6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OFFOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the Month of April 2024

Commission File Number: 001-39487

Silence Therapeutics plc

(Exact Name of Registrant as Specified in Its Charter)

72Hammersmith Road

London W14 8TH

United Kingdom

(Address ofprincipal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒   Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

INCORPORATION BY REFERENCE

This Report on Form 6-K (the “Report”) and Exhibit 99.1 to this Report shall be deemed to be incorporated by reference into the registration statements on Form S-8 (File Nos. 333-248682 and 333-273576) and registration statement on Form F-3 (File No. 333-260265) of Silence Therapeutics plc (including any prospectuses forming a part of such registration statements) and to be a part thereof from the date on which this Report is furnished, to the extent not superseded by documents or reports subsequently filed or furnished.

INFORMATION CONTAINED IN THIS REPORT ON FORM 6-K

Retirement of Director

On April 29, 2024, Silence Therapeutics plc (the “Company”) announced that Alistair Gray is retiring from the Company’s Board of Directors effective May 1, 2024. The Company issued a press release announcing the retirement of Mr. Gray from the Board, which is furnished as Exhibit 99.1 to this Report.

EXHIBIT LIST

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, thereunto duly authorized.

Date: April 29, 2024

EX-99.1

Exhibit 99.1

Silence Therapeutics Announces Retirement of Alistair Gray from Board of Directors

29 April 2024

LONDON, Silence Therapeutics plc (Nasdaq: SLN) (“Silence” or the “Company”), an experienced and innovative biotechnology company committed to transforming people’s lives by silencing diseases through precision engineered medicines, today announced that Alistair Gray, who has served as an independent member of Silence’s Board of Directors (the “Board”) since 2015, informed the Company that he will retire from the Board, effective May 1, 2024.

Iain Ross, Silence’s Chairman of the Board, commented, “Alistair has made significant contributions to the Board and the Company over the past nine years. During his time on the Board, the Company has transitioned into a global player focused on the development of a new generation of medicines harnessing the body’s natural mechanism of RNA interference, developed a pipeline of innovative product candidates, secured meaningful big pharma partnerships and established a first-class management team. I want to recognise and thank Alistair for his input on behalf of the Board and management over almost a decade. We wish him well in the future.”

Mr. Gray stated, “Nearly 10 years after joining the Silence Board and at age 75, I feel the time is right to retire as a director. When I joined Silence, there were few targets in the clinic and the organisation was in an early stage of development. Since 2019, we have enjoyed a period of stability under the leadership of Iain Ross, our Chair, and I have been privileged to serve as Senior Independent Director. Under the executive leadership of Craig Tooman, our President and Chief Executive Officer, our business has been transformed both clinically and financially to a point where we have a number of product candidates advancing in the clinic and increasing recognition of Silence as a true platform company. I would like to thank my colleagues on the Board and the executives as well as our staff in Berlin, London and New Jersey for their support and encouragement over our time together.”

About Silence Therapeutics

Silence Therapeutics is developing a new generation of medicines by harnessing the body’s natural mechanism of RNA interference, or RNAi, to inhibit the expression of specific target genes thought to play a role in the pathology of diseases with significant unmet need. Silence’s proprietary mRNAi GOLD^™^ platform can be used to create siRNAs (short interfering RNAs) that precisely target and silence disease-associated genes in the liver, which represents a substantial opportunity. Silence’s wholly owned product candidates include zerlasiran (SLN360) designed to address the high and prevalent unmet medical need in reducing cardiovascular risk in people born with high levels of lipoprotein(a) and divesiran (SLN124) designed to address rare hematological diseases, including polycythemia vera. Silence also maintains ongoing research and development collaborations with AstraZeneca and Hansoh Pharma, among others. For more information, please visit https://www.silence-therapeutics.com/.

Inquiries: