Silence Therapeutics plc

(Unaudited)

1. General information

1.1. Nature of the business

Silence Therapeutics plc and its subsidiaries, or together, the Group or Company, are primarily involved in the discovery, delivery and development of RNA therapeutics. Silence Therapeutics plc, a public company limited by shares registered in England and Wales, with company number 02992058, is the Group’s ultimate parent company. The Company’s registered office is 27 Eastcastle Street, London, United Kingdom W1W 8DH and the principal place of business is 12 Hammersmith Grove, London, United Kingdom W6 7AP.

2. Summary of significant accounting policies

2.1. Basis of preparation

The accompanying unaudited condensed consolidated interim financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP, for interim financial reporting and pursuant to the requirements for reporting on Form 10-Q and Article 10 of Regulation S-X. Accordingly, certain information and disclosures required by U.S. GAAP for complete consolidated financial statements are not included herein. These interim statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025 filed with the Securities and Exchange Commission, or the SEC, on March 5, 2026. In the opinion of management, all adjustments considered necessary for a fair statement of these interim statements have been included and are of a normal and recurring nature. The results for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the year ending December 31, 2026, any other interim periods, or any future year or period.

2.2. Functional and reporting currency

The reporting currency of the condensed consolidated financial statements is U.S. Dollars, or USD or $. The functional currency of the Group’s subsidiaries reflects the economic environment of their respective operations. All amounts disclosed have been rounded to the nearest thousand, unless otherwise stated.

The Group changed the functional currency of its U.K. entity from British pound sterling, or GBP, to USD on January 1, 2026. Management determined that changes in economic facts and circumstances, such as a significant shift in mix of the currencies used in the U.K. entity's operating cash flows, represented a significant change that was other-than-temporary and required a change in functional currency from GBP to USD. Accordingly, the change in functional currency from GBP to USD was accounted for prospectively beginning January 1, 2026.

The translated balances of monetary and nonmonetary assets and liabilities recorded in the reporting entity’s consolidated financial statements as of the end of the prior reporting period become the new accounting basis for those assets and liabilities in the period of the change. To the extent that the distinct and separable operation has monetary assets and liabilities denominated in the old functional currency, such balances will create transaction gains and losses subsequent to the change in functional currency. The balances previously recorded in accumulated comprehensive loss for prior periods through December 31, 2025 were not reversed upon this prospective change in functional currency. Monetary assets and liabilities not denominated in the new functional currency, USD, will create transaction gains and losses subsequent to the change in functional currency. The Company does not expect that the impact of such gains and losses will be material to the Company’s consolidated statements of operations.

2.3. Principles of consolidation

The condensed consolidated financial information comprises the financial statements of Silence Therapeutics plc and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated on consolidation.

2.4. Use of estimates

The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of revenues, expenses, and compensation during the reporting period. The Group considers that the carrying amount of trade and other payables approximates their fair value. Bonus accrual and accruals and other payables include accrued severance and other compensation costs, which may include a contingent element, that are currently subject to ongoing negotiation. Significant estimates and assumptions reflected in the Group’s condensed consolidated financial statements include, but are not limited to, the recognition of revenue and research and development expenses. The Group bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates when there are changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ materially from those estimates.

2.5. Going concern

The Group has incurred recurring losses since inception, including net losses of $15.0 million for the three months ended March 31, 2026. As of March 31, 2026, the Group had accumulated losses of $577.5 million and cash outflows from operating activities for the three months ended March 31, 2026 was $15.6 million.

The Group expects to incur operating losses for the foreseeable future as it continues its research and development efforts, seeks to obtain regulatory approval of its product candidates and pursues any future product candidates the Group may develop.

To date, the Group has funded its operations through upfront payments and milestones from collaboration agreements, equity offerings and proceeds from private placements, as well as management of expenses and other financing options to support its continued operations. In 2024, the Group raised additional proceeds of $27.7 million before deducting $0.9 million in placement agent fees and other expenses, from sales of American Depositary Shares or ADSs, under its Open Market Sale Agreement with Jefferies LLC, dated October 15, 2021, or the Sales Agreement. On February 5, 2024, the Group announced a private placement of 5,714,286 of the ADSs, each representing three ordinary shares, at a price of $21.00 per ADS, with new and existing institutional and accredited investors, or the Private Placement. The aggregate gross proceeds of the Private Placement were $120.0 million before deducting approximately $7.7 million in placement agent fees and other expenses. In 2024, the Group received a $10.0 million milestone payment from the AstraZeneca collaboration and received another $2.0 million in milestone payments from the Hansoh collaboration. As of March 31, 2026, the Group had cash and cash equivalents and short-term investments of $70.1 million.

In accordance with Accounting Standards Codification ("ASC") 205, "Disclosure of Uncertainties about and Entity's Ability to Continue as a Going Concern, the Group has the responsibility to evaluate whether conditions and/or events raise substantial doubt about its ability to meet its future financial obligations as they become due within one year after the date that the financial statements are issued. The forecast for evaluating the going concern basis of the Group includes continued investment in our technology platform and product pipeline. The forecast does not include collaboration milestones which have not been fully achieved or other assumptions for potential future non-dilutive or dilutive funding sources. Based on this evaluation, the Group believes that its current cash and cash equivalents and short-term investment as of March 31, 2026 are sufficient to fund its forecasted operating expenses and capital expenditure requirements into 2028.

The Group will need to raise additional funding to fund its operating expenses and capital expenditure requirements in relation to its clinical development activities. The Group may seek additional funding through public or private financings, debt financing or collaboration agreements. Specifically, the Group may receive future milestone payments from collaboration agreements which will extend the ability to fund operations. However, these future milestone payments are dependent on achievement of certain development or regulatory objectives that may not occur. The inability to obtain future funding could impact the Group’s financial condition and ability to pursue its business strategies, including being required to delay, reduce or eliminate some of its research and development programs, or being unable to continue operations or unable to continue as a going concern.

These consolidated financial statements have been prepared assuming that the Company will continue as a going concern which contemplates the continuity of operations, realization of assets and the satisfaction of liabilities in the ordinary course of business and do not include adjustments that would result if the Company were unable to continue as a going concern.

2.6. Recently Issued Accounting Pronouncements

Recently adopted accounting standards

There were no accounting standards adopted in the current period.

Accounting standards issued but not yet adopted

In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40). Additionally, in January 2025, the FASB issued ASU 2025-01 to clarify the effective date of ASU 2024-03. The amendments in this update require disclosure, in the notes to financial statements, of specified information about certain costs and expenses at each interim and annual reporting period. The amendments are effective for annual periods beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. This guidance should be applied either prospectively to financial statements issued for reporting periods after the effective date or retrospectively to any or all prior periods presented in the financial statements. The Group is currently evaluating the impact of this guidance on its related disclosures.

In December 2025, the FASB issued ASU 2025-10, Accounting for Government Grants Received by Business Entities which adds guidance to ASC 832 on the recognition, measurement, and presentation of government grants. The amendments are effective for annual periods beginning after December 15, 2028. The Group is currently evaluating the impact to its consolidated financial statements.

3. Revenue

Revenue from collaboration agreements for the three months ended March 31, 2026 related to the research collaboration agreement the Group entered into with AstraZeneca in March 2020.

Disaggregation of revenue from contracts with customers is as follows:

Under its collaboration agreement with AstraZeneca, the Group received an upfront cash payment of $20.0 million in 2020 with a further payment of $40 million received in May 2021. The Group is also eligible to receive specified development and commercial milestone payments as well as tiered royalties on net sales, if any. The Group recognizes the upfront payment and milestone payments over time, in accordance with ASC 606. During the three months ended March 31, 2026, the Group achievedno milestone payments from the collaboration agreement with AstraZeneca (three months ended March 31, 2025: nil). During the three months ended March 31, 2026, the Group recognized a total of $0.4 million in revenue under its collaboration agreement with AstraZeneca (three months ended March 31, 2025: $0.1 million).

4. Segment reporting

Thechief operating decision maker, or CODM, reviews consolidated net loss for the period when assessing the Group’s performance, allocating resources and establishing management’s compensation. In addition to consolidated net loss, the

CODM receives discrete information for revenue and geographic location. Consolidated net loss is used to monitor budget versus actual results and is reviewed against the Group’s peers and competitors as benchmarking. The Group operates asone reportable segment in the specific technology field of RNA therapeutics.

The accounting policies of its operating segment are the same as those described in the Group’s summary of significant accounting policies.

The Group derives revenues from customers through royalty income and research collaboration agreements, each representing a major customer, specifically related to the development of RNAi-based medicines. Refer to Note 3 – "Revenue" for a further description of the Group revenues.

The measure of segment assets is reported on the balance sheet as total consolidated assets.

The table below provides segment information about the Group:

(a)

Contracted development costs primarily consist of costs incurred under agreements with contract research

organizations and investigative sites that conduct its preclinical studies and clinical trials; costs related to manufacturing active pharmaceutical ingredients and drug products for its preclinical studies and clinical trials; and costs for materials used for in-house research and development activities.

(b)

Personnel R&D costs primarily consist of salaries and personnel-related costs for personnel performing R&D activities or managing those activities that have been out-sourced; and consultants’ costs associated with target selection, preclinical and clinical research activities, and the progression of programs towards clinical trials.

(c)

Other R&D costs include associated facility costs, equipment and other overheads that are directly attributable to R&D and depreciation of capital assets used for research and development activities.

(d)

The other segment items include foreign currency gain/(loss), net, benefit from R&D credit, and other income, net inclusive of bank interest receivable and accretion on U.S. treasury bills.

An analysis of the Group’s assets and revenues by location is shown below: