Silence Therapeutics plc

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31,2025

or

For the transition period from to

Commission File Number 001-39487

Silence Therapeutics plc

(Exact name of registrant as specified in its charter)

Tel:+44 20 3457 6900

(Registrant’s telephone number, including area code)

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

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

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

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

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. ☐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, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

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. ☐

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 whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). ☐Yes☒ No

The aggregate market value of the ordinary shares held by non-affiliates of the registrant, based upon $5.80, the closing price of the registrant’s American Depositary Shares on the Nasdaq Global Market on June 30, 2025 (the last business day of the registrant’s most recently completed second fiscal quarter) was approximately $206.2 million.

As of January 31, 2026, the registrant had 141,701,848 ordinary shares (including ordinary shares in the form of American Depositary Shares) outstanding, nominal value £0.05 per share.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s proxy statement to be filed with the Securities and Exchange Commission pursuant to Regulation 14A in connection with the registrant’s 2026 Annual General Meeting of Shareholders are incorporated by reference into Part III of this Annual Report on Form 10-K. Such proxy statement will be filed with the Securities and Exchange Commission not later than 120 days following the end of the registrant’s fiscal year ended December 31, 2025.

TABLE OF CONTENTS

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K, or the 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, but are not limited to, statements about:

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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;

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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;

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

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

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the timing of our regulatory filings for our product candidates;

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

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our ability to raise additional capital;

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our commercialization, marketing and manufacturing capabilities and strategy;

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

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

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

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

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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 2028; and

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

You should refer to the section titled “Risk Factors” in Part I, Item 1A. of this Annual Report 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, therefore, not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this Annual Report.

GENERAL INFORMATION

Unless context otherwise requires, all references in this Annual Report on Form 10-K, or Annual Report, to “Silence,” “Silence Therapeutics,” “Silence Therapeutics plc,” “the Company,” “we,” “us” and “our” refer to Silence Therapeutics plc and, where appropriate, its consolidated subsidiaries.

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 Annual 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 endorsement or sponsorship of us by, these other parties.

RISK FACTORS SUMMARY

Our business is subject to a number of risks and uncertainties. If any of the following risks are realized, our business, financial condition and results of operations could be materially and adversely affected. You should carefully review and consider the full discussion of our risk factors in the section titled “Risk Factors” in Part I, Item 1A. of this Annual Report. Set forth below is a summary list of the principal risk factors as of the date of the filing this Annual Report:

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We have a history of net losses, and we anticipate that we will continue to incur significant losses for the foreseeable future.

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We have never generated any revenue from product sales and may never be profitable.

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We will require additional financial resources to continue the ongoing development of our product candidates and pursue our business objectives. If we are unable to obtain these additional resources when needed or on acceptable terms, we may be forced to delay or discontinue our planned operations, including clinical testing of our product candidates.

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Raising additional capital may cause dilution to our holders, including holders of our American Depositary Shares representing our ordinary shares, or ADSs, restrict our operations or require us to relinquish rights to our technologies or product candidates.

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The approach we are taking to discover and develop drugs is novel and may never lead to marketable products.

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We rely on third parties to conduct some aspects of our manufacturing, research and development activities, and those third parties may not perform satisfactorily, including failing to meet deadlines for the completion of research or clinical testing, or may terminate our agreements.

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Even if we complete the necessary preclinical studies and clinical trials, we cannot predict whether or when we will obtain regulatory approval to commercialize a product candidate and we cannot, therefore, predict the timing of any revenue from a future product.

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Even if we obtain regulatory approval for a product candidate, we will still face extensive regulatory requirements, and our products may face future development and regulatory difficulties.

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We face competition from other companies that are working to develop novel drugs and technology platforms using technologies similar to ours. If these companies develop drugs more rapidly than we do or their technologies, including delivery technologies, are more effective, our ability to successfully commercialize drugs may be adversely affected.

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If we fail to introduce new products or keep pace with advances in technology, our business, financial condition and results of operations could be adversely affected.

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We face potential product liability and other claims, and, if successful claims are brought against us, we may incur substantial liability and costs.

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Cybersecurity risks and the failure to maintain the confidentiality, integrity, and availability of our computer hardware, software, data and internet applications and related tools and functions, or those of third parties with whom we work, could result in damage to our reputation and/or subject us to costs, fines or lawsuits.

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We and the third parties with whom we work are subject to stringent and evolving U.S. and foreign data privacy and security laws, regulations contractual obligations, industry standards, policies, and other obligations, and our (or the third parties with whom we work) actual or perceived failure to comply with such obligations could lead to regulatory investigations or actions; litigation (including class actions); fines and penalties; disruptions of our business operations; reputational harm; loss of revenue or profits; and other adverse business consequences.

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If we are unable to obtain or protect intellectual property rights related to our current or future products and product candidates, we may not be able to compete effectively in our markets.

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We may be involved in lawsuits to protect or enforce our patents or the patents of our licensors, which could be expensive, time-consuming and unsuccessful.

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We have incurred and will continue to incur increased costs as a result of operating as a public company, and our management has devoted and will continue to be required to devote substantial time to new compliance initiatives and corporate governance practices.

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The trading price of our ADSs may be volatile, and you could lose all or part of your investment.

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Future sales, or the possibility of future sales, of a substantial number of our ADSs could adversely affect the price of such securities.

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We may identify material weaknesses in our internal control over financial reporting. If we experience material weaknesses or significant deficiencies in the future or otherwise fail to maintain an effective system of internal controls, we may not be able to accurately or timely report our financial condition or results of operations, which may adversely affect our business.

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Holders of our ADSs have fewer rights than our shareholders and must act through the depositary to exercise their rights.

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If a United States person is treated as owning at least 10% of our ordinary shares, such United States person may be subject to adverse U.S. federal income tax consequences.

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Claims of U.S. civil liabilities may not be enforceable against us.

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Our articles of association provide that the U.S. federal district courts are the exclusive forum for the resolution of any complaint asserting a cause of action arising under the Securities Act.