Avantor chair transition: Peacock exits Dec 31, 2025; Summe to lead

Rhea-AI Filing Summary

Avantor, Inc. announced that Jonathan Peacock will step down as chairman, director, and member of the Nominating and Governance Committee on December 31, 2025. The company stated his decision was not due to any disagreement regarding its operations, policies, or practices.

Current director Gregory L. Summe will serve as the next chairman effective January 1, 2026. The transition details were also provided in a press release furnished under Regulation FD.

Insights

Corporate Governance Analyst

Board chair transition disclosed with advance notice and no stated dispute; continuity appears orderly with a named successor and defined dates.

The company disclosed that **Jonathan Peacock** will step down as chairman and director on December 31, 2025, with no disagreement cited regarding operations, policies, or practices. The Board identified **Gregory L. Summe** to become the next chairman effective January 1, 2026. A press release was furnished under Item 7.01 (Exhibit 99), which is not deemed filed.

What it means: this is a planned governance transition with a clear handoff date and continuity in leadership. The absence of a reported disagreement lowers the risk of underlying disputes. The disclosure focuses on chair and Board roles; committee changes beyond the Nominating and Governance Committee seat vacated by Mr. Peacock are not detailed here.

Why it matters: chair transitions can influence Board oversight agendas and meeting cadence. The defined dates (12/31/2025 and 01/01/2026) set a clean year-end handover. Items to watch include any subsequent filings detailing committee reassignments, Board composition changes, or updates tied to the chair transition as the effective date approaches.

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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 10, 2025

Avantor, Inc.

(Exact name of registrant as specified in its charter)

Delaware			001-38912			82-2758923
(State or other jurisdiction of incorporation)			(Commission File Number)			(I.R.S. Employer Identification No.)

Radnor Corporate Center, Building One, Suite 200

100 Matsonford Road

Radnor, Pennsylvania 19087

(Address of principal executive offices, including zip code)

(610) 386-1700

(Registrant’s telephone number, including area code)

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:

☐    Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐    Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐    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

Exchange on which registered

Common Stock, $0.01 par value

AVTR

New York Stock Exchange

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

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. ☐

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

On October 10, 2025, Jonathan Peacock informed Avantor, Inc. (the “Company”) that he will step down as the Company’s chairman, member of the Board of Directors (the “Board”) and member of the Nominating and Governance Committee on December 31, 2025. Mr. Peacock’s decision to step down from the Board was not a result of any disagreement with the Company on any matter relating to the Company’s operations, policies or practices.

Item 7.01.    Regulation FD Disclosure.

On October 13, 2025, the Company issued a press release announcing that Mr. Peacock informed the Company of his decision to step down from the Board on December 31, 2025, and that current Board member, Gregory L. Summe, will serve as the Company’s next chairman from January 1, 2026. A copy of the press release is furnished herewith as Exhibit No. 99 to this Current Report on Form 8-K, and shall not be deemed filed for the purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section and shall not be deemed to be incorporated by reference into any filing by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01.    Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.						Description
99						Press Release, dated October 13, 2025
104						The cover page from this Current Report on Form 8-K, formatted in Inline XBRL

SIGNATURE

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.

			Avantor, Inc.
Date: October 14, 2025			By:			/s/ Claudius Sokenu
						Name:			Claudius Sokenu
						Title:			Executive Vice President, Chief Legal and Compliance Officer and Corporate Secretary (Duly Authorized Officer)

FAQ

When will Avantor (AVTR) Chairman Jonathan Peacock step down?

On December 31, 2025, he will step down as chairman, director, and Nominating and Governance Committee member.

Did Jonathan Peacock’s departure involve any disagreement with Avantor (AVTR)?

No. The company reported it was not due to any disagreement on operations, policies, or practices.

Who will be Avantor’s next chairman and when is it effective?

Gregory L. Summe will become chairman effective January 1, 2026.

What SEC form disclosed Avantor’s board transition?

An 8-K reported the changes under Item 5.02 and furnished a press release under Item 7.01.

Was the press release filed or furnished?

It was furnished under Regulation FD and not deemed filed for Section 18 liability.

Which board committee role is affected at Avantor (AVTR)?

Jonathan Peacock will leave the Nominating and Governance Committee on December 31, 2025.