Silence Therapeutics (NASDAQ: SLN) CEO steps down; chairman becomes interim chief

Rhea-AI Filing Summary

Silence Therapeutics plc is undergoing significant leadership changes, as President, Chief Executive Officer and director Craig Tooman agreed by mutual consent to end his employment and step down from the Board effective December 14, 2025.

On the same date, Board Chairman Iain Ross was appointed as interim principal executive officer, with additional compensation terms still to be determined and to be covered in a later amendment. The Board also appointed James Ede-Golightly, age 46, to serve as a director with an initial term running until the Company’s 2026 annual general meeting, with his director compensation to be finalised later. The Company issued a December 15, 2025 press release about these changes, filed as Exhibit 99.1.

Positive

• None.

Negative

• President, CEO and director Craig Tooman departs the company and Board effective December 14, 2025, with long-term leadership plans not yet defined.

Insights

Equity analyst – corporate governance

CEO departure and interim leadership introduce governance uncertainty despite continuity steps.

Silence Therapeutics plc disclosed that President, CEO and director Craig Tooman agreed by mutual consent to end his employment and leave the Board effective December 14, 2025. At the same time, Board Chairman Iain Ross was appointed interim principal executive officer, concentrating leadership roles in a single individual on an interim basis.

This kind of senior transition can affect how investors assess strategic direction and execution, especially in a company where the chief executive also sat on the Board. The interim designation signals that the longer-term leadership structure is still to be decided, while separation terms for Mr. Tooman and additional compensation for Mr. Ross are yet to be determined and will be detailed in later amendments.

The appointment of James Ede-Golightly as a director, with prior Board experience at the company and an initial term through the 2026 annual general meeting, partially offsets board-level disruption by adding familiarity. Further clarity is expected when the company files the planned amendments covering the separation agreement and compensation arrangements and as the Board progresses its leadership plans.

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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): December 14, 2025

Silence Therapeutics plc

(Exact name of Registrant as Specified in Its Charter)

England and Wales	001-39487	Not Applicable
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)
12 Hammersmith Grove London United Kingdom		W6 7AP
(Address of Principal Executive Offices)		(Zip Code)

Registrant’s Telephone Number, Including Area Code: +44 20 3457 6900

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(s)		Name of each exchange on which registered
American Depositary Shares, each representing 3 ordinary shares, nominal value £0.05 per share		SLN		The Nasdaq Stock Market LLC
Ordinary share, nominal value £0.05 per share*		*		The Nasdaq Stock Market LLC

* Not for trading, but only in connection with the listing of the American Depositary Shares on The Nasdaq Stock Market LLC.

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 December 15, 2025, Silence Therapeutics plc (the “Company”) announced that Craig Tooman, who has served as the Company’s President, Chief Executive Officer and a member of the Company’s Board of Directors (the “Board”) since 2022, agreed by mutual consent to end his employment with the Company and step down from the Board effective December 14, 2025 (the “Effective Date”).

The Company and Mr. Tooman intend to enter into a separation agreement (the “Separation Agreement”), which will provide for the terms of Mr. Tooman’s separation from employment. The Company will file an amendment to this Current Report on Form 8-K to update this disclosure after the terms of the Separation Agreement are finalised.

Appointment of Principal Executive Officer

On the Effective Date, Iain Ross, Chairman of the Company’s Board, was appointed as interim principal executive officer of the Company, effective immediately. The biography for Mr. Ross is contained in the Company’s definitive proxy statement, filed with the U.S. Securities and Exchange Commission on May 16, 2025. The terms of Mr. Ross’ additional compensation for service as principal executive officer, in addition to his current role as Chairman of the Board, have yet to be determined. The Company will file an amendment to this Current Report on Form 8-K when such compensation has been determined.

Appointment of Director

On the Effective Date, upon the recommendation of the Nominations Committee, the Board appointed James Ede-Golightly to serve as a director of the Company, effective immediately. In accordance with the Company’s articles of association, Mr. Ede-Golightly will serve for an initial term expiring at the end of the Company’s 2026 annual general meeting and expects to stand for re-appointment at the 2026 annual general meeting. Mr. Ede-Golightly has not been appointed to a committee of the Board at this time.

Mr. Ede-Golightly, age 46, previously served a member of the Board from April 2019 to June 26, 2025. He currently serves as Chairman of Oxehealth Ltd, EBP Holdings Ltd and ORA Global Ltd. Among other directorships, Mr. Ede-Golightly is also Non-Executive Director of Gulfsands Petroleum Plc and C4X Discovery Holdings Ltd. Mr. Ede-Golightly was a founder of ORA Capital Partners in 2006, having previously worked as an analyst at Merrill Lynch Investment Managers and Commerzbank. Mr. Ede-Golightly is a CFA Charterholder and holds an M.A. degree in economics from Cambridge University.

The terms of Mr. Ede-Golightly’ compensation for service as a director have yet to be determined. The Company will file an amendment to this Current Report on Form 8-K after the terms of the compensation have been finalised.

The Company also intends to enter into a standard form of deed of indemnity with Mr. Ede-Golightly in connection with his appointment to the Board, the form of which was previously filed by the Company as Exhibit 10.7 to the Company’s Registration Statement on Form F-1 (File No. 333-248203), filed with the Securities and Exchange Commission on August 20, 2020.

There is no arrangement or understanding between Mr. Ede-Golightly and any other person pursuant to which Mr. Ede-Golightly was selected as a director of the Company, and there is no family relationship between Mr. Ede-Golightly and any of the Company’s other directors or executive officers. Mr. Ede-Golightly does not have a material interest in any transaction that is required to be disclosed under Item 404(a) of Regulation S-K.

Item 7.01 Regulation FD Disclosure.

On December 15, 2025, the Company issued a press release announcing the executive changes discussed above. A copy of this press release is filed as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated by reference herein.

The information contained in Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.1 attached hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and shall not be deemed incorporated by reference into any of the Company’s filings under the Securities Act of 1933, as amended, or the Exchange Act, whether made before or after the date hereof, regardless of any general incorporation language in such filing, except as shall be expressly set forth by specific reference in such filing.

Item 9.01 Exhibits.

Exhibit Number		Description
99.1		Press Release dated December 15, 2025
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

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.

		Silence Therapeutics plc
Date: December 15, 2025		By:	/s/ Rhonda Hellums
			Name: Rhonda Hellums
			Title: Chief Financial Officer

FAQ

What leadership changes did Silence Therapeutics (SLN) disclose on December 15, 2025?

The company announced that President, Chief Executive Officer and director Craig Tooman agreed by mutual consent to end his employment and step down from the Board effective December 14, 2025. It also appointed Board Chairman Iain Ross as interim principal executive officer and added James Ede-Golightly as a director.

When is Craig Toomans departure from Silence Therapeutics effective?

Craig Toomans employment with Silence Therapeutics and service on the Board ended effective December 14, 2025, as disclosed by the company.

Who is serving as interim principal executive officer at Silence Therapeutics (SLN)?

Iain Ross, the Chairman of the Board, was appointed as interim principal executive officer effective December 14, 2025, while continuing in his role as Chairman.

Who is the new director on the Silence Therapeutics board and how long will he serve?

James Ede-Golightly was appointed as a director effective December 14, 2025. Under the companys articles of association, he will serve an initial term expiring at the end of the 2026 annual general meeting and expects to stand for re-appointment then.

Have compensation terms for Iain Ross and James Ede-Golightly been set?

No. The company states that the additional compensation for Iain Ross as principal executive officer and the compensation for James Ede-Golightly as a director have yet to be determined and that amendments will be filed once those terms are finalised.

What further disclosures does Silence Therapeutics plan regarding these executive changes?

The company intends to enter into a separation agreement with Craig Tooman and will file an amendment once its terms are finalised. It also plans to amend its disclosure when compensation terms for Iain Ross in his interim executive role and for James Ede-Golightly as a director are determined. A press release describing the changes was filed as Exhibit 99.1 dated December 15, 2025.