SILENCE THERAPEUTICS PLC, 10-K filed on 3/5/2026
Annual Report
v3.25.4
Document and Entity Information - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Jan. 31, 2026
Jun. 30, 2025
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Document Financial Statement Error Correction [Flag] false    
ICFR Auditor Attestation Flag false    
Amendment Flag false    
Document Period End Date Dec. 31, 2025    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Entity Registrant Name Silence Therapeutics plc    
Entity Central Index Key 0001479615    
Entity File Number 001-39487    
Entity Tax Identification Number 00-0000000    
Entity Incorporation, State or Country Code X0    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Shell Company false    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Public Float     $ 206.2
Entity Address, Address Line One 12 Hammersmith Grove    
Entity Address, City or Town London    
Entity Address, Country GB    
Entity Address, Postal Zip Code W6 7AP    
City Area Code +44 20    
Local Phone Number 3457 6900    
Documents Incorporated by Reference [Text Block]

DOCUMENTS INCORPORATED BY REFERENCE

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

    
Auditor Firm ID 876    
Auditor Location Reading, United Kingdom    
Auditor Name PricewaterhouseCoopers LLP    
Auditor Opinion [Text Block]

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

    
Entity Common Stock, Shares Outstanding   141,701,848  
American Depositary Shares      
Document Information [Line Items]      
Title of 12(b) Security American Depositary Shares, each representing three ordinary shares, nominal value £0.05 per share    
Trading Symbol SLN    
Security Exchange Name NASDAQ    
Ordinary Shares      
Document Information [Line Items]      
Title of 12(b) Security Ordinary share, nominal value £0.05 per share    
No Trading Symbol Flag true    
Security Exchange Name [1] NASDAQ    
[1] Not for trading, but only in connection with the listing of the American Depositary Shares on The Nasdaq Stock Market LLC.
v3.25.4
Consolidated Balance Sheets - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Current assets    
Cash and cash equivalents $ 11,277 $ 121,330
Short-term investments 73,837 26,004
R&D benefit receivable 22,007 24,396
Other current assets 11,537 14,664
Trade receivables 0 972
Total current assets 118,658 187,366
Property, plant and equipment, net 1,581 1,818
Operating lease right-of-use asset 167 157
Goodwill 10,621 9,392
Intangible assets 288 312
Other long-term assets 127 3,590
Total assets 131,442 202,635
Current liabilities    
Contract liabilities (168) (306)
Trade and other payables (13,356) (16,399)
Operating lease liabilities, current (89) (117)
Total current liabilities (13,613) (16,822)
Contract liabilities (55,454) (51,790)
Operating lease liabilities, long-term (71) 0
Total liabilities (69,138) (68,612)
Commitments and contingencies (Note 21)
Shareholders' equity    
Ordinary shares - par value &#0.05 per share; 141,701,848 shares issued at December 31, 2025 (2024: 141,674,074) (10,290) (10,288)
Additional paid-in capital (617,562) (609,560)
Accumulated deficit 562,572 474,044
Accumulated other comprehensive loss 2,976 11,781
Total shareholders' equity (62,304) (134,023)
Total liabilities and shareholders' equity $ (131,442) $ (202,635)
v3.25.4
Consolidated Balance sheets (Parenthetical) - £ / shares
Dec. 31, 2025
Dec. 31, 2024
Statement of Financial Position [Abstract]    
Ordinary shares - par value £ 0.05 £ 0.05
Shares issued 141,701,848 141,674,074
v3.25.4
Consolidated Statements of Income (Loss) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Income Statement [Abstract]    
Revenue $ 559 $ 43,258
Cost of sales (215) (11,810)
Gross profit 344 31,448
Research and development costs (67,753) (67,883)
General and administrative expenses (22,344) (26,884)
Restructuring charges (1,324) 0
Operating loss (91,077) (63,319)
Foreign currency (loss)/gain, net (8,467) 646
Other income, net 3,480 4,472
Benefit from R&D credit 7,463 13,737
Loss before income tax expense (88,601) (44,464)
Income tax expense (11) (845)
Net Loss $ (88,612) $ (45,309)
Loss per share basic $ (0.63) $ (0.33)
Loss per share diluted $ (0.63) $ (0.33)
Weighted-average shares outstanding basic 141,694,702 138,752,224
Weighted-average shares outstanding diluted 141,694,702 138,752,224
v3.25.4
Consolidated Statements of Comprehensive Income (Loss) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Statement of Comprehensive Income [Abstract]    
Net loss $ (88,612) $ (45,309)
Other comprehensive income (loss) net of tax:    
Foreign exchange differences arising on consolidation of foreign operations (net of tax) 8,804 (1,055)
Total other comprehensive income/(loss) for the year 8,804 (1,055)
Total comprehensive loss for the year $ (79,808) $ (46,364)
v3.25.4
Consolidated statements of Changes in Shareholders' equity - USD ($)
$ in Thousands
Total
Ordinary Shares
Additional Paid-in Capital
Accumulated Other Comprehensive Income
Accumulated Deficit
Beginning balance at Dec. 31, 2023 $ 21,993 $ 8,847 $ 455,765 $ (10,725) $ (431,894)
Beginning balance, Shares at Dec. 31, 2023   118,846,966      
Net loss (45,309)       (45,309)
Foreign currency translation adjustments (net of tax) (1,055)     (1,055)  
Recognition of share-based payments 16,307   16,307    
Options exercised in the year     (3,158)   3,158
Options exercised in the year, Shares   1,408,443      
Proceeds from shares issued 142,087 $ 1,441 140,646    
Proceeds from shares issued, Shares   21,418,665      
Ending balance at Dec. 31, 2024 134,023 $ 10,288 609,560 (11,780) (474,045)
Ending balance, Shares at Dec. 31, 2024   141,674,074      
Net loss (88,612)       (88,612)
Foreign currency translation adjustments (net of tax) 8,804     8,804  
Recognition of share-based payments $ 8,074   8,074    
Options exercised in the year     (85)   85
Options exercised in the year, Shares 27,774 27,774      
Proceeds from shares issued $ 15 $ 2 13    
Ending balance at Dec. 31, 2025 $ 62,304 $ 10,290 $ 617,562 $ (2,976) $ (562,572)
Ending balance, Shares at Dec. 31, 2025   141,701,848      
v3.25.4
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Cash flow from operating activities    
Net loss after tax $ (88,612) $ (45,309)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:    
Depreciation expense 312 336
Amortization expense 243 257
Share-based compensation expense 8,074 16,307
Net foreign exchange impacts 11,022 (2,581)
Other income, net (3,480) (4,472)
Income tax expense 11 845
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    
Redemption of term deposits 118,476 117,412
Purchase of term deposits (166,413) (139,167)
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, end of period 11,277 121,330
Supplemental disclosures of cash flow information:    
Income Tax Paid net of refunds $ (637) $ (433)
v3.25.4
Pay vs Performance Disclosure - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Pay vs Performance Disclosure    
Net Income (Loss) $ (88,612) $ (45,309)
v3.25.4
Insider Trading Arrangements
 3 Months Ended
Dec. 31, 2025
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.25.4
Insider Trading Policies and Procedures
 12 Months Ended
Dec. 31, 2025
Insider Trading Policies and Procedures [Line Items]  
Insider Trading Policies and Procedures Adopted true
v3.25.4
Cybersecurity Risk Management, Strategy and Governance
 12 Months Ended
Dec. 31, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]  
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]

Item 1C. Cybersecurity

Risk management and strategy

We have implemented and maintain various information security processes designed to identify, assess, and manage material risks from cybersecurity threats to our critical computer networks, third party hosted services, communications systems, hardware and software, and our critical data, including intellectual property, confidential information that is proprietary, strategic or competitive in nature, and our clinical trial and related data, or Information Systems and Data.

Our information security function, which is led by our Vice President and Head of Information Technology, known as our Head of IT, and supported by our security management, risk management, and legal teams, helps identify, assess, and manage our cybersecurity threats and risks, including through the use of our risk register. The information security function identifies and assesses cybersecurity threats and risks by monitoring and evaluating our threat environment and risk profile using various methods including, for example: automated tools, subscribing to reports and services that identify cybersecurity threats, analyzing reports of threats, evaluating threats reported to us, coordinating with law enforcement concerning threats, internal and external audits, leveraging internal and third party threat assessments, conducting vulnerability identification assessments, and leveraging external threat intelligence.

Depending on the environment or system, we implement and maintain various technical, physical, and organizational measures, processes, standards and policies designed to manage and mitigate material risks from cybersecurity threats to our Information Systems and Data, including, for example: incident detection and response, vulnerability management, disaster recovery and business continuity plans, risk assessments, achievement of certain security certifications, encryption of certain data, network security controls, data segregation for certain data, access controls, physical controls, systems monitoring, employee training, penetration testing, and asset management and disposal.

Our assessment and management of identified material risks from cybersecurity threats are integrated into our overall risk management processes. For example, certain information about our assessment and management of material risks from cybersecurity threats is included in risk management reports as applicable to senior leadership and the audit committee.

We use third-party service providers to assist us from time to time to identify, assess, and manage material risks from cybersecurity threats, including for example: threat intelligence providers, cybersecurity consultants and software providers, managed cybersecurity service providers, and penetration testing service providers.

We use third-party service providers to perform a variety of functions throughout our business, such as software-as-a-service providers, hosting companies, contract research organizations, and contract manufacturing organizations. Depending on the nature of the services provided, the sensitivity of the critical systems, information and assets at issue, and the identity of the provider, we may conduct a review of security assessments provided by the vendor, review the vendor’s written security program and/or requested security assessment and security questionnaire responses, and impose contractual obligations on vendors regarding their cybersecurity practices.

For a description of the risks from cybersecurity threats that may materially affect us, please, see our risk factors under Part 1. Item 1A. Risk Factors in this Annual Report, including “Cybersecurity risks and the failure to maintain the confidentiality, integrity, and availability of our computer hardware, software, data and internet applications and related tools and functions, or those of third parties with whom we work, could result in damage to our reputation and/or subject us to costs, fines or lawsuits.”

Governance

Our board of directors addresses the review of our IT and cybersecurity risk management as part of its general oversight function. The board of directors’ audit and risk committee is responsible for overseeing our cybersecurity risk management processes.

Our cybersecurity risk assessment and management processes are implemented and maintained by our Head of IT, who has achieved ACC Internetworking Engineer and Global Secure Systems Internetworking Engineer qualifications and has over 25 years of experience leading international IT departments and owning responsibility for organizations’ cybersecurity efforts.

Our Head of IT is responsible for hiring appropriate personnel, helping to integrate cybersecurity risk considerations into the Company’s overall risk management strategy, and communicating key priorities to relevant personnel. Our Head of IT is also responsible for approving budgets, helping prepare for cybersecurity incidents, approving cybersecurity processes, and reviewing security assessments and other security-related reports.

Our cybersecurity incident response processes are designed to escalate certain cybersecurity incidents to members of management depending on the circumstances, including the Executive Leadership Team, or ELT. The ELT works with our incident response team to help us mitigate and remediate cybersecurity incidents of which they are notified. In addition, our incident response process includes notifying the audit and risk committee of the board of directors, as appropriate.

The board of directors’ audit and risk committee receives annual reports from our Head of IT, concerning our significant cybersecurity threats and risk and the processes we have implemented to address them. The audit and risk committee also has access to various reports, summaries or presentations related to cybersecurity threats, risk, and mitigation.
Cybersecurity Risk Management Processes Integrated [Flag] true
Cybersecurity Risk Management Processes Integrated [Text Block]

We have implemented and maintain various information security processes designed to identify, assess, and manage material risks from cybersecurity threats to our critical computer networks, third party hosted services, communications systems, hardware and software, and our critical data, including intellectual property, confidential information that is proprietary, strategic or competitive in nature, and our clinical trial and related data, or Information Systems and Data.
Cybersecurity Risk Management Third Party Engaged [Flag] true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag] true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag] true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Text Block]

For a description of the risks from cybersecurity threats that may materially affect us, please, see our risk factors under Part 1. Item 1A. Risk Factors in this Annual Report, including “Cybersecurity risks and the failure to maintain the confidentiality, integrity, and availability of our computer hardware, software, data and internet applications and related tools and functions, or those of third parties with whom we work, could result in damage to our reputation and/or subject us to costs, fines or lawsuits.”
Cybersecurity Risk Board of Directors Oversight [Text Block]

Governance

Our board of directors addresses the review of our IT and cybersecurity risk management as part of its general oversight function. The board of directors’ audit and risk committee is responsible for overseeing our cybersecurity risk management processes.

Our cybersecurity risk assessment and management processes are implemented and maintained by our Head of IT, who has achieved ACC Internetworking Engineer and Global Secure Systems Internetworking Engineer qualifications and has over 25 years of experience leading international IT departments and owning responsibility for organizations’ cybersecurity efforts.

Our Head of IT is responsible for hiring appropriate personnel, helping to integrate cybersecurity risk considerations into the Company’s overall risk management strategy, and communicating key priorities to relevant personnel. Our Head of IT is also responsible for approving budgets, helping prepare for cybersecurity incidents, approving cybersecurity processes, and reviewing security assessments and other security-related reports.

Our cybersecurity incident response processes are designed to escalate certain cybersecurity incidents to members of management depending on the circumstances, including the Executive Leadership Team, or ELT. The ELT works with our incident response team to help us mitigate and remediate cybersecurity incidents of which they are notified. In addition, our incident response process includes notifying the audit and risk committee of the board of directors, as appropriate.

The board of directors’ audit and risk committee receives annual reports from our Head of IT, concerning our significant cybersecurity threats and risk and the processes we have implemented to address them. The audit and risk committee also has access to various reports, summaries or presentations related to cybersecurity threats, risk, and mitigation.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block] Our board of directors addresses the review of our IT and cybersecurity risk management as part of its general oversight function.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block] The board of directors’ audit and risk committee is responsible for overseeing our cybersecurity risk management processes.
Cybersecurity Risk Role of Management [Text Block]

Depending on the environment or system, we implement and maintain various technical, physical, and organizational measures, processes, standards and policies designed to manage and mitigate material risks from cybersecurity threats to our Information Systems and Data, including, for example: incident detection and response, vulnerability management, disaster recovery and business continuity plans, risk assessments, achievement of certain security certifications, encryption of certain data, network security controls, data segregation for certain data, access controls, physical controls, systems monitoring, employee training, penetration testing, and asset management and disposal.
Cybersecurity Risk Management Positions or Committees Responsible [Flag] true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]

Our Head of IT is responsible for hiring appropriate personnel, helping to integrate cybersecurity risk considerations into the Company’s overall risk management strategy, and communicating key priorities to relevant personnel. Our Head of IT is also responsible for approving budgets, helping prepare for cybersecurity incidents, approving cybersecurity processes, and reviewing security assessments and other security-related reports.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]

Our cybersecurity risk assessment and management processes are implemented and maintained by our Head of IT, who has achieved ACC Internetworking Engineer and Global Secure Systems Internetworking Engineer qualifications and has over 25 years of experience leading international IT departments and owning responsibility for organizations’ cybersecurity efforts.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]

The board of directors’ audit and risk committee receives annual reports from our Head of IT, concerning our significant cybersecurity threats and risk and the processes we have implemented to address them. The audit and risk committee also has access to various reports, summaries or presentations related to cybersecurity threats, risk, and mitigation.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag] true
v3.25.4
General Information
 12 Months Ended
Dec. 31, 2025
General Information [Abstract]  
General Information

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.
v3.25.4
Summary of Significant Accounting Policies
 12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies

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.

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

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

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

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.

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.

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.

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.
v3.25.4
Revenue
 12 Months Ended
Dec. 31, 2025
Revenues [Abstract]  
Revenue

3. Revenue

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,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

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

 

Royalties

 

 

-

 

 

 

144

 

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).
v3.25.4
Segment Reporting
 12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Segment Reporting

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:

 

 

Year Ended December 31,

 

 

 

2025

 

 

 

2024

 

 

$000s

 

 

$000s

 

Revenue

 

 

559

 

 

 

43,258

 

Less:

 

 

 

 

 

 

Cost of sales

 

 

(215

)

 

 

(11,810

)

Contracted research and development costs (a)

 

 

(44,873

)

 

 

(42,902

)

Personnel research and development costs (b)

 

 

(18,086

)

 

 

(20,503

)

Other R&D costs (c)

 

 

(4,794

)

 

 

(4,478

)

General & administrative expenses

 

 

(22,344

)

 

 

(26,884

)

Restructuring

 

 

(1,324

)

 

 

-

 

Tax expense

 

 

(11

)

 

 

(845

)

Other segment items (d)

 

 

2,476

 

 

 

18,855

 

Consolidated net loss

 

 

(88,612

)

 

 

(45,309

)

 

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

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

 

 

U.S.A.

 

 

U.K.

 

 

Germany

 

 

Total

 

 

$000s

 

 

$000s

 

 

$000s

 

 

$000s

 

Non-current assets

 

 

 

 

 

 

 

 

 

 

 

 

As at December 31, 2024

 

 

-

 

 

 

4,103

 

 

 

11,166

 

 

 

15,269

 

As at December 31, 2025

 

 

-

 

 

 

600

 

 

 

12,184

 

 

 

12,784

 

 

 

 

 

 

 

 

 

 

 

 

 

Revenue analysis for the year ended December 31, 2023

 

 

 

 

 

 

 

 

 

 

 

 

Research collaboration

 

 

-

 

 

 

30,934

 

 

 

-

 

 

 

30,934

 

Royalties

 

 

-

 

 

 

-

 

 

 

709

 

 

 

709

 

 

 

-

 

 

 

30,934

 

 

 

709

 

 

 

31,643

 

 

 

 

 

 

 

 

 

 

 

 

 

Revenue analysis for the year ended December 31, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Research collaboration

 

 

-

 

 

 

43,114

 

 

 

-

 

 

 

43,114

 

Royalties

 

 

-

 

 

 

-

 

 

 

144

 

 

 

144

 

 

 

-

 

 

 

43,114

 

 

 

144

 

 

 

43,258

 

 

 

 

 

 

 

 

 

 

 

 

 

Revenue analysis for the year ended December 31, 2025

 

 

 

 

 

 

 

 

 

 

 

 

Research collaboration

 

 

-

 

 

 

559

 

 

 

-

 

 

 

559

 

Royalties

 

 

-

 

 

 

-

 

 

 

-

 

 

 

-

 

 

 

 

-

 

 

 

559

 

 

 

-

 

 

 

559

 

 
v3.25.4
Directors and Staff Costs
 12 Months Ended
Dec. 31, 2025
Compensation Related Costs [Abstract]  
Directors and Staff Costs

5. Directors and staff costs

Staff costs, including Directors’ remuneration, during the year for the Group were as follows:

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Wages and salaries

 

 

19,254

 

 

 

19,434

 

Social security costs

 

 

1,673

 

 

 

1,744

 

Other pension costs

 

 

748

 

 

 

666

 

Share-based payments charge

 

 

8,074

 

 

 

16,307

 

Total aggregate remuneration

 

 

29,749

 

 

 

38,151

 

 

The decrease in costs for share-based payments is largely due to credit of previously accrued expense for those grants forfeited or cancelled due to reduction in number of employees, as well as lower fair value of 2025 issued grants.
v3.25.4
Restructuring Charges
 12 Months Ended
Dec. 31, 2025
Restructuring and Related Activities [Abstract]  
Restructuring Charges

6. Restructuring charges

 

During the twelve months ended December 30, 2025, the Group initiated a non-recurring reduction in workforce which resulted in total restructuring charges of $1.3 million. The charges consist of severance costs for terminated employees. The remaining accrual at December 31, 2025 was $0.1 million.
v3.25.4
Other Income, Net
 12 Months Ended
Dec. 31, 2025
Other Income and Expenses [Abstract]  
Other Income, Net

7. Other income, net

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Bank interest receivable

 

 

15

 

 

 

704

 

Accretion on U.S. Treasury Bills

 

 

3,465

 

 

 

3,768

 

Total other income

 

 

3,480

 

 

 

4,472

 
v3.25.4
Loss Per Share (Basic and Diluted)
 12 Months Ended
Dec. 31, 2025
Earnings Per Share [Abstract]  
Loss Per Share (Basic and Diluted)

8. Loss per share (basic and diluted)

Basic net loss per share is computed by dividing net loss (the numerator) by the weighted average shares outstanding for the period (the denominator). Diluted net loss per share is computed by dividing net income by the weighted average shares outstanding during the period adjusted for the dilutive effects of the exercise of the stock options. In periods when losses from continuing operations are reported, the weighted-average shares outstanding excludes common stock equivalents because their inclusion would be anti-dilutive. The computation of net loss per share for the years ended December 31, 2025 and 2024, respectively was as follows:

 

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Net loss

 

 

(88,612

)

 

 

(45,309

)

Weighted-average shares outstanding (basic and diluted)

 

 

141,694,702

 

 

 

138,752,224

 

Net loss per share (basic and diluted)

 

$

(0.63

)

 

$

(0.33

)

 

The following outstanding potentially dilutive securities were excluded from the calculation of diluted net loss per share because their impact would have been anti-dilutive for the period presented.

 

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

Potentially Dilutive Securities

 

 

 

 

 

 

Stock options

 

 

20,884,098

 

 

 

17,455,390

 
v3.25.4
Property, Plant and Equipment
 12 Months Ended
Dec. 31, 2025
Property, Plant and Equipment [Abstract]  
Property, Plant and Equipment

9. Property, plant and equipment

Property, plant, and equipment balances were as follows:

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

 

$000s

 

 

$000s

 

Equipment & Furniture

 

 

5,542

 

 

 

6,343

 

Accumulated Depreciation

 

 

(3,961

)

 

 

(4,525

)

Property, plant, and equipment, net

 

 

1,581

 

 

 

1,818

 

 

Depreciation expense of $0.3 million and $0.3 million, was recognized in fiscal years 2025 and 2024 respectively.
v3.25.4
Goodwill
 12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill

10. Goodwill

Goodwill is assessed annually at a reporting unit level, or whenever events and circumstances indicate impairment may have occurred. The Group has one reporting unit and performs a qualitative impairment test (also known as “Step 0"), and when necessary, a quantitative test. After assessing the totality of events and circumstances as part of the Step 0 test, it was determined that it is not more likely than not (a likelihood that is more than 50%) that the fair value of the reporting unit is less than its carrying amount and therefore a quantitative test is unnecessary. No triggering events were identified during the year.

The following table presents the changes in the carrying amount of goodwill:

 

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

 

$000s

 

 

$000s

 

Balance at start of year

 

 

9,392

 

 

 

9,981

 

Translation adjustment

 

 

1,229

 

 

 

(589

)

Balance at end of year

 

 

10,621

 

 

 

9,392

 
v3.25.4
Other Intangible Assets
 12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Other Intangible Assets

11. Other intangible assets

Intangible assets as of December 31, 2025 are as follows:

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

 

$000s

 

 

$000s

 

License and software

 

 

481

 

 

 

481

 

Accumulated Depreciation

 

 

(193

)

 

 

(169

)

License and software, net

 

 

288

 

 

 

312

 

 

The intangible assets are amortized beginning from the date of acquisition, over their useful life or written down if they are considered to be impaired.

Amortization expense is included in General and administrative expenses, which included on the consolidated statements of income (loss), and was nominal for the years ended December 31, 2025 and 2024, respectively.

Expected future amortization expense is as follows:

 

Year

Expected Amortization

 

 

$000s

 

2026

 

46

 

2027

 

41

 

2028

 

41

 

2029

 

41

 

2030

 

41

 

Thereafter

 

78

 

 

No impairment charges related to intangible assets were recorded for the years ended December 31, 2025 and 2024.
v3.25.4
Cash and Cash Equivalents and Short-Term Investments
 12 Months Ended
Dec. 31, 2025
Cash and Cash Equivalents and Short-Term Investments [Abstract]  
Cash and Cash Equivalents and Short-Term Investments

12. Cash and cash equivalents and short-term investments

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Cash at bank and in hand

 

 

11,277

 

 

 

56,590

 

U.S. treasury bills

 

 

-

 

 

 

64,740

 

Total cash and cash equivalents

 

 

11,277

 

 

 

121,330

 

 

 

 

 

 

 

 

U.S. treasury bills

 

 

73,837

 

 

 

26,004

 

Total short-term investments

 

 

73,837

 

 

 

26,004

 

 

Cash at bank comprises balances held by the Group in current, short-term bank deposits, and U.S. Treasury Bills with an original maturity of three months or less. The carrying amount of these assets approximates to their fair value.
v3.25.4
Other Assets
 12 Months Ended
Dec. 31, 2025
Other Assets [Abstract]  
Other Assets

13. Other assets

 

 

Year ended December 31,

 

 

2025

 

2024

 

 

$000s

 

$000s

 

Prepayments

 

8,930

 

 

13,124

 

VAT receivable

 

2,607

 

 

1,540

 

Total other current assets

 

11,537

 

 

14,664

 

 

 

 

 

 

Deposits for properties

 

-

 

 

356

 

Prepayments

 

127

 

 

3,234

 

Other long-term assets

 

127

 

 

3,590

 

 

At December 31, 2025 and 2024, the largest component of prepayments are prepaid third party costs for clinical trials, as well as manufacturing for clinical supplies and associated development, and pre-clinical studies which fluctuate based on timing of payments and related expense.

 

Included within prepayments at December 31, 2025 and 2024 is $6.8 million and $11.0 million respectively, are expenditures relating to contracted research and development costs.
v3.25.4
Trade Receivables
 12 Months Ended
Dec. 31, 2025
Receivables [Abstract]  
Trade Receivables

14. Trade receivables

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Trade receivables

 

 

-

 

 

 

972

 

 

 

The Group considers that the carrying amount of trade receivables approximates their fair value.

No interest is charged on outstanding receivables. There were no overdue trade receivables balances.

The Group has applied an expected credit loss model to the balance and determined that no allowance is required for the periods ended December 31, 2025 and 2024.
v3.25.4
Trade and Other Payables
 12 Months Ended
Dec. 31, 2025
Payables and Accruals [Abstract]  
Trade and Other Payables

15. Trade and other payables

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Trade payables

 

 

4,409

 

 

 

3,697

 

Social security and other taxes

 

 

195

 

 

 

244

 

Accruals and other payables

 

 

5,749

 

 

 

8,361

 

Bonus accrual

 

 

2,964

 

 

 

3,445

 

Corporate income tax payable

 

 

39

 

 

 

652

 

Total trade and other payables

 

 

13,356

 

 

 

16,399

 

 

The Group considers that the carrying amount of trade and other payables approximates their fair value. Bonus accrual and accruals and other payables include accrued severance and other compensation costs that are currently subject to ongoing negotiation.

 

Included within accruals and other payables at December 31, 2025 and 2024 is $3.0 million and $5.9 million respectively, are expenditures relating to contracted research and development costs.
v3.25.4
Leases
 12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
Leases

16. Leases

The Group has one operating lease for office space in London, which was moved to a new location upon completion of the original lease term, with the new lease beginning in September 2025. The Group determines whether a contract is a lease or contains a lease at inception date. Upon commencement, the Group recognizes a right-of-use asset and lease liability. Right-of-use assets represent the Group’s right to use the underlying asset for the lease term. Lease liabilities are the Group’s obligation to make the lease payments arising from a lease. As the Group’s lease does not provide an implicit rate, the Group’s lease liabilities are measured on a discounted basis using the Group’s incremental borrowing rate. Lease terms used in the recognition of right-of-use assets and lease liabilities include only options to extend the lease that are reasonably certain to be exercised. Additionally, lease terms underlying the right-of-use assets and lease liabilities consider terminations that are reasonably certain to be executed.

There are two short-term leases in Berlin, Germany and six leases in Hoboken, U.S., that have not been recognized as right-of-use assets. Both leases in Berlin are on a rolling contract basis with either party being able to end the lease with a cancellation notice period of 11.5 months, while the leases in the United States are on a rolling contract basis with a notice period of 3 months. Expense related to these short-term leases are recorded to the consolidated statements of income (loss) over the lease term.

The following table presents supplemental balance sheet information related to the Group’s operating lease:

 

 

 

 

Year ended December 31,

 

 

 

 

2025

 

 

2024

 

 

Classification

 

$000s

 

 

$000s

 

Operating lease right-of-use asset

 

Other non-current assets

 

 

167

 

 

 

157

 

 

 

 

 

 

 

 

 

 

Lease liability - current

 

Current liabilities

 

 

89

 

 

 

117

 

Lease liability - non-current

 

Non-current liabilities

 

 

71

 

 

 

-

 

 

 

The following table summarizes the weighted-average remaining lease term and weighted-average discount rate for the Group’s operating leases at December 31, 2025 and 2024:

 

 

2025

 

2024

Weighted-average remaining lease term

 

1.75 years

 

0.75 years

Weighted-average discount rate

 

10.5%

 

7.0%

 

The following table summarizes the components of total operating lease cost for fiscal year 2025 and 2024:

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

 

$000s

 

 

$000s

 

Operating lease cost

 

 

197

 

 

 

248

 

Short-term lease cost

 

 

721

 

 

 

736

 

Total operating lease cost

 

 

918

 

 

 

984

 

 

The following table summarizes the maturities of the Group’s operating leases at December 31, 2025:

 

Fiscal year

 

Operating Leases

 

2026

 

 

89

 

2027

 

 

71

 

2028

 

 

-

 

2029

 

 

-

 

2030

 

 

-

 

Thereafter

 

 

-

 

Total expected lease payments

 

 

160

 

Less: Imputed interest

 

 

-

 

Total lease liability

 

 

160

 
v3.25.4
Contract Liabilities
 12 Months Ended
Dec. 31, 2025
Revenue from Contract with Customer [Abstract]  
Contract Liabilities

17. Contract liabilities

 

Contract liabilities represent the Group’s obligation to transfer services to a customer for which the Group has received advanced consideration, before the performance obligation has been satisfied. These liabilities are recognized when a customer prepays for services or when the Group has an unconditional right to consideration before the performance obligation is fulfilled.

Contract liabilities comprise entirely of advance consideration received from customers (deferred revenue) in respect of the AstraZeneca research collaboration. The current contract liabilities represent the amount of estimated revenue to be reported in the next 12 months related to amounts invoiced to its partners, while the non-current portion represents everything beyond 12 months. Current and non-current contract liabilities include future revenue from collaboration recharged expenses, upfront payments, and milestones achieved to December 31, 2025.

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Contract liabilities:

 

 

 

 

 

 

Current

 

 

168

 

 

 

306

 

Non-current

 

 

55,454

 

 

 

51,790

 

Total contract liabilities

 

 

55,622

 

 

 

52,096

 

 

 

 

 

 

 

 

Contract liabilities:

 

 

 

 

 

 

At January 1,2025

 

 

52,096

 

 

 

81,572

 

Foreign exchange impact

 

 

3,860

 

 

 

(691

)

Additions during period

 

 

225

 

 

 

14,328

 

Revenue unwound during period

 

 

(559

)

 

 

(43,113

)

At December 31, 2025

 

 

55,622

 

 

 

52,096

 

 

During the years ended December 31, 2025 and 2024 contract liabilities decreased primarily due to the recognition of revenue in the amount of $0.6 million and $43.1 million, respectively, that was included in the contract liabilities balance at the beginning of the year.
v3.25.4
Income Taxes
 12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Income Taxes

18. Income taxes

The Group operates in the U.K. and is subject to income taxes in that jurisdiction. The U.K. tax rate applied for 2025 was 25% (25% for 2024). U.K. deferred tax assets and liabilities have been measured at a rate of 25%. The entire tax expense relates to current tax as shown below. No deferred tax was recognized in the year.

Income (loss) from continuing operations before income taxes:

 

 

 

Year ended December 31,

 

 

 

2025

 

 

$000s

 

(Loss)/Income from continuing operations:

 

 

 

UK

 

 

(89,679

)

Foreign

 

 

1,078

 

Total

 

 

(88,601

)

 

The significant components of income tax expense attributable to income from continuing operations for the years ended December 31, 2025 and December 31, 2024 are as follows:

 

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Current Tax Expense

 

 

 

 

 

 

Current Year

 

 

11

 

 

 

845

 

Changes in estimate related to prior years

 

 

-

 

 

 

-

 

Total current tax

 

 

11

 

 

 

845

 

Deferred Tax Expense

 

 

 

 

 

 

Origination and reversal of temporary differences

 

 

-

 

 

 

-

 

Recognition of previously unrecognized tax losses

 

 

-

 

 

 

-

 

Recognition of previously unrecognized tax losses (derecognition of
   previously recognized) deductible temporary differences

 

 

-

 

 

 

-

 

Taxation

 

 

11

 

 

 

845

 

 

Income tax expense (benefit) attributable to income (loss) from continuing operations for the year ended December 31, 2025 differed from the amounts computed by applying the statutory UK federal income tax rate of 25 percent to pretax income (loss) from continuing operations as a result of the following:

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

%

 

 

 

$000s

 

 

 

 

UK Statutory Income Tax (Benefit) at 25%

 

 

(22,150

)

 

 

25.00

%

Domestic Federal

 

 

 

 

 

 

Tax credits

 

 

(1,948

)

 

 

2.20

%

Changes in valuation allowance

 

 

14,857

 

 

 

-16.77

%

Non-taxable and non-deductible items

 

 

 

 

 

 

Stock Compensation

 

 

1,726

 

 

 

-1.95

%

Research and Development costs

 

 

7,881

 

 

 

-8.89

%

Other reconciling items

 

 

(108

)

 

 

0.12

%

Foreign tax effects

 

 

 

 

 

 

Other foreign jurisdictions

 

 

(269

)

 

 

0.30

%

Total

 

 

(11

)

 

 

0.01

%

 

Reconciliation of the income tax credit at standard rate of U.K. corporation tax to the current tax credit for the year ended December 31, 2024 is as follows:

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

 

$000s

 

Loss before tax

 

 

(44,464

)

 

 

 

 

UK Statutory Income Tax (Benefit) at 25%

 

 

11,116

 

Income not taxable

 

 

3,356

 

Foreign Tax Rate Differential

 

 

308

 

Change in valuation allowance

 

 

(15,423

)

Effect of overseas taxes

 

 

(202

)

Total

 

 

(845

)

 

A schedule of income taxes paid by jurisdiction is as follows:

 

 

2025

 

 

$000s

 

UK Federal

 

 

—

 

Foreign

 

 

 

Germany

 

 

637

 

Other

 

 

—

 

Total

 

 

637

 

 

 

The Group did not have any deferred tax liabilities as at December 31, 2025 and 2024. Components of the Group’s deferred tax assets as at December 31, 2025 and 2024 are as follows:

 

 

Year ended December 31,

 

 

Gross

 

 

Gross

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Deferred tax assets:

 

 

 

 

 

 

Trading Losses 1

 

 

73,529

 

 

 

55,316

 

Share-based payments

 

 

4,233

 

 

 

3,663

 

Capital losses

 

 

2,651

 

 

 

2,467

 

Gross deferred tax asset

 

 

80,413

 

 

 

61,446

 

Valuation allowance

 

 

(80,413

)

 

 

(61,446

)

Total deferred tax, net

 

 

-

 

 

 

-

 

 

(1)
Included in trading losses is $8.2 million of accumulated tax losses as of December 31, 2025 ($7.4 million as of December 31, 2024) related to its operations in Germany for corporate income taxes and $7.1 million of accumulated losses related to trade taxes in its German entity ($6.5 million as of December 31, 2024).

Movements in deferred tax valuation allowance:

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

Valuation allowance at January 1

 

 

61,446

 

 

 

63,739

 

Increase/(decrease) in valuation allowance

 

 

18,967

 

 

 

(2,293

)

Valuation allowance at December 31

 

 

80,413

 

 

 

61,446

 

 

Management has reviewed cumulative tax losses and projections of future taxable losses and determined that it is not more likely than not that they will be realized. Accordingly, valuation allowances have been provided over deferred tax assets.

Since the Group does not have an establishment or place of business in China, the Group is subject to withholding tax on gross income from dividends, interest, lease of property, royalties, and other China-source passive income. In 2021 the Group entered into a collaboration agreement with Hansoh, a biopharmaceutical company in China. In 2024 the Group received a milestone payment of $2.0 million, which required withholding tax of $0.2 million. We did not receive a milestone in 2025.

During the year, the Group had not yet received the research and development tax credit related to the prior year. The Group has recognized $7.5 million in respect of the current year for unfunded projects that are permissible to claim under the SME scheme (2024: $13.2). In addition, in 2024 we have also recognized $0.3 million related to the RDEC scheme which is not applicable for 2025.
v3.25.4
Shareholders' Equity
 12 Months Ended
Dec. 31, 2025
Stockholders' Equity Note [Abstract]  
Shareholders' Equity

19. Shareholders’ equity

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

 

 

 

 

 

 

Authorized, allotted, called up and fully paid ordinary shares,
   par value £0.05

 

 

10,290

 

 

 

10,288

 

 

 

 

 

 

 

 

 

Number

 

 

Number

 

Number of shares in issue

 

 

141,701,848

 

 

 

141,674,074

 

Number of ADS in issue

 

 

47,233,949

 

 

 

47,224,691

 

 

 

The Group has only one class of share. All ordinary shares have equal voting rights and rank pari passu for the distribution of dividends.

On August 11, 2022, the Group announced a registered direct offering (the “Offering”) of 5,950,000 of the Group’s ADSs, each representing three ordinary shares, at a price of $9.50 per ADS, with new and existing institutional and accredited investors. The aggregate gross proceeds of the Offering were $56.5 million before deducting $4.1 million in underwriting discounts, commissions and estimated offering expenses.

On October 15, 2021, the Group entered into an Open Market Sale Agreement (the "Sales Agreement"), with Jefferies LLC ("Jefferies"), pursuant to which the Group may offer and sell, from time to time, its ADSs through Jefferies. On October 15, 2021, the Group filed a registration statement, which became effective on October 22, 2021, for the issuance and sale of up to $100.0 million of ADSs. During the year ended December 31, 2024 the Group 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, the Group 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 million of its shares represented by ADSs under the Sales Agreement. As of this filing, approximately $139.6 million of ADSs remained.

On February 5, 2024, the Group announced a private placement of 5,714,286 of the Group’s ADSs, each representing three ordinary shares, at a price of $21.00 per ADS, with new and existing institutional and accredited investors. The aggregate gross proceeds of the Private Placement were $120.0 million before deducting $7.7 million in placement agent fees and other expenses.

Details of the shares issued during the current year is as follows:

 

Number of shares in issue at December 31, 2024

 

 

141,674,074

 

Number of ADS in issue at December 31, 2024

 

 

47,224,691

 

Shares issued during the year

 

 

 

Options exercised at $0.20/ADS or $0.07/ordinary share

 

 

17,775

 

Options exercised at $4.23/ADS or $1.41/ordinary share

 

 

9,999

 

Number of shares in issue at December 31, 2025

 

 

141,701,848

 

Number of equivalent ADS in issue at December 31, 2025

 

 

47,233,949

 

 

At December 31, 2025, there were options outstanding of 20,884,098 (2024: 17,455,390) unissued ordinary shares.

Details of the options outstanding are as follows:

 

Year of issue

 

Weighted average Exercise price ($)

 

 

At
January 1, 2025

 

 

Options granted

 

 

Options forfeited

 

 

Options expired

 

 

Options exercised

 

 

At
December 31, 2025

 

 

Weighted average years to expiry date

 

2014

 

 

4.23

 

 

 

-

 

 

 

-

 

 

 

-

 

 

 

 

 

 

 

 

 

-

 

 

 

-

 

2015

 

 

4.23

 

 

 

3,333

 

 

 

-

 

 

 

-

 

 

 

-

 

 

 

(3,333

)

 

 

-

 

 

 

0.00

 

2016

 

 

5.14

 

 

 

6,524

 

 

 

-

 

 

 

-

 

 

 

 

 

 

 

 

 

6,524

 

 

 

0.18

 

2017

 

 

8.05

 

 

 

23,333

 

 

 

-

 

 

 

-

 

 

 

 

 

 

 

 

 

23,333

 

 

 

1.91

 

2018

 

 

0.20

 

 

 

30,593

 

 

 

-

 

 

 

-

 

 

 

(568

)

 

 

(2,259

)

 

 

27,766

 

 

 

2.27

 

2019

 

 

5.36

 

 

 

229,997

 

 

 

-

 

 

 

-

 

 

 

 

 

 

 

 

 

229,997

 

 

 

3.76

 

2020

 

 

8.23

 

 

 

234,178

 

 

 

-

 

 

 

(2,400

)

 

 

(3,833

)

 

 

(3,666

)

 

 

224,279

 

 

 

4.41

 

2021

 

 

22.37

 

 

 

576,136

 

 

 

-

 

 

 

(1,615

)

 

 

(5,999

)

 

 

 

 

 

568,522

 

 

 

5.81

 

2022

 

 

18.49

 

 

 

1,310,498

 

 

 

 

 

 

(123,132

)

 

 

(12,668

)

 

 

 

 

 

1,174,698

 

 

 

6.29

 

2023

 

 

13.88

 

 

 

2,148,357

 

 

 

-

 

 

 

(290,974

)

 

 

(9,287

)

 

 

 

 

 

1,848,096

 

 

 

7.21

 

2024

 

 

18.05

 

 

 

1,255,514

 

 

 

 

 

 

(138,543

)

 

 

(4,438

)

 

 

 

 

 

1,112,533

 

 

 

8.05

 

2025

 

 

6.96

 

 

 

 

 

 

1,966,485

 

 

 

(220,867

)

 

 

 

 

 

 

 

 

1,745,618

 

 

 

8.87

 

Total (ADSs)

 

 

 

 

 

5,818,463

 

 

 

1,966,485

 

 

 

(777,531

)

 

 

(36,793

)

 

 

(9,258

)

 

 

6,961,366

 

 

 

 

Total (Ordinary
   Shares)

 

 

 

 

 

17,455,390

 

 

 

5,899,455

 

 

 

(2,332,593

)

 

 

(110,379

)

 

 

(27,774

)

 

 

20,884,098

 

 

 

 

 

ADSs represent three ordinary shares.
v3.25.4
Equity-Settled Share-Based Compensation
 12 Months Ended
Dec. 31, 2025
Share-Based Payment Arrangement [Abstract]  
Equity-Settled Share-Based Compensation

20. Equity-settled share-based compensation

The Group has issued share options under the 2018 Long Term Incentive Plan (“LTIP”), 2018 Non-Employee Long Term Inventive Plan (“Non-Employee LTIP”), and individual share option contracts, open to all employees of the Group, as well as EMI shares (none of which remain outstanding at December 31, 2024). Under the 2023 Plan, LTIP, Non-Employee LTIP, individual contracts and schemes available, the options typically vest after three years, with the exception of some options granted to certain members of key management personnel. The vesting period for these options ranges from 3 to 33 months. The options usually lapse after one year following the employee leaving the Group.

 

 

2025

 

 

2024

 

 

Number of
ADSs

 

 

Weighted
Average
Exercise
price

 

 

Aggregate Intrinsic Value

 

 

Number of
ADSs

 

 

Weighted
Average
Exercise
price

 

 

Aggregate Intrinsic Value

 

 

 

 

 

$

 

 

$

 

 

 

 

 

$

 

 

$

 

Options

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Outstanding at the beginning of the year

 

 

5,818,463

 

 

 

15.95

 

 

 

 

 

 

5,284,486

 

 

 

14.80

 

 

 

 

Granted during the year

 

 

1,966,485

 

 

 

6.96

 

 

 

 

 

 

1,267,514

 

 

 

18.05

 

 

 

 

Lapsed or forfeited during the year

 

 

(814,324

)

 

 

13.11

 

 

 

 

 

 

(264,056

)

 

 

19.82

 

 

 

 

Exercised during the year

 

 

(9,258

)

 

 

1.65

 

 

 

 

 

 

(469,481

)

 

 

6.55

 

 

 

 

Outstanding at the year-end (ADS/$)

 

 

6,961,366

 

 

 

13.76

 

 

 

-

 

 

 

5,818,463

 

 

 

15.95

 

 

 

-

 

Exercisable at the year-end

 

 

4,211,644

 

 

 

16.12

 

 

 

 

 

 

2,870,106

 

 

 

15.94

 

 

 

 

 

The table above shows the number of options in relation to ordinary shares and equivalent ADSs outstanding and exercisable at year end, on the conversion ratio of three ordinary share options to one ADS.

The options outstanding at the year-end have a weighted average remaining contractual life of 7.28 years (2024: 7.7 years).

As of December 31, 2025, there was $6.0 million of total unrecognized compensation cost related to stock options granted but not vested under the Company’s plans. That cost will be recognized over an expected remaining weighted-average period of 1.3 years.

In the years ended December 31, 2025 and 2024 the total intrinsic value of stock options exercised was negligible and $6.8 million, respectively. The weighted average share price at the date of exercise of the options during the year was $1.65 per ADS (2024: $20.99).

The Group granted 5,899,455 share options during the year (2024: 3,802,542). The fair value of options granted were calculated using Black Scholes model. Inputs into the model were as follows:

 

 

2025

 

 

2024

 

Inputs and assumptions for options granted in the year:

 

 

 

 

 

 

Weighted average ADS price ($)

 

 

7.0

 

 

 

18.1

 

Option life (years)

 

6.2

 

 

 

6.2

 

Expected volatility

 

77.5%-79.8%

 

 

74.4%-78.6%

 

Risk free rate

 

3.75%-4.7%

 

 

3.39%-3.97%

 

Expected dividend yield

 

nil

 

 

nil

 

 

 

 

 

 

 

 

Weighted average grant date fair value ($)

 

6.93

 

 

12.6

 

 

The Group recognized total charges of $8.1 million (2024: $16.3 million) related to equity settled share-based payment transactions during the year. The decrease in costs for share-based payments is largely due to credit of previously accrued expense for those grants forfeited or cancelled due to reduction in number of employees, as well as lower fair value of 2025 issued grants.

The Group does not bear any responsibility to settle any employee tax obligations that arise on the exercise of share options. The estimated employer tax obligation on outstanding options at the year-end was negligible for 2025 and 2024.
v3.25.4
Capital Commitments and Contingent Liabilities
 12 Months Ended
Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]  
Capital Commitments and Contingent Liabilities

21. Capital commitments and contingent liabilities

There were no capital commitments at December 31, 2025 (2024: nil).
v3.25.4
Commitments Under Short Leases
 12 Months Ended
Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]  
Commitments Under Short Leases

22. Commitments under short leases

At December 31, 2025, the Group had a gross commitment on its office rental and service charge in Berlin, Germany and the Hoboken, U.S. lease equal to $0.6 million (2024: $0.5 million) in the next year. No amounts are payable after more than one year.

In addition, the Group enters into contracts in the normal course of business with contract research organizations to assist in the performance of research and development activities and other services and products for operating purposes. These contracts generally provide for termination on notice, and therefore are cancellable contracts and not reflected in the disclosure above.
v3.25.4
Financial Instruments and Risk Management
 12 Months Ended
Dec. 31, 2025
Investments, All Other Investments [Abstract]  
Financial Instruments and Risk Management

23. Financial instruments and risk management

The Group’s financial instruments comprise primarily cash and other financial assets and various items such as receivables and trade payables which arise directly from its operations. The main purpose of these financial instruments is to provide working capital for the Group’s operations. The Group assesses counterparty risk on a regular basis. Board approval is required for adoption of any new financial instrument or counterparty. The primary focus of the treasury function is preservation of capital.

The Directors consider that the carrying amount of these financial instruments approximates to their fair value.

Concentration of credit risk

Financial instruments that potentially subject the Company to concentration of credit risk consist of principally cash and cash equivalents and U.S. Treasury Bills. Cash and cash equivalents, term deposits and U.S. Treasury Bills are not considered to be exposed to significant credit risk due to the fact they are held in a financial institution with an “A” rating. The Group considers the possibility of significant loss in the event of non-performance by a financial counterparty to be remote.

The Group regularly monitors the creditworthiness of its collaborators and at the reporting date, no financial assets are credit impaired.

Capital management

The Group considers its capital to be equal to the sum of its total equity. The Group monitors its capital using a number of measures including cash flow projections, working capital ratios, the cost to achieve preclinical and clinical milestones and potential revenue from existing partnerships and ongoing licensing activities. The Group’s objective when managing its capital is to ensure it obtains sufficient funding for continuing as a going concern. The Group funds its capital requirements through the issue of new shares to investors, milestone and research support payments received from existing licensing partners and potential new licensees.

Interest rate risk

The nature of the Group’s activities and the basis of funding are such that the Group has significant liquid resources. The Group uses these resources to meet the cost of future research and development activities. Consequently, it seeks to minimize risk in the holding of its bank deposits while maintaining a reasonable rate of interest. The Group is not

financially dependent on the income earned on these resources and therefore the risk of interest rate fluctuations is not significant to the business. Nonetheless, the Directors take steps to secure rates of interest which generate a return for the Group.

Credit and liquidity risk

Credit risk is managed on a Group basis. Funds are deposited with financial institutions with a credit rating equivalent to, or above, the main U.K. clearing banks. The Group’s liquid resources are invested having regard to the timing of payments to be made in the ordinary course of the Group’s activities. All financial liabilities are payable in the short term (between zero and three months) and the Group maintains adequate bank balances in either instant access or short-term deposits to meet those liabilities as they fall due.

The Group only enters into collaboration agreements with large, reputable companies and the creditworthiness of collaborators is monitored on an ongoing basis.

Expected loss rates are based on payment profiles of past receivables and the aging profiles of outstanding balances at the reporting period end date. The historical loss rates are adjusted to reflect current and forward-looking information on macroeconomic factors affecting the ability of the customer to settle the receivables. At the year-end there were no debts that were past due or are expected to be past due. It was therefore concluded on this basis that there were no expected credit losses for the trade receivable.

Trade receivables are written off where there is no reasonable expectation of recovery. Indicators that there is no reasonable expectation of recovery includes, but is not limited to, a failure to engage in a repayment plan with the Group.

Currency risk

The Group’s transactions are commonly denominated in U.K pounds sterling; however, the Group receives payments under its collaboration agreements in U.S. dollars and it incurs a portion of its expenses in other currencies, primarily U.S. dollars, and are exposed to the effects of these exchange rates. The Group seeks to minimize this exposure by maintaining currency cash balances at levels appropriate to meet foreseeable short to mid-term expenses in these other currencies. Where significant foreign currency cash receipts are expected, the Group considers the use of forward exchange contracts to manage its exchange rate exposure.
v3.25.4
Related Party Transactions
 12 Months Ended
Dec. 31, 2025
Related Party Transactions [Abstract]  
Related Party Transactions

24. Related party transactions

The Group did not have any related party transactions in 2024 or 2025.
v3.25.4
Subsequent Events
 12 Months Ended
Dec. 31, 2025
Subsequent Events [Abstract]  
Subsequent Events

25. Subsequent events

None.
v3.25.4
Summary of Significant Accounting Policies (Policies)
 12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Basis of preparation

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.
Functional and reporting currency

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.
Principles of consolidation

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.
Use of estimates

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.
Going concern

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.

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.
Segment reporting

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).
Revenue recognition

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

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.
Research and development

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

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.
Taxation

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.
Foreign currency translation

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.
Cash and cash equivalents

2.11. Cash and cash equivalents

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.
Property, plant and equipment

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.
Leases

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.

Goodwill

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.
Other intangible assets

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.
Fair value measurements

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.
Stock-based compensation expense

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.
Equity

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).
Loss per share

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.
Recently Issued Accounting Pronouncements

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.
v3.25.4
Revenue (Tables)
 12 Months Ended
Dec. 31, 2025
Revenues [Abstract]  
Summary of Disaggregation of Revenue from Contracts with Customers

Disaggregation of revenue from contracts with customers is as follows:

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

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

 

Royalties

 

 

-

 

 

 

144

 

Total revenue from contracts with customers

 

 

559

 

 

 

43,258

 
v3.25.4
Segment Reporting (Tables)
 12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Summary of Segment Information

The table below provides segment information about the Group:

 

 

Year Ended December 31,

 

 

 

2025

 

 

 

2024

 

 

$000s

 

 

$000s

 

Revenue

 

 

559

 

 

 

43,258

 

Less:

 

 

 

 

 

 

Cost of sales

 

 

(215

)

 

 

(11,810

)

Contracted research and development costs (a)

 

 

(44,873

)

 

 

(42,902

)

Personnel research and development costs (b)

 

 

(18,086

)

 

 

(20,503

)

Other R&D costs (c)

 

 

(4,794

)

 

 

(4,478

)

General & administrative expenses

 

 

(22,344

)

 

 

(26,884

)

Restructuring

 

 

(1,324

)

 

 

-

 

Tax expense

 

 

(11

)

 

 

(845

)

Other segment items (d)

 

 

2,476

 

 

 

18,855

 

Consolidated net loss

 

 

(88,612

)

 

 

(45,309

)

 

(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)
The other segment items include foreign currency gain/(loss), net, benefit from R&D credit, and other income/ (expense), net inclusive of bank interest receivable and accretion on U.S. Treasury Bills.
Summary of Group's Assets and Revenues by Location

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

 

 

U.S.A.

 

 

U.K.

 

 

Germany

 

 

Total

 

 

$000s

 

 

$000s

 

 

$000s

 

 

$000s

 

Non-current assets

 

 

 

 

 

 

 

 

 

 

 

 

As at December 31, 2024

 

 

-

 

 

 

4,103

 

 

 

11,166

 

 

 

15,269

 

As at December 31, 2025

 

 

-

 

 

 

600

 

 

 

12,184

 

 

 

12,784

 

 

 

 

 

 

 

 

 

 

 

 

 

Revenue analysis for the year ended December 31, 2023

 

 

 

 

 

 

 

 

 

 

 

 

Research collaboration

 

 

-

 

 

 

30,934

 

 

 

-

 

 

 

30,934

 

Royalties

 

 

-

 

 

 

-

 

 

 

709

 

 

 

709

 

 

 

-

 

 

 

30,934

 

 

 

709

 

 

 

31,643

 

 

 

 

 

 

 

 

 

 

 

 

 

Revenue analysis for the year ended December 31, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Research collaboration

 

 

-

 

 

 

43,114

 

 

 

-

 

 

 

43,114

 

Royalties

 

 

-

 

 

 

-

 

 

 

144

 

 

 

144

 

 

 

-

 

 

 

43,114

 

 

 

144

 

 

 

43,258

 

 

 

 

 

 

 

 

 

 

 

 

 

Revenue analysis for the year ended December 31, 2025

 

 

 

 

 

 

 

 

 

 

 

 

Research collaboration

 

 

-

 

 

 

559

 

 

 

-

 

 

 

559

 

Royalties

 

 

-

 

 

 

-

 

 

 

-

 

 

 

-

 

 

 

 

-

 

 

 

559

 

 

 

-

 

 

 

559

 

 
v3.25.4
Directors and Staff Costs (Tables)
 12 Months Ended
Dec. 31, 2025
Compensation Related Costs [Abstract]  
Schedule of Staff Costs Including Director's Remuneration

Staff costs, including Directors’ remuneration, during the year for the Group were as follows:

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Wages and salaries

 

 

19,254

 

 

 

19,434

 

Social security costs

 

 

1,673

 

 

 

1,744

 

Other pension costs

 

 

748

 

 

 

666

 

Share-based payments charge

 

 

8,074

 

 

 

16,307

 

Total aggregate remuneration

 

 

29,749

 

 

 

38,151

 
v3.25.4
Other Income, Net (Tables)
 12 Months Ended
Dec. 31, 2025
Other Income and Expenses [Abstract]  
Schedule of Other Income, Net

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Bank interest receivable

 

 

15

 

 

 

704

 

Accretion on U.S. Treasury Bills

 

 

3,465

 

 

 

3,768

 

Total other income

 

 

3,480

 

 

 

4,472

 
v3.25.4
Loss Per Share (Basic and Diluted) (Tables)
 12 Months Ended
Dec. 31, 2025
Earnings Per Share [Abstract]  
Schedule of Computation of Net Loss Per Share The computation of net loss per share for the years ended December 31, 2025 and 2024, respectively was as follows:

 

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Net loss

 

 

(88,612

)

 

 

(45,309

)

Weighted-average shares outstanding (basic and diluted)

 

 

141,694,702

 

 

 

138,752,224

 

Net loss per share (basic and diluted)

 

$

(0.63

)

 

$

(0.33

)
Schedule of Outstanding Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share

The following outstanding potentially dilutive securities were excluded from the calculation of diluted net loss per share because their impact would have been anti-dilutive for the period presented.

 

 

 

Year ended December 31,

 

 

2025

 

 

2024

 

Potentially Dilutive Securities

 

 

 

 

 

 

Stock options

 

 

20,884,098

 

 

 

17,455,390

 
v3.25.4
Property, Plant and Equipment (Tables)
 12 Months Ended
Dec. 31, 2025
Property, Plant and Equipment [Abstract]  
Schedule of Property, Plant, and Equipment

Property, plant, and equipment balances were as follows:

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

 

$000s

 

 

$000s

 

Equipment & Furniture

 

 

5,542

 

 

 

6,343

 

Accumulated Depreciation

 

 

(3,961

)

 

 

(4,525

)

Property, plant, and equipment, net

 

 

1,581

 

 

 

1,818

 
v3.25.4
Goodwill (Tables)
 12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of Change in Carrying Value of Goodwill

The following table presents the changes in the carrying amount of goodwill:

 

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

 

$000s

 

 

$000s

 

Balance at start of year

 

 

9,392

 

 

 

9,981

 

Translation adjustment

 

 

1,229

 

 

 

(589

)

Balance at end of year

 

 

10,621

 

 

 

9,392

 
v3.25.4
Other Intangible Assets (Tables)
 12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of Intangible Assets

Intangible assets as of December 31, 2025 are as follows:

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

 

$000s

 

 

$000s

 

License and software

 

 

481

 

 

 

481

 

Accumulated Depreciation

 

 

(193

)

 

 

(169

)

License and software, net

 

 

288

 

 

 

312

 
Schedule of Expected Future Amortization Expense

Expected future amortization expense is as follows:

 

Year

Expected Amortization

 

 

$000s

 

2026

 

46

 

2027

 

41

 

2028

 

41

 

2029

 

41

 

2030

 

41

 

Thereafter

 

78

 
v3.25.4
Cash and Cash Equivalents and Short-Term Investments (Tables)
 12 Months Ended
Dec. 31, 2025
Cash and Cash Equivalents and Short-Term Investments [Abstract]  
Schedule of Cash and Cash Equivalents and Short-Term Investments

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Cash at bank and in hand

 

 

11,277

 

 

 

56,590

 

U.S. treasury bills

 

 

-

 

 

 

64,740

 

Total cash and cash equivalents

 

 

11,277

 

 

 

121,330

 

 

 

 

 

 

 

 

U.S. treasury bills

 

 

73,837

 

 

 

26,004

 

Total short-term investments

 

 

73,837

 

 

 

26,004

 
v3.25.4
Other Assets (Tables)
 12 Months Ended
Dec. 31, 2025
Other Assets [Abstract]  
Schedule of Other Assets

 

Year ended December 31,

 

 

2025

 

2024

 

 

$000s

 

$000s

 

Prepayments

 

8,930

 

 

13,124

 

VAT receivable

 

2,607

 

 

1,540

 

Total other current assets

 

11,537

 

 

14,664

 

 

 

 

 

 

Deposits for properties

 

-

 

 

356

 

Prepayments

 

127

 

 

3,234

 

Other long-term assets

 

127

 

 

3,590

 
v3.25.4
Trade Receivables (Tables)
 12 Months Ended
Dec. 31, 2025
Receivables [Abstract]  
Schedule of Trade Receivables

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Trade receivables

 

 

-

 

 

 

972

 

 
v3.25.4
Trade and Other Payables (Tables)
 12 Months Ended
Dec. 31, 2025
Payables and Accruals [Abstract]  
Schedule of Trade and Other Payables

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Trade payables

 

 

4,409

 

 

 

3,697

 

Social security and other taxes

 

 

195

 

 

 

244

 

Accruals and other payables

 

 

5,749

 

 

 

8,361

 

Bonus accrual

 

 

2,964

 

 

 

3,445

 

Corporate income tax payable

 

 

39

 

 

 

652

 

Total trade and other payables

 

 

13,356

 

 

 

16,399

 
v3.25.4
Leases (Tables)
 12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
Summary of Supplemental Balance Sheet Information Related to Operating Lease

The following table presents supplemental balance sheet information related to the Group’s operating lease:

 

 

 

 

Year ended December 31,

 

 

 

 

2025

 

 

2024

 

 

Classification

 

$000s

 

 

$000s

 

Operating lease right-of-use asset

 

Other non-current assets

 

 

167

 

 

 

157

 

 

 

 

 

 

 

 

 

 

Lease liability - current

 

Current liabilities

 

 

89

 

 

 

117

 

Lease liability - non-current

 

Non-current liabilities

 

 

71

 

 

 

-

 

 
Summary of Weighted-average Remaining Lease Term and Weighted-average Discount rate for Operating Leases

The following table summarizes the weighted-average remaining lease term and weighted-average discount rate for the Group’s operating leases at December 31, 2025 and 2024:

 

 

2025

 

2024

Weighted-average remaining lease term

 

1.75 years

 

0.75 years

Weighted-average discount rate

 

10.5%

 

7.0%
Summary of Components of Total Operating Lease Cost

The following table summarizes the components of total operating lease cost for fiscal year 2025 and 2024:

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

 

$000s

 

 

$000s

 

Operating lease cost

 

 

197

 

 

 

248

 

Short-term lease cost

 

 

721

 

 

 

736

 

Total operating lease cost

 

 

918

 

 

 

984

 
Summarizes of Maturities of Operating Leases

The following table summarizes the maturities of the Group’s operating leases at December 31, 2025:

 

Fiscal year

 

Operating Leases

 

2026

 

 

89

 

2027

 

 

71

 

2028

 

 

-

 

2029

 

 

-

 

2030

 

 

-

 

Thereafter

 

 

-

 

Total expected lease payments

 

 

160

 

Less: Imputed interest

 

 

-

 

Total lease liability

 

 

160

 
v3.25.4
Contract Liabilities (Tables)
 12 Months Ended
Dec. 31, 2025
Revenue from Contract with Customer [Abstract]  
Schedule of Contract Liabilities

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Contract liabilities:

 

 

 

 

 

 

Current

 

 

168

 

 

 

306

 

Non-current

 

 

55,454

 

 

 

51,790

 

Total contract liabilities

 

 

55,622

 

 

 

52,096

 

 

 

 

 

 

 

 

Contract liabilities:

 

 

 

 

 

 

At January 1,2025

 

 

52,096

 

 

 

81,572

 

Foreign exchange impact

 

 

3,860

 

 

 

(691

)

Additions during period

 

 

225

 

 

 

14,328

 

Revenue unwound during period

 

 

(559

)

 

 

(43,113

)

At December 31, 2025

 

 

55,622

 

 

 

52,096

 
v3.25.4
Income Taxes (Tables)
 12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Schedule of Income (Loss) from Continuing Operations Before Income Taxes

Income (loss) from continuing operations before income taxes:

 

 

 

Year ended December 31,

 

 

 

2025

 

 

$000s

 

(Loss)/Income from continuing operations:

 

 

 

UK

 

 

(89,679

)

Foreign

 

 

1,078

 

Total

 

 

(88,601

)
Schedule of Components of Tax Expense

The significant components of income tax expense attributable to income from continuing operations for the years ended December 31, 2025 and December 31, 2024 are as follows:

 

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Current Tax Expense

 

 

 

 

 

 

Current Year

 

 

11

 

 

 

845

 

Changes in estimate related to prior years

 

 

-

 

 

 

-

 

Total current tax

 

 

11

 

 

 

845

 

Deferred Tax Expense

 

 

 

 

 

 

Origination and reversal of temporary differences

 

 

-

 

 

 

-

 

Recognition of previously unrecognized tax losses

 

 

-

 

 

 

-

 

Recognition of previously unrecognized tax losses (derecognition of
   previously recognized) deductible temporary differences

 

 

-

 

 

 

-

 

Taxation

 

 

11

 

 

 

845

 
Schedule of Reconciliation of Income Tax Credit

Income tax expense (benefit) attributable to income (loss) from continuing operations for the year ended December 31, 2025 differed from the amounts computed by applying the statutory UK federal income tax rate of 25 percent to pretax income (loss) from continuing operations as a result of the following:

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

%

 

 

 

$000s

 

 

 

 

UK Statutory Income Tax (Benefit) at 25%

 

 

(22,150

)

 

 

25.00

%

Domestic Federal

 

 

 

 

 

 

Tax credits

 

 

(1,948

)

 

 

2.20

%

Changes in valuation allowance

 

 

14,857

 

 

 

-16.77

%

Non-taxable and non-deductible items

 

 

 

 

 

 

Stock Compensation

 

 

1,726

 

 

 

-1.95

%

Research and Development costs

 

 

7,881

 

 

 

-8.89

%

Other reconciling items

 

 

(108

)

 

 

0.12

%

Foreign tax effects

 

 

 

 

 

 

Other foreign jurisdictions

 

 

(269

)

 

 

0.30

%

Total

 

 

(11

)

 

 

0.01

%

 

Reconciliation of the income tax credit at standard rate of U.K. corporation tax to the current tax credit for the year ended December 31, 2024 is as follows:

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

 

$000s

 

Loss before tax

 

 

(44,464

)

 

 

 

 

UK Statutory Income Tax (Benefit) at 25%

 

 

11,116

 

Income not taxable

 

 

3,356

 

Foreign Tax Rate Differential

 

 

308

 

Change in valuation allowance

 

 

(15,423

)

Effect of overseas taxes

 

 

(202

)

Total

 

 

(845

)
Schedule of Income Taxes Paid

A schedule of income taxes paid by jurisdiction is as follows:

 

 

2025

 

 

$000s

 

UK Federal

 

 

—

 

Foreign

 

 

 

Germany

 

 

637

 

Other

 

 

—

 

Total

 

 

637

 

 
Schedule of Deferred Tax Assets Components of the Group’s deferred tax assets as at December 31, 2025 and 2024 are as follows:

 

 

Year ended December 31,

 

 

Gross

 

 

Gross

 

 

2025

 

 

2024

 

 

$000s

 

 

$000s

 

Deferred tax assets:

 

 

 

 

 

 

Trading Losses 1

 

 

73,529

 

 

 

55,316

 

Share-based payments

 

 

4,233

 

 

 

3,663

 

Capital losses

 

 

2,651

 

 

 

2,467

 

Gross deferred tax asset

 

 

80,413

 

 

 

61,446

 

Valuation allowance

 

 

(80,413

)

 

 

(61,446

)

Total deferred tax, net

 

 

-

 

 

 

-

 

 

(1)
Included in trading losses is $8.2 million of accumulated tax losses as of December 31, 2025 ($7.4 million as of December 31, 2024) related to its operations in Germany for corporate income taxes and $7.1 million of accumulated losses related to trade taxes in its German entity ($6.5 million as of December 31, 2024).
Schedule of Movements in Deferred Tax Valuation Allowance

Movements in deferred tax valuation allowance:

 

 

Year ended December 31,

 

 

 

2025

 

 

2024

 

Valuation allowance at January 1

 

 

61,446

 

 

 

63,739

 

Increase/(decrease) in valuation allowance

 

 

18,967

 

 

 

(2,293

)

Valuation allowance at December 31

 

 

80,413

 

 

 

61,446

 
v3.25.4
Shareholders' Equity (Tables)
 12 Months Ended
Dec. 31, 2025
Stockholders' Equity Note [Abstract]  
Schedule of Shares Outstanding

 

Year ended December 31,

 

 

2025

 

 

2024

 

 

 

 

 

 

 

 

Authorized, allotted, called up and fully paid ordinary shares,
   par value £0.05

 

 

10,290

 

 

 

10,288

 

 

 

 

 

 

 

 

 

Number

 

 

Number

 

Number of shares in issue

 

 

141,701,848

 

 

 

141,674,074

 

Number of ADS in issue

 

 

47,233,949

 

 

 

47,224,691

 

 
Details of Shares Issued

Details of the shares issued during the current year is as follows:

 

Number of shares in issue at December 31, 2024

 

 

141,674,074

 

Number of ADS in issue at December 31, 2024

 

 

47,224,691

 

Shares issued during the year

 

 

 

Options exercised at $0.20/ADS or $0.07/ordinary share

 

 

17,775

 

Options exercised at $4.23/ADS or $1.41/ordinary share

 

 

9,999

 

Number of shares in issue at December 31, 2025

 

 

141,701,848

 

Number of equivalent ADS in issue at December 31, 2025

 

 

47,233,949

 
Schedule of Options Outstanding

Details of the options outstanding are as follows:

 

Year of issue

 

Weighted average Exercise price ($)

 

 

At
January 1, 2025

 

 

Options granted

 

 

Options forfeited

 

 

Options expired

 

 

Options exercised

 

 

At
December 31, 2025

 

 

Weighted average years to expiry date

 

2014

 

 

4.23

 

 

 

-

 

 

 

-

 

 

 

-

 

 

 

 

 

 

 

 

 

-

 

 

 

-

 

2015

 

 

4.23

 

 

 

3,333

 

 

 

-

 

 

 

-

 

 

 

-

 

 

 

(3,333

)

 

 

-

 

 

 

0.00

 

2016

 

 

5.14

 

 

 

6,524

 

 

 

-

 

 

 

-

 

 

 

 

 

 

 

 

 

6,524

 

 

 

0.18

 

2017

 

 

8.05

 

 

 

23,333

 

 

 

-

 

 

 

-

 

 

 

 

 

 

 

 

 

23,333

 

 

 

1.91

 

2018

 

 

0.20

 

 

 

30,593

 

 

 

-

 

 

 

-

 

 

 

(568

)

 

 

(2,259

)

 

 

27,766

 

 

 

2.27

 

2019

 

 

5.36

 

 

 

229,997

 

 

 

-

 

 

 

-

 

 

 

 

 

 

 

 

 

229,997

 

 

 

3.76

 

2020

 

 

8.23

 

 

 

234,178

 

 

 

-

 

 

 

(2,400

)

 

 

(3,833

)

 

 

(3,666

)

 

 

224,279

 

 

 

4.41

 

2021

 

 

22.37

 

 

 

576,136

 

 

 

-

 

 

 

(1,615

)

 

 

(5,999

)

 

 

 

 

 

568,522

 

 

 

5.81

 

2022

 

 

18.49

 

 

 

1,310,498

 

 

 

 

 

 

(123,132

)

 

 

(12,668

)

 

 

 

 

 

1,174,698

 

 

 

6.29

 

2023

 

 

13.88

 

 

 

2,148,357

 

 

 

-

 

 

 

(290,974

)

 

 

(9,287

)

 

 

 

 

 

1,848,096

 

 

 

7.21

 

2024

 

 

18.05

 

 

 

1,255,514

 

 

 

 

 

 

(138,543

)

 

 

(4,438

)

 

 

 

 

 

1,112,533

 

 

 

8.05

 

2025

 

 

6.96

 

 

 

 

 

 

1,966,485

 

 

 

(220,867

)

 

 

 

 

 

 

 

 

1,745,618

 

 

 

8.87

 

Total (ADSs)

 

 

 

 

 

5,818,463

 

 

 

1,966,485

 

 

 

(777,531

)

 

 

(36,793

)

 

 

(9,258

)

 

 

6,961,366

 

 

 

 

Total (Ordinary
   Shares)

 

 

 

 

 

17,455,390

 

 

 

5,899,455

 

 

 

(2,332,593

)

 

 

(110,379

)

 

 

(27,774

)

 

 

20,884,098

 

 

 

 
v3.25.4
Equity-Settled Share-Based Compensation (Tables)
 12 Months Ended
Dec. 31, 2025
Share-Based Payment Arrangement [Abstract]  
Summary of Options The options usually lapse after one year following the employee leaving the Group.

 

 

2025

 

 

2024

 

 

Number of
ADSs

 

 

Weighted
Average
Exercise
price

 

 

Aggregate Intrinsic Value

 

 

Number of
ADSs

 

 

Weighted
Average
Exercise
price

 

 

Aggregate Intrinsic Value

 

 

 

 

 

$

 

 

$

 

 

 

 

 

$

 

 

$

 

Options

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Outstanding at the beginning of the year

 

 

5,818,463

 

 

 

15.95

 

 

 

 

 

 

5,284,486

 

 

 

14.80

 

 

 

 

Granted during the year

 

 

1,966,485

 

 

 

6.96

 

 

 

 

 

 

1,267,514

 

 

 

18.05

 

 

 

 

Lapsed or forfeited during the year

 

 

(814,324

)

 

 

13.11

 

 

 

 

 

 

(264,056

)

 

 

19.82

 

 

 

 

Exercised during the year

 

 

(9,258

)

 

 

1.65

 

 

 

 

 

 

(469,481

)

 

 

6.55

 

 

 

 

Outstanding at the year-end (ADS/$)

 

 

6,961,366

 

 

 

13.76

 

 

 

-

 

 

 

5,818,463

 

 

 

15.95

 

 

 

-

 

Exercisable at the year-end

 

 

4,211,644

 

 

 

16.12

 

 

 

 

 

 

2,870,106

 

 

 

15.94

 

 

 

 
Summary Fair Value of Options Granted were Calculated Using Black Scholes Model The fair value of options granted were calculated using Black Scholes model. Inputs into the model were as follows:

 

 

2025

 

 

2024

 

Inputs and assumptions for options granted in the year:

 

 

 

 

 

 

Weighted average ADS price ($)

 

 

7.0

 

 

 

18.1

 

Option life (years)

 

6.2

 

 

 

6.2

 

Expected volatility

 

77.5%-79.8%

 

 

74.4%-78.6%

 

Risk free rate

 

3.75%-4.7%

 

 

3.39%-3.97%

 

Expected dividend yield

 

nil

 

 

nil

 

 

 

 

 

 

 

 

Weighted average grant date fair value ($)

 

6.93

 

 

12.6

 
v3.25.4
Summary of Significant Accounting Policies - Additional Information (Details)
 12 Months Ended
Feb. 05, 2024
USD ($)
OrdinaryShare
$ / shares
shares
Dec. 31, 2025
USD ($)
Segment
Dec. 31, 2024
USD ($)
Summary Of Significant Accounting Policies [Line Items]      
Net loss   $ (88,612,000) $ (45,309,000)
Accumulated losses   562,572,000 474,044,000
Cash outflows from operating activities   (62,271,000) (67,640,000)
Cash and cash equivalents and short-term investments   $ 85,100,000  
Number of reportable segments | Segment   1  
Goodwill impairment loss   $ 0 0
Change in accounting principle, accounting standards update, adopted [true false]   true  
Change in accounting principle, accounting standards update, adoption date   Dec. 31, 2025  
Accounting standards update [extensible enumeration]   us-gaap:AccountingStandardsUpdate202309Member  
American Depositary Shares      
Summary Of Significant Accounting Policies [Line Items]      
Gross proceeds from private placement $ 120,000,000    
Open Market Sale Agreement | American Depositary Shares | Jefferies LLC      
Summary Of Significant Accounting Policies [Line Items]      
Gross proceeds from sale of stock     27,700,000
Placement agent fees and other expenses     900,000
Gross proceeds from private placement     27,700,000
Private Placement | American Depositary Shares      
Summary Of Significant Accounting Policies [Line Items]      
Placement agent fees and other expenses $ 7,700,000    
Sale of stock, number of shares issued | shares 5,714,286    
Number of ordinary shares in American Depositary Share | OrdinaryShare 3    
Sale of stock, price per share | $ / shares $ 21    
Gross proceeds from private placement $ 120,000,000    
Collaboration Agreement with AstraZeneca      
Summary Of Significant Accounting Policies [Line Items]      
Milestone payments received   $ 0 10,000,000
Collaboration Agreement with Hansoh      
Summary Of Significant Accounting Policies [Line Items]      
Milestone payments received   $ 0 $ 2,000,000
Minimum | Licenses and Software      
Summary Of Significant Accounting Policies [Line Items]      
Estimated useful lives of intangible assets   3 years  
Minimum | Furniture and Equipment      
Summary Of Significant Accounting Policies [Line Items]      
Estimated useful life of property, plant and equipment   3 years  
Maximum | Licenses and Software      
Summary Of Significant Accounting Policies [Line Items]      
Estimated useful lives of intangible assets   10 years  
Maximum | Furniture and Equipment      
Summary Of Significant Accounting Policies [Line Items]      
Estimated useful life of property, plant and equipment   10 years  
v3.25.4
Revenue - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2021
May 31, 2021
Dec. 31, 2020
Disaggregation of Revenue [Line Items]            
Revenue $ 559,000 $ 43,258,000 $ 31,643,000      
Upfront cash payment received 55,622,000 52,096,000 $ 81,572,000      
Collaboration Agreement with AstraZeneca            
Disaggregation of Revenue [Line Items]            
Revenue 600,000 18,000,000        
Upfront cash payment received         $ 40,000,000 $ 20,000,000
Milestone payments received 0 10,000,000        
Collaboration Agreement with Hansoh            
Disaggregation of Revenue [Line Items]            
Revenue 0 24,600,000        
Upfront cash payment received       $ 16,000,000    
Upfront cash payments received, net of tax       $ 14,400,000    
Milestone payments received 0 2,000,000        
Royalty Income            
Disaggregation of Revenue [Line Items]            
Revenue 0 144,000        
Research Collaboration Income            
Disaggregation of Revenue [Line Items]            
Revenue $ 559,000 $ 43,114,000        
v3.25.4
Revenue - Schedule of Disaggregation of Revenue From Contracts With Customers (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Revenue [Line Items]      
Total revenue from contracts with customers $ 559 $ 43,258 $ 31,643
Research Collaboration      
Disaggregation of Revenue [Line Items]      
Total revenue from contracts with customers 559 43,114  
Research Collaboration | Research Collaboration - AstraZeneca      
Disaggregation of Revenue [Line Items]      
Total revenue from contracts with customers 559 17,957  
Research Collaboration | Research collaboration - Hansoh      
Disaggregation of Revenue [Line Items]      
Total revenue from contracts with customers 0 24,573  
Research Collaboration | Research Collaboration - Other      
Disaggregation of Revenue [Line Items]      
Total revenue from contracts with customers 0 584  
Royalties      
Disaggregation of Revenue [Line Items]      
Total revenue from contracts with customers $ 0 $ 144  
v3.25.4
Segment Reporting - Additional Information (Details)
 12 Months Ended
Dec. 31, 2025
Segment
Segment Reporting [Abstract]  
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description 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.
Number of reportable segments 1
v3.25.4
Segment Reporting - Summary of Segment Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting [Abstract]      
Revenue $ 559 $ 43,258 $ 31,643
Cost of sales (215) (11,810)  
Contracted development costs (44,873) (42,902)  
Personnel research and development costs (18,086) (20,503)  
Other R&D costs (4,794) (4,478)  
General and administrative expenses (22,344) (26,884)  
Restructuring (1,324) 0  
Tax expense (11) (845)  
Other segment items 2,476 18,855  
Net Loss $ (88,612) $ (45,309)  
v3.25.4
Segment Reporting - Summary of Group's Assets and Revenues by Location (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting Information [Line Items]      
Non-current assets $ 12,784 $ 15,269  
Research collaboration 559 43,114 $ 30,934
Royalties   144 709
Revenue 559 43,258 31,643
UK      
Segment Reporting Information [Line Items]      
Non-current assets 600 4,103  
Research collaboration 559 43,114 30,934
Revenue 559 43,114 30,934
Germany      
Segment Reporting Information [Line Items]      
Non-current assets $ 12,184 11,166  
Royalties   144 709
Revenue   $ 144 $ 709
v3.25.4
Directors and Staff Costs - Schedule of Staff Costs Including Director's Remuneration (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Compensation Related Costs [Abstract]    
Wages and salaries $ 19,254 $ 19,434
Social security costs 1,673 1,744
Other pension costs 748 666
Share-based payments charge 8,074 16,307
Total aggregate remuneration $ 29,749 $ 38,151
v3.25.4
Restructuring Charges - Additional Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Restructuring and Related Activities [Abstract]    
Restructuring charges $ 1,324 $ 0
Restructuring remaining accrual $ 100  
v3.25.4
Other Income, Net - Schedule of Other Income, Net (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Other Income and Expenses [Abstract]    
Bank interest receivable $ 15 $ 704
Accretion on U.S Treasury Bills 3,465 3,768
Total other income $ 3,480 $ 4,472
v3.25.4
Loss Per Share (Basic and Diluted) - Schedule of Computation of Net Loss Per Share (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Earnings Per Share [Abstract]    
Net loss $ (88,612) $ (45,309)
Weighted-average shares outstanding basic 141,694,702 138,752,224
Weighted-average shares outstanding diluted 141,694,702 138,752,224
Net loss per share basic $ (0.63) $ (0.33)
Net loss per share diluted $ (0.63) $ (0.33)
v3.25.4
Loss Per Share (Basic and Diluted) - Schedule of Outstanding Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Earnings Per Share [Abstract]    
Potentially dilutive securities 20,884,098 17,455,390
v3.25.4
Property, Plant, and Equipment - Schedule of Property, Plant, and Equipment (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Property, Plant and Equipment [Abstract]    
Equipment & Furniture $ 5,542 $ 6,343
Accumulated Depreciation (3,961) (4,525)
Property, plant, and equipment, net $ 1,581 $ 1,818
v3.25.4
Property, Plant and Equipment - Additional Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Property, Plant and Equipment [Abstract]    
Depreciation expense $ 312 $ 336
v3.25.4
Goodwill - Schedule of Change in Carrying Value of Goodwill (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]    
Balance at start of year $ 9,392 $ 9,981
Translation adjustment 1,229 (589)
Balance at end of year $ 10,621 $ 9,392
v3.25.4
Other Intangible Assets - Schedule of Intangible Assets (Details) - License and Software, Net - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Finite-Lived Intangible Assets [Line Items]    
Finite-lived intangible assets, gross $ 481 $ 481
Finite-lived intangible assets, accumulated depreciation (193) (169)
Finite-lived intangible assets, net $ 288 $ 312
v3.25.4
Other Intangible Assets - Schedule of Expected Future Amortization Expense (Details)
$ in Thousands
Dec. 31, 2025
USD ($)
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]  
2026 $ 46
2027 41
2028 41
2029 41
2030 41
Thereafter $ 78
v3.25.4
Other Intangible Assets - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]    
Impairment of intangible assets $ 0 $ 0
v3.25.4
Cash and Cash Equivalents and Short-Term Investments - Schedule of Cash and Cash Equivalents and Short-term Investments (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Cash and Cash Equivalents and Short-Term Investments [Abstract]    
Cash at bank and in hand $ 11,277 $ 56,590
US Treasury Bills 0 64,740
Total Cash and cash equivalents 11,277 121,330
U.S. treasury bills 73,837 26,004
Total short-term investments $ 73,837 $ 26,004
v3.25.4
Other Assets - Schedule of Other Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Other Assets [Abstract]    
Prepayments $ 8,930 $ 13,124
VAT receivable 2,607 1,540
Total other current assets 11,537 14,664
Deposits for properties 0 356
Prepayments 127 3,234
Other long-term assets $ 127 $ 3,590
v3.25.4
Other Assets - Additional Information (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Contracted Development Costs    
Other Assets [Line Items]    
Prepayments assets $ 6.8 $ 11.0
v3.25.4
Trade receivables - Schedule of Trade Receivable (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Receivables [Abstract]    
Trade receivables $ 0 $ 972
v3.25.4
Trade Receivables - Additional Information (Details) - USD ($)
Dec. 31, 2025
Dec. 31, 2024
Receivables [Abstract]    
Allowance for expected credit loss $ 0 $ 0
v3.25.4
Trade and Other Payables - Schedule of Trade and Other Payables (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Payables and Accruals [Abstract]    
Trade payables $ 4,409 $ 3,697
Social security and other taxes 195 244
Accruals and other payables 5,749 8,361
Bonus accrual 2,964 3,445
Corporate income tax payable 39 652
Total trade and other payables $ 13,356 $ 16,399
v3.25.4
Trade and Other Payables - Additional Information (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Trade And Other Payables [Line Items]    
Accruals and other payables $ 5,749 $ 8,361
Contracted Development Costs    
Trade And Other Payables [Line Items]    
Accruals and other payables $ 3,000 $ 5,900
v3.25.4
Leases - Additional Information (Details)
 12 Months Ended
Dec. 31, 2025
Lease
Lessee, Lease, Description [Line Items]  
Number of operating lease for office space in London 1
Operating lease new term beginning period. 2025-09
Berlin, Germany  
Lessee, Lease, Description [Line Items]  
Number of short-term leases 2
Lease contract notice period 11 months 15 days
Hoboken, U. S.  
Lessee, Lease, Description [Line Items]  
Number of leases 6
Lease contract notice period 3 months
v3.25.4
Leases - Summary of Supplemental Balance Sheet Information Related to Operating Lease (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Leases [Abstract]    
Operating lease right-of-use asset $ 167 $ 157
Lease liability - current 89 117
Lease liability - non-current $ 71 $ 0
v3.25.4
Leases - Summary of Weighted-average Remaining Lease Term and Weighted-average Discount rate for Operating Leases (Details)
Dec. 31, 2025
Dec. 31, 2024
Leases [Abstract]    
Weighted-average remaining lease term 1 year 9 months 9 months
Weighted-average discount rate 10.50% 7.00%
v3.25.4
Leases - Summary of Components of Total Operating Lease Cost (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Leases [Abstract]    
Operating lease cost $ 197 $ 248
Short-term lease cost 721 736
Total operating lease cost $ 918 $ 984
v3.25.4
Leases - Summarizes of Maturities of Operating Leases (Details)
$ in Thousands
Dec. 31, 2025
USD ($)
Operating Leases  
2026 $ 89
2027 71
2028 0
2029 0
2030 0
Thereafter 0
Total expected lease payments 160
Less: Imputed interest 0
Total lease liability $ 160
v3.25.4
Contract Liabilities - Schedule of Contract Liabilities (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Contract liabilities:    
Current $ 168 $ 306
Non-current 55,454 51,790
Total contract liabilities 55,622 52,096
Contract liabilities, beginning 52,096 81,572
Foreign exchange impact 3,860 (691)
Additions during period 225 14,328
Revenue unwound during period (559) (43,113)
Contract liabilities, ending $ 55,622 $ 52,096
v3.25.4
Contract Liabilities - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Revenue from Contract with Customer [Abstract]    
Recognition of revenue $ 0.6 $ 43.1
v3.25.4
Income taxes - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Income Taxes [Line Items]    
U.K. tax rate 25.00% 25.00%
Tax expense related to current tax $ 11,000 $ 845,000
Deferred tax expense 0  
Deferred tax liabilities 0 0
SME scheme    
Income Taxes [Line Items]    
Tax credit 7,500,000 13,200,000
RDEC scheme    
Income Taxes [Line Items]    
Tax credit   300,000
Collaboration Agreement with Hansoh    
Income Taxes [Line Items]    
Milestone payments received $ 0 2,000,000
Milestone payment, tax withholding   $ 200,000
v3.25.4
Income Taxes - Schedule of Income (Loss) from Continuing Operations Before Income Taxes (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
(Loss)/Income from continuing operations:    
UK $ (89,679)  
Foreign 1,078  
Loss before income tax expense $ (88,601) $ (44,464)
v3.25.4
Income Taxes - Schedule of Components of Tax Expense (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Current Tax Expense    
Current Year $ 11 $ 845
Total current tax 11 845
Deferred Tax Expense    
Taxation $ 11 $ 845
v3.25.4
Income Taxes - Schedule of Reconciliation of Income Tax Credit (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Effective Income Tax Rate Reconciliation, Amount [Abstract]    
Loss before tax $ (88,601) $ (44,464)
UK Statutory Income Tax (Benefit) at 25% (22,150) (11,116)
Tax credits (1,948)  
Income not taxable   3,356
Foreign Tax Rate Differential   308
Change in valuation allowance 14,857 (15,423)
Non-taxable and non-deductible items    
Stock Compensation 1,726  
Research and Development costs 7,881  
Other reconciling items (108)  
Effect of overseas taxes   (202)
Total $ (11) $ (845)
Effective Income Tax Rate Reconciliation, Percent [Abstract]    
UK Statutory Income Tax (Benefit) at 25% 25.00% 25.00%
Tax credits 2.20%  
Changes in valuation allowance (16.77%)  
Non-taxable and non-deductible items    
Stock Compensation (1.95%)  
Research and Development costs (8.89%)  
Other reconciling items 0.12%  
Total 0.01%  
Other    
Effective Income Tax Rate Reconciliation, Amount [Abstract]    
Foreign Tax Rate Differential $ (269)  
Non-taxable and non-deductible items    
Foreign tax effects 0.30%  
v3.25.4
Income Taxes - Schedule of Reconciliation of Income Tax Credit (Parenthetical) (Details)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Income Tax Disclosure [Abstract]    
UK Statutory Income Tax (Benefit) at 25% 25.00% 25.00%
v3.25.4
Income Taxes - Schedule of Income Taxes Paid (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Income Tax Paid, by Individual Jurisdiction [Line Items]    
Total $ 637 $ 433
Germany    
Income Tax Paid, by Individual Jurisdiction [Line Items]    
Foreign $ 637  
v3.25.4
Income Taxes - Schedule of Deferred Tax Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Deferred tax assets:      
Trading Losses [1] $ 73,529 $ 55,316  
Share-based payments 4,233 3,663  
Capital losses 2,651 2,467  
Gross deferred tax asset 80,413 61,446  
Valuation allowance (80,413) (61,446) $ (63,739)
Total deferred tax, net $ 0 $ 0  
[1] Included in trading losses is $8.2 million of accumulated tax losses as of December 31, 2025 ($7.4 million as of December 31, 2024) related to its operations in Germany for corporate income taxes and $7.1 million of accumulated losses related to trade taxes in its German entity ($6.5 million as of December 31, 2024).
v3.25.4
Income Taxes - Schedule of Deferred Tax Assets (Parenthetical) (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Income Tax Disclosure [Abstract]    
Accumulated tax losses related to corporate income taxes $ 8.2 $ 7.4
Accumulated losses related to trade taxes $ 7.1 $ 6.5
v3.25.4
Income Taxes - Schedule of Movements in Deferred Tax Valuation Allowance (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Income Tax Disclosure [Abstract]    
Valuation allowance at January 1 $ 61,446 $ 63,739
Increase/(decrease) in valuation allowance 18,967 (2,293)
Valuation allowance at December 31 $ 80,413 $ 61,446
v3.25.4
Shareholders' Equity - Schedule of Shares Outstanding (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Class of Stock [Line Items]    
Authorized, allotted, called up and fully paid ordinary shares, par value 0.05 $ 10,290 $ 10,288
Number of shares in issue 141,701,848 141,674,074
American Depositary Shares    
Class of Stock [Line Items]    
Number of ADS in issue 47,233,949 47,224,691
v3.25.4
Shareholders' Equity - Schedule of Shares Outstanding (Parenthetical) (Details) - £ / shares
Dec. 31, 2025
Dec. 31, 2024
Stockholders' Equity Note [Abstract]    
Ordinary shares, par value £ 0.05 £ 0.05
v3.25.4
Shareholders' Equity - Additional Information (Details) - USD ($)
 12 Months Ended
Oct. 22, 2024
Feb. 05, 2024
Aug. 11, 2022
Dec. 31, 2025
Dec. 31, 2024
Oct. 15, 2021
Class of Stock [Line Items]            
Number of authorized shares not disclosed       true    
Options outstanding       20,884,098 17,455,390  
American Depositary Shares            
Class of Stock [Line Items]            
Number of ordinary shares per ADS       3    
Gross proceeds of offering   $ 120,000,000        
Increase in maximum value of shares to be sold $ 100,000,000          
Value of ADS remained $ 139,600,000          
Options outstanding       6,961,366 5,818,463  
Registered Direct Offering | American Depositary Shares            
Class of Stock [Line Items]            
Sale of stock, number of shares issued     5,950,000      
Number of ordinary shares per ADS     3      
Sale of stock, price per share     $ 9.5      
Gross proceeds of offering     $ 56,500,000      
Stock issuance costs     $ 4,100,000      
Open Market Sale Agreement | Jefferies LLC | Ordinary Shares | Maximum            
Class of Stock [Line Items]            
Maximum value of shares to be sold           $ 100,000,000
Open Market Sale Agreement | Jefferies LLC | American Depositary Shares            
Class of Stock [Line Items]            
Gross proceeds of offering         $ 27,700,000  
Stock issuance costs         $ 900,000  
Private Placement | American Depositary Shares            
Class of Stock [Line Items]            
Sale of stock, number of shares issued   5,714,286        
Number of ordinary shares per ADS   3        
Sale of stock, price per share   $ 21        
Gross proceeds of offering   $ 120,000,000        
Stock issuance costs   $ 7,700,000        
v3.25.4
Shareholders' Equity - Details of Shares Issued (Details) - shares
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Class of Stock [Line Items]    
Number of shares in issue 141,701,848 141,674,074
Options exercised 27,774  
American Depositary Shares    
Class of Stock [Line Items]    
Number of ADS in issue 47,233,949 47,224,691
Options exercised 9,258 469,481
Options exercised at $0.20/ADS or $0.07/ordinary share    
Class of Stock [Line Items]    
Options exercised 17,775  
Options exercised at $2.40/ADS or $0.80/ordinary share    
Class of Stock [Line Items]    
Options exercised 9,999  
v3.25.4
Shareholders' Equity - Details of Shares Issued (Parenthetical) (Details)
Dec. 31, 2025
$ / shares
Options exercised at $0.20/ADS or $0.07/ordinary share | American Depositary Shares  
Class of Stock [Line Items]  
Exercise price of stock option $ 0.2
Options exercised at $0.20/ADS or $0.07/ordinary share | Ordinary Shares  
Class of Stock [Line Items]  
Exercise price of stock option 0.07
Options exercised at $2.40/ADS or $0.80/ordinary share | American Depositary Shares  
Class of Stock [Line Items]  
Exercise price of stock option 4.23
Options exercised at $2.40/ADS or $0.80/ordinary share | Ordinary Shares  
Class of Stock [Line Items]  
Exercise price of stock option $ 1.41
v3.25.4
Shareholders' Equity - Schedule of Options Outstanding (Details)
 12 Months Ended
Dec. 31, 2025
$ / shares
shares
Class of Stock [Line Items]  
Number of Options, Outstanding at the beginning of the year 17,455,390
Number of Options, Granted during the year 5,899,455
Number of Options, Lapsed or forfeited during the year (2,332,593)
Options expired (110,379)
Number of Options, Exercised during the year (27,774)
Number of Options, Outstanding at the year end 20,884,098
American Depositary Shares  
Class of Stock [Line Items]  
Number of Options, Outstanding at the beginning of the year 5,818,463
Number of Options, Granted during the year 1,966,485
Number of Options, Lapsed or forfeited during the year (777,531)
Options expired (36,793)
Number of Options, Exercised during the year (9,258)
Number of Options, Outstanding at the year end 6,961,366
Options Issued in 2014  
Class of Stock [Line Items]  
Year of issue 2014
Weighted average Exercise price | $ / shares $ 4.23
Options Issued in 2015  
Class of Stock [Line Items]  
Year of issue 2015
Weighted average Exercise price | $ / shares $ 4.23
Number of Options, Outstanding at the beginning of the year 3,333
Number of Options, Exercised during the year (3,333)
Number of Options, Outstanding at the year end  
Weighted average years to expiry date 0 years
Options Issued in 2016  
Class of Stock [Line Items]  
Year of issue 2016
Weighted average Exercise price | $ / shares $ 5.14
Number of Options, Outstanding at the beginning of the year 6,524
Number of Options, Outstanding at the year end 6,524
Weighted average years to expiry date 2 months 4 days
Options Issued in 2017  
Class of Stock [Line Items]  
Year of issue 2017
Weighted average Exercise price | $ / shares $ 8.05
Number of Options, Outstanding at the beginning of the year 23,333
Number of Options, Outstanding at the year end 23,333
Weighted average years to expiry date 1 year 10 months 28 days
Options Issued in 2018  
Class of Stock [Line Items]  
Year of issue 2018
Weighted average Exercise price | $ / shares $ 0.2
Number of Options, Outstanding at the beginning of the year 30,593
Options expired (568)
Number of Options, Exercised during the year (2,259)
Number of Options, Outstanding at the year end 27,766
Weighted average years to expiry date 2 years 3 months 7 days
Options Issued in 2019  
Class of Stock [Line Items]  
Year of issue 2019
Weighted average Exercise price | $ / shares $ 5.36
Number of Options, Outstanding at the beginning of the year 229,997
Number of Options, Outstanding at the year end 229,997
Weighted average years to expiry date 3 years 9 months 3 days
Options Issued in 2020  
Class of Stock [Line Items]  
Year of issue 2020
Weighted average Exercise price | $ / shares $ 8.23
Number of Options, Outstanding at the beginning of the year 234,178
Number of Options, Lapsed or forfeited during the year (2,400)
Options expired (3,833)
Number of Options, Exercised during the year (3,666)
Number of Options, Outstanding at the year end 224,279
Weighted average years to expiry date 4 years 4 months 28 days
Options Issued in 2021  
Class of Stock [Line Items]  
Year of issue 2021
Weighted average Exercise price | $ / shares $ 22.37
Number of Options, Outstanding at the beginning of the year 576,136
Number of Options, Lapsed or forfeited during the year (1,615)
Options expired (5,999)
Number of Options, Outstanding at the year end 568,522
Weighted average years to expiry date 5 years 9 months 21 days
Options Issued in 2022  
Class of Stock [Line Items]  
Year of issue 2022
Weighted average Exercise price | $ / shares $ 18.49
Number of Options, Outstanding at the beginning of the year 1,310,498
Number of Options, Lapsed or forfeited during the year (123,132)
Options expired (12,668)
Number of Options, Outstanding at the year end 1,174,698
Weighted average years to expiry date 6 years 3 months 14 days
Options Issued in 2023  
Class of Stock [Line Items]  
Year of issue 2023
Weighted average Exercise price | $ / shares $ 13.88
Number of Options, Outstanding at the beginning of the year 2,148,357
Number of Options, Lapsed or forfeited during the year (290,974)
Options expired (9,287)
Number of Options, Outstanding at the year end 1,848,096
Weighted average years to expiry date 7 years 2 months 15 days
Options Issued in 2024  
Class of Stock [Line Items]  
Year of issue 2024
Weighted average Exercise price | $ / shares $ 18.05
Number of Options, Outstanding at the beginning of the year 1,255,514
Number of Options, Lapsed or forfeited during the year (138,543)
Options expired (4,438)
Number of Options, Outstanding at the year end 1,112,533
Weighted average years to expiry date 8 years 18 days
Options Issued in 2025  
Class of Stock [Line Items]  
Year of issue 2025
Weighted average Exercise price | $ / shares $ 6.96
Number of Options, Granted during the year 1,966,485
Number of Options, Lapsed or forfeited during the year (220,867)
Number of Options, Outstanding at the year end 1,745,618
Weighted average years to expiry date 8 years 10 months 13 days
v3.25.4
Equity-Settled Share-Based Compensation - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]    
Vesting rights Under the 2023 Plan, LTIP, Non-Employee LTIP, individual contracts and schemes available, the options typically vest after three years, with the exception of some options granted to certain members of key management personnel. The vesting period for these options ranges from 3 to 33 months.  
Options outstanding, weighted average remaining contractual life 7 years 3 months 10 days 7 years 8 months 12 days
Number of share options granted 5,899,455  
Equity settled share-based payment transactions $ 8,074 $ 16,307
Total unrecognized compensation cost granted but not vested $ 6,000  
Expected remaining weighted-average period 1 year 3 months 18 days  
Total intrinsic value of stock options exercised $ 6,800 $ 6,800
Weighted Average Exercise price, Exercised during the year $ 1.65 $ 0.99
Employee Stock Option    
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]    
Number of share options granted 5,899,455 3,802,542
Maximum    
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]    
Vesting period for options 33 months  
Minimum    
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]    
Vesting period for options 3 months  
v3.25.4
Equity-Settled Share-Based Compensation - Summary of Options (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]    
Number of Options, Outstanding at the beginning of the year 17,455,390  
Number of Options, Granted during the year 5,899,455  
Number of Options, Lapsed or forfeited during the year (2,332,593)  
Number of Options, Exercised during the year (27,774)  
Number of Options, Outstanding at the year end 20,884,098 17,455,390
Weighted Average Exercise price, Exercised during the year $ 1.65 $ 0.99
American Depositary Shares    
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]    
Number of Options, Outstanding at the beginning of the year 5,818,463 5,284,486
Number of Options, Granted during the year 1,966,485 1,267,514
Number of Options, Lapsed or forfeited during the year (814,324) (264,056)
Number of Options, Exercised during the year (9,258) (469,481)
Number of Options, Outstanding at the year end 6,961,366 5,818,463
Number of Options, Exercisable at the year-end 4,211,644 2,870,106
Weighted Average Exercise Price, Outstanding at the beginning of the year $ 15.95 $ 14.8
Weighted Average Exercise Price, Granted during the year 6.96 18.05
Weighted Average Exercise price, Lapsed or forfeited during the year 13.11 19.82
Weighted Average Exercise price, Exercised during the year 1.65 6.55
Weighted Average Exercise price, Outstanding at the year-end 13.76 15.95
Weighted Average Exercise Price, Exercisable at the year-end $ 16.12 $ 15.94
Aggregate Intrinsic Value   $ 0
v3.25.4
Equity-Settled Share-Based Compensation - Summary Fair Value of Options Granted were Calculated Using Black Scholes Model (Details) - $ / shares
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Inputs and assumptions for options granted in the year:    
Option life (years) 6 years 2 months 12 days 6 years 2 months 12 days
Expected volatility, minimum 77.50% 74.40%
Expected volatility, maximum 79.80% 78.60%
Risk free rate, minimum 3.75% 3.39%
Risk free rate, maximum 4.70% 3.97%
Weighted average grant date fair value $ 6.93 $ 12.6
American Depositary Shares    
Inputs and assumptions for options granted in the year:    
Weighted average share price $ 7 $ 18.1
v3.25.4
Capital Commitments and Contingent Liabilities - Additional Information (Details) - USD ($)
Dec. 31, 2025
Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]    
Capital commitments $ 0
v3.25.4
Commitments Under Short Leases - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]    
Gross commitment $ 600,000 $ 500,000
Lease amount payable $ 0  
v3.25.4
Related Party Transactions - Additional Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Related Party Transactions [Abstract]    
Amount paid $ 0 $ 0