C4 Therapeutics (NASDAQ: CCCC) names CFO as principal accountant

Rhea-AI Filing Summary

C4 Therapeutics reported a change in its senior finance leadership roles. The company determined that Mark Mossler will no longer serve as Chief Accounting Officer, effective May 15, 2026, and stated that his departure does not involve any disagreement about financial reporting, operations, policies or practices.

Kendra R. Adams, currently Chief Financial Officer, Head of Corporate Affairs and Treasurer, has been designated as the company’s principal accounting officer, also effective May 15, 2026. She will not receive additional compensation for this role, and no existing plans or arrangements involving her have been changed.

8-K Event Classification

Item 5.02 — Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers

1 item

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers Governance

Key personnel changes including departures, elections, or appointments of directors and executive officers.

Key Figures

Effective date of Mossler departure: May 15, 2026 Effective date of Adams appointment: May 15, 2026 Proxy statement filing date: April 29, 2026

3 metrics

Effective date of Mossler departure May 15, 2026 Date he ceases serving as Chief Accounting Officer

Effective date of Adams appointment May 15, 2026 Date she is designated principal accounting officer

Proxy statement filing date April 29, 2026 Date of 2026 definitive proxy referenced for Adams’ background

Key Terms

principal accounting officer, definitive proxy statement, Schedule 14A, related party transactions

4 terms

principal accounting officer financial

"has been designated as the Company’s principal accounting officer, effective May 15, 2026"

The Principal Accounting Officer is the person responsible for making sure a company's financial records are accurate and follow the rules. They play a key role in preparing financial reports that show how well the company is doing. This helps investors, managers, and regulators trust the company's financial information.

definitive proxy statement regulatory

"the Company’s 2026 definitive proxy statement on Schedule 14A"

A Definitive Proxy Statement is a detailed document that a company sends to its shareholders before a big meeting, like voting on important decisions. It explains what's being voted on and gives important information so shareholders can make informed choices. It matters because it helps shareholders understand and participate in key company decisions.

Schedule 14A regulatory

"definitive proxy statement on Schedule 14A, which was filed"

Schedule 14A is a document that companies file with regulators to share important information with shareholders before a big vote, like approving a merger or election of directors. It matters because it helps investors understand what’s happening so they can make informed decisions about the company’s future.

related party transactions financial

"any related party transactions involving Ms. Adams is incorporated by reference"

Transactions between a company and people or entities that have close ties to it—such as executives, board members, major shareholders, family members, or related companies—where the parties are not independent. These deals matter to investors because they can create conflicts of interest or hide favorable terms that distort a company’s true profits and risks; think of it like a business buying or selling to a family member instead of using the open market, which can lead to biased prices or undisclosed obligations.

Understanding 8-K Material Events →

0001662579false00016625792026-05-152026-05-15

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)			(Commission File Number)			(IRS Employer Identification No.)
490 Arsenal Way,   Suite 120 Watertown,  MA						02472
(Address of Principal Executive Offices)						(Zip Code)

Registrant’s Telephone Number, Including Area Code: (617) 231-0700

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

_________________________________________________________________

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o			Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
o			Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
o			Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
o			Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, $0.0001 par value per share

CCCC

The Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company o

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

Departure of Principal Accounting Officer

On May 12, 2026, C4 Therapeutics, Inc. (the “Company”) determined that Mark Mossler will no longer serve as the Company’s Chief Accounting Officer, effective May 15, 2026. Mr. Mossler’s departure from the Company is not due to any disagreement with the Company or the Company’s Board of Directors on any matter relating to the Company’s financial reporting, operations, policies or practices.

Appointment of Principal Accounting Officer

Kendra R. Adams, the Company’s Chief Financial Officer, Head of Corporate Affairs and Treasurer, has been designated as the Company’s principal accounting officer, effective May 15, 2026. Information regarding Ms. Adams’ background and business experience, contracts between the Company and Ms. Adams and any related party transactions involving Ms. Adams is incorporated by reference herein from the Company’s 2026 definitive proxy statement on Schedule 14A, which was filed with the U.S. Securities and Exchange Commission on April 29, 2026. Ms. Adams will not receive any additional compensation for assuming the additional role of principal accounting officer, and no changes have been made to any plans or arrangements in which Ms. Adams participates as a result of this appointment.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

			C4 Therapeutics, Inc.
Date: May 15, 2026			By:			/s/ Kendra R. Adams
						Kendra R. Adams
						Chief Financial Officer and Treasurer

FAQ

What leadership change did C4 Therapeutics (CCCC) disclose in this 8-K?

C4 Therapeutics disclosed that Chief Accounting Officer Mark Mossler will leave his role effective May 15, 2026. The company also designated CFO Kendra R. Adams as principal accounting officer, consolidating financial leadership responsibilities under her without altering her compensation.

When is the C4 Therapeutics principal accounting officer change effective?

The change is effective May 15, 2026. On that date, Mark Mossler will cease serving as Chief Accounting Officer and CFO Kendra R. Adams will assume the role of principal accounting officer alongside her existing responsibilities at C4 Therapeutics.

Did C4 Therapeutics report any disagreement related to the accounting officer’s departure?

The company stated Mr. Mossler’s departure is not due to any disagreement with C4 Therapeutics or its Board. This includes matters related to financial reporting, operations, policies, or practices, indicating the change is not tied to a disclosed dispute over accounting issues.

Will C4 Therapeutics’ CFO receive additional pay for becoming principal accounting officer?

C4 Therapeutics reported that CFO Kendra R. Adams will not receive any additional compensation for serving as principal accounting officer. The filing also notes no changes were made to any existing plans or arrangements in which she participates due to this appointment.

Where can investors find background information on C4 Therapeutics’ CFO Kendra R. Adams?

Background and business experience details for Kendra R. Adams are incorporated by reference from C4 Therapeutics’ 2026 definitive proxy statement. That Schedule 14A filing, submitted on April 29, 2026, also covers contracts with her and any related party transactions involving her.

Filing Exhibits & Attachments

3 documents

Other Documents

• EX-101 XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT 1.8 KB
• EX-101 XBRL TAXONOMY EXTENSION LABEL LINKBASE DOCUMENT 22.9 KB
• EX-101 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE DOCUMENT 13.3 KB