Silence Therapeutics plc

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

Form 20-F

(Mark One)

OR

For the fiscal year ended December 31,2023

OR

For the transition period from to

OR

Date of event requiring this shell company report

Commission file number 001-39487

Silence Therapeutics plc

(EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

Not Applicable

(Translation of Registrant’s Name into English)

(Jurisdiction of incorporation or organization)

72 Hammersmith Road

London W14 8TH

(Address of principal executive offices)

Craig Tooman

Chief Executive Officer

Silence Therapeutics plc

72 Hammersmith Road

London W14 8TH

Tel:+44 20 3457 6900

(Name, Telephone, E-mail and/or Facsimile number and Address of Company Contact Person)

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

Securities registered or to be registered pursuant to Section 12(g) of the Act: None

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act: None

Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report.

Ordinary shares, nominal value £0.05 per share:118,846,966 asof December 31, 2023

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.☐ Yes☒ No

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.☐ Yes☒ No

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days☒ Yes ☐ No

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).☒ Yes ☐ No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or an emerging growth company. See definition of “large accelerated filer,” “accelerated filer,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer☐ Accelerated filer ☒ Non-accelerated filer☐ Emerging growth company☒

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, 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.☐

† The term “new or revised financial accounting standard” refers to any update issued by the Financial Accounting Standards Board to its Accounting Standards Codification after April 5, 2012.

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).☐

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow.☐ Item 17☐ Item 18

If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).☐ Yes☒ No

TABLE OF CONTENTS

i

GENERAL INFORMATION

Unless otherwise indicated or the context otherwise requires, all references in this report to the terms “Silence,” “Silence Therapeutics,” “Silence Therapeutics plc,” “the company,” “we,” “us” and “our” refer to Silence Therapeutics plc together with its subsidiaries. In this Annual Report, the U.S. Securities and Exchange Commission is referred to as the “SEC”, the Securities Act of 1933, as amended, is referred to as the “Securities Act” and the Securities Exchange Act of 1934, as amended, is referred to as the “Exchange Act.”

PRESENTATION OF FINANCIAL AND OTHER DATA

We maintain our books and records in pounds sterling and report under International Financial Reporting Standards, or IFRS, as issued by the International Accounting Standards Board, or IASB. None of the financial statements included in this report were prepared in accordance with generally accepted accounting principles in the United States. All references in this report to “$” are to U.S. dollars and all references to “£” are to pounds sterling. Except with respect to U.S. dollar amounts presented as contractual terms or otherwise indicated, all amounts presented in this report in U.S. dollars have been translated from pounds sterling solely for convenience at an assumed exchange rate of $1.27 per £1.00, based on the noon buying rate of the Federal Reserve Bank of New York on December 31, 2023. We make no representation that any pounds sterling or U.S. dollar amounts referred to in this Annual Report could have been, or could be, converted into U.S. dollars or pounds sterling, as the case may be, at any particular rate, or at all. These translations should not be considered representations that any such amounts have been, could have been or could be converted from pounds sterling into U.S. dollars at that or any other exchange rate as of that or any other date.

We have made rounding adjustments to some of the figures included in this Annual Report. Accordingly, numerical figures shown as totals in some tables may not be an arithmetic aggregation of the figures that preceded them. Additionally, numerical figures under £100,000 have been rounded to the nearest thousand in this Annual Report.

All references to “shares” or “ordinary shares” in this Annual Report refer to ordinary shares of Silence Therapeutics plc with a nominal value of £0.05 per share. All references to ADSs refer to American Depositary Shares, each representing three ordinary shares of Silence Therapeutics plc, which are denominated in U.S. dollars and listed on Nasdaq.

TRADEMARKS, TRADENAMES AND SERVICE MARKS

This Annual Report includes trademarks, tradenames and service marks, certain of which belong to us and others that are the property of other organizations. Solely for convenience, trademarks, tradenames and service marks referred to in this report appear without the®, ™ and SM symbols, but the absence of those symbols is not intended to indicate, in any way, that we will not assert our rights or that the applicable owner will not assert its rights to these trademarks, tradenames and service marks to the fullest extent under applicable law. We do not intend our use or display of other parties’ trademarks, trade names or service marks to imply, and such use or display should not be construed to imply, a relationship with, or endrorsement or sponsorship of us by, these other parties.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report contains forward-looking statements that involve substantial risks and uncertainties. In some cases, you can identify forward-looking statements by the words “may,” “might,” “will,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “objective,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “continue” and “ongoing,” or the negative of these terms, or other comparable terminology intended to identify statements about the future. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. The forward-looking statements and opinions contained in this Annual Report are based upon information available to us as of the date of this Annual Report and, while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. Forward-looking statements include statements about:

•

the development of our product candidates, including statements regarding the timing of initiation, completion and the outcome of preclinical studies or clinical trials and related preparatory work, the period during which the results of the trials will become available and our research and development programs;

•

our ability to obtain and maintain regulatory approval of our product candidates in the indications for which we plan to develop them, and any related restrictions, limitations or warnings in the label of an approved drug or therapy;

•

our plans to collaborate, or statements regarding the ongoing collaborations, with third parties;

•

our plans to research, develop, manufacture and commercialize our product candidates;

•

the timing of our regulatory filings for our product candidates;

•

the size and growth potential of the markets for our product candidates;

•

our ability to raise additional capital;

•

our commercialization, marketing and manufacturing capabilities and strategy;

•

our expectations regarding our ability to obtain and maintain intellectual property protection;

•

our ability to attract and retain qualified employees and key personnel;

•

our ability to contract with third-party suppliers and manufacturers and their ability to perform adequately;

•

our estimates regarding future revenue, expenses and needs for additional financing;

•

our belief that our existing cash, cash equivalents and future anticipated milestone payments from our existing collaborations will be sufficient to fund our operating expenses and capital expenditure requirements into 2026; and

•

regulatory developments in the United States, United Kingdom, European Union, or EU, and other jurisdictions.

You should refer to the section of this Annual Report titled “Risk Factors” for a discussion of important factors that may cause our actual results to differ materially from those expressed or implied by our forward-looking statements. As a result of these factors, we cannot assure you that the forward-looking statements in this Annual Report will prove to be accurate. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. In light of the significant uncertainties in these forward-looking statements, you should not regard these statements as a representation or warranty by us or any other person that we will achieve our objectives and plans in any specified time frame, or at all. Forward-looking statements speak only as of the date they are made, and we do not undertake any obligation to update them in light of new information or future developments or to release publicly any revisions to these statements in order to reflect later events or circumstances or to reflect the occurrence of unanticipated events.

You should read this Annual Report and the documents that we reference in this Annual Report and have filed as exhibits to the Annual Report completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements.