53%

FORM OF CLASS B WARRANT TO PURCHASE COMMON STOCK OR PRE-FUNDED WARRANTS C4 THERAPEUTICS, INC.

EX-4.3 Exhibit 4.3 FORM OF CLASS B WARRANT TO PURCHASE COMMON STOCK OR PRE-FUNDED WARRANTS C4 THERAPEUTICS, INC. Number of Shares: [   ] (subject to adjustment) Class B Warrant No. Initial Exercise Date: October [ ], 2025 C4 Therapeutics, Inc., a Delaware corporation (the “Company”), hereby certifies that, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowl

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 16, 2025 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 16, 2025 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

Protein degraded. Disease targeted. Lives transformed. October 2025 Legal Disclaimer Statements and Intellectual Property LEGAL DISCLAIMER STATEMENTS The following presentation contains forward-looking statements. All statements other than statements

octoberdeck10152025xfin Protein degraded. Disease targeted. Lives transformed. October 2025 Legal Disclaimer Statements and Intellectual Property LEGAL DISCLAIMER STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “anticipate,” “believe,” “could

21,895,000 Shares of Common Stock Pre-funded Warrants to Purchase up to 28,713,500 Shares of Common Stock Class A Warrants to Purchase up to 50,608,500 Shares of Common Stock (or Pre-Funded Warrants) Class B Warrants to Purchase up to 50,608,500 Shar

424B5 Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-282933 PROSPECTUS SUPPLEMENT (to Prospectus dated November 13, 2024) 21,895,000 Shares of Common Stock Pre-funded Warrants to Purchase up to 28,713,500 Shares of Common Stock Class A Warrants to Purchase up to 50,608,500 Shares of Common Stock (or Pre-Funded Warrants) Class B Warrants to Purchase up to 50,608,500 Shares

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 16, 2025 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 16, 2025 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

FORM OF CLASS A WARRANT TO PURCHASE COMMON STOCK OR PRE-FUNDED WARRANTS C4 THERAPEUTICS, INC.

EX-4.2 Exhibit 4.2 FORM OF CLASS A WARRANT TO PURCHASE COMMON STOCK OR PRE-FUNDED WARRANTS C4 THERAPEUTICS, INC. Number of Shares: [   ] (subject to adjustment) Class A Warrant No.    Initial Exercise Date: October [ ], 2025 C4 Therapeutics, Inc., a Delaware corporation (the “Company”), hereby certifies that, for good and valuable consideration, the receipt and sufficiency of which are hereby ackn

21,895,000 Shares of Common Stock Pre-Funded Warrants to Purchase Up to 28,713,500 Shares of Common Stock Class A Warrants to Purchase Up to 50,608,500 Shares of Common Stock (or Pre-Funded Warrants in lieu thereof) Class B Warrants to Purchase Up to

EX-1.1 Exhibit 1.1 21,895,000 Shares of Common Stock Pre-Funded Warrants to Purchase Up to 28,713,500 Shares of Common Stock Class A Warrants to Purchase Up to 50,608,500 Shares of Common Stock (or Pre-Funded Warrants in lieu thereof) Class B Warrants to Purchase Up to 50,608,500 Shares of Common Stock (or Pre-Funded Warrants in lieu thereof) C4 Therapeutics, Inc. UNDERWRITING AGREEMENT October 16

FORM OF PRE-FUNDED WARRANT TO PURCHASE COMMON STOCK C4 THERAPEUTICS, INC.

EX-4.1 Exhibit 4.1 FORM OF PRE-FUNDED WARRANT TO PURCHASE COMMON STOCK C4 THERAPEUTICS, INC. Number of Shares: [   ] (subject to adjustment) Warrant No.    Original Issue Date: [ ], 2025 C4 Therapeutics, Inc., a Delaware corporation (the “Company”), hereby certifies that, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, [ ] or its registered assign

     Shares of Common Stock Pre-funded Warrants to Purchase      Shares of Common Stock Class A Warrants to Purchase      Shares of Common Stock (or Pre-Funded Warrants) Class B Warrants to Purchase      Shares of Common Stock (or Pre-Funded Warrants

FWP Issuer Free Writing Prospectus Filed Pursuant to Rule 433 Dated October 16, 2025 Registration Statement No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 1, 2025 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 1, 2025 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission F

C4 Therapeutics Announces Clinical Trial Collaboration and Supply Agreement with Pfizer for the Combination of Cemsidomide and Elranatamab for the Treatment of Relapsed/Refractory Multiple Myeloma

Exhibit 99.1 C4 Therapeutics Announces Clinical Trial Collaboration and Supply Agreement with Pfizer for the Combination of Cemsidomide and Elranatamab for the Treatment of Relapsed/Refractory Multiple Myeloma WATERTOWN, Mass., October 1, 2025 (GLOBE NEWSWIRE) - C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC), a clinical-stage biopharmaceutical company dedicated to advancing targeted protein degradatio

C4 Therapeutics Presents Cemsidomide Phase 1 Multiple Myeloma Data Supporting Potential Best-in-Class Profile at the International Myeloma Society Annual Meeting Cemsidomide in Combination With Dexamethasone Achieved a 50% Overall Response Rate (ORR)

Exhibit 99.1 C4 Therapeutics Presents Cemsidomide Phase 1 Multiple Myeloma Data Supporting Potential Best-in-Class Profile at the International Myeloma Society Annual Meeting Cemsidomide in Combination With Dexamethasone Achieved a 50% Overall Response Rate (ORR) at the Highest Dose Level (100 µg) and a 40% ORR at the 75 µg Dose Level in a Heavily Pre-Treated Relapsed/Refractory Multiple Myeloma P

Updated Data From Phase 1 Trial of Cemsidomide in Multiple Myeloma & Next Steps International Myeloma Society (IMS) Annual Meeting September 2025 Legal Disclaimer Statements and Intellectual Property LEGAL DISCLAIMER STATEMENTS The following presenta

cemsiimsinvestorpresent Updated Data From Phase 1 Trial of Cemsidomide in Multiple Myeloma & Next Steps International Myeloma Society (IMS) Annual Meeting September 2025 Legal Disclaimer Statements and Intellectual Property LEGAL DISCLAIMER STATEMENTS The following presentation contains forward-looking statements.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 22, 2025 (September 20,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 22, 2025 (September 20, 2025) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Inco

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2025 C4 THERAPEUTICS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2025 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission Fi

Protein degraded. Disease targeted. Lives transformed. August 2025 Forward-looking Statements and Intellectual Property FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of

augustcorporatedeckfina Protein degraded. Disease targeted. Lives transformed. August 2025 Forward-looking Statements and Intellectual Property FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “anticipate,” “believe,” “could,”

C4 Therapeutics Reports Second Quarter 2025 Financial Results and Recent Business Highlights Cemsidomide Phase 1 Data in Multiple Myeloma Accepted as an Oral Presentation at the International Myeloma Society (IMS) Annual Meeting; As of the July 23, 2

Exhibit 99.1 C4 Therapeutics Reports Second Quarter 2025 Financial Results and Recent Business Highlights Cemsidomide Phase 1 Data in Multiple Myeloma Accepted as an Oral Presentation at the International Myeloma Society (IMS) Annual Meeting; As of the July 23, 2025, Data Cutoff, Phase 1 ORR Remains at 40% at the 75 µg Dose Level and at 50% at the 100 µg Dose Level Productive Type C Meeting Held W

Certificate of Amendment to the Fifth Amended and Restated Certificate of Incorporation

Delaware The First State Page 1 5840223 8100 Authentication: 203978031 SR# 20253108061 Date: 06-18-25 You may verify this certificate online at corp.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 18, 2025 C4 THERAPEUTICS, IN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 18, 2025 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission Fil

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 7, 2025 C4 THERAPEUTICS, INC.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 7, 2025 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission File

C4 Therapeutics Reports First Quarter 2025 Financial Results and Recent Business Highlights Updated Cemsidomide Multiple Myeloma Data Further Demonstrate Compelling Response Rates at Multiple Doses and Potential for Best-in-Class Profile; 50% ORR Obs

Exhibit 99.1 C4 Therapeutics Reports First Quarter 2025 Financial Results and Recent Business Highlights Updated Cemsidomide Multiple Myeloma Data Further Demonstrate Compelling Response Rates at Multiple Doses and Potential for Best-in-Class Profile; 50% ORR Observed at the Highest Dose Level of 100 µg, Including One Patient With a Minimal Residual Disease Negative Complete Response; 40% ORR Achi

Protein degraded. Disease targeted. Lives transformed. May 2025 Forward-looking Statements and Intellectual Property FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of hi

Protein degraded. Disease targeted. Lives transformed. May 2025 Forward-looking Statements and Intellectual Property FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “anticipate,” “believe,” “could,” “estimate,” “expect,” “goal

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)(

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant o

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 _____________________________________ FORM 10-K _____________________________________ (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39567 C4 Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant o

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: x Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 14, 2025 (April 10, 2025) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporatio

Filing Fee Table

Exhibit 107 CALCULATION OF FILING FEE TABLE Form S-8 (Form Type) C4 Therapeutics, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-395

Company Policy on Insider Trading and Disclosure, Special Trading Procedures for Insiders, and Rule 10b5-1 Trading Plan Policy

ACTIVE/129481757.2 C4 THERAPEUTICS, INC. STATEMENT OF COMPANY POLICY ON INSIDER TRADING AND DISCLOSURE This memorandum sets forth the policy of C4 Therapeutics, Inc. and its subsidiaries (collectively, the “Company”) regarding trading in the Company’s securities as described below and the disclosure of information concerning the Company. This Statement of Company Policy on Insider Trading and Disc

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 27, 2025 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

Subsidiaries of the Registrant

Exhibit 21.1 SUBSIDIARIES Subsidiary Jurisdiction of Incorporation C4T Securities Corporation Massachusetts

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT Under The Securities Act of 1933 C4 Therapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 47-5617627 (State or other

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT Under The Securities Act of 1933 C4 Therapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 47-5617627 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 490 Arsenal Way, Suite 120 Watertown, MA 02472 (Address of princip

C4 Therapeutics Reports Fourth Quarter and Full Year 2024 Financial Results and Recent Business Highlights Planning Activities Are Ongoing for Next Phase of Cemsidomide Clinical Development in Multiple Myeloma and Non-Hodgkin’s Lymphoma; Trials Expec

Exhibit 99.1 C4 Therapeutics Reports Fourth Quarter and Full Year 2024 Financial Results and Recent Business Highlights Planning Activities Are Ongoing for Next Phase of Cemsidomide Clinical Development in Multiple Myeloma and Non-Hodgkin’s Lymphoma; Trials Expected to Initiate in Early 2026 CFT1946 Phase 1/2 Trial Continues to Progress Across Multiple Cohorts; Data in Melanoma and Colorectal Canc

ACTIVE/128326788.11 Confidential Execution Copy Certain identified information has been excluded from this exhibit because it is both not material and is the type that the registrant treats as private or confidential. Information that was omitted has

ACTIVE/128326788.11 Confidential Execution Copy Certain identified information has been excluded from this exhibit because it is both not material and is the type that the registrant treats as private or confidential. Information that was omitted has been noted in this document with a placeholder identified by the mark “[***]”. RESEARCH COLLABORATION AND LICENSE AGREEMENT by and between C4 THERAPE

C4 Therapeutics Announces 2025 Milestones Across Clinical Portfolio of Degrader Medicines Pursuing Targets of High Unmet Need in Oncology Cemsidomide Data Presented at American Society of Hematology (ASH) Annual Meeting Support Best-in-Class Profile;

Exhibit 99.1 C4 Therapeutics Announces 2025 Milestones Across Clinical Portfolio of Degrader Medicines Pursuing Targets of High Unmet Need in Oncology Cemsidomide Data Presented at American Society of Hematology (ASH) Annual Meeting Support Best-in-Class Profile; Program Advancing to Next Phase of Clinical Development in Multiple Myeloma and Non-Hodgkin’s Lymphoma CFT1946 Phase 1 Trial Continues t

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 14, 2025 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

Protein degraded. Disease targeted. Lives transformed. January 2025 Forward-looking Statements and Intellectual Property 2 FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements

Protein degraded. Disease targeted. Lives transformed. January 2025 Forward-looking Statements and Intellectual Property 2 FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “anticipate,” “believe,” “could,” “estimate,” “expect,”

Updated Data in Multiple Myeloma and First Data in Non-Hodgkin’s Lymphoma from the Ongoing Cemsidomide Phase 1/2 Trial American Hematology Annual Meeting (ASH) December 8, 2024 Forward-looking Statements and Intellectual Property 2 FORWARD-LOOKING ST

Updated Data in Multiple Myeloma and First Data in Non-Hodgkin’s Lymphoma from the Ongoing Cemsidomide Phase 1/2 Trial American Hematology Annual Meeting (ASH) December 8, 2024 Forward-looking Statements and Intellectual Property 2 FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements.

December 2024 Protein degraded. Disease targeted. Lives transformed. Forward-looking Statements and Intellectual Property 2 Forward-looking Statements The following presentation contains forward-looking statements. All statements other than statement

December 2024 Protein degraded. Disease targeted. Lives transformed. Forward-looking Statements and Intellectual Property 2 Forward-looking Statements The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “anticipate,” “believe,” “could,” “estimate,” “expect,

In Multiple Myeloma, Cemsidomide in Combination with Dexamethasone at Highest Dose Level Explored to Date Achieved 36 Percent Overall Response Rate (ORR) and 45 Percent Clinical Benefit Rate (CBR); Responses Seen Across All Dose Levels Multiple Myelo

Exhibit 99.2 C4 Therapeutics Presents Cemsidomide Phase 1 Data at the American Society for Hematology (ASH) Annual Meeting that Demonstrated Potential to Become Best-in-Class IKZF1/3 Degrader In Multiple Myeloma, Cemsidomide in Combination with Dexamethasone at Highest Dose Level Explored to Date Achieved 36 Percent Overall Response Rate (ORR) and 45 Percent Clinical Benefit Rate (CBR); Responses

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 9, 2024 (December 8, 202

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 9, 2024 (December 8, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorpor

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 20, 2024 (November 19, 2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 20, 2024 (November 19, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorp

C4 Therapeutics Appoints Accomplished Oncology Executive Steve Hoerter to Board of Directors Hoerter Brings Over Three Decades of Oncology Commercialization and Leadership Experience Appointment Underscores Continued Transformation of Board to Lead C

Exhibit 99.1 C4 Therapeutics Appoints Accomplished Oncology Executive Steve Hoerter to Board of Directors Hoerter Brings Over Three Decades of Oncology Commercialization and Leadership Experience Appointment Underscores Continued Transformation of Board to Lead C4T into Next Phase of Pipeline Progress WATERTOWN, Mass., November 20, 2024 (GLOBE NEWSWIRE) - C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC)

Up to $200,000,000 Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-282933 PROSPECTUS SUPPLEMENT (to Prospectus dated November 13, 2024) Up to $200,000,000 Common Stock We have entered into a sales agreement, or the Sales Agreement, with TD Securities (USA) LLC, which we refer to as TD Cowen or the Sales Agent, relating to shares of our common stock, par value $0.0001 per share, offered by this prospectus suppl

Up to 4,874,550 Shares of Common Stock

Filed Pursuant to Rule 424(b)(3) Registration No. 333-282934 PROSPECTUS Up to 4,874,550 Shares of Common Stock This prospectus relates to the resale, from time to time, by the selling stockholder named in this prospectus, or the Selling Stockholder, or any of their pledgees, donees, assignees and successors-in-interest, or collectively, the permitted transferees, of shares of our common stock that

CCCC / C4 Therapeutics, Inc. / Soleus Capital Master Fund, L.P. - AMENDMENT NO. 1 TO SCHEDULE 13G Passive Investment

SC 13G/A 1 ea0221047-13ga1soleusc4ther.htm AMENDMENT NO. 1 TO SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* C4 THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) September 30, 2024 (Date of Event Which Re

CCCC / C4 Therapeutics, Inc. / PRICE T ROWE ASSOCIATES INC /MD/ Passive Investment

SC 13G/A 1 cccc13gasep24.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 3) C4 THERAPEUTICS INC (Name of Issuer) COMMON STOCK (Title of Class of Securities) 12529R107 (CUSIP NUMBER) September 30, 2024 (Date of Event which Requires Filing of Statement) Check the appropriate box to designate the Rule pu

CCCC / C4 Therapeutics, Inc. / COMMODORE CAPITAL LP Passive Investment

SC 13G/A 1 formsc13ga.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropri

CCCC / C4 Therapeutics, Inc. / Point72 Asset Management, L.P. - C4 THERAPEUTICS, INC. Passive Investment

SC 13G/A 1 p24-3172sc13ga.htm C4 THERAPEUTICS, INC. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 12529R107 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Ch

CCCC / C4 Therapeutics, Inc. / ORBIMED ADVISORS LLC - SCHEDULE 13G Passive Investment

SC 13G 1 ss4113334sc13g.htm SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 C4 THERAPEUTICS, INC. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 12529R107 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropriate

CCCC / C4 Therapeutics, Inc. / Lynx1 Capital Management LP - C4 THERAPEUTICS, INC. Passive Investment

SC 13G/A 1 p24-3207sc13ga.htm C4 THERAPEUTICS, INC. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Ch

Up to 4,874,550 Shares of Common Stock

Filed Pursuant to Rule 424(b)(3) Registration No. 333-282934 PROSPECTUS Up to 4,874,550 Shares of Common Stock This prospectus relates to the resale, from time to time, by the selling stockholder named in this prospectus, or the Selling Stockholder, or any of their pledgees, donees, assignees and successors-in-interest, or collectively, the permitted transferees, of shares of our common stock that

Up to $200,000,000 Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-282933 PROSPECTUS SUPPLEMENT (to Prospectus dated November 13, 2024) Up to $200,000,000 Common Stock We have entered into a sales agreement, or the Sales Agreement, with TD Securities (USA) LLC, which we refer to as TD Cowen or the Sales Agent, relating to shares of our common stock, par value $0.0001 per share, offered by this prospectus suppl

490 Arsenal Way, Suite 120, Watertown, MA 02472

November 8, 2024 VIA EDGAR Office of Life Sciences Division of Corporation Finance U.

490 Arsenal Way, Suite 120, Watertown, MA 02472

November 8, 2024 VIA EDGAR Office of Life Sciences Division of Corporation Finance U.

CCCC / C4 Therapeutics, Inc. / BlackRock, Inc. Passive Investment

SC 13G 1 us12529r1077110824.txt us12529r1077110824.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: ) C4 Therapeutics, Inc. - (Name of Issuer) Common Stock - (Title of Class of Securities) 12529R107 - (CUSIP Number) September 30, 2024 - (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

LETTER

November 7, 2024 Andrew J. Hirsch President and Chief Executive Officer C4 Therapeutics, Inc. 490 Arsenal Way, Suite 120 Watertown, Massachusetts 02472 Re: C4 Therapeutics, Inc. Registration Statement on Form S-3 Filed October 31, 2024 File No. 333-282934 Dear Andrew J. Hirsch: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 46

LETTER

November 7, 2024 Andrew J. Hirsch President and Chief Executive Officer C4 Therapeutics, Inc. 490 Arsenal Way, Suite 120 Watertown, Massachusetts 02472 Re: C4 Therapeutics, Inc. Registration Statement on Form S-3 Filed October 31, 2024 File No. 333-282933 Dear Andrew J. Hirsch: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 46

, 2024 between the Registrant and TD Securities (USA) LLC

Exhibit 1.2 ACTIVE/132189260.2 ACTIVE/132189260.4 C4 THERAPEUTICS, INC. SHARES OF COMMON STOCK SALES AGREEMENT October 31, 2024 TD Securities (USA) LLC 1 Vanderbilt Avenue New York, New York 10017 Ladies and Gentlemen: C4 Therapeutics, Inc., a Delaware corporation (the “Company”), confirms its agreement (this “Agreement”) with TD Securities (USA) LLC (“TD Cowen”), as follows: 1. Issuance and Sale

As filed with the Securities and Exchange Commission on October 31, 2024

As filed with the Securities and Exchange Commission on October 31, 2024 Registration No.

Form of Senior Indenture between Registrant and one or more trustees to be named

ACTIVE/122185840.2 Exhibit 4.3 C4 THERAPEUTICS, INC., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [●], 202[●] Senior Debt Securities TABLE OF CONTENTS1 ARTICLE 1 DEFINITIONS Section 1.01 Definitions of Terms ARTICLE 2 ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION AND EXCHANGE OF SECURITIES Section 2.01 Designation and Terms of Securities Section 2.02 Form of Securities and Trustee’s C

Filing Fee Table

‘Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) C4 Therapeutics, Inc.

C4 Therapeutics Reports Third Quarter 2024 Financial Results and Recent Business Highlights Cemsidomide Phase 1/2 Trial in Multiple Myeloma and non-Hodgkin’s Lymphoma Continues to Progress: Data from Both Indications to be Presented at the 66th Ameri

Exhibit 99.1 C4 Therapeutics Reports Third Quarter 2024 Financial Results and Recent Business Highlights Cemsidomide Phase 1/2 Trial in Multiple Myeloma and non-Hodgkin’s Lymphoma Continues to Progress: Data from Both Indications to be Presented at the 66th American Society of Hematology (ASH) Annual Meeting in San Diego, CA Initial Monotherapy CFT1946 Phase 1 Data Demonstrated Well-Tolerated Safe

Form of Subordinated Indenture between Registrant and one or more trustees to be named

ACTIVE/122185841.2 Exhibit 4.5 C4 THERAPEUTICS, INC., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [●], 202[●] Subordinated Debt Securities TABLE OF CONTENTS1 ARTICLE 1 DEFINITIONS Section 1.01 Definitions of Terms ARTICLE 2 ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION AND EXCHANGE OF SECURITIES Section 2.0 Designation and Terms of Securities Section 2.02 Form of Securities and Truste

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 31, 2024 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

As filed with the Securities and Exchange Commission on October 31, 2024

As filed with the Securities and Exchange Commission on October 31, 2024 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) C4 Therapeutics, Inc.

CCCC / C4 Therapeutics, Inc. / BlackRock, Inc. Passive Investment

SC 13G 1 us12529r1077102224.txt us12529r1077102224.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: ) C4 Therapeutics, Inc. - (Name of Issuer) Common Stock - (Title of Class of Securities) 12529R107 - (CUSIP Number) September 30, 2024 - (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2024 (October 11, 2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2024 (October 11, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorp

Consulting Agreement dated as of October 15, 2024, between C4 Therapeutics, Inc. and Stewart Fisher

REDACTED REDACTED

C4 Therapeutics Appoints Paige Mahaney, Ph.D., as Chief Scientific Officer and Announces Retirement of Stewart Fisher, Ph.D. Mahaney Brings More Than 25 Years of Pharmaceutical and Biotech Experience Overseeing Drug Discovery and Expansion of Leading

Exhibit 99.1 C4 Therapeutics Appoints Paige Mahaney, Ph.D., as Chief Scientific Officer and Announces Retirement of Stewart Fisher, Ph.D. Mahaney Brings More Than 25 Years of Pharmaceutical and Biotech Experience Overseeing Drug Discovery and Expansion of Leading Discovery and Clinical Portfolios Fisher Will Serve as Senior Scientific Advisor Until December 31, 2024 WATERTOWN, Mass., October 15, 2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2024 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2024 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

Consulting Agreement dated as of October 15, 2024, between C4 Therapeutics, Inc. and Stewart Fisher

REDACTED REDACTED

C4 Therapeutics Appoints Paige Mahaney, Ph.D., as Chief Scientific Officer and Announces Retirement of Stewart Fisher, Ph.D. Mahaney Brings More Than 25 Years of Pharmaceutical and Biotech Experience Overseeing Drug Discovery and Expansion of Leading

Exhibit 99.1 C4 Therapeutics Appoints Paige Mahaney, Ph.D., as Chief Scientific Officer and Announces Retirement of Stewart Fisher, Ph.D. Mahaney Brings More Than 25 Years of Pharmaceutical and Biotech Experience Overseeing Drug Discovery and Expansion of Leading Discovery and Clinical Portfolios Fisher Will Serve as Senior Scientific Advisor Until December 31, 2024 WATERTOWN, Mass., October 15, 2

Amendment No. 1 to C4 Therapeutics, Inc. 2020 Stock Option and Incentive Plan

ACTIVE/104115174.6 C4 THERAPEUTICS, INC. AMENDMENT NO. 1 TO 2020 STOCK OPTION AND INCENTIVE PLAN This Amendment No. 1 (the “Amendment”) to the C4 Therapeutics, Inc. (“Company”) 2020 Stock Option and Incentive Plan (the “Plan”) amends the Plan as set forth below, effective as of October 7, 2024, which is the date this Amendment was approved by the Company’s Board of Directors (the “Board”). All cap

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 11, 2024 (October 7, 2024

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 11, 2024 (October 7, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorpora

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 3, 2024 (August 29, 202

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 3, 2024 (August 29, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorpor

C4 Therapeutics Appoints Veteran Biotechnology Leader Stephen Fawell, Ph.D. to Board of Directors

Exhibit 99.1 C4 Therapeutics Appoints Veteran Biotechnology Leader Stephen Fawell, Ph.D. to Board of Directors WATERTOWN, Mass., September 3, 2024 (GLOBE NEWSWIRE) - C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC), a clinical-stage biopharmaceutical company dedicated to advancing targeted protein degradation science, today announced the continued evolution of its Board of Directors with the appointment

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 1, 2024 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission Fi

C4 Therapeutics Reports Second Quarter 2024 Financial Results and Recent Business Highlights Preliminary Monotherapy Data from the Ongoing CFT1946 Phase 1 Trial in BRAF V600X Solid Tumors to be Presented at ESMO Congress 2024; Initiated Monotherapy E

EX-99.1 2 cccc-20240801xexx991.htm EX-99.1 Exhibit 99.1 C4 Therapeutics Reports Second Quarter 2024 Financial Results and Recent Business Highlights Preliminary Monotherapy Data from the Ongoing CFT1946 Phase 1 Trial in BRAF V600X Solid Tumors to be Presented at ESMO Congress 2024; Initiated Monotherapy Expansion Cohort in Melanoma and Combination Cohort with Cetuximab in Colorectal Cancer Cemsido

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

CCCC / C4 Therapeutics, Inc. / STATE STREET CORP Passive Investment

SC 13G/A 1 C4TherapeuticsInc.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 EXIT FILING C4 THERAPEUTICS INC (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 12529R107 (CUSIP NUMBER) 06/30/2024 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUAN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 21, 2024 (June 20, 2024) C4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 21, 2024 (June 20, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 10, 2024 (June 7, 2024) C4 T

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 10, 2024 (June 7, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation)

C4 Therapeutics Appoints Ron Cooper as Chairman of the Board of Directors Cooper Brings Decades of Global Pharmaceutical and Biotechnology Leadership Experience Bruce Downey Remains a Member of the Board of Directors and Chair of the Organization, Le

Exhibit 99.1 C4 Therapeutics Appoints Ron Cooper as Chairman of the Board of Directors Cooper Brings Decades of Global Pharmaceutical and Biotechnology Leadership Experience Bruce Downey Remains a Member of the Board of Directors and Chair of the Organization, Leadership and Compensation Committee Transition Further Highlights Commitment to Strategically Transform the Board to Lead C4T into Next P

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 8, 2024 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

Research Collaboration and License Agreement dated March 1, 2024, by and among C4 Therapeutics, Inc., and Merck KGaA, Darmstadt, Germany

ACTIVE/128326788.11 Confidential Execution Copy Certain identified information has been excluded from this exhibit because it is both not material and is the type that the registrant treats as private or confidential. Information that was omitted has been noted in this document with a placeholder identified by the mark “[***]”. RESEARCH COLLABORATION AND LICENSE AGREEMENT by and between C4 THERAPE

C4 Therapeutics Reports First Quarter 2024 Financial Results and Recent Business Highlights Successfully Delivered First Development Candidate to Biogen; $8 Million Payment Earned Established a Strategic Discovery Research Collaboration with Merck KG

Exhibit 99.1 C4 Therapeutics Reports First Quarter 2024 Financial Results and Recent Business Highlights Successfully Delivered First Development Candidate to Biogen; $8 Million Payment Earned Established a Strategic Discovery Research Collaboration with Merck KGaA, Darmstadt, Germany, Focused on Two Critical Oncogenic Proteins Progressed Phase 1 Dose Escalation Trials for Cemsidomide (CFT7455) an

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 _____________________________________ FORM 10-K _____________________________________ (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended DECEMBER 31, 2023 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39567 C4 Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)(

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant o

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)

CCCC / C4 Therapeutics, Inc. / STATE STREET CORP Passive Investment

SC 13G 1 C4TherapeuticsInc.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 INITIAL FILING C4 THERAPEUTICS INC (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 12529R107 (CUSIP NUMBER) 03/31/2024 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUA

CCCC / C4 Therapeutics, Inc. / WASATCH ADVISORS INC Passive Investment

SC 13G/A 1 cccc324.txt SCHEDULE 13G Amendment No. 3 Name of Issuer: C4 Therapeutics, Inc. Title of Class of Securities: Common Stock CUSIP Number: 12529R107 Item 1: Reporting Person: Wasatch Advisors LP 87-0319391 Item 2: Check Box If Member of Group: Not Applicable Item 3: SEC Use Item 4: Place of Organization: Utah Items 5-8: Number of Shares Owned With: Item 5: Sole Voting Power: 5,516,718 Item

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 8, 2024 (March 7, 2024) C4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 8, 2024 (March 7, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation)

C4 Therapeutics Announces Strategic Discovery Research Collaboration with Merck KGaA, Darmstadt, Germany, Against Critical Oncogenic Proteins Collaboration Focused on Two Targeted Protein Degraders from C4T’s Internal Discovery Pipeline C4T to Receiv

Exhibit 99.1 C4 Therapeutics Announces Strategic Discovery Research Collaboration with Merck KGaA, Darmstadt, Germany, Against Critical Oncogenic Proteins Collaboration Focused on Two Targeted Protein Degraders from C4T’s Internal Discovery Pipeline C4T to Receive a $16 Million Upfront Payment; Merck KGaA, Darmstadt, Germany, to Cover Discovery Research Costs Under the Collaboration C4T Eligible f

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 2024 (March 1, 2024) C4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 2024 (March 1, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation)

C4 Therapeutics Reports Fourth Quarter and Full Year 2023 Financial Results and Recent Business Highlights CFT1946 Preclinical Data Accepted for a Poster Presentation at the AACR Annual Meeting 2024 Phase 1 Dose Escalation Trials for CFT7455 and CFT1

Exhibit 99.1 C4 Therapeutics Reports Fourth Quarter and Full Year 2023 Financial Results and Recent Business Highlights CFT1946 Preclinical Data Accepted for a Poster Presentation at the AACR Annual Meeting 2024 Phase 1 Dose Escalation Trials for CFT7455 and CFT1946 Continue to Progress; Data from Both Trials Expected in 2H 2024 Well Capitalized with Cash Runway Expected into 2027 WATERTOWN, Mass.

Executive Compensation Clawback Policy

ACTIVE/119833921.13 C4 THERAPEUTICS, INC. EXECUTIVE COMPENSATION RECOVERY POLICY 1. Overview This Executive Compensation Recovery Policy (the “Policy”) sets forth the circumstances and procedures under which the C4 Therapeutics, Inc. (together with any of its parent companies or subsidiaries, the “Company”) shall recover Erroneously Awarded Compensation from current and former Executive Officers o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 22, 2024 C4 THERAPEUTICS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 22, 2024 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT Under The Securities Act of 1933 C4 Therapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 47-5617627 (State or other

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT Under The Securities Act of 1933 C4 Therapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 47-5617627 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 490 Arsenal Way, Suite 120 Watertown, MA 02472 (Address of princip

Form of Non-Qualified Stock Option Agreement Inducement Award

ACTIVE/104115192.2 C4 THERAPEUTICS, INC. NON-QUALIFIED STOCK OPTION AGREEMENT (INDUCEMENT GRANT) Name of Optionee: No. of Option Shares: Option Exercise Price per Share: $ [FMV on Grant Date] Grant Date: Expiration Date: C4 Therapeutics, Inc. (the “Company”) hereby grants to the Optionee named above an option (the “Stock Option”) to purchase on or prior to the Expiration Date specified above all o

Filing Fee Table

Exhibit 107 CALCULATION OF FILING FEE TABLE Form S-8 (Form Type) C4 Therapeutics, Inc.

, dated December 11, 2023, by and between C4 Therapeu

EXECUTION VERSION Certain identified information has been excluded from this exhibit because it is both not material and is the type that the registrant treats as private or confidential.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended DECEMBER 31, 2023 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-395

Subsidiaries of the Registrant

Exhibit 21.1 SUBSIDIARIES Subsidiary Jurisdiction of Incorporation C4T Securities Corporation Massachusetts

CCCC / C4 Therapeutics, Inc. / PRICE T ROWE ASSOCIATES INC /MD/ Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2) C4 THERAPEUTICS INC (Name of Issuer) COMMON STOCK (Title of Class of Securities) 12529R107 (CUSIP NUMBER) December 31, 2023 (Date of Event which Requires Filing of Statement) Check the appropriate box to designate the Rule pursuant to which this Schedule

CCCC / C4 Therapeutics, Inc. / RTW INVESTMENTS, LP - C4 THERAPEUTICS, INC. Passive Investment

SC 13G/A 1 p24-0391sc13ga.htm C4 THERAPEUTICS, INC. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 12529R107 (CUSIP Number) December 31, 2023 (Date of event which requires filing of this statement) Che

CCCC / C4 Therapeutics, Inc. / Lynx1 Capital Management LP - C4 THERAPEUTICS, INC. Passive Investment

SC 13G/A 1 p24-0772sc13ga.htm C4 THERAPEUTICS, INC. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Che

CCCC / C4 Therapeutics, Inc. / WASATCH ADVISORS INC Passive Investment

SC 13G/A 1 cccc224.txt SCHEDULE 13G Amendment No. 2 Name of Issuer: C4 Therapeutics, Inc. Title of Class of Securities: Common Stock CUSIP Number: 12529R107 Item 1: Reporting Person: Wasatch Advisors LP 87-0319391 Item 2: Check Box If Member of Group: Not Applicable Item 3: SEC Use Item 4: Place of Organization: Utah Items 5-8: Number of Shares Owned With: Item 5: Sole Voting Power: 7,138,949 Item

CCCC / C4 Therapeutics, Inc. / Soleus Capital Master Fund, L.P. - SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* C4 THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) January 26, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the ru

CCCC / C4 Therapeutics, Inc. / Soleus Capital Master Fund, L.P. - AMENDMENT NO. 1 TO SCHEDULE 13G Passive Investment

SC 13G/A 1 ea192410-13ga1soleusc4thera.htm AMENDMENT NO. 1 TO SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* C4 THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) December 31, 2023 (Date of Event Which Req

CCCC / C4 Therapeutics, Inc. / Betta Investment (Hong Kong) Ltd. - SC 13G Passive Investment

SC 13G 1 d636659dsc13g.htm SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) January 4, 2024 (Date of Event Which Requires Filing of this Statement) Check the ap

Joint Filing Agreement

EX-99.1 2 d636659dex991.htm EX-99.1 EXHIBIT 99.1 Joint Filing Agreement The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing statements. The unders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 11, 2024 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 11, 2024 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

January 2024 Protein degraded. Disease targeted. Lives transformed. Forward-looking Statements and Intellectual Property 2 Forward-looking Statements The following presentation contains forward-looking statements. All statements other than statements

c4tjanuarycorporateprese January 2024 Protein degraded. Disease targeted. Lives transformed. Forward-looking Statements and Intellectual Property 2 Forward-looking Statements The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward- looking statements, which are often indicated by terms such as “anticipate,” “believe,” “cou

C4 Therapeutics Announces 2024 Priorities and Extended Cash Runway to Advance Portfolio of Targeted Protein Degradation Medicines Multiple 2024 Clinical Updates Expected, Including Data from the Ongoing CFT7455 and CFT1946 Phase 1 Dose Escalation Tri

C4 Therapeutics Announces 2024 Priorities and Extended Cash Runway to Advance Portfolio of Targeted Protein Degradation Medicines Multiple 2024 Clinical Updates Expected, Including Data from the Ongoing CFT7455 and CFT1946 Phase 1 Dose Escalation Trials Prioritization of CFT7455, CFT1946, Discovery Collaborations and Focused Discovery Research Efforts Results in Workforce Reduction of Approximately 30% Unaudited Cash, Cash Equivalents and Marketable Securities Totaling Approximately $330 million as of January 5, 2024, Combined with Cost Savings from Restructured Operations, Results in Cash Runway into 2027 Company to Present at the 42nd Annual J.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 9, 2024 (January 8, 2024)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 9, 2024 (January 8, 2024) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporat

JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(k)

EXHIBIT 99.1 JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(k) The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements. The undersigned ackn

CCCC / C4 Therapeutics, Inc. / Point72 Asset Management, L.P. - C4 THERAPEUTICS, INC. Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 12529R107 (CUSIP Number) January 3, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to

CCCC / C4 Therapeutics, Inc. / RA CAPITAL MANAGEMENT, L.P. - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* C4 THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) December 14, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the r

Joint Filing Agreement dated as of December 22, 2023, by and between Commodore Capital LP and Commodore Capital Master LP (incorporated by reference to Exhibit 1 to the Schedule 13G filed with the Securities and Exchange Commission on December 22, 2023).

Exhibit 1 JOINT FILING AGREEMENT The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned, and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint acquisition statements.

CCCC / C4 Therapeutics, Inc. / COMMODORE CAPITAL LP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 12, 2023 C4 THERAPEUTICS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 12, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

C4 Therapeutics Announces Positive Data from CFT7455 Phase 1 Trial in Relapsed/Refractory Multiple Myeloma Data Support 14 Days On/14 Days Off as Optimal Dosing Schedule; CFT7455 is Well Tolerated with Promising Signs of Anti-Myeloma Activity Complet

Exhibit 99.1 C4 Therapeutics Announces Positive Data from CFT7455 Phase 1 Trial in Relapsed/Refractory Multiple Myeloma Data Support 14 Days On/14 Days Off as Optimal Dosing Schedule; CFT7455 is Well Tolerated with Promising Signs of Anti-Myeloma Activity Completed Monotherapy Dose Escalation Demonstrates Anti-Myeloma Activity and Immunomodulatory Effects to Support CFT7455 in Combination with Nov

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 12, 2023 C4 THERAPEUTICS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 12, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

C4 Therapeutics Announces License and Research Collaboration with Merck to Discover and Develop Degrader-Antibody Conjugates (DACs) Initial Focus on One Oncology Target, Exclusive to Collaboration; Merck has Option for Three Additional Targets

Exhibit 99.1 C4 Therapeutics Announces License and Research Collaboration with Merck to Discover and Develop Degrader-Antibody Conjugates (DACs) Initial Focus on One Oncology Target, Exclusive to Collaboration; Merck has Option for Three Additional Targets WATERTOWN, Mass., Dec. 12, 2023 (GLOBE NEWSWIRE) – C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC), a clinical-stage biopharmaceutical company dedic

CFT7455, IKZF1/3 Degrader, for the Potential Treatment of Relapsed Refractory Multiple Myeloma (R/R MM) December 12, 2023 Phase 1 Dose Escalation Data Forward-looking Statements and Intellectual Property 2 Forward-looking Statements The following pre

cft7455datapresentation CFT7455, IKZF1/3 Degrader, for the Potential Treatment of Relapsed Refractory Multiple Myeloma (R/R MM) December 12, 2023 Phase 1 Dose Escalation Data Forward-looking Statements and Intellectual Property 2 Forward-looking Statements The following presentation contains forward-looking statements.

C4 Therapeutics Strengthens Board of Directors with Owen Hughes Appointment Owen Hughes, Accomplished Life Sciences Executive with Deep Experience Across Investing, Operations and Governance, Appointed as Independent Member of the Board of Directors

Exhibit 99.1 C4 Therapeutics Strengthens Board of Directors with Owen Hughes Appointment Owen Hughes, Accomplished Life Sciences Executive with Deep Experience Across Investing, Operations and Governance, Appointed as Independent Member of the Board of Directors WATERTOWN, Mass., November 20, 2023 (GLOBE NEWSWIRE) – C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC), a clinical-stage biopharmaceutical com

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 20, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

JOINT FILING AGREEMENT

EX-99.1 2 p23-2700exhibit99.htm JOINT FILING AGREEMENT Exhibit 99.1 JOINT FILING AGREEMENT The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agr

CCCC / C4 Therapeutics Inc / Lynx1 Capital Management LP - C4 THERAPEUTICS, INC. Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) November 1, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 1, 2023 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 1, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

ve Compensation Recovery Po

ACTIVE/119833921.13 C4 THERAPEUTICS, INC. EXECUTIVE COMPENSATION RECOVERY POLICY 1. Overview This Executive Compensation Recovery Policy (the “Policy”) sets forth the circumstances and procedures under which the C4 Therapeutics, Inc. (together with any of its parent companies or subsidiaries, the “Company”) shall recover Erroneously Awarded Compensation from current and former Executive Officers o

C4 Therapeutics Reports Third Quarter 2023 Financial Results and Recent Business Highlights Portfolio Decision to Prioritize Ongoing Phase 1/2 Trials of CFT7455, an IKZF1/3 Degrader, and CFT1946, a BRAF V600 Degrader CFT8634, a BRD9 Degrader, Will No

Exhibit 99.1 C4 Therapeutics Reports Third Quarter 2023 Financial Results and Recent Business Highlights Portfolio Decision to Prioritize Ongoing Phase 1/2 Trials of CFT7455, an IKZF1/3 Degrader, and CFT1946, a BRAF V600 Degrader CFT8634, a BRD9 Degrader, Will Not Advance in Synovial Sarcoma and SMARCB-1 Null Tumors Due to Insufficient Single Agent Efficacy, Despite High Levels of BRD9 Degradation

C4 Therapeutics Announces Chief Financial Officer Succession

Exhibit 99.1 C4 Therapeutics Announces Chief Financial Officer Succession WATERTOWN, Mass., September 5, 2023 (GLOBE NEWSWIRE) - C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC), a clinical-stage biopharmaceutical company dedicated to advancing targeted protein degradation science to develop a new generation of small-molecule medicines and transform how disease is treated, today announced the appointmen

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 5, 2023 (August 30, 2023) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorpor

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

C4 Therapeutics Reports Second Quarter 2023 Financial Results and Recent Business Highlights Established Exclusive Licensing Agreement for CFT8919, an EGFR L858R BiDAC™ Degrader, with Betta Pharmaceuticals in Greater China for NSCLC; U.S. IND Cleared

Exhibit 99.1 C4 Therapeutics Reports Second Quarter 2023 Financial Results and Recent Business Highlights Established Exclusive Licensing Agreement for CFT8919, an EGFR L858R BiDAC™ Degrader, with Betta Pharmaceuticals in Greater China for NSCLC; U.S. IND Cleared Ongoing Phase 1/2 Clinical Trials of CFT7455, an IKZF1/3 MonoDAC™ Degrader, and CFT8634, a BRD9 BiDAC Degrader, Continue to Progress; Ph

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 8, 2023 C4 THERAPEUTICS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 8, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission Fi

CCCC / C4 Therapeutics Inc / MILLENNIUM MANAGEMENT LLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 C4 THERAPEUTICS, INC. (Name of Issuer) COMMON STOCK, PAR VALUE $0.0001 PER SHARE (Title of Class of Securities) 12529R107 (CUSIP Number) JULY 19, 2023 (Date of event which requires filing of this statement) Check the appropriate box to designate the rule pursuant to which

CCCC / C4 Therapeutics Inc / BlackRock Inc. Passive Investment

us12529r1077070723.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 2) C4 Therapeutics, Inc. - (Name of Issuer) Common Stock - (Title of Class of Securities) 12529R107 - (CUSIP Number) June 30, 2023 - (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 20, 2023 (June 15, 2023) C4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 20, 2023 (June 15, 2023) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation)

C4 Therapeutics Appoints Leonard Reyno, M.D., as Chief Medical Officer

C4 Therapeutics Appoints Leonard Reyno, M.D., as Chief Medical Officer WATERTOWN, Mass., June 20, 2023 (GLOBE NEWSWIRE) – C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC), a clinical-stage biopharmaceutical company dedicated to advancing targeted protein degradation science to develop a new generation of small-molecule medicines and transform how disease is treated, today announced the appointment of Le

CCCC / C4 Therapeutics Inc / ArrowMark Colorado Holdings LLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No.

C4 Therapeutics and Betta Pharmaceuticals Announce Exclusive Licensing Agreement for the Development and Commercialization in Greater China of CFT8919, an Orally Bioavailable BiDAC™ Degrader of EGFR L858R for NSCLC C4 Therapeutics to Receive a $10 Mi

C4 Therapeutics and Betta Pharmaceuticals Announce Exclusive Licensing Agreement for the Development and Commercialization in Greater China of CFT8919, an Orally Bioavailable BiDAC™ Degrader of EGFR L858R for NSCLC C4 Therapeutics to Receive a $10 Million Upfront Payment, a $25 Million Equity Investment and is Eligible to Receive up to $357 Million for Development and Commercial Milestones Plus Royalties on Net Sales in Greater China Betta Pharmaceuticals to Develop and Commercialize CFT8919 in Greater China and Eligible to Receive Royalties on Net Sales Outside of Greater China The Exclusive Licensing Agreement with Betta Pharmaceuticals Accelerates Development of CFT8919 in Key International Markets WATERTOWN, Mass.

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 29, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission File

License and Collaboration Agreement, dated May 29, 2023, by and between C4 Therapeutics, Inc. and Betta Pharmaceuticals Co., Ltd.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [*], HAS BEEN OMITTED BECAUSE C4 THERAPEUTICS, INC.

Stock Purchase Agreement, dated May 29, 2023, by and among C4 Therapeutics, Inc., Betta Pharmaceuticals Co., Ltd. and Betta Investment (Hong Kong) Limited.

Execution Version STOCK PURCHASE AGREEMENT between C4 Therapeutics, Inc., Betta Investment (Hong Kong) Limited and Betta Pharmaceuticals Co., Ltd. Dated as of May 29, 2023 ACTIVE/120028238.25 STOCK PURCHASE AGREEMENT This Stock Purchase Agreement (this “Agreement”) is made as of May 29, 2023, by and among C4 Therapeutics, Inc., a Delaware corporation (the “Company”), Betta Investment (Hong Kong) L

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 4, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

C4 Therapeutics Reports First Quarter 2023 Financial Results and Recent Business Highlights Preclinical Data Presented at AACR Demonstrated CFT1946 is a Potent and Mutant-Selective BRAF V600 BiDAC™ Degrader; Phase 1/2 Clinical Trial Enrolling Patient

Exhibit 99.1 C4 Therapeutics Reports First Quarter 2023 Financial Results and Recent Business Highlights Preclinical Data Presented at AACR Demonstrated CFT1946 is a Potent and Mutant-Selective BRAF V600 BiDAC™ Degrader; Phase 1/2 Clinical Trial Enrolling Patients Phase 1 Dose Escalation Data from the Ongoing Phase 1/2 Clinical Trials of CFT7455, an IKZF1/3 MonoDAC™ Degrader, and CFT8634, a BRD9 B

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 _____________________________________ FORM 10-K _____________________________________ (Mark One) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39567 C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitte

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)(

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: x Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitte

JOINT FILING AGREEMENT

EX-99.A EXHIBIT A JOINT FILING AGREEMENT Soleus Capital Master Fund, L.P., a Cayman Islands exempted limited partnership, Soleus Capital, LLC, a Delaware limited liability company, Soleus Capital Group, LLC, a Delaware limited liability company, and Guy Levy, an individual, hereby agree to file jointly the statement on Schedule 13G to which this Joint Filing Agreement is attached, and any amendmen

CCCC / C4 Therapeutics Inc / Soleus Capital Master Fund, L.P. - SC 13G Passive Investment

SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* C4 THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) April 13, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate t

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-395

Subsidiaries of the Registrant

Exhibit 21.1 SUBSIDIARIES Subsidiary Jurisdiction of Incorporation C4T Securities Corporation Massachusetts

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) C4 Therapeutics, Inc.

As filed with the Securities and Exchange Commission on February 23, 2023

As filed with the Securities and Exchange Commission on February 23, 2023 Registration No.

2020 Stock Option and Incentive Plan and forms of award agreements thereunder

C4 THERAPEUTICS, INC. 2020 STOCK OPTION AND INCENTIVE PLAN SECTION 1. GENERAL PURPOSE OF THE PLAN; DEFINITIONS The name of the plan is the C4 Therapeutics, Inc. 2020 Stock Option and Incentive Plan (the “Plan”). The purpose of the Plan is to encourage and enable the officers, employees, Non-Employee Directors and Consultants of C4 Therapeutics, Inc. (the “Company”) and its Affiliates upon whose ju

C4 Therapeutics Reports Fourth Quarter and Full Year 2022 Financial Results and Recent Business Highlights Phase 1 Dose Escalation Data from the Ongoing Phase 1/2 Clinical Trials of CFT7455, an IKZF1/3 MonoDAC™ Degrader, and CFT8634, a BRD9 BiDAC™ De

Exhibit 99.1 C4 Therapeutics Reports Fourth Quarter and Full Year 2022 Financial Results and Recent Business Highlights Phase 1 Dose Escalation Data from the Ongoing Phase 1/2 Clinical Trials of CFT7455, an IKZF1/3 MonoDAC™ Degrader, and CFT8634, a BRD9 BiDAC™ Degrader, Expected in 2H 2023 Phase 1/2 Clinical Trial of CFT1946, a BRAF V600 BiDAC Degrader, Enrolling Patients; New CFT1946 Preclinical

C4 Therapeutics Reports Fourth Quarter and Full Year 2022 Financial Results and Recent Business Highlights Phase 1 Dose Escalation Data from the Ongoing Phase 1/2 Clinical Trials of CFT7455, an IKZF1/3 MonoDAC™ Degrader, and CFT8634, a BRD9 BiDAC™ De

Exhibit 99.1 C4 Therapeutics Reports Fourth Quarter and Full Year 2022 Financial Results and Recent Business Highlights Phase 1 Dose Escalation Data from the Ongoing Phase 1/2 Clinical Trials of CFT7455, an IKZF1/3 MonoDAC™ Degrader, and CFT8634, a BRD9 BiDAC™ Degrader, Expected in 2H 2023 Phase 1/2 Clinical Trial of CFT1946, a BRAF V600 BiDAC Degrader, Enrolling Patients; New CFT1946 Preclinical

Filing Fee Table

Exhibit 107 CALCULATION OF FILING FEE TABLE Form S-8 (Form Type) C4 Therapeutics, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 23, 2023 C4 THERAPEUTICS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 23, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 23, 2023 C4 THERAPEUTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 23, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commissi

As filed with the Securities and Exchange Commission on February 23, 2023

As filed with the Securities and Exchange Commission on February 23, 2023 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT Under The Securities Act of 1933 C4 Therapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 47-5617627 (State or other

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT Under The Securities Act of 1933 C4 Therapeutics, Inc. (Exact name of Registrant as specified in its Charter) Delaware 47-5617627 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 490 Arsenal Way, Suite 120 Watertown, MA 02472 (Address of princip

CCCC / Cache Capital Corp. / PRICE T ROWE ASSOCIATES INC /MD/ Passive Investment

SC 13G/A 1 cccc13gadec22.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1) C4 THERAPEUTICS INC (Name of Issuer) COMMON STOCK (Title of Class of Securities) 12529R107 (CUSIP NUMBER) December 31, 2022 (Date of Event which Requires Filing of Statement) Check the appropriate box to designate the Rule pur

CCCC / Cache Capital Corp. / ArrowMark Colorado Holdings LLC Passive Investment

SC 13G 1 arrowmark-cccc123122a1.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, $0.0001 par value per share (Title of Class of Securities) 12529R107 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check t

CCCC / Cache Capital Corp. / RTW INVESTMENTS, LP - C4 THERAPEUTICS, INC. Passive Investment

SC 13G/A 1 p23-0581sc13ga.htm C4 THERAPEUTICS, INC. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* C4 Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 12529R107 (CUSIP Number) December 31, 2022 (Date of event which requires filing of this statement) Che

CCCC / Cache Capital Corp. / WASATCH ADVISORS INC Passive Investment

SC 13G/A 1 cccc223.txt SCHEDULE 13G Amendment No. 1 Name of Issuer: C4 Therapeutics, Inc. Title of Class of Securities: Common Stock CUSIP Number: 12529R107 Item 1: Reporting Person: Wasatch Advisors LP 87-0319391 Item 2: Check Box If Member of Group: Not Applicable Item 3: SEC Use Item 4: Place of Organization: Utah Items 5-8: Number of Shares Owned With: Item 5: Sole Voting Power: 5,775,698 Item

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 30, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

CCCC / Cache Capital Corp. / BlackRock Inc. Passive Investment

SC 13G/A 1 us12529r1077013123.txt us12529r1077013123.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 1) C4 Therapeutics, Inc. - (Name of Issuer) Common Stock - (Title of Class of Securities) 12529R107 - (CUSIP Number) December 31, 2022 - (Date of Event Which Requires Filing of this Statement) Check the appropriate

Investor presentation of the Company dated January 2023 (furnished herewith)

C4 Therapeutics Announces 2023 Strategic Priorities to Advance Portfolio of Targeted Protein Degradation Medicines Phase 1/2 Trial of CFT7455, an IKZF1/3 MonoDAC™ Degrader, Continues to Progress with Phase 1 Dose Escalation Data Expected in 2H 2023;

C4 Therapeutics Announces 2023 Strategic Priorities to Advance Portfolio of Targeted Protein Degradation Medicines Phase 1/2 Trial of CFT7455, an IKZF1/3 MonoDAC™ Degrader, Continues to Progress with Phase 1 Dose Escalation Data Expected in 2H 2023; Enrollment Open for Arm Evaluating CFT7455 in Combination with Dexamethasone Phase 1/2 Trial of CFT8634, a BRD9 BiDAC™ Degrader, Continues to Progress with Phase 1 Dose Escalation Data Expected in 2H 2023; Clinical Pharmacokinetic and Pharmacodynamic Data is Supportive of Proof of Mechanism Phase 1/2 Trial of CFT1946, a BRAF-V600 BiDAC Degrader, Initiated in Solid Tumors Cash, Cash Equivalents and Marketable Securities of $366.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 9, 2023 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 9, 2023 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 3, 2022 C4 THERAPEUTICS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 3, 2022 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

C4 Therapeutics Reports Third Quarter 2022 Financial Results and Recent Business Highlights

Exhibit 99.1 C4 Therapeutics Reports Third Quarter 2022 Financial Results and Recent Business Highlights The Phase 1/2 Clinical Trials of CFT7455, an IKZF1/3 MonoDAC™ Degrader, and CFT8634, a BRD9 BiDAC™ Degrader, Continue to Enroll Patients and Advance Through Dose Escalation IND Clearance Achieved for CFT1946, a BRAF-V600 BiDAC Degrader; On Track to Initiate the Phase 1/2 Clinical Trial by Year-

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 19, 2022 (June 22, 2022) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporatio

C4 Therapeutics Reports Second Quarter 2022 Financial Results and Recent Business Highlights

Exhibit 99.1 C4 Therapeutics Reports Second Quarter 2022 Financial Results and Recent Business Highlights ? CFT7455, a Novel IKZF1/3 Degrader, Advancing Through Dose Escalation Portion of Phase 1/2 Clinical Trial ? ? Phase 1/2 Clinical Trial for CFT8634, a BRD9 Degrader, Enrolling Patients and Progressing Through Phase 1 Dose Escalation ? ? Investigational New Drug (IND) Application for CFT1946, a

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 4, 2022 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission Fi

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 2, 2022 (July 29, 2022) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation

C4 Therapeutics Appoints Experienced Clinical Development Leaders Laura Bessen, M.D. and Donna Grogan, M.D. to Board of Directors

Exhibit 99.1 C4 Therapeutics Appoints Experienced Clinical Development Leaders Laura Bessen, M.D. and Donna Grogan, M.D. to Board of Directors ? Dr. Laura Bessen Brings More Than Two Decades of Experience Across Medical Affairs and Clinical Development in Support of Successful Product Launches ? ? Dr. Donna Grogan Joins as Accomplished Drug Development and Regulatory Strategy Leader With More than

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 24, 2022 (June 22, 2022) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)(

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 17, 2022 (June 15, 2022) C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation)

CCCC / Cache Capital Corp. / ArrowMark Colorado Holdings LLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.

CCCC / Cache Capital Corp. / WASATCH ADVISORS INC Passive Investment

SCHEDULE 13G Amendment No. Name of Issuer: C4 Therapeutics Inc. Title of Class of Securities: Common Stock CUSIP Number: 12529R107 Item 1: Reporting Person: Wasatch Advisors, Inc. 87-0319391 Item 2: Check Box If Member of Group: Not Applicable Item 3: SEC Use Item 4: Place of Organization: Utah Items 5-8: Number of Shares Owned With: Item 5: Sole Voting Power: 4,986,072 Item 6: Shared Voting Power

C4 Therapeutics Announces First Patient Dosed in Phase 1/2 Clinical Trial Evaluating CFT8634, an Orally Bioavailable BiDAC™ Degrader for the Treatment of Synovial Sarcoma and SMARCB1-EX-99.1 Tumors

Exhibit 99.1 C4 Therapeutics Announces First Patient Dosed in Phase 1/2 Clinical Trial Evaluating CFT8634, an Orally Bioavailable BiDAC? Degrader for the Treatment of Synovial Sarcoma and SMARCB1-null Tumors WATERTOWN, Mass., May 16, 2022 (GLOBE NEWSWIRE) ? C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC), a clinical-stage biopharmaceutical company dedicated to advancing targeted protein degradation sci

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 16, 2022 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)(

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39567 C4 Therapeutics, Inc.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 5, 2022 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission File

C4 Therapeutics Reports First Quarter 2022 Financial Results and Recent Business Highlights

Exhibit 99.1 C4 Therapeutics Reports First Quarter 2022 Financial Results and Recent Business Highlights ? Data from Ongoing CFT7455 Phase 1/2 Trial Presented at the American Association for Cancer Research (AACR) Annual Meeting; Enrollment Continues in Cohorts B1 and C ? ? Phase 1/2 Clinical Trial Initiated for CFT8634, a BRD9 Degrader, for Patients with Synovial Sarcoma and SMARCB1-null Solid Tu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitte

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. ) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14a6(e)(

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 8, 2022 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission Fil

C4 Therapeutics Presents Clinical Data from Cohort A of the Ongoing Phase 1/2 Clinical Trial of CFT7455, a Novel IKZF1/3 Degrader

Exhibit 99.1 C4 Therapeutics Presents Clinical Data from Cohort A of the Ongoing Phase 1/2 Clinical Trial of CFT7455, a Novel IKZF1/3 Degrader ? Single Agent CFT7455 Induces Deep and Durable Degradation of IKZF1/3 and Meaningful Decreases in Serum Free Light Chain at Doses Lower than Expected Based on Pre-clinical Studies ? ? CFT7455 Exhibits Differentiated Pharmacokinetics (PK) and Potency Relati

Forward-looking Statements The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “anticipate,” “believe,” “co

CFT7455 Phase 1/2 Cohort A Data Investor Call American Association for Cancer Research Annual Meeting 2022 Abstract CT186 April 8, 2022 Exhibit 99.

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 10, 2022 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission Fi

C4 Therapeutics Appoints Utpal Koppikar to Board of Directors – Utpal Koppikar, Veteran Life Sciences Industry Financial Executive, Appointed as Independent Member of the Board of Directors, Chair of Audit Committee and Member of Organization, Leader

Exhibit 99.1 C4 Therapeutics Appoints Utpal Koppikar to Board of Directors ? Utpal Koppikar, Veteran Life Sciences Industry Financial Executive, Appointed as Independent Member of the Board of Directors, Chair of Audit Committee and Member of Organization, Leadership and Compensation Committee ? ? Appointment Reflects C4T?s Continued Commitment to Corporate Governance to Support Company Growth ? W

Filing Fee Table

Exhibit 107 CALCULATION OF FILING FEE TABLE Form S-8 (Form Type) C4 Therapeutics, Inc.

As filed with the Securities and Exchange Commission on February 24, 2022

As filed with the Securities and Exchange Commission on February 24, 2022 Registration No.

C4 Therapeutics Reports Full Year 2021 Financial Results and Recent Business Highlights – Data from Cohort A of the Ongoing Phase 1/2 Trial of CFT7455, a Novel IKZF1/3 Degrader, Accepted for Presentation at the American Association for Cancer Researc

Exhibit 99.1 C4 Therapeutics Reports Full Year 2021 Financial Results and Recent Business Highlights ? Data from Cohort A of the Ongoing Phase 1/2 Trial of CFT7455, a Novel IKZF1/3 Degrader, Accepted for Presentation at the American Association for Cancer Research (AACR) Annual Meeting ? ? Pre-clinical Data on CFT7455; CFT8634, a BRD9 Degrader; and CFT1946, a BRAF V600X Degrader, Accepted for Pres

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39567 C4 Therapeutics

Subsidiaries of the Registrant

Exhibit 21.1 SUBSIDIARIES Subsidiary Jurisdiction of Incorporation C4T Securities Corporation Massachusetts

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 24, 2022 C4 THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-39567 47-5617627 (State or Other Jurisdiction of Incorporation) (Commission

AGREEMENT

EXHIBIT 1 AGREEMENT The persons below hereby agree that the Schedule 13G to which this agreement is attached as an exhibit, as well as all future amendments to such Schedule 13G, shall be filed on behalf of each of them.