Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

You should read the following discussion and analysis of our financial condition and results of operations together with our consolidated financial statements and the related notes thereto appearing elsewhere in this Annual Report. The following discussion is based on our financial information prepared in accordance with U.S. GAAP and regulations of the SEC. Some of the information contained in this discussion and analysis or set forth elsewhere in this Annual Report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. You should review the section titled “Risk Factors” for a discussion of important factors that could cause actual results to differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis, as well as the section titled “Special Note Regarding Forward-Looking Statements.”

Overview

We are a biotechnology company focused on discovering and developing novel molecules incorporating short interfering ribonucleic acid, or siRNA, to inhibit the expression of specific target genes thought to play a role in the pathology of diseases with significant unmet medical need. Our siRNA molecules are designed to harness the body’s natural mechanism of RNAi by specifically binding to and degrading messenger RNA, or mRNA, molecules that encode specific targeted disease-associated proteins in a cell. By degrading the message that encodes the disease-associated protein, the production of that protein is reduced and its level of activity is lowered. In the field of RNAi therapeutics, this reduction of disease-associated protein production and activity is referred to as “gene silencing.” Our proprietary mRNAi GOLDTM (GalNAc Oligonucleotide Discovery) platform consists of siRNA product candidates designed to precisely target and ‘silence’ specific disease-associated genes in the liver. Using our mRNAi GOLD platform, we have generated siRNA product candidates targeting areas of high unmet need across rare and common diseases where treatments are limited or inadequate.

Rare Diseases

Divesiran (SLN124) is our potential first-in-class siRNA in Phase 2 development for polycythemia vera, or PV. PV is a rare myeloproliferative neoplasm characterized by the overproduction of red blood cells, or RBCs. Elevated hematocrit, or HCT, - an index of RBC mass - is a hallmark of the disease and HCT levels above 45% increases the risk of thrombotic and cardiovascular events. The current standard of care in all PV patients to control HCT is phlebotomy, daily low-dose aspirin therapy, sometimes in combination with cytoreductive therapies. PV patients have low levels of hepcidin the body’s master regulator of iron. Divesiran works by "silencing" the TMPRSS6 gene, lifting the natural brake on hepcidin - the body's master iron regulator. When TMPRSS6 is turned down in people living with PV, hepcidin levels rise, reducing iron availability to the bone marrow. With less iron available, the overproduction of RBCs seen in PV is reduced. This helps keep HCT levels in a safer range and can reduce or eliminate the need for phlebotomies. Additionally, siRNA therapies have a highly potent and durable effect - enabling less frequent and more convenient dosing. In the Phase 1 part of the SANRECO clinical trial evaluating divesiran treatment in 21 PV patients, divesiran produced durable HCT control and substantially reduced phlebotomy use following infrequent dosing (Q6W). Based on the strong durability observed in Phase 1, the ongoing Phase 2 part of the SANRECO trial is evaluating both a Q6W and Q12W dosing interval. The SANRECO Phase 2 trial is fully enrolled and topline results are anticipated in the third quarter of 2026. The U.S. Food and Drug Administration, or FDA, has granted divesiran Fast Track and orphan drug designations for PV. Divesiran has also been granted orphan drug designation by the European Commission for PV in Europe. While our initial focus is on PV, divesiran has shown the potential in preclinical studies to address multiple hematological conditions through the unifying mechanism of elevating hepcidin in conditions with dysregulation of iron homeostasis.

SLN548 is our Phase 1 ready siRNA product candidate that works by "silencing" the complement factor B, or CFB, gene, potentially playing a therapeutic role in conditions associated with over activation of this pathway, including complement-mediated renal diseases, among others. SLN548 has demonstrated positive preclinical results and we are seeking a third-party partner to initiate clinical development.

Cardiometabolic Diseases

Zerlasiran (SLN360) is our Phase 3 ready siRNA product candidate for cardiovascular disease that works by "silencing" the LPA gene, lowering production of apolipoprotein(a), a key component of lipoprotein(a), or Lp(a), that has been associated with an increased risk of cardiovascular events. High Lp(a), defined as 125nmol/L or higher, is a genetically determined cardiovascular risk factor affecting at least 20% of the world’s population and is associated with a high risk of heart attack, stroke and aortic stenosis. Unlike low-density lipoprotein, or LDL, Lp(a) levels are predominantly genetically determined, typically by age five, and unaffected by diet or lifestyle. There are currently no approved medicines that selectively lower Lp(a). Guidelines from the European Atherosclerosis Society, or EAS, Canadian Cardiovascular Society, or CCS, and the National Lipid Association, or NLA, suggest at least one test in an adult lifetime. The American College of Cardiology, or ACC, and American Heart Association, or AHA, recommend testing for those with a family history of premature atherosclerotic cardiovascular disease, or ASCVD, or personal history of ASCVD. In Phase 1 and Phase 2 clinical trials, zerlasiran showed the potential to substantially lower Lp(a) levels in ASCVD patients with persisting effects following infrequent dosing and was well tolerated with no major safety concerns. We have received positive regulatory feedback from the FDA and European Medicines Agency, or EMA, on the Phase 3 cardiovascular outcomes study design for zerlasiran in patients with high Lp(a). In 2025, we completed core Phase 3 readiness activities, including manufacturing and supply scale up. Zerlasiran is Phase 3 ready and we are seeking a third-party partner for potential Phase 3 development as well as potential future commercialization.

SLN312 is our siRNA product candidate under our collaboration with AstraZeneca that works by "silencing" ANGPTL3, an important modulator of lipid metabolism. Inhibition of ANGPTL3 has emerged as a promising new therapeutic approach to reduce triglycerides (TG) and LDL-C levels, the latter independent of the LDL-C receptor (LDLR) function. Since ANGPTL3 suppresses lipoprotein lipase, or LPL, and endothelial lipase, or EL, activity, its inhibition facilitates the clearance of very low-density lipoprotein cholesterol, decreasing both LDL-C and TG levels. AstraZeneca shared interim results from its Phase 1 randomized, single-blind, placebo-controlled trial assessing SLN312 in 98 patients with dyslipidemia. Interim results showed SLN312 produced durable dose-dependent reductions in ANGPTL3, triglycerides and atherogenic lipoproteins after single and multiple doses. The strong duration of effect observed supports potential for infrequent dosing. SLN312 was well tolerated with no safety concerns identified. Phase 1 data presentations are planned for medical and research congresses in 2026. On March 4, 2026, AstraZeneca notified Silence that they will not pursue further development of SLN312 beyond Phase 1. We will re-gain full development, manufacturing and commercialization rights globally to this clinical asset following Phase 1 and are evaluating plans for further clinical development.

SLN365 is our potential first-in-class siRNA product candidate that works by "silencing" GPR146, a novel mechanism of action for the management of cholesterol levels in patients, independent of LDLR function. Hypercholesterolemia is a highly prevalent indication with an estimated one in 300 individuals worldwide living with the familial form HeFH (heterozygous) and around one in 300,000 individuals suffering from the form HoFH (homozygous) globally. SLN365 has demonstrated promising preclinical results in non-human primates and we anticipate additional preclinical data in the second quarter of 2026.

SLN098 is our siRNA product candidate that works by "silencing" INHBE, a novel target for obesity supported by human genetics, strong preclinical data and emerging third-party clinical data demonstrating early efficacy and safety. Despite recent advances in obesity treatment, limitations of current standards of care leave millions at risk of further complications. Around one billion patients worldwide are affected by obesity and associated co-morbidities. Current obesity treatments offer weight loss around 15-20% which plateaus after 12-24 months and are associated with up to 40% lean muscle mass loss. More than two thirds of weight loss is regained within the first year after discontinuation of treatment. There is also poor tolerability and compliance with up to 30% of patients discontinuing GLP/GIP agonists treatment. SLN098 has the opportunity to address unmet needs including increasing fat loss, preventing muscle mass loss and slowing weight regain. SLN098 has demonstrated deep and durable knockdown in nonhuman primates and we anticipate additional disease model data in the second quarter of 2026 to further validate the mechanism of action. We believe there is an opportunity to develop SLN098 either as a monotherapy or add-on to GLP/GIP agonists or as a weight maintenance treatment.

Fourth Quarter and Fiscal Year 2025 and Recent Business Highlights

Divesiran: Potential first-in-class siRNA for polycythemia vera (PV)

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Accelerated timing for topline results in the Phase 2 SANRECO trial of divesiran, a potential first-in-class siRNA for PV; now anticipated in the third quarter of 2026, as opposed to our prior guidance of the second half of 2026 due to faster than expected enrollment.

Zerlasiran: Phase 3 ready program for cardiovascular disease due to high Lp(a)

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Completed core Phase 3 readiness activities; program is well positioned for a potential third-party partner to initiate Phase 3 development.

SLN312: Phase 1 siRNA with a competitive profile for dyslipidemia

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AstraZeneca shared results from an interim analysis of a Phase 1 randomized, single-blind, placebo-controlled trial of SLN312, an siRNA silencing ANGPTL3 discovered using Silence’s mRNAi GOLDTM platform and developed by AstraZeneca, in 98 patients with dyslipidemia. Data highlights include:

SLN312 demonstrated durable dose-dependent reductions in ANGPTL3, triglycerides and atherogenic lipoproteins after single and multiple doses.

Strong durability profile observed supporting potential for infrequent dosing.

SLN312 was observed to be well tolerated with no safety concerns identified.

Phase 1 data presentations are planned for medical and research congresses in 2026.

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On March 4, 2026, AstraZeneca notified Silence that they will not pursue further development of SLN312 beyond Phase 1. Silence will re-gain exclusive rights globally to this clinical asset following Phase 1 and is evaluating plans for further development.AstraZeneca and Silence maintain a broader collaboration leveraging Silence's mRNAi GOLDTM platform for cardiovascular, cardiometabolic, renal and respiratory diseases.

Discovery Pipeline

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Generated promising preclinical data for two new mRNAi GOLDTM platform programs.

SLN365, a potential first-in-class siRNA silencing GPR146, a novel mechanism-of-action for cholesterol management independent of LDL-C receptor function.

SLN098, an siRNA silencing INHBE, a novel target for obesity supported by human genetics and strong pre-clinical data

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Advanced extra-hepatic cell targeting leveraging our proprietary siRNA platform, generating promising preliminary results in several cell types.

Anticipated 2026 Milestones

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Topline results for the Phase 2 SANRECO trial of divesiran in PV in the third quarter of 2026.

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Additional preclinical data for SLN365 (GPR146) in the second quarter of 2026.

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Additional preclinical data for SLN098 (INHBE) in the second quarter of 2026.

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Phase 1 data presentations for SLN312 at medical and research congresses in 2026.

Corporate Updates

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On December 15, 2025, Iain Ross, Chairman of the Board of Directors, was announced as Interim Principal Executive Officer following the departure of the Company’s former CEO; a search is underway for a new CEO.

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In December 2025, James Ede Golightly, a former Silence Non-Executive Director, was reappointed to the Board. Additionally, Rhonda Hellums, CFO of Silence, was appointed to the Board as an Executive Director.

We have incurred significant operating losses and expect to continue to incur significant expenses and operating losses for the near future. These net losses were $88.6 million and $45.3 million for the years ended December 31,

2025 and 2024, respectively. As of December 31, 2025, our accumulated deficit was $562.6 million. We expect to continue to incur significant and increasing expenses and to incur operating losses for the foreseeable future, as we advance our product candidates through preclinical and clinical development and seek regulatory approvals, manufacture drug product and drug supply, maintain and expand our intellectual property portfolio, as well as hire additional personnel, pay for further accounting, audit, legal, regulatory and consulting services, and pay costs associated with maintaining compliance with Nasdaq listing rules and the requirements of the U.S. Securities and Exchange Commission, or SEC, director and officer liability insurance, investor and public relations activities and other expenses associated with operating as a public company.

Collaboration Agreement with AstraZeneca

In March 2020, we entered into a collaboration agreement with AstraZeneca to discover, develop and commercialize siRNA therapeutics for the treatment of cardiovascular, renal, metabolic and respiratory diseases. Under this agreement, AstraZeneca made an upfront cash payment to us of $20.0 million in May 2020. AstraZeneca made an additional unconditional cash payment to us of $40.0 million which was received in May 2021. In March 2020, an affiliate of AstraZeneca also subscribed for 4,276,580 new ordinary shares for an aggregate subscription price of $20.0 million.

The collaboration covered five targets initially with AstraZeneca opting to extend the collaboration to a further five targets. AstraZeneca agreed to pay us $10.0 million upon the exercise of each option to collaborate on an additional target. For each target selected, we are eligible to receive up to $140.0 million in potential milestone payments upon the achievement of milestones relating to the initiation of specified clinical trials, the acceptance of specified regulatory filings and the first commercial sale in specified jurisdictions. For each target selected, we are also eligible to receive up to $250.0 million in potential commercial milestone payments, upon the achievement of specified annual net sales levels, as well as tiered royalties as a percentage of net sales ranging from the high single digits to the low double digits.

In May 2023, AstraZeneca nominated the first product candidate under our collaboration, SLN312 (ANGPTL3), triggering a $10.0 million option fee to us. In February 2024, AstraZeneca initiated a Phase 1 clinical trial for SLN312 which triggered another $10.0 million milestone payment to us. On March 4, 2026, AstraZeneca notified Silence that they will not pursue further development of SLN312 beyond Phase 1. We will re-gain full development, manufacturing and commercialization rights globally to this clinical asset following Phase 1 and are evaluating plans for further clinical development.

Collaboration Agreement with Hansoh

In October 2021, we announced a collaboration agreement with Hansoh, one of the leading biopharmaceutical companies in China, to develop siRNAs for three undisclosed targets leveraging our proprietary mRNAi GOLDTM platform. Under the terms of the agreement, Hansoh had the exclusive option to license rights to the first two targets in Greater China, Hong Kong, Macau and Taiwan following the completion of phase 1 trials. We retained exclusive rights for those two targets in all other territories. We were responsible for all activities up to option exercise and retained responsibility for development outside the China region post phase 1 trials. Hansoh also had the exclusive option to license global rights to a third target at the point of IND filing. Hansoh was responsible for all development activities post option exercise for the third target. Hansoh made a $16 million upfront payment to us in December 2021. We achieved our first $2 million research milestone payment in the Hansoh collaboration in April 2022. In 2023, we achieved two additional preclinical milestones and received $4 million from the collaboration. In 2024, we achieved an additional preclinical milestone of $2.0 million from the Hansoh collaboration. In December 2024, Hansoh notified us that it will not pursue further development under the Hansoh collaboration. This represented the conclusion of all required development activities and commitments under the terms of the Hansoh Collaboration and we retain exclusive rights globally for all three targets.

Components of Results of Operations

Revenue

We do not have any approved products. Accordingly, we have not generated any revenue from product sales, and we do not expect to generate any revenue from the sale of any products unless and until we obtain regulatory approvals for, and commercialize any of, our product candidates. In the future, we will seek to generate revenue primarily from product sales and, potentially, regional or global strategic collaborations with third parties.

Under our collaboration agreement with AstraZeneca, we received an upfront cash payment of $20.0 million in May 2020 and an additional payment of $40.0 million in May 2021. We are also eligible to receive specified development and commercial milestone payments as well as tiered royalties on net sales, if any. During the year ended December 31, 2024, we achieved milestone payments totaling $10.0 million. During the year ended December 31, 2025, we did not achieve any milestone payments. We recognize the upfront payment and milestone payments over time. During the year ended December 31, 2025, we recognized a total of $0.6 million in revenue under the AstraZeneca agreement.

We entered into a collaboration agreement with Hansoh in October 2021. We received a $16.0 million upfront payment to us in December 2021. We are eligible to receive up to $1.3 billion in additional development, regulatory and commercial milestones. We will also receive royalties tiered from low double-digit to mid-teens on Hansoh net product sales. During the year ended December 31, 2024, we achieved milestone payments totaling $2.0 million related to the Hansoh collaboration. We did not achieve any milestone payments for the year ended December 31, 2025. We recognized the upfront payment and milestone payments over time.

In December 2024, Hansoh notified us that it will not pursue further development under the Hansoh collaboration. This represented the conclusion of all required development activities and commitments under the terms of the Hansoh collaboration. During the year ended December 31, 2025, we did not recognize any revenue related to the Hansoh collaboration.

Cost of sales

Cost of sales consists of research and development expenditure that is directly related to work carried out on revenue generating contracts. This includes salary costs that are apportioned based on time spent by employees working on these contracts as well as costs of materials and costs incurred under agreements with CROs.

Operating Expenses

We classify our operating expenses into two categories: research and development costs and general and administrative expenses. Personnel costs, including salaries, benefits, bonuses and share-based payment expenses, comprise a significant component of each of these expense categories. We allocate expenses associated with personnel costs based on the function performed by the respective employees.

Research and Development Costs

The largest component of our total operating expenses since inception has been costs related to our research and development activities, including the preclinical and clinical development of our product candidates. We expense research and development costs as they are incurred and classify them as contracted development, personnel and other.

Our contracted development costs primarily consist of:

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costs incurred under agreements with CROs and investigative sites that conduct our preclinical studies and clinical trials;

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costs related to manufacturing active pharmaceutical ingredients and drug products for our preclinical studies and clinical trials; and

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costs for materials used for in-house research and development activities.

Our personnel research and development expense primarily consists of:

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salaries and personnel-related costs, including bonuses, benefits, recruitment costs and any share-based payment expenses, for our personnel performing research and development activities or managing those activities that have been out-sourced; and

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consultants’ costs associated with target selection, preclinical and clinical research activities, and the progression of programs towards clinical trials.

Our other research and development costs primarily consists of

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costs of related facilities, equipment and other overhead expenses that are considered directly attributable to research and development; and

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depreciation of capital assets used for research and development activities.

The successful development of our product candidates is highly uncertain. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. Accordingly, we expect research and development costs to increase significantly for the foreseeable future as programs progress.

The duration, costs and timing of clinical trials and development of our product candidates will depend on a variety of factors, including:

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the scope, rate of progress, results and expenses of our ongoing and future clinical trials, preclinical studies and research and development activities;

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the potential need for additional clinical trials or preclinical studies requested by regulatory authorities;

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potential uncertainties in clinical trial enrollment rates or drop-out or discontinuation rates of patients;

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competition with other drug development companies in, and the related expense of, identifying and enrolling patients in our clinical trials and contracting with third-party manufacturers for the production of the drug product needed for our clinical trials;

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the achievement of milestones requiring payments under in-licensing agreements, if any;

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any significant changes in government regulation;

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the terms and timing of any regulatory approvals;

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the ability to market, commercialize and achieve market acceptance for any of our product candidates, if they are approved.

We have not historically tracked research and development expenses on a program-by-program basis for our preclinical product candidates.

General and Administrative Expenses

General and administrative expenses consist of personnel costs, allocated expenses and other expenses for outside professional services, including legal, audit, tax and accounting services, public relations and investor relations services. Personnel costs consist of salaries, bonuses, benefits, recruitment costs and share-based payment expenses for personnel in executive, finance, business development and other support functions. Other administrative expenses include office space-related costs not otherwise allocated to research and development costs, insurance expenses, and costs of our information systems and costs for compliance with the day-to-day requirements of being a listed public company in the United States. We anticipate that our administrative expenses will remain consistent to support our continued research and development and potential commercialization of our product candidates. We also expect to continue incurring additional expenses as a public company in the United States, including expenses related to compliance with the rules and regulations of the SEC and Nasdaq, additional insurance expenses, expenses related to investor relations activities and other administrative and professional services.

Restructuring Charges

We have incurred non-recurring restructuring charges associated with a limited reduction in workforce during the year ended December 31, 2025.

Foreign Currency Gain/(Loss), net

Foreign exchange gains and losses relate to cash held in foreign currencies (primarily U.S. Dollars and Euros).

Other Income, net

Other income (expense) primarily relates to interest earned on our cash, cash equivalents, as well as accretion earned on our U.S. treasury bills.

Taxation and Benefit from R&D Tax Credit

We are subject to corporate taxation in the United Kingdom, United States and Germany. Due to the nature of our business, we have generated losses since inception. Our income tax credit recognized represents the sum of the research and development, or R&D, tax credits recoverable in the United Kingdom. The U.K. R&D tax credit, as described below, is fully refundable to us. We have recorded the entire benefit from the U.K. R&D tax credit as a credit to “Benefit from R&D tax credit.”

As a company that carries out extensive research and development, or R&D, activities, we seek to benefit from the U.K. R&D tax credit regime. In respect of accounting periods in which we qualify as a Small and Medium-sized Enterprise, or SME, and in which our qualifying R&D expenditure represents 30% (for periods from April 1, 2024) or more of the total (meaning we are considered as “R&D-intensive” during such accounting period), we may, under this regime, surrender the trading losses that arise from our R&D activities for a cash rebate of up to 26.97% of qualifying R&D expenditure. Accordingly, if we cease to qualify as an R&D-intensive SME, in future, we will either cease to be able to claim cash rebates in respect of our R&D activities, or only be able to receive cash payments or other tax relief (under other provisions of the U.K. R&D tax credit regime) at a significantly lower rate than at present. Further, the regime’s rules are complex, and if a tax authority were to challenge or seek to disallow our claims (in whole or in part), for example by asserting that we do not (or the relevant expenditure does not) meet the technical conditions to be granted tax credits (or cash rebates), then such challenge or disallowance, if successful, could have a material impact on our cash-flow and financial performance. In addition, future changes to the U.K. R&D tax credit regime may mean that we no longer qualify for it or have a material impact on the extent to which we can make claims (or benefit from them).

Unsurrendered U.K. tax losses may be carried forward indefinitely to be offset against future taxable profits, subject to numerous utilization criteria and restrictions. The amount that can be offset each year is limited to £5.0 million plus an incremental 50% of U.K. taxable profits. After accounting for tax credits receivable, we had accumulated tax losses for carry forward in the United Kingdom of $231.6 million as of December 31, 2025 ($164.8 million as of December 31, 2024). However, in the event of a change in ownership of a U.K. company, certain provisions may apply to restrict the utilization of carried forward tax losses in future periods. These provisions apply where there is a major change in the nature or conduct of a trade in connection with the change in ownership. For the avoidance of doubt, we do not recognize a deferred tax asset in respect of the accumulated tax losses. In addition to our accumulated tax losses in the United Kingdom, we also had $52.1 million of accumulated tax losses as of December 31, 2025 ($47.0 million as of December 31, 2024) related to our operations in Germany for corporate income taxes. We also had $50.4 million of accumulated losses related to trade taxes in our German entity ($45.6 million as of December 31, 2024). Foreign tax expenses in Germany were negligible (2024: $0.6 million). Tax losses in the U.S. were negligible.

In the event we generate revenues in the future, we may benefit from the U.K. “patent box” regime that allows profits attributable to revenues from patents or patented products to be taxed at an effective rate of 10%.

Value Added Tax, or VAT, is charged on all qualifying goods and services by VAT-registered businesses. Where applicable, an amount of 20% of goods and services is added to all sales invoices and is payable to the U.K. tax authorities. Similarly, VAT paid on purchase invoices is reclaimable from the U.K. tax authorities.

Results of Operations

Comparison of the years ended December 31, 2025 and 2024

The following tables summarize the results of our operations for the years ended December 31, 2025 and 2024.

Year ended December 31,

Restructuring charges (1,324 ) (1,324 ) -

Loss per share (basic and diluted) $ (0.63 ) $ (0.33 )

Revenue

Revenue for the year ended December 31, 2025 was $0.6 million (2024: $43.3million). The significant decrease in revenue for 2025 was primarily due to the recognition of revenue associated with the Hansoh collaboration in 2024. In 2024, we recognized $24.6 million related to the Hansoh collaboration resulting from a cumulative catch up as we have now completed all required obligations under the Hansoh collaboration. Revenue from our AstraZeneca collaboration also decreased by $17.4 million due to decreased activity under the AstraZeneca collaboration. Further, we did not achieve any milestones under the AstraZeneca collaboration in 2025 as compared to achievement of a milestone payment of $10.0 million in 2024.

Cost of Sales

Cost of sales consists of research and development expenditure that is directly related to work carried out on revenue generating contracts, which decreased to $0.2million for the year ended December 31, 2025 (2024: $11.8 million). The change was due to activity associated with our collaboration agreements, which fluctuates based on the timing of activities and project progression.

Research and Development Expenses

The following table summarizes our research and development costs for the years ended December 31, 2025 and 2024.

Year ended December 31,

Research and development costs for the year ended December 31, 2025, were $67.8million as compared to $67.9million for the year ended December 31, 2024. This slight decrease was mainly due to a reduction in personnel costs of $2.4 million associated with decreased headcount. Contracted development costs in 2025 increased by $2.0million from 2024 as a result of additional clinical trials and an increase in contract manufacturing activities for our proprietary programs.

The following table summarizes our research and development costs by program for our clinical development candidates for the years ended December 31, 2025 and 2024.

Year ended December 31,

Contracted development costs

Other contracted development costs 4,408 3,596

The increase in contracted development costs was largely due to advancement of our proprietary programs, including specifically our Phase 2 clinical trial for divesiran and an increase in costs related to contract manufacturing activities related to our zerlasiran Phase 3 readiness.

General and Administrative Expenses

General and administrative expenses were $22.3 million for the year ended December 31, 2025, as compared to $26.9 million for the year ended December 31, 2024. The slight decrease general and administrative expenses for 2025 is mainly due to reduced personnel costs and reduced legal expenses. The reduced personnel costs are largely due a $1.9 million credit in share-based compensation expense related to forfeiture of certain awards for executive officer that is no longer with the company, which was partly offset by the accrued expense related to their cash severance payment.

Restructuring Charges

We have incurred non-recurring restructuring charges associated with a limited reduction in workforce, which was implemented in June 2025.

Foreign Currency Gain/(Loss), Net

Net foreign exchange gains and losses result primarily from foreign currency (U.S. dollar and EUR) denominated bank accounts. As the functional currency for our parent entity is U.K. pounds sterling and our cash and cash

equivalents and U.S. treasury bills are primarily held in U.S. dollars, the loss in the year ended December 31, 2025 is mainly related to the fluctuation in the U.S. dollar.

Other Income, Net

Other income (expense) relates to accretion from U.S. treasury bills and interest on cash accounts.

Benefit from R&D Credit

Benefit from R&D tax credit relates to U.K. research and development tax credits. The decrease in benefit in the current year was mainly related to changes in the U.K R&D tax credit regime which apply in respect of accounting periods commencing on or after April 1, 2024. These changes led to a reduction in costs that are eligible for the claim.

Taxation

Taxation expense relates to foreign taxation.

Functional Currency

On January 1, 2026, the functional currency of our U.K. entity has changed from U.K. pound sterling to U.S. dollar as the primary economic environment in which the entity operates had changed. This is a prospective change and will not impact historical reporting periods.

Liquidity and Capital Resources

Sources of Liquidity

Since our inception, we have incurred significant operating losses and negative cash flows. We anticipate that we will continue to incur losses for the foreseeable future. We expect that our research and development and administrative expenses will increase in connection with conducting clinical trials and seeking marketing approval for our product candidates, as well as costs associated with operating as a public company.

As of December 31, 2025, we had cash, cash equivalents and U.S. treasury bills of $85.1 million. We believe that our current cash, cash equivalents and U.S. treasury bills will be sufficient to fund our forecasted operating expenses and capital expenditure requirements into 2028, based on the Company’s evaluation as described in the consolidated financial statements, footnote 2.5 Going Concern. As a result, we will need additional capital to fund our operations, which we may obtain from additional equity financings, debt financings, research funding, collaborations, contract and grant revenue or other sources. However, there is no assurance that we will be successful in obtaining sufficient funding on acceptable terms, or at all.

To date, we have financed our operations primarily through the issuances of our equity securities and from upfront, milestone and research payments under collaboration agreements with third parties.

On October 15, 2021, we entered into an Open Market Sale Agreement, or the Sales Agreement, with Jefferies LLC, or Jefferies, pursuant to which we may offer and sell, from time to time, our ADSs through Jefferies. On October 15, 2021, we filed a registration statement, which became effective on October 22, 2021, for the issuance and sale of up to $100.0 million of ADSs. In 2024, we raised proceeds of $27.7 million before deducting $0.9 million in placement agent fees and other expenses, from sales of ADSs under the Sales Agreement. On October 22, 2024, we filed a new registration statement on Form F-3, which replaced the registration statement originally filed on October 15, 2021, for the issuance and sale, if any, of up to an additional $100.0 million of its shares represented by ADSs under the Sales Agreement. As of this filing, approximately $139.6 million of ADSs remained for potential issuance under the ADS facility.

On February 2, 2024, we entered into a Securities Purchase Agreement, or the Purchase Agreement, with the purchasers named therein, or the Investors. Pursuant to the Purchase Agreement, we agreed to sell an aggregate of

5,714,286 of our ADSs to the Investors, at a purchase price equal to $21.00 per ADS, or the Private Placement. The Purchase Agreement contained customary representations and warranties from us and the investors and customary closing conditions. The closing of the Private Placement occurred on February 7, 2024, and we received aggregate gross proceeds from the Private Placement of approximately $120.0 million before deducting $7.7 million in placement agent fees and other expenses.

Pursuant to the Purchase Agreement, we filed a registration statement on Form F-3 (File No. 333-279185), which was declared effective by the SEC on May 14, 2024, covering the resale of the Registrable Securities (as such term is defined in the Purchase Agreement). We have agreed to use our commercially reasonable efforts to keep such registration statement effective until the earlier of (i) the date on which all Registrable Securities covered by such Registration Statement, as amended from time to time, have been sold, and (ii) the date on which there cease to be any Registrable Securities.

We have no ongoing material financing commitments, such as lines of credit or guarantees, that are expected to affect our liquidity over the next five years, other than operating leases.

Refer to Note 2 of our consolidated financial statements appearing elsewhere in this Annual Report on for additional discussion of liquidity and capital resources.

Operating and Capital Expenditure Requirements

We have not achieved profitability on an annual basis since our inception, and we expect to incur net losses in the future. We expect that our operating expenses will increase as we continue to invest to grow our product candidate pipeline, hire additional employees and increase research and development expenses.

Additionally, as a public company, we incur significant additional audit, legal and other expenses. We believe that our existing capital resources will be sufficient to fund our operations, including currently anticipated research and development activities and planned capital spending, at least for the next twelve months from the issuance of the December 31, 2025 financial statements.

Our future funding requirements will depend on many factors, including but not limited to:

•

the scope, rate of progress and cost of our clinical trials, preclinical programs and other related activities;

•

the extent of success in our early preclinical and clinical-stage research programs, which will determine the amount of funding required to further the development of our product candidates;

•

the cost of manufacturing clinical supplies and establishing commercial supplies of our product candidates and any products that we may develop;

•

the costs involved in filing and prosecuting patent applications and enforcing and defending potential patent claims;

•

the outcome, timing and cost of regulatory approvals of our product candidates;

•

the cost and timing of establishing sales, marketing and distribution capabilities; and

•

the costs of hiring additional skilled employees to support our growth and the related costs of leasing additional office space.

Cash Flows

The following table summarizes the results of our cash flows for the years ended December 31, 2025 and 2024.

Year ended December 31,

Net cash outflow from operating activities (62,271 ) (67,640 )

Net cash outflow from investing activities (47,992 ) (21,966 )

Net cash inflow from financing activities 15 142,087

(Decrease)/increase in cash and cash equivalents $ (110,248 ) $ 52,481

Operating activities

Net cash outflow from operating activities was $62.3 million for the year ended December 31, 2025, reflecting a decrease from a net cash outflow of $67.6 million for the year ended December 31, 2024. This decrease in cash outflow is largely due to decreased spend in fiscal 2025 associated with partnered programs and our efforts to reduce general and administrative expenses.

Investing activities

Net cash used in investing activities was $48.0 million for the year ended December 31, 2025, as compared to an outflow of $22.0 million for the year ended December 31, 2024. This change was primarily due to the purchase of U.S. treasury bills with maturities over three months of $166.4 million in 2025 partially offset by redemptions of $118.5 million. For the year ended December 31, 2024, we had purchases of $139.2 million partially offset by redemptions of $117.4 million.

Financing activities

In 2024, we raised aggregate gross proceeds from the Private Placement of $120.0 million before deducting $7.7 million in placement agent fees and other expenses. The remainder of the inflow was due to proceeds from sales under our at-the-market facility. There were no related financing activities in 2025.

Contractual Obligations and Commitments

Research and Development and Manufacturing Agreements

We enter into agreements with certain vendors for the provision of goods and services, which includes manufacturing services with CDMOs and development and clinical trial services with CROs. These agreements may include certain provisions for purchase obligations and termination obligations that could require payments for the cancellation of committed purchase obligations or for early termination of the agreements. The amount of the cancellation or termination payments vary and are based on the timing of the cancellation or termination and the specific terms of the agreement. These obligations and commitments are not separately presented.

Collaboration Agreements

See “—Collaboration Agreements” included above for further details on our collaboration agreements. We have not included milestone or royalty payments or other contractual payment obligations under such collaboration agreements as the timing and amount of such obligations are unknown or uncertain and are contingent upon the initiation and successful completion of future activities.

Critical Accounting Policies and Critical Accounting Estimates

Our financial statements are prepared in accordance with U.S. GAAP. The preparation of the financial statements and related disclosures requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, costs and expenses, and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events and various other factors that management believes are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Management evaluates estimates and assumptions on a periodic basis. Our actual results may differ from these estimates.

While our significant accounting policies are described in more detail in the notes to our consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K, we believe the following accounting policies to be most critical to the judgments and estimates used in the preparation of our consolidated financial statements.

Revenue Recognition under Collaboration Agreements

During the years ended December 31, 2025 and 2024, a significant portion of our revenue recognized under collaboration agreements was derived from our collaborations with AstraZeneca and Hansoh.

We have out-licensed the rights to some of our intellectual property associated with our siRNA stabilization chemistry technology to AstraZeneca in the context of a Research Collaboration, Option and License Agreement dated March 24, 2020, under which we and AstraZeneca will collaborate to discover, develop and commercialize siRNA therapeutics for the treatment of cardiovascular, renal, metabolic and respiratory diseases. AstraZeneca made an upfront cash payment of $60.0 million, of which $20.0 million was paid in May 2020 and the remaining $40.0 million was paid in May 2021. The upfront payment has been allocated evenly between the ten targets on the basis of a benchmarking exercise that took into account the standalone selling price per target, of similar precedent transactions that had been publicly announced by comparable companies. Subsequent milestones are allocated to the target to which they are related. The upfront and milestone payments will be recognized as revenue as the services are provided. We anticipate initiating work on up to five targets in the early stages of the collaboration, with AstraZeneca having the option to extend the collaboration to a further five targets. Under the collaboration, utilizing our technology, we are responsible for designing siRNA molecules against gene targets selected by AstraZeneca, and for manufacturing of material to support GLP toxicology studies and phase 1 clinical trials. We and AstraZeneca will collaborate during the discovery phase, and AstraZeneca will lead clinical development and commercialization of molecules arising from the collaboration. For each target selected under the collaboration, we will be eligible to receive up to $140.0 million in milestone payments upon the achievement of milestones relating to initiation of specified clinical trials, the acceptance of specified regulatory filings and the first commercial sale in specified jurisdictions. AstraZeneca has the right to terminate the agreement in its entirety or on a target-by-target basis, for any reason upon specified prior written notice to us. We may terminate the agreement on a target-by-target basis in the event that AstraZeneca begins a legal or administrative proceeding challenging the patentability, validity, ownership or enforceability of our patents. Either party may terminate the agreement on a target-by-target basis upon a material breach by the other party that is not cured within a specified period after receiving written notice, or in its entirety upon giving written notice following the other party’s bankruptcy, insolvency or similar instance. The license of the intellectual property and the R&D services are not distinct, as AstraZeneca cannot benefit from the intellectual property absent the R&D services, as those R&D services are used to discover and develop a drug candidate and to enhance the value in the underlying intellectual property, which could not be performed by another party, indicating that the two are highly interrelated. On this basis, we have concluded that there is a single performance obligation covering both the R&D services and the license of the intellectual property in respect of each target (i.e., one for the initial target and one for each additional optioned complement-mediated disease target). We recognize revenue over the duration of the contract based on an input method based on percentage of cost incurred.

We granted an exclusive option to license two targets in Greater China, Hong Kong, Macau and Taiwan following the completion of Phase 1 trials to Hansoh on October 15, 2021. We will retain exclusive rights for those two targets in all other territories. Silence will be responsible for all activities up to option exercise and will retain responsibility for development outside the China region post phase 1 trials. Hansoh will also have the exclusive option to license global rights to a third target at the point of IND filing. Hansoh made a $16.0 million upfront payment to us in December 2021 which has been allocated between the three targets based on geography for each option, amount of

reimbursable costs for activities provided by us for each target, as well as a benchmarking exercise that took into account the standalone selling price per target based on similar precedent transactions that had been publicly announced by comparable companies. Subsequent milestones are allocated to the target to which they are related. The upfront payment and subsequent milestone payments, which are variable and depend upon probability of achievement of specified development, regulatory and commercial milestones, will be recognized as revenue as the services are provided. The license of the intellectual property and the R&D services are not distinct, as Hansoh cannot benefit from the intellectual property absent the R&D services, as those R&D services are used to discover and develop a drug candidate and to enhance the value in the underlying intellectual property, which could not be performed by another party, indicating that the two are highly interrelated. On this basis, we have concluded that there is a single performance obligation covering both the R&D services and the license of the intellectual property in respect of each target (i.e., one for the initial target and one for each additional optioned complement-mediated disease target). We recognized revenue over the duration of the contract based on an input method based on cost to cost.

For all the collaboration agreements listed above, as there is only a single performance obligation per target, the revenue for each element of consideration will be recognized over the contract period based on a cost-to-cost method, which is considered to be the best available measure of our effort during the contract period. The total cost estimate for the contract includes costs expected to be incurred during the contract period. Other variable elements of consideration will only begin to be recognized when it is considered highly probable that a significant reversal of the amounts will not occur.

For the years ended December 31, 2025 and 2024, we determined actual costs and forecast costs for the remainder of the contract. We calculated total contract costs across the contract term, including costs that will be reimbursed to us, and costs incurred to date as a percentage of total contract costs. We multiplied this percentage by the consideration deemed highly probable of not having a significant reversal, calculating the cumulative revenue to be recognized. When variable consideration increases due to a further milestone becoming highly probable that a significant reversal of revenue will not occur, a catch-up in revenue is recorded to reflect efforts already expended by us up to that point. In 2025 the estimated forecasted cost for partnered programs was not material and the related judgment was not significant.

Recognition of Clinical Trial Expenses

As part of the process of preparing our consolidated financial statements, we may be required to estimate stage of completion of our preclinical studies and clinical trials to calculate the contracted research and development costs. To obtain reasonable estimates, we review open contracts and purchase orders. In addition, we communicate with applicable personnel in order to identify services that have been performed, but for which we have not yet been invoiced. In most cases, our vendors provide us with monthly invoices in arrears for services performed. We confirm our estimates with these vendors and make adjustments as needed. Examples of our expenses include fees paid to CROs for services performed on preclinical studies and clinical trials and fees paid for professional services, which was approximately 13% of our total research and development expense for the year ended December 31, 2025.

Recently Issued and Adopted Accounting Pronouncements

We discuss the effect of recently issued and adopted pronouncements in Note 2.20 to the consolidated financial statements appearing elsewhere in this Annual Report.

Recent Accounting Pronouncements

See note 2.20 to our consolidated financial statements for the year ended December 31, 2025, appearing elsewhere in this Annual Report for a discussion of new standards and interpretations recently and not yet adopted by us.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

We are a smaller reporting company as defined in Item 10(f)(1) of Regulation S-K. As a result, pursuant to Item 305(e) of Regulation S-K, we are not required to provide the information required by this Item 7A.

Item 8. Financial Statements and Supplementary Data

Our consolidated financial statements, together with the report of the independent registered public accounting firm required to be filed pursuant to this Item 8 are appended at the end of this Annual Report. An index of those financial statements is found in Item 15 of Part IV of this Annual Report.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

None.

Item 9A. Controls and Procedures

Disclosure Controls and Procedures

We maintain “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate to allow timely decisions regarding required disclosure.

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, has evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a- 15(e) and 15d- 15(e) under the Exchange Act), as of the end of the period covered by this Annual Report. Based on such evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that as of December 31, 2025, our disclosure controls and procedures were effective.

Management’s Annual Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Exchange Act Rules 13a-15(f) and 15d-15(f) define this as a process designed by, or under the supervision of, our Chief Executive Officer and our Chief Financial Officer and effected by the Board of Directors, management and other personnel, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements in accordance with U.S. GAAP.

Due to its inherent limitations, internal control over financial reporting may not prevent or detect all misstatements. Furthermore, projections of any evaluation of the effectiveness of internal controls to future periods may prove invalid due to changes in our circumstances and the risk that compliance with policies, procedures and controls is not sustained.

Management has assessed the effectiveness of internal control over financial reporting as of December 31, 2025, based on the Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). Based on this assessment, management has concluded that our internal control over financial reporting as of December 31, 2025, was effective.

This Annual Report on Form 10-K does not include an attestation report of our independent registered public accounting firm regarding internal control over financial reporting. Pursuant to rules of the SEC, such attestation is not required for non-accelerated filers, which permit us to provide only management’s report in this Annual Report on Form 10-K.

Changes in Internal Control over Financial Reporting

There was no change in our internal control over financial reporting that occurred during the quarter ended December 31, 2025, that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

Item 9B. Other Information

During the three months ended December 31, 2025, no director or officer (as defined in Rule 16a-1(f) under the Exchange Act) of the Company adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Not applicable.

PART III

Item 10. Directors, Executive Officers and Corporate Governance

The information required by this item is incorporated by reference to our Proxy Statement for our 2026 Annual General Meeting of Shareholders to be filed with the SEC within 120 days after the end of the fiscal year ended December 31, 2025.

We have adopted a Code of Business Conduct and Ethics that is applicable to all our employees, executive officers, including our principal executive, principal financial and principal accounting officers, members of our board of directors, and consultants. If we make any amendment to the Code of Business Conduct and Ethics or grant any waivers, including any implicit waiver, to the principal executive officer, principal financial officer and principal accounting officer or controller or persons performing similar functions from a provision of the Code of Business Conduct and Ethics, we will disclose the nature of such amendment or waiver on our website to the extent required by the rules and regulations of the SEC. The Code of Business Conduct and Ethics is available on our website at https://silence-therapeutics.com/investors/governance/governance-documents. Information contained on, or that can be accessed through, our website does not constitute a part of this Annual Report and is not incorporated by reference herein.

We have adopted an Insider Trading Policy governing the purchase, sale and/or other dispositions of our securities by our directors, officers and employees. A copy of the Insider Trading Policy is filed as an exhibit to this Annual Report. In addition, it is our practice to comply with the applicable laws and regulations relating to insider trading.

Item 11. Executive Compensation

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13. Certain Relationships and Related Transactions, and Director Independence

Item 14. Principal Accountant Fees and Services

PART IV

Item 15. Exhibits and Financial Statement Schedules

(a) Documents filed as part of Form 10-K.

(1) Financial Statements

Report of Independent Registered Public Accounting Firm

Consolidated Balance Sheets

Consolidated Statements of Income (Loss)

Consolidated Statements of Comprehensive Income (Loss)

Consolidated Statements of Changes in Equity

Consolidated Statements of Cash Flows

Notes to the Consolidated Financial Statements

(2) Schedules

Schedules have been omitted as all required information has been disclosed in the financial statements and related footnotes.

(3) Exhibits

The following exhibits are filed as part of this Annual Report on Form 10-K or are incorporated herein by reference.

Incorporated by Reference to Filings Indicated

23.1 Consent of PricewaterhouseCoopers LLP X

101.SCH Inline XBRL Taxonomy Extension Schema with Embedded Linkbase Documents X

# Indicates management contract or compensatory plan.

† Portions of this exhibit (indicated by asterisks) have been omitted because the registrant has determined they are not material and would likely cause competitive harm to the registrant if publicly disclosed.

+ Certain schedules have been omitted pursuant to Item 601(a)(5) of Regulation S-K. The registrant hereby undertakes to furnish supplementally a copy of any omitted exhibit or schedule upon request by the SEC.

* These certifications are being furnished solely to accompany this annual report pursuant to 18 U.S.C. Section 1350 and are not being filed for purposes of Section 18 of the Securities Exchange Act of 1934 and are not to be incorporated by reference into any filing of the registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing.

Item 16. Form 10-K Summary

None.

SIGNATURES

Pursuant to the requirements of Section 13 or 15 (d) 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.

SILENCE THERAPEUTICS PLC

By: /s/ Iain Ross

Iain Ross

Interim Principal Executive Officer and Chairman of the Board of Directors

(Principal Executive Officer)

POWER OF ATTORNEY

Each of the undersigned officers and directors of Silence Therapeutics plc hereby constitutes and appoints Iain Ross and Rhonda Hellums, and each of them, their true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for them and in their name, place and stead, in any and all capacities, to sign any and all amendments to this Annual Report on Form 10-K, with all exhibits thereto, and other related documents, and to cause the same to be filed with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing necessary and proper to be done in connection therewith, as fully to all intents and purposes as the undersigned could do if personally present, and each of the undersigned for himself or herself hereby ratifies and confirms that all said attorneys-in-fact and agents, or any of them, or his or her substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

Signature Title Date

/s/ Dave LemusDave Lemus Director March 5, 2026

/s/ Tim McInerneyTim McInerney Director March 5, 2026

/s/ James Ede-GolightlyJames Ede-Golightly Director March 5, 2026

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Report of Independent Registered Public Accounting firm (PCAOB ID 876) F-2

Consolidated Balance Sheets F-3

Consolidated Statements of Income (Loss) F-4

Consolidated Statements of Comprehensive Income (Loss) F-5

Consolidated Statements of Changes in Shareholders' Equity F-6

Consolidated Statements of Cash Flows F-7

Notes to the Consolidated Financial Statements F-8

F-1

Report of Independent Registered Public Accounting Firm

To theBoard of Directors and Shareholders ofSilence Therapeutics plc

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Silence Therapeutics plc and its subsidiaries (the “Company”) as of December 31, 2025 and 2024, and the related consolidated statements of income (loss), of comprehensive income (loss), of changes in shareholders’ equity and of cash flows for the years then ended, including the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for the years then ended in conformity with accounting principles generally accepted in the United States of America

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits of these consolidated financial statements in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion..

Emphasis of Matter

As discussed in Note 2.5 to the consolidated financial statements, the Company has incurred recurring losses since inception and expects to incur operating losses for the foreseeable future as it continues its research and development efforts. Management’s evaluation of the events and conditions and management’s plans to mitigate these matters are also described in Note 2.5.

Critical Audit Matters

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the

F-2

critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Third party contracted research and development costs

As described in Notes 2.8, 4, 13 and 15 to the consolidated financial statements, third party contracted research and developments costs of $44.9 million were incurred during the year ended December 31, 2025 and associated prepayments and accruals and other payables were $6.8 million and $3.0 million as of December 31, 2025, respectively. Management recognizes expenditure incurred in carrying out its research and development activities in line with their best estimation of the costs incurred to date for each separately contracted study or activity. This requires estimation of the full costs to complete each study or activity and also estimation of the current stage of completion for open contracts and purchase orders. In all cases, the full cost of each study or activity is expensed by the time the final report or, where applicable, product, has been received.

The principal considerations for our determination that performing procedures relating to third party contracted research and development costs is a critical audit matter are (i) the significant judgment by management when developing the estimate of the third party contracted research and development costs for open contracts and purchase orders; (ii) a high degree of auditor judgment, subjectivity and effort in performing procedures and evaluating management’s significant assumption related to the stage of completion.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included, among others (i) reading significant research and development contracts; (ii) testing external research and development costs on a sample basis, which included tracing relevant information to the underlying contracts, purchase orders, invoices received, and information received from certain third party providers, where applicable; (iii) testing management’s process for estimating the third party contracted research and development costs for open contracts and purchase orders; (iv) testing the completeness and accuracy of underlying data used by management; and (v) evaluating the reasonableness of the significant assumption used by management related to the stage of completion on a sample of contracts. Evaluating management’s assumption related to the stage of completion involved (i) obtaining and examining a sample of third party contracts to evaluate the completeness and consistency of the costs and milestones in the contract with those used in developing the estimate; and (ii) considering whether the assumption is consistent with external confirmations, other information received from suppliers or other areas of the audit.

/s/PricewaterhouseCoopers LLP

Reading, United Kingdom

March 5, 2026

We have served as the Company’s auditor since 2014.

F-3

SILENCE THERAPEUTICS plc

Consolidated balance sheets

(in thousands, except share data)

Year ended December 31,

Current assets

Trade receivables 14 - 972

Property, plant and equipment, net 9 1,581 1,818

Operating lease right-of-use assets 16 167 157

Current liabilities

Contract liabilities 17 $ (168 ) $ (306 )

Operating lease liabilities, current 16 (89 ) (117 )

Operating lease liabilities, long-term 16 (71 ) -

Commitments and contingencies (Note 21)

Shareholders’ equity

Accumulated other comprehensive loss 2,976 11,781

Total liabilities and shareholders' equity $ (131,442 ) $ (202,635 )

The accompanying notes form an integral part of these consolidated financial statements.

F-4

SILENCE THERAPEUTICS plc

Consolidated Statements of income (loss)

(in thousands, except for loss per share and share data)

Year ended December 31,

General and administrative expenses (22,344 ) (26,884 )

Restructuring charges 6 (1,324 ) -

Foreign currency (loss)/gain, net (8,467 ) 646

Loss per share (basic and diluted) 8 $ (0.63 ) $ (0.33 )

The accompanying notes form an integral part of these consolidated financial statements.

F-5

SILENCE THERAPEUTICS plc

Consolidated statements of comprehensive income (loss)

(in thousands)

Year ended December 31,

Other comprehensive income (loss) net of tax:

Total other comprehensive income/(loss) for the year 8,804 (1,055 )

Total comprehensive loss for the year $ (79,808 ) $ (46,364 )

The accompanying notes form an integral part of these consolidated financial statements.

F-6

SILENCE THERAPEUTICS PLC

Consolidated statements of changes in SHAREHOLDERS' equity

(in thousands, except share data)

Ordinary Shares

Foreign currency translation adjustments (net of tax) - - - (1,055 ) - (1,055 )

Foreign currency translation adjustments (net of tax) - - - 8,804 - 8,804

Recognition of share-based payments 20 - - 8,074 - - 8,074

Proceeds from shares issued - 2 13 - - 15

The accompanying notes form an integral part of these consolidated financial statements.

F-7

SILENCE THERAPEUTICS plc

Consolidated statements of cash flows

(in thousands)

Year ended December 31,

Cash flow from operating activities

Change in operating assets and liabilities:

Decrease/(increase) in trade receivables 1,024 (904 )

Decrease/(increase) in other current assets 6,016 (1,330 )

Decrease/(increase) in R&D benefit receivable 4,041 (2,337 )

Decrease in other long-term assets 3,658 -

(Decrease)/increase in trade and other payables (4,078 ) 499

Decrease in contract liabilities (334 ) (28,786 )

Decrease in operating lease liabilities (168 ) (165 )

Net cash used in operating activities (62,271 ) (67,640 )

Cash flow from investing activities

Purchase of property, plant and equipment (55 ) (211 )

Net cash used in investing activities (47,992 ) (21,966 )

Cash flow from financing activities

Proceeds from issue of ordinary shares 15 142,087

Net cash provided by financing activities 15 142,087

(Decrease)/increase in cash and cash equivalents (110,248 ) 52,481

Cash and cash equivalents at start of period 121,330 68,789

Effect of exchange rate fluctuations on cash and cash equivalents held 195 60

Cash and cash equivalents at end of period $ 11,277 $ 121,330

Supplemental disclosures of cash flow information:

Income Tax Paid net of refunds (637 ) (433 )

The accompanying notes form an integral part of these consolidated financial statements.

F-8

SILENCE THERAPEUTICS plc

Notes to the consolidated financial statements

1. General information

1.1. Nature of the business

Silence Therapeutics plc and its subsidiaries (together the "Group") 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, W1W 8DH and the principal place of business is 12 Hammersmith Grove, London, W6 7AP.

2. Summary of significant accounting policies

2.1. Basis of preparation

The Group’s consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and the rules and regulations of the U.S. Securities and Exchange Commission (“SEC"). Any reference in these notes to the applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). The consolidated financial statements include the accounts of the Group and its wholly owned subsidiaries, after elimination of intercompany accounts and transactions.

2.2. Functional and reporting currency

The reporting currency of the consolidated financial statements is the U.S. Dollars (“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.

2.3. Principles of consolidation

The 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 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 consolidated financial statements, the reported amounts of revenues and expenses during the reporting period, and compensation. Significant estimates and assumptions reflected in the Group’s 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 $88.6 million for the year ended December 31, 2025. As of December 31, 2025, the Group had accumulated losses of $562.6 million and cash outflows from operating activities for the year ended 31, December 2025 of $62.3 million.

SILENCE THERAPEUTICS plc

NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS – (Continued)

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 ADSs under its Sales Agreement. On February 5, 2024, the Group announced a private placement of 5,714,286 of the Group’s American Depositary Shares (“ADSs”), each representing three ordinary shares, at a price of $21.00 per ADS, with new and existing institutional and accredited investors (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 achieved another $2.0 million in milestone payments from the Hansoh collaboration. As of December 31, 2025, the Group had cash and cash equivalents and short-term investments of $85.1 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 U.S. treasury bills as of December 31, 2025 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 operation 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. Segment reporting

The Group has determined that its chief executive officer is the chief operating decision maker (“CODM”). The CODM reviews financial information presented on a consolidated basis. Resource allocation decisions are made by the CODM based on consolidated results. There are no segment managers who are held accountable by the CODM for operations, operating results, and planning for levels or components below the consolidated unit level. As such, the Group has concluded that it operates as a single reportable segment (see Note 4).

2.7. Revenue recognition

The Group’s revenue for the year ended December 31, 2025, consists of revenue from collaboration agreements (royalty income and revenue from collaboration agreements for the year ended December 31, 2024). To determine revenue recognition for arrangements that the Group determines are within the scope of ASC 606: Revenue from Contracts with Customers, (“ASC 606”), it performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when, or as, the Group

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NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS – (Continued)

satisfies the performance obligations. The Group only applies the five-step model to contracts when it is probable that the entity will collect substantially all the consideration it is entitled to in exchange for the goods or services it transfers to the customer. As part of the accounting for these arrangements, the Group must make significant judgments, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each performance obligation.

Revenue from collaboration agreements

The Group has considered the AstraZeneca and Hansoh contracts and assessed whether the research and development services and license of the IP in respect of each target are distinct.

For all contracts the Group has concluded the license of the intellectual property and the R&D services are not distinct, as AstraZeneca and Hansoh cannot benefit from the intellectual property absent the R&D services, as those R&D services are used to discover and develop a drug candidate and to enhance the value in the underlying intellectual property, and these services could not be performed by another party, indicating that the two are highly interrelated. On this basis, the Group has concluded that there is a single performance obligation covering both the R&D services and the license of the intellectual property in respect of each target. The Group recognizes revenue over the duration of the contract based on an input method based on cost to cost.

The contracts have multiple elements of consideration (some or all of the following), namely:

•

Upfront payments (fixed);

•

Subsequent milestone payments (variable);

•

FTE costs rechargeable (variable);

•

Recharges of direct costs for certain research activities (variable).

The Group’s effort under the contracts continues throughout their entire duration. On this basis revenue is recognized over the contract period based on costs to completion.

Revenue has been calculated on the following ongoing basis for the year ended December 31, 2025:

•

Total contract costs which includes actual FTE and direct costs incurred up to December 31, 2025 and forecast FTE and direct costs for the remainder of the contract

•

Actual costs incurred up until December 31, 2025 are calculated as a percentage of total contract costs (actual and forecast)

•

This percentage is then multiplied by the transaction price allocated to the performance obligation in question, thus calculating the cumulative revenue which is then used to calculate the revenue to be recognized in that period. In the case of the upfront and milestones, the consideration that is multiplied is in relation to the upfront and completed milestones only. Consideration in relation to milestones not yet been achieved is excluded from the calculation.

Forecast costs are monitored each period, with revenue recognized reflecting any changes in forecast or over/under spend in actuals. In 2025 the estimated forecasted cost for partnered programs was not material and the related Judgment was not significant.

Further details of the revenue amounts recognized in the year ended December 31, 2025 can be found in note 3.

2.8. Research and development

Research and development costs consist of salary and personnel related costs and third party costs for the Group's research and development activities. Personnel related costs include a share based compensation charge relating to its stock option plan. The largest component of third party costs is for clinical trials, as well as manufacturing for clinical

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NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS – (Continued)

supplies and associated development, and pre-clinical studies. Research and development costs are expensed as incurred.

The Group recognizes expenditure incurred in carrying out its research and development activities in line with management’s best estimation of the costs incurred to date for each separately contracted study or activity. This includes the calculation of research and development accruals and prepayments at each period to account for expenditure that has been incurred. This requires estimations of the full costs to complete each study or activity and also estimation of the current stage of completion for open contracts and purchase orders. In all cases, the full cost of each study or activity is expensed by the time the final report or, where applicable, product, has been received.

2.9. Taxation

Current tax payable is based on taxable profit for the year. Taxable profit differs from profit as reported in the income statement because it excludes items of income or expense that are taxable or deductible in other years and it further excludes items that are never taxable or deductible. Current tax liabilities are calculated using tax rates that have been enacted or substantively enacted by the balance sheet date.

As a company that carries out extensive research and development activities, the Group currently benefits from the U.K. research and development tax credit regime for small or medium-sized enterprises (“SMEs”). A benefit receivable arises from the U.K. legislation regarding the treatment of certain qualifying research and development costs, allowing for the surrender of tax losses attributable to such costs in return for a tax rebate. Research and development tax credits are recognized when the receipt is probable. Amounts receivable under the scheme are presented within the consolidated statements of income (loss) within Benefit from R&D credit. The U.K. R&D tax credit is fully refundable to the Group and is not dependent on current or future taxable income. As a result, the Company has recorded the entire benefit from the U.K. R&D tax credit as a benefit which is included in net loss before income tax and, accordingly, not reflected it as part of the income tax provision.

Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial reporting basis and the respective tax basis of the Group’s assets and liabilities, and expected benefits of utilizing net operating loss, capital loss, and tax-credit carryforwards. The Group assesses the likelihood that its deferred tax assets will be realized and, to the extent management does not believe these assets are more likely than not to be realized, a valuation allowance is established. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates or laws is recognized in consolidated statements of income (loss) in the period that includes the enactment date.

2.10. Foreign currency translation

Monetary assets and liabilities denominated in currencies other than the functional currency are remeasured into the functional currency at exchange rates prevailing at the balance sheet dates. Non-monetary assets and liabilities denominated in foreign currencies area remeasured into the functional currency at the exchange rates prevailing at the date of the transaction. Exchange gains or losses arising from foreign currency transactions are included in the consolidated statements of income (loss) and comprehensive income (loss) for each respective period.

For financial reporting purposes, the consolidated financial statements of the Group have been presented in USD, the reporting currency. The financial statements of the Group’s entities are translated from their functional currency into USD as follows: assets and liabilities are translated at the exchange rates at the balance sheet dates, revenues and expenses are translated at the average exchange rates for the periods presented, and shareholders’ equity is translated at the prevailing historical exchange rates. Translation adjustments are not included in determining net loss but are included as a foreign exchange adjustment to other comprehensive income, a component of shareholders’ equity.

2.11. Cash and cash equivalents

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NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS – (Continued)

The Group considers cash and cash equivalents to comprise of cash on hand and demand deposits with original maturities of three months or less that are readily convertible to a known amount of cash and are subject to an insignificant risk of change in value.

2.12. Property, plant and equipment

The Group only holds equipment and furniture. These are stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful life of the asset. The estimated useful life of furniture and equipment is 3 to 10 years. Estimated useful life and residual values are reviewed each year and amended if necessary.

Property, plant and equipment is assessed for impairment upon triggering events that indicate the carrying value of an asset group may not be recoverable. Recoverability is measured by a comparison of the carrying amount to future net undiscounted cash flows of the asset group expected to be generated from its use and eventual disposition. If the asset group’s carrying value is determined to not be recoverable, the impairment to be recognized is measured by which the carrying amount exceeds the fair value of the asset group. No impairment charges related to property and equipment were recorded in any of the periods presented.

2.13. Leases

The Group determines if an arrangement contains a lease at inception. The Group currently only has operating leases. The Group recognizes a right-of-use ("ROU") operating lease asset and associated short- and long-term operating lease liability in its consolidated balance sheets for operating leases greater than one year. Its right-of-use assets represent its right to use an underlying asset for the lease term and its lease liabilities represent its obligation to make lease payments arising from the lease arrangement. The Group recognizes its right-of-use operating lease assets and lease liabilities based on the present value of the future minimum lease payments it will pay over the lease term. The Group determines the lease term at the inception of each lease, and in certain cases its lease term could include renewal options if the Group concludes it is reasonably certain to exercise the renewal option. When the Group exercises a lease option that was not previously included in the initial lease term, it reassesses its right-of-use asset and lease liabilities for the new lease term.

As its operating lease do not provide an interest rate implicit in the lease, the Group uses its incremental borrowing rate, based on the information available as of the lease inception date or at the lease option extension date in determining the present value of future payments. The Group recognizes lease expense for its minimum lease payments on a straight-line basis over the expected term of its lease. Its leases do not include material variable or contingent lease payments.

Leases with an initial term of 12 months or less are not recorded on the balance sheet. Instead, these lease payments are recognized on the consolidated statements of income (loss) on a straight-line basis over the lease term.

Similar to property, plant and equipment, ROU lease asset impairment is assessed upon triggering events that indicate the carrying amount may not be recovered by comparison to the future net undiscounted cash flows.

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NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS – (Continued)

2.14. Goodwill

Goodwill is the excess of the purchase price over the estimated fair values of the underlying net assets of an acquired business. The Group assesses goodwill for impairment annually, or immediately if conditions indicate that such impairment could exist. Impairment testing for goodwill is performed at the reporting unit level. The Group first evaluates qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the qualitative assessment indicates potential impairment, or if the Group elects to bypass the qualitative assessment, a quantitative test is performed. The quantitative test calculates the excess of the reporting unit’s fair value over its carrying amount, including goodwill, utilizing a discounted cash flow method. The test for impairment of goodwill requires the Group to make several assumptions and estimates regarding market conditions and its future profitability to determine the fair value of the goodwill at the reporting unit. Significant assumptions used in the reporting unit fair value measurements include forecasted cash flows, including revenue and expense growth rates, discount rates, and revenue and earnings multiples. An impairment loss is recognized when the carrying amount of the reporting unit net assets exceeds the estimated fair value of the reporting unit. Impairment losses recognized for the reporting unit to which goodwill has been allocated are credited initially to the carrying amount of goodwill. Any remaining impairment loss is charged pro rata to the other assets in the reporting unit.

All goodwill for the Group is attributed to an acquisition that occurred in 2005 and the Group has determined that no impairment was recorded as of December 31, 2025 and 2024.

2.15. Other intangible assets

Other intangible assets that are acquired by the Group are stated at cost less accumulated amortization and less accumulated impairment losses. Amortization is charged to the consolidated statements of income (loss) on a straight-line basis over the estimated useful lives of intangible assets unless such lives are indefinite. Intangible assets with an indefinite useful life and goodwill are systematically tested for impairment at each balance sheet date. Other intangible assets are amortized from the date they are available for use. The estimated useful lives are as follows:

Licenses and software: 3 - 10 years.

Costs associated with research activities are treated as an expense in the period in which they are incurred.

Costs that are directly attributable to the development phase of software will only be recognized as intangible assets provided they meet the following requirements:

•

an asset is created that can be separately identified;

•

the technical feasibility exists to complete the intangible asset so that it will be available for sale or use and the Group has the intention and ability to do so;

•

it is probable that the asset created will generate future economic benefits either through internal use or sale;

•

sufficient technical, financial and other resources are available for completion of the asset; and

•

the expenditure attributable to the intangible asset during its development can be reliably measured.

Careful judgment by management is applied when deciding whether recognition requirements for software development costs have been met. This is necessary as the economic success of any product development is uncertain and may be subject to future technical problems at the time of recognition. Judgments are based on the information available at each balance sheet date.

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NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS – (Continued)

2.16. Fair value measurements

The Group’s financial instruments include cash and cash equivalents, trade receivables, U.S. treasury bills, trade and other payables and accrued expenses. These are initially recorded at fair value and subsequently measured at cost, which is considered to approximate their fair value due to the short-term nature of such financial instruments.

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The guidance prioritizes the inputs used in measuring fair value into the following hierarchy:

•

Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities;

•

Level 2: Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability; or

•

Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).

To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.

2.17. Share-based compensation expense

Historically the Group has issued equity settled share-based compensation to certain employees (see note 20). Equity settled share-based payments are measured at fair value (excluding the effect of non-market-based vesting conditions) at the date of grant. The fair value so determined is expensed on a straight-line basis over the vesting period, based on the number of stock that will eventually vest and adjusted for the effect of non-market-based vesting conditions.

The value of the charge is adjusted to reflect expected and actual levels of award vesting, except where failure to vest is as a result of not meeting a market condition.

Cancellations of equity instruments are treated as an acceleration of the vesting period and therefore any amount unrecognized that would otherwise have been recorded in future accounting periods is recognized immediately. The Group has elected to recognize the effect of forfeitures on share-based compensation when they occur. Any differences in compensation recognized at the time of forfeiture are recorded as a cumulative adjustment in the period in which the forfeiture occurs.

Fair value is measured using a Black Scholes model. The key assumptions used in the model have been adjusted, based on management’s best estimate, for the effects of non-transferability, exercise restrictions and behavioral considerations.

Any payment made to a counterparty on the cancellation or settlement of a grant of equity instruments (even if this occurs after the vesting date) should be accounted for as a repurchase of an equity interest (that is, as a deduction from equity). But, if the payment exceeds the fair value of the equity instruments repurchased (measured at the repurchase date), any such excess should be recognized as an expense.

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NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS – (Continued)

2.18. Equity

Ordinary shares is determined using the nominal value of shares issued.

The additional paid-in capital account includes any premiums received on the initial issuing of the ordinary shares. Any transaction costs associated with the issuing of shares are deducted from the additional paid-in capital account, net of any related income tax benefits.

Equity settled share-based payments are credited to a share-based payment reserve as a component of additional paid-in capital, until related options or warrants are exercised.

Foreign currency translation differences are included in the accumulated other comprehensive income.

Accumulated deficit includes all current and prior period results as disclosed in the consolidated statements of income (loss).

2.19. Loss per share

Basic income/(loss) per share is computed by dividing the net income/(loss) attributable to ordinary shareholders by the weighted-average number of ordinary shares outstanding for the reporting period without consideration for potentially dilutive securities. Net income/(loss) attributable to ordinary shareholders is computed as if all net income/(loss) for the period had been distributed.

The Group computes diluted income/(loss) per ordinary share after giving consideration to all potentially dilutive ordinary equivalents, except where the effect of such non-participating securities would be antidilutive. The Group been loss making for each fiscal year and therefore all potentially dilutive ordinary equivalents are considered to be antidilutive.

2.20. Recently Issued Accounting Pronouncements

Recently adopted accounting standards

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which provides for improvements to income tax disclosures primarily related to the rate reconciliation and income taxes paid information. The company adopted this guidance for the year ended December 31, 2025 and applied the guidance prospectively. See Note 18 below for further detail.

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). 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 reporting periods beginning after December 15, 2027, with early adoption permitted. The Group is currently evaluating the impact to its consolidated financial statements.

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

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NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS – (Continued)

Revenue from collaboration agreements for the years ended December 31, 2025 and 2024 predominately relates to the research collaboration agreements the Group entered into with AstraZeneca in March 2020 and Hansoh in October 2021.

Disaggregation of revenue from contracts with customers is as follows:

Year ended December 31,

Revenue from Contracts with Customers

Research collaboration - AstraZeneca 559 17,957

Research collaboration - Hansoh - 24,573

Research collaboration - other - 584

Research collaboration - total 559 43,114

Total revenue from contracts with customers 559 43,258

Under its collaboration agreement with AstraZeneca, the Group received an upfront cash payment of $20.0 million in 2020 with a further amount of $40.0 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 year ended December 31, 2025, the Group did not achieve any milestone payments (2024: $10.0 million). During the year ended December 31, 2025, the Group recognized a total of $0.6 million in revenue under this agreement (2024: $18.0 million).

The Group entered into a collaboration agreement with Hansoh on October 15, 2021. The Group received a $16.0 million ($14.4 million, net of taxes) upfront payment to us in December 2021. The Group is eligible to receive development, regulatory and commercial milestones as well as royalties on Hansoh net product sales. During the year ended December 31, 2025, the Group did not achieve any milestone payments (2024: $2.0 million). The Group recognizes the upfront payment and milestone payments over time, in accordance with ASC 606.

In December 2024, Hansoh notified the Group that it will not pursue further development under the Hansoh Collaboration. This represented the conclusion of all required development activities and commitments under the terms of the Hansoh Collaboration. During the year ended December 31, 2025, the Group did not recognize revenue under this agreement (2024: $24.6 million).

4. Segment reporting

The CODM reviews Consolidated net loss for the year 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 by major customer 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 as one 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 types of products from which the Group derives its 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:

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NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS – (Continued)

Year Ended December 31,

Less:

Contracted research and development costs (a) (44,873 ) (42,902 )

Personnel research and development costs (b) (18,086 ) (20,503 )

General & administrative expenses (22,344 ) (26,884 )

Restructuring (1,324 ) -

(a)

Contracted research and development costs primarily consist of costs incurred under agreements with CROs 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)

SLN US Equity

SLN · 10-K · period ended 2025-12-31

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

Item 8. Financial Statements and Supplementary Data

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Item 9A. Controls and Procedures

Item 9B. Other Information

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Item 10. Directors, Executive Officers and Corporate Governance

Item 11. Executive Compensation

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13. Certain Relationships and Related Transactions, and Director Independence

Item 14. Principal Accountant Fees and Services

Item 15. Exhibits and Financial Statement Schedules

Item 16. Form 10-K Summary

SLN US Equity☆

SLN · 10-K · period ended 2025-12-31

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

Item 8. Financial Statements and Supplementary Data

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Item 9A. Controls and Procedures

Item 9B. Other Information

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Item 10. Directors, Executive Officers and Corporate Governance

Item 11. Executive Compensation

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13. Certain Relationships and Related Transactions, and Director Independence

Item 14. Principal Accountant Fees and Services

Item 15. Exhibits and Financial Statement Schedules

Item 16. Form 10-K Summary

SLN US Equity