What changed in this filing

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Item 1A. Risk Factors

2026-03-13 compared with 2025-03-20 · 280 added, 189 removed, 1599 unchanged (23% of the section changed)

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In that event, the market price of our ADSs could decline, and you could lose part or all of your investment.

Risks Related to the Contemplated Transactions with Clywedog

Our failure to complete the Contemplated Transactions would have a material adverse effect on our business, results of operations, financial condition and stock price.

Completion of the Contemplated Transactions is subject to the satisfaction of various conditions, including (i) the effectiveness of a registration statement to register shares of common stock, $0.0001 par value per share, of Topco (the “Topco Common Stock”), to be issued in connection with the Combinations;

(ii) the absence of any law or order that enjoins, prevents, prohibits, or makes illegal the consummation of the Contemplated Transactions;

(iii) approvals by our shareholders of the Scheme Transaction and certain related matters, and sanction by the Court of the Scheme Transaction;

(iv) approval by Clywedog’s stockholders of the Merger Agreement, the Merger and Contemplated Transactions;

(v) the approval for listing by Nasdaq of the shares of Topco Common Stock issuable in the Combinations;

(vi) certain consents, clearances and expirations or terminations of waiting periods under applicable antitrust laws;

(vii) the absence of a material adverse effect with respect to either party;

(viii) the completion of the Self-Tender Offer to the extent that Topco elects to commence the Self-Tender Offer;

(ix) minimum cash requirements for each party;

and (xi) subject to certain materiality and material adverse effect qualifiers, the accuracy of the representatives and warranties of the parties contained in the Merger Agreement and the compliance by each party with the covenants contained in the Merger Agreement.

As of the date of this report, the transaction is expected to close in the second quarter of 2026, subject to the satisfaction or waiver of these conditions.

There is no assurance that all of the various conditions will be satisfied or waived, or that the Contemplated Transactions will be completed on the proposed terms, within the expected timeframe, or at all.

The Contemplated Transactions may be delayed, and may ultimately not be completed, due to a number of factors, including the following:

• We may fail to obtain the approval of the Scheme Transaction by our shareholders.

Despite our board of directors having carefully and thoroughly considered a variety of strategic options and having determined that such strategic options either were unavailable to the Company, or would not provide value to shareholders greater than the value that would be provided in the Contemplated Transactions, we may be unable to secure the requisite approval of our shareholders.

• We may fail to obtain regulatory approvals from various governmental entities (or conditions, limitations or restrictions may be imposed on such approvals).

We cannot provide any assurance that we will not face regulatory hurdles, blocks or delays with respect to the Contemplated Transactions.

Material delays in obtaining any required approvals may result in the termination of the Contemplated Transactions, as either party may terminate the Contemplated Transactions if the Contemplated Transactions is not consummated by September 30, 2026, subject to certain extensions as further described in the Merger Agreement.

• Potential shareholder litigation and other legal and regulatory proceedings may delay or prevent the Contemplated Transactions.

• The parties may fail to satisfy one or more of the conditions to the completion of the Contemplated Transactions.

Additional risks if the Contemplated Transactions are not completed include:

• to the extent the current market price of our ADSs reflects an assumption that the Contemplated Transactions will be completed, the price of our ADSs could decrease;

• investor confidence could decline, stockholder litigation could be brought against us, relationships with existing and prospective customers, distributors, retailers, service providers, investors, lenders and other business partners may be adversely impacted, we may be unable to retain key personnel, and profitability may be adversely impacted due to costs incurred in connection with the Contemplated Transactions.

The failure to successfully integrate our business with that of Clywedog in the expected timeframe would adversely affect our future business and financial performance and the value of our stockholders’ investment following the Combinations.

The combination of two independent companies is a complex, costly and time-consuming process.

As a result, Topco will be required to devote significant management attention and resources to integrate our business practices and operations with those of Clywedog.

The integration process may disrupt the business of either or both of the companies and, if implemented ineffectively, could preclude realization of the full benefits expected by us and our shareholders from the Contemplated Transactions.

The failure of Topco to meet the challenges involved in successfully integrating our operations with those of Clywedog or otherwise to realize the anticipated benefits of the Contemplated Transactions could cause an interruption of the activities of Topco and could seriously harm its results of operations.

In addition, the overall integration of the two companies may result in material unanticipated problems, expenses, liabilities, competitive responses, loss of customer relationships and diversion of management’s attention, and may cause Topco’s stock price to decline.

The difficulties of combining our operations with those of Clywedog include, among others:

• managing a significantly larger company;

• coordinating geographically separate organizations, including extensive international operations;

• the potential diversion of management’s focus and resources from other strategic opportunities and from operational matters;

• performance shortfalls at one or both of the companies as a result of the diversion of management’s attention caused by completing the Combinations and integrating the companies’ operations;

• aligning and executing the strategy of the combined companies;

• retaining existing business relationships and executing new strategic or commercial relationships;

• maintaining employee morale and retaining key management and other employees;

• the disruption of, or the loss of momentum in, each company’s ongoing business or inconsistencies in standards, controls, systems, procedures and policies;

• integrating two unique business cultures, which may prove to be incompatible;

• the possibility of faulty assumptions underlying expectations regarding the integration process;

• consolidating corporate and administrative infrastructures and eliminating duplicative operations;

• integrating IT, communications and other systems;

• changes in applicable laws and regulations;

• managing tax costs or inefficiencies associated with integrating the operations of each company;

• unforeseen expenses or delays associated with the Contemplated Transactions;

• taking actions that may be required in connection with obtaining regulatory approvals.

Many of these factors will be outside of our control and any one of them could result in increased costs and diversion of management’s time and energy, which could materially impact our business, financial condition and results of operations

In addition, even if our operations are integrated successfully with those of Clywedog, Topco may not realize the full benefits of the Contemplated Transactions, including the synergies, cost savings or growth opportunities that we and our shareholders expect.

These benefits may not be achieved within the anticipated timeframe, or at all.

As a result, we cannot assure our shareholders that the Contemplated Transactions will be completed successfully, that the integration will be accomplished within the expected timeframe, or that Topco will realize the full benefits anticipated from the Contemplated Transactions, any of which could adversely affect the value of our shareholders’ investment.

Our shareholders and Clywedog’s stockholders may not realize a benefit from the Contemplated Transactions commensurate with the ownership dilution they will experience in connection with the Contemplated Transactions.

If Topco is unable to realize the full strategic and financial benefits currently anticipated from the Contemplated Transactions, our shareholders and Clywedog’s stockholders will have experienced substantial dilution of their ownership interests without receiving any commensurate benefit, or only receiving part of the commensurate benefit to the extent Topco is able to realize only part of the strategic and financial benefits currently anticipated from the Contemplated Transactions.

Our shareholders and Clywedog’s stockholders will generally have a reduced ownership and voting interest in, and will exercise less influence over the management of, Topco following the completion of the Contemplated Transactions as compared to their current ownership and voting interests in the respective companies.

After the completion of the Contemplated Transactions, our current shareholders and the current stockholders of Clywedog will generally own a smaller percentage of Topco than their ownership of their respective companies prior to the Contemplated Transactions.

Immediately after the Contemplated Transactions, our shareholders as of immediately prior to the Scheme Transaction are expected to own approximately 34% of the outstanding shares of Topco and former Clywedog stockholders are expected to own approximately 66% of the outstanding shares of Topco.

During the period prior to the closing of the Contemplated Transactions, our business is exposed to certain inherent risks due to the effect of the announcement or pendency of the Contemplated Transactions on our business relationships, financial condition, operating results and business.

Inherent risks to our business during the period prior to the closing of the Contemplated Transactions that may adversely affect our business relationships, financial condition, operating results and business include:

• the possibility of disruption to our business and operations, including diversion of management attention and resources;

• the inability to attract and retain key personnel, and the possibility that our current employees could be distracted, and their productivity decline as a result, due to uncertainty regarding the Contemplated Transactions;

• the inability to pursue alternative business opportunities or make changes to our business pending the completion of the Contemplated Transactions, and other restrictions on our ability to conduct our business included in the Merger Agreement;

• our inability to solicit other acquisition proposals during the pendency of the Contemplated Transactions;

• the amount of the costs, fees, expenses and charges related to the Contemplated Transactions and the Contemplated Transactions;

• other developments beyond our control, including, but not limited to, changes in domestic or global economic conditions that may affect the timing or success of the Contemplated Transactions.

Litigation may arise in connection with the Contemplated Transactions, which could be costly, prevent consummation of the Contemplated Transactions, divert management’s attention and otherwise materially harm our business.

Regardless of the outcome of any future litigation related to the Contemplated Transactions, such litigation may be time-consuming and expensive and may distract our management from running the day-to-day operations of our business.

The litigation costs and diversion of management’s attention and resources to address the claims and counterclaims in any litigation related to the Contemplated Transactions may materially adversely affect our business, financial condition and

operating results, including by decreasing our cash reserves for related expenses.

If the Contemplated Transactions are not consummated, for any reason, litigation could be filed in connection with the failure to consummate the Contemplated Transactions.

Any litigation related to the Contemplated Transactions may result in negative publicity or an unfavorable impression of our company, which could adversely affect the price of our common stock, impair our ability to recruit or retain employees, damage our relationships with our clients, or otherwise materially harm our operations and financial performance.

We are subject to restrictions on our business activities under the Merger Agreement.

While the Merger Agreement is in effect, we are generally required to conduct our business in the ordinary course consistent with past practice, and are restricted from taking certain actions without Clywedog’s prior consent, which is not to be unreasonably withheld, conditioned or delayed.

These limitations include, among other things, certain restrictions on our ability to amend our organizational documents, acquire other businesses and assets, dispose of our assets, make investments, repurchase, reclassify or issue securities, make loans, pay dividends, incur indebtedness, make capital expenditures, enter into, amend or terminate certain contracts, change accounting policies or procedures, initiate or settle certain litigation, change tax classifications and elections, or take certain actions relating to intellectual property.

Risks Related to Our Financial Position and Capital Needs

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We have incurred net losses each year since inception through to December 31, 2021.

For the year ended December 31, 2022, we generated net income of $5.3 million, primarily as a result of revenues (royalties/milestone payments) arising from AstraZeneca sales of Vaxzevria and our agreement with OUI.

In December 2025, we delivered written notice to OUI to terminate the OUI License Agreement.

The OUI License Agreement will remain in effect during the three-month notice period and terminated on March 2, 2026 in accordance with its terms.

For the years ending December 31, 2025 and 2024, we incurred net losses of $66.5 million and $61.2 million, respectively.

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• attract, hire and retain additional clinical, regulatory, quality control and other personnel;

• conduct preclinical studies and clinical trials for our current and future product candidates based on our proprietary biologic and synthetic platforms, including the Chimpanzee Adenovirus Oxford ("ChAdOx") and Modified vaccinia Ankara ("MVA"), vectors, SNAP-TI, SNAP-CI and our other technologies;

• conduct preclinical studies and clinical trials for our current and future product candidates based on our proprietary synthetic platform, SNAP-TI and our other technologies;

• expand our operational, financial and management systems and increase personnel, including personnel to support our clinical development, manufacturing and commercialization efforts and our operations as a public company;

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• the timely receipt of necessary marketing approvals from the FDA and similar foreign regulatory authorities;

• the willingness of physicians, operators of clinics and patients to utilize or adopt any of our product candidates or future product candidates over alternative or more conventional approaches, including antivirals, immune modulators, monoclonal antibodies, siRNA, CRISPR editing, capsid inhibitors, novel entry inhibitors, or other small molecules, RNA, DNA, nanoparticle, VLP, peptide, protein, whole-killed or other vaccine technologies;

• the actual and perceived availability, cost, risk profile and side effects and efficacy of our product candidates, if approved, relative to existing and future alternative immunotherapies, therapeutic and prophylactic vaccines and competitive product candidates and technologies;

• the willingness of physicians, operators of clinics and patients to utilize or adopt any of our product candidates or future product candidates over alternative or more conventional approaches, including immune modulators, monoclonal antibodies, CRISPR editing, or other small molecules, RNA, DNA, nanoparticle, peptide, protein, other technologies;

• the actual and perceived availability, cost, risk profile and side effects and efficacy of our product candidates, if approved, relative to existing and future alternative immunotherapies and competitive product candidates and technologies;

our ability and the ability of third parties with whom we contract to manufacture adequate clinical and commercial supplies of our product candidates or any future product candidates, remain in good standing with regulatory authorities and develop, validate and maintain commercially viable manufacturing processes that are compliant with cGMP;

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• the ability of our licensees and collaborators to develop and commercialize our products effectively;

• the risk that some or all of the patients that receive the AstraZeneca product Vaxzevria develop neutralizing antibodies against ChAdOx, which could limit the immunological response from subsequent dosing with one of our viral vector product candidates;

• the possibility that immunogenicity of our viral vectors or immune tolerance with SNAP-TI may not translate into clinical benefit;

• the possibility that immune tolerance with our SNAP-TI platform may not translate into clinical benefit;

• the increased costs and complexities associated with manufacturing.

• funding for the development of product candidates contributed by third parties, such as CRUK, CEPI and CanSino, whether spent directly by them or by grant or other funding into our company.

Many of the factors listed above are beyond our control and could cause us to experience significant delays or prevent us from obtaining marketing authorizations for, or commercializing, our product candidates.

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• risks and uncertainties associated with the other party to such a transaction, including the prospects of that party and their existing products or product candidates to achieve marketing authorizations;

• risks and uncertainties arising from disagreements or other relationship-related matters with the other party to such a transaction;

• a failure to generate revenue from acquired intellectual property, technology and/or products sufficient to meet our objectives or even to offset the associated transaction and maintenance costs.

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Our operations to date have been limited to organizing and staffing our company, business planning, raising capital, filing patent applications, identifying potential product candidates, undertaking preclinical studies, in-licensing product candidates for development, and establishing arrangements with third parties for the manufacture of initial quantities of our product candidates and component materials, as well as sponsoring and conducting clinical trials up to Phase 2b.

We have not yet demonstrated our ability to successfully complete clinical trials beyond Phase 2b, obtain marketing approvals,

manufacture a commercial-scale product or arrange for a third party to do so on our behalf, or conduct sales, marketing and distribution activities necessary for successful product commercialization.

We have not yet demonstrated our ability to successfully complete clinical trials beyond Phase 2b, obtain marketing approvals, manufacture a commercial-scale product or arrange for a third party to do so on our behalf, or conduct sales, marketing and distribution activities necessary for successful product commercialization.

Consequently, any predictions you make about our future success or viability may not be as accurate as they could be if we had a longer operating history.

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Failure to obtain this necessary capital when needed may force us to delay, limit or terminate our product development efforts or other operations.

We are currently advancing current and future product candidates based on our proprietary biologic and synthetic platforms, including the ChAdOx and MVA vectors, SNAP-TI, and our other technologies through clinical development.

We are currently advancing current and future product candidates based on our proprietary synthetic platform, SNAP-TI, and our other technologies through clinical development.

Developing and commercializing products for therapeutic indications is expensive, and we do not expect to generate meaningful product revenues in the foreseeable future.

As of December 31, 2025, our cash, cash equivalents and restricted cash were $71.9 million.

Based on our current business plan, our management believes that we have sufficient cash and other financial resources to support our operations into the start of 2027, without additional financing.

Based on our current business plan, our management believes that we have sufficient cash and other financial resources to support our operations for at least the next 12 months, without additional financing.

Our fundraising efforts to raise additional capital may divert our management from their day-to-day activities, which may adversely affect our ability to develop our platforms.

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We expect the research and development expenses for our programs to increase in parallel with the ongoing activities, particularly as we continue our preclinical and clinical development activities to identify new product candidates and conduct clinical trials of, and seek marketing approval for, our product candidates.

In addition, if we obtain marketing approval for any of our product candidates, we expect to incur significant commercialization expenses related to product launch, product sales, marketing, manufacturing and distribution.

In addition, if we obtain marketing approval for any of our

product candidates, we expect to incur significant commercialization expenses related to product launch, product sales, marketing, manufacturing and distribution.

Furthermore, we expect to incur significant additional costs associated with operating as a public company.

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• the timing of, success achieved and the costs involved in obtaining regulatory and marketing approvals and developing our ability to establish license or sale transactions and/or sales and marketing capabilities, if any, for our current and future product candidates if clinical trials and approval processes are successful;

• the success of our collaborations with CEPI, Oxford University/OUI, Arbutus, CanSino, CRUK and the Ludwig Institute and any future collaboration partners;

• our ability to establish and maintain collaborations, strategic licensing or other arrangements and the financial terms of such agreements;

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• the costs of preparing, filing and prosecuting patent applications, obtaining, maintaining, enforcing and protecting our intellectual property rights and defending intellectual property-related claims including litigation costs and any damages awarded in such litigation;

• the emergence and success or otherwise of competing autoimmune or infectious disease therapies and other market developments.

• the emergence and success or otherwise of competing autoimmune disease therapies and other market developments.

Identifying potential product candidates, manufacturing them and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to obtain marketing approval and achieve product sales.

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If we are not successful with respect to one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully commercialize the product candidates we develop, which would materially harm our business.

We have no control over third-party use of ChAdOx and MVA technologies outside of our exclusively licensed field under license from OUI, and such third-party use could have a negative impact on our ability to partner or develop current and future product candidates, which would materially harm our business.

Clinical development involves a lengthy and expensive process with uncertain outcomes, and results of earlier preclinical studies and clinical trials may not be predictive of future clinical trial results.

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• our third-party contractors may fail to comply with regulatory requirements, fail to maintain adequate quality controls or be unable to provide us with sufficient or timely product supply to conduct and complete preclinical studies or clinical trials of our product candidates in a timely manner, or at all;

• we or our investigators might have to suspend or terminate clinical trials of our product candidates for various reasons, including non-compliance with regulatory requirements, a finding that our product candidates have undesirable side effects or other unexpected characteristics or a finding that the participants are being exposed to unacceptable health risks;

undesirable side effects or other unexpected characteristics or a finding that the participants are being exposed to unacceptable health risks;

• the cost of clinical trials of our product candidates may be greater than we anticipate, for example, if we experience delays or challenges in identifying participants with the eligibility criteria required for our clinical trials, we may have to reimburse sites for the cost of testing of additional participants in order to encourage enrollment of additional participants;

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• future collaborators may conduct clinical trials in ways they view as advantageous to them but that are suboptimal for us.

In addition, the ChAdOx vectors are currently being evaluated in clinical trials outside of our licensed fields conducted by Oxford and other third parties to which OUI has granted licenses.

We have no control over these other clinical trials and any adverse results in these clinical trials could impact public perception and regulatory approval of our product candidates.

Even after any of our product candidates obtain regulatory marketing authorization, the announcement of adverse events observed in individuals who receive these products may impact public perception and may result in increased regulatory scrutiny across our platform.

For example, in March 2021, several countries announced plans to either temporarily suspend the use of a particular batch of Vaxzevria or the use of Vaxzevria altogether following reports of very rare thromboembolic events in people following vaccination.

While the EMA subsequently issued an update confirming the overall risk-benefit profile of Vaxzevria remains positive, and Vaxzevria later received full marketing authorization in the EU in November 2022, these types of announcements may affect public perception of the safety of Vaxzevria, which may extend to product candidates we are developing.

Other very rare events have been reported in people who have received Vaxzevria, including thrombocytopenia (low platelet numbers in the blood), capillary leak syndrome, and neurological syndromes such as Guillain Barre Syndrome and transverse myelitis.

Perception about the efficacy of Vaxzevria, such as its effectiveness against emerging COVID-19 variants, may also impact perception of our other product candidates.

Additionally, these announcements may lead to additional inquiries or scrutiny from regulators on whether similar safety or efficacy signals have been observed with our other candidates.

In addition, even after any of our product candidates obtain regulatory marketing authorization, the announcement of adverse events observed in individuals who receive these products may impact public perception and may result in increased regulatory scrutiny across our platform.

If we are required to conduct additional clinical trials or other testing of our product candidates beyond those that we currently contemplate, if we are unable to successfully complete clinical trials of our product candidates or other testing, if the results of these trials or tests are not positive or are only moderately positive or if there are safety concerns, our business and results of operations may be adversely affected and we may incur significant additional costs.

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Any of these occurrences may significantly harm our business, financial condition and prospects.

In addition, many of the

factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of marketing authorization for our product candidates.

In addition, many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of marketing authorization for our product candidates.

If one or more of our product candidates generally prove to be ineffective, unsafe or commercially unviable, this would have a material and adverse effect on our business, financial condition, results of operations and prospects.

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We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data.

As a result, the topline or preliminary results that we report may differ from future results of the same studies or clinical trials, or different conclusions or considerations may qualify such results, once additional data have been received and fully evaluated.

As a result, the topline or preliminary results that we report may differ from future results of the same studies or clinical trials, or different conclusions or considerations may

qualify such results, once additional data have been received and fully evaluated.

Topline data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously published.

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Further, disclosure of interim data by us or by our competitors could result in volatility in the price of our ADSs.

In addition, the ChAdOx vectors are currently being evaluated in clinical trials conducted by Oxford University/OUI and other third parties to which Oxford University/OUI has granted licenses.

We have no control over these other clinical trials and any adverse results in these clinical trials could impact public perception and regulatory approval of our product candidates.

The information these third parties choose to publicly disclose regarding a particular study or clinical trial is based on what is typically extensive information, and shareholders may not agree with what these third parties determine is material or otherwise appropriate information to include in their disclosure.

Further, others, including regulatory authorities, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and our company in general.

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If the interim, topline, or preliminary data that we report differ from more complete results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain marketing authorization for, and commercialize, our product candidates may be harmed, which could harm our business, operating results, prospects or financial condition.

Our product candidates are based on a novel approach to the treatment of infectious disease and autoimmunity, which makes it difficult to predict the time and cost of product candidate development.

We have concentrated our research and development efforts on components of our proprietary platforms to develop product candidates that either stimulate powerful, targeted immune responses against pathogens or promote immune tolerance for suppressing unwanted inflammation, which are novel approaches.

Our product candidates are based on a novel approach to the treatment of autoimmunity, which makes it difficult to predict the time and cost of product candidate development.

We have concentrated our research and development efforts on components of our proprietary platforms to develop product candidates that promote immune tolerance for suppressing unwanted inflammation.

Our future success depends on the successful development of these platforms.

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• reporting of the preliminary results of any of our clinical trials;

• the risk that some or all of the patients that receive Vaxzevria develop neutralizing antibodies against ChAdOx, which could limit the immunogenicity from subsequent dosing with one of our product candidates that utilize ChAdOx;

• the risk that participants enrolled in clinical trials will drop out of the clinical trials before clinical trial completion;

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Because of our dose escalation design for our clinical trials, undesirable side effects in initial cohorts could also result in the need to expand the size of our clinical trials, increasing the expected costs and timeline of our clinical trials.

Additionally, because certain of our product candidates, including Vaxzevria, have been administered to substantial numbers of participants on a more rapid basis than is standard in clinical trials, undesirable side effects could result in a negative impact across a larger participant population.

Results of our clinical trials could reveal a high and unacceptable severity and prevalence of side effects or unexpected characteristics.

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In addition, these side effects may not be appropriately recognized or managed by the treating medical staff.

We intend to develop certain of our product candidates in combination with other therapies, which exposes us to additional risks.

We intend to develop certain of our product candidates in combination with one or more other approved therapies, such as anti-PD-1 antibodies and other checkpoint inhibitors to treat certain cancers and infectious diseases.

Even if any product candidate we develop were to receive marketing authorization or be commercialized for use in combination with other existing therapies, we would continue to be subject to the risks that the FDA, the EMA or comparable foreign regulatory authorities outside of the United States could revoke approval of the therapy used in combination with our product or that safety, efficacy, manufacturing or supply issues could arise with any of those existing therapies.

If the therapies we use in combination with our product candidates are replaced as the standard of care for the indications we choose for any of our product candidates, the FDA, the EMA or comparable foreign regulatory authorities may require us to conduct additional clinical trials.

The occurrence of any of these risks could result in our own products, if approved, being removed from the market or being less successful commercially.

We also may choose to evaluate our current product candidates and any other future product candidates in combination with one or more therapies that have not yet been approved for marketing by the FDA, the EMA or comparable foreign regulatory authorities.

We will not be able to market and sell our current product candidates or any product candidate we develop in combination with any unapproved therapies for a combination indication if that unapproved therapy does not ultimately obtain marketing approval either alone or in combination with our product.

In addition, unapproved therapies face the same risks described with respect to our product candidates currently in development and clinical trials, including the potential for serious adverse effects, delay in their clinical trials and lack of FDA approval.

If the FDA, the EMA or comparable foreign regulatory authorities do not approve these other products or revoke their approval of, or if safety, efficacy, quality, manufacturing or supply issues arise with, the products we choose to evaluate in combination with our product candidate we develop, we may be unable to obtain approval of or market such combination therapy.

Risks Related to Our Approach

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Immunotherapies for treating patients with autoimmune and other inflammatory diseases are sometimes staged based on disease severity or may be characterized by line of therapy (first line, second line, third line, fourth line, etc.), and the regulatory authorities, including the FDA, often approve new therapies initially only for a particular line or lines of use.

Our product candidates based on SNAP-TI are at early stages of development and there is currently uncertainty as to how the may fit into existing treatment paradigms.

We expect to seek approval of VTP-1000 as a first line therapy but for our other SNAP-TI product candidates we may need to seek approval for use as a second or later line of therapy or in patients who do not respond to more conservative management.

Similarly, cancer therapies are sometimes characterized by line of therapy (first line, second line, third line, fourth line, etc.), and the regulatory authorities, including the FDA, often approve new therapies initially only for a particular line or lines of use.

When cancer is detected early enough, first line therapy is sometimes adequate to cure the cancer or prolong life without a cure.

Whenever first line therapy, usually chemotherapy, antibody drugs, tumor-targeted small molecules, hormone therapy, radiation therapy, surgery, or a combination of these, proves unsuccessful, second line therapy may be administered.

Second line therapies often consist of more chemotherapy, radiation, antibody drugs, tumor-targeted small molecules, or a combination of these.

Third line therapies can include chemotherapy, antibody drugs and small molecule tumor-targeted therapies, more invasive forms of surgery and new technologies.

We expect to advance VTP-600 as a component of first line therapy but we expect to advance our other oncology product candidates initially as second or third line therapy, for use in patients with relapsed or refractory metastatic cancer.

Subsequently, for those product candidates that prove to be sufficiently safe and beneficial as third line or second line therapies, if any, we would expect to advance as earlier line therapies, but there is no guarantee that our product candidates, even if approved as a second or third line of therapy, would be approved for an earlier line of therapy, and, prior to any such approvals, we may have to conduct additional clinical trials.

Our product candidate VTP-1000 based on SNAP-TI is at an early stage of development and there is currently uncertainty as to how the may fit into existing treatment paradigms.

We expect to seek approval of VTP-1000 as a first line therapy, but FDA or other regulatory authorities may disagree with this plan, and we may need to seek approval for use as a second or later line of therapy.

Our projections of both the number of people who have the disease that we are targeting, as well as the subset of people with these conditions in a position to receive a particular line of therapy and who have the potential to benefit from treatment with our product candidates, are based on our beliefs and estimates.

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Negative developments in the field of immunotherapeutics could damage public perception of any of our product candidates and negatively affect our business.

The commercial success of our product candidates will depend in part on public acceptance of the use of immunotherapies and viral vector-based antigen-delivery platforms.

The commercial success of our product candidates will depend in part on public acceptance of the use of immunotherapies and nanoparticle-based antigen-delivery platforms.

Adverse events in clinical trials of VTP-1000, or in clinical trials of similar products developed by others and the resulting publicity, as well as any other negative developments in the field of immunotherapeutics that may occur in the future, including in connection with competitor therapies, could result in a decrease in demand for any product candidates that we may develop.

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As a result, we may not be able to continue or may be delayed in conducting our development programs.

Several of our product candidates utilize SNAP-TI to induce immune tolerance.

VTP-1000 utilizes SNAP-TI to induce immune tolerance.

Adverse developments in clinical trials of other immunotherapy products that promote antigen-specific immune tolerance, may result in a disproportionately negative effect for our platform, as compared to other products within the I&I field that do not rely on antigen-specific immune tolerance.

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Any increased scrutiny could delay or increase the costs of obtaining marketing approval for our product candidates.

Several of our product candidates consist of modified viruses.

Adverse developments in clinical trials of other immunotherapy products based on viruses, may result in a disproportionately negative effect for our platform as compared to other products that are not based on viruses.

Future negative developments in the biopharmaceutical industry could also result in greater governmental regulation, stricter labeling requirements and potential regulatory delays in the testing or approvals of our products.

Any increased scrutiny could delay or increase the costs of obtaining marketing approval for our product candidates.

We may not be successful in our efforts to identify and successfully commercialize additional product candidates.

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, antibodies, CAR-T cells and T cell engagers) immunomodulatory small molecules, transgenic T cells, genetic therapies and other antigen-specific immune tolerance therapies based on proteins, DNA, RNA and peptides or other technologies.

We expect that our product candidates based on our viral vector platforms will compete against alternative or more conventional approaches, including antivirals, immune modulators, antisense oligonucleotides, siRNA, CRISPR editing, capsid inhibitors, novel entry

inhibitors, or other small molecules, RNA, DNA, nanoparticle, VLP, peptide, protein, whole-killed vaccines or other technologies.

If our product candidates are approved for the indications for which we are currently conducting or planning clinical trials, they will likely compete with the competitor products mentioned above and with other products that are currently in development.

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In some instances, there can be significant variability in safety, potency, purity, or efficacy results between different preclinical studies and clinical trials of the same product candidate due to numerous factors, including changes in trial procedures set forth in protocols, differences in the size and type of the patient populations, changes in and adherence to the clinical trial protocols and the rate of dropout among clinical trial participants.

As is the case with all investigational biologics and drugs, including novel immunotherapeutics such as those based on our viral vector and SNAP-TI platforms, it is likely that there may be side effects associated with their use.

As is the case with all investigational biologics and drugs, including novel immunotherapeutics such as those based on our SNAP-TI platform, it is likely that there may be side effects associated with their use.

Results of our trials could reveal a high and unacceptable severity and prevalence of these side effects.

In such an event, our trials could be suspended or terminated and the FDA or comparable foreign regulatory authorities could order us to cease further

development of or deny authorization of certain of our product candidates for any or all targeted indications.

In such an event, our trials could be suspended or terminated and the FDA or comparable foreign regulatory authorities could order us to cease further development of or deny authorization of certain of our product candidates for any or all targeted indications.

Treatment-related side effects could also affect participant recruitment or the ability of enrolled participants to complete the trial or result in potential product liability claims.

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Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open-label clinical trials are aware when they are receiving treatment.

Open-label clinical trials may be subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment.

Open-label clinical trials may be

subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment.

In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge.

The results from an open-label trial may not be predictive of future clinical trial results with any of our product candidates for which we include an open-label clinical trial when studied in a controlled environment with a placebo or active control.

Even if we obtain marketing authorization for our product candidates, the products may not gain market acceptance among physicians, patients, hospitals, cancer treatment centers and others in the medical community.

The use of novel immunotherapeutics, such as our SNAP-TI and viral-vector based product candidates to target the treatment and prevention of autoimmune diseases, infectious disease and cancer is a recent development and may not become broadly accepted by physicians, patients, hospitals, cancer treatment centers and others in the medical community.

Even if we obtain marketing authorization for our product candidates, the products may not gain market acceptance among physicians, patients, hospitals and others in the medical community.

The use of novel immunotherapeutics, such as our SNAP-TI product candidate to target the treatment and prevention of autoimmune diseases is a recent development and may not become broadly accepted by physicians, patients, hospitals and others in the medical community.

Various factors will influence whether our product candidates are accepted in the market, including:

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• the prevalence and severity of any side effects for other immunotherapeutics and public perception of other immunotherapeutics;

• the prevalence and severity of any side effects for other viral-vector based antigen-delivery platforms and public perception of other viral-vector based antigen-delivery platforms;

• the prevalence and severity of any side effects for other nanoparticle-based therapeutics and public perception of other nanoparticle-based therapeutics;

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If our product candidates are licensed but fail to achieve market acceptance among physicians, patients, hospitals or others in the medical community, we will not be able to generate significant revenue.

In addition, although our product candidates differ in certain ways from other immunotherapeutic based approaches, serious adverse events or deaths in other clinical trials involving immunotherapeutic based product candidates, even if not ultimately attributable to our product or product candidates, could result in increased government regulation, unfavorable public perception and publicity, potential regulatory delays in the testing or licensing of our product candidates, stricter labeling requirements for those product candidates that are licensed, and a decrease in demand for any such product candidates.

labeling requirements for those product candidates that are licensed, and a decrease in demand for any such product candidates.

Even if our products achieve market acceptance, we may not be able to maintain that market acceptance over time if new products or technologies are introduced that are more favorably received than our products, are more cost effective or render our products obsolete.

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Regulatory authorities enforce GCP through periodic inspections of trial sponsors, principal investigators and trial sites.

If we, or any of these third parties fail to comply with applicable GCP regulations, the clinical data generated in our clinical trials may be deemed unreliable and the FDA or comparable foreign regulatory authorities may require us to perform additional clinical trials before approving our MMAs.

We cannot assure you that, upon inspection, such regulatory authorities will determine that any of our clinical trials comply with the GCP regulations.

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Manufacturing of biologic and synthetic products is complex and requires significant expertise and capital investment, including the development of advanced manufacturing techniques and process controls.

Manufacturers of biologic products often encounter difficulties in production, particularly in scaling up, validating the production process and assuring high reliability of the manufacturing process, including the absence of contamination.

Manufacturers of synthetic products often encounter difficulties in production, particularly in scaling up, validating the production process and assuring high reliability of the manufacturing process, including the absence of contamination.

These problems include logistics and shipping, difficulties with production costs and yields, quality control, including lot consistency, stability of the product, product testing, operator error and availability of qualified personnel, as well as compliance with strictly enforced federal, state and foreign regulations.

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• the FDA, the EMA, MHRA or other comparable foreign regulatory authorities may find deficiencies with or fail to approve the manufacturing processes or facilities of third-party manufacturers with which we contract for clinical and commercial supplies;

• Inadequate funding for the FDA, the SEC and other government agencies, including from government shutdowns, or other disruptions to these agencies’ operations, could hinder their ability to hire and retain key leadership and other personnel, prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

• Inadequate funding for the FDA, the SEC and other government agencies, including from prolonged government shutdowns, or other disruptions to these agencies’ operations, could hinder their ability to hire and retain key leadership and other personnel, prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

• the approval policies or regulations of the FDA, the EMA, MHRA or other comparable foreign regulatory authorities may significantly change in a manner rendering our clinical data insufficient for approval;

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There can be no assurance the FDA will accept data from trials conducted outside of the United States.

Additionally, recent policy proposals in the U.S., if enacted in the future, may make acceptance by the FDA or inclusion in a marketing application of foreign data more difficult or costly.

The FDA, the EMA and other comparable foreign regulatory authorities have substantial discretion in the approval process, and determining when or whether marketing authorization will be obtained for any product candidate that we develop.

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The EU exclusivity period can be reduced to six years if a drug no longer meets the criteria for Orphan Drug Designation or if the drug is sufficiently profitable such that market exclusivity is no longer justified.

Even if we obtain orphan drug exclusivity for a drug candidate, that exclusivity may not effectively protect the drug candidate from competition because different therapies can be approved for the same condition.

Even after an orphan drug is approved, the FDA can subsequently approve a second drug candidate for the same condition if the FDA concludes that the later drug is clinically superior in that it is shown to be safer, more effective or makes a major contribution to patient care.

Even after an orphan drug is approved, the FDA can subsequently approve a second drug candidate for the same indication if the FDA concludes that the later drug is clinically superior in that it is shown to be safer, more effective or makes a major contribution to patient care.

In addition, a designated orphan drug may not receive orphan drug exclusivity if it is approved for a use that is broader than the indication for which it received orphan designation.

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In addition, even if one or more of our product candidates qualify as breakthrough therapies, the FDA may later decide that the product no longer meets the conditions for qualification.

Thus, even though we intend to seek Breakthrough Therapy designation for certain of our current and future product candidates for the treatment and prevention of infectious diseases and cancer, there can be no assurance that we will receive breakthrough therapy designation.

Thus, even though we intend to seek Breakthrough Therapy designation for certain of our current and future product candidates, there can be no assurance that we will receive breakthrough therapy designation.

A Fast Track designation by the FDA, even if granted for certain of our current or future product candidates, may not lead to a faster development or regulatory review or approval process, and does not increase the likelihood that our product candidates will receive marketing approval.

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However, there is a risk that this exclusivity could be shortened due to congressional action or otherwise, or that the FDA will not consider our investigational medicines to be reference products for competing products, potentially creating the opportunity for biosimilar competition sooner than anticipated.

Moreover, the extent to which a biosimilar, once licensed, will be substituted for any one of our reference products in a way that is similar to traditional generic substitution for non-biologic products is not yet clear, and will depend on a number of marketplace and regulatory factors that are still developing, including the potential for sponsors under FDA draft guidance issued in 2024 to demonstrate interchangeability without conducting so-called "switching" studies and the potential for sponsors under FDA draft guidance issued in 2025 to demonstrate biosimilarity without conducting comparative efficacy studies.

Although the FDA has yet to finalize these draft guidance documents, these or similar efforts may increase the risk of competition for our biologic product candidates, if approved.

If competitors are able to obtain marketing approval for biosimilars referencing our products, our products may become subject to competition from such biosimilars, with the attendant competitive pressure and consequences.

Even if we obtain FDA, European Commission or MHRA approval for our current or future product candidates that we may identify and pursue in the United States, the European Union or the United Kingdom, we may never obtain approval to commercialize any such product candidates outside of those jurisdictions, including in Asian markets wherein we intend to commercialize VTP-300, which would limit our ability to realize their full market potential.

Even if we obtain FDA, European Commission or MHRA approval for our current or future product candidates that we may identify and pursue in the United States, the European Union or the U.K.

, we may never obtain approval to commercialize any such product candidates outside of those jurisdictions.

Obtaining and maintaining marketing authorization for our product candidates in one jurisdiction does not guarantee that we will be able to obtain or maintain marketing authorizations in any other jurisdiction, while a failure or delay in obtaining marketing authorization in one jurisdiction may have a negative effect on the approval process in others.

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The foreign marketing authorization process may include all of the risks associated with obtaining FDA, European Commission or MHRA approval, in addition to country-specific risks and challenges.

For example, we are looking to partner the further development of VTP-300 for chronic hepatitis B, which is a condition most prevalent in China and other countries in Asia.

We have limited development experience in this market and we may need to rely on a local, third-party partner to help us navigate the applicable regulatory requirements.

Additionally, governments in this target market may deem the eradication of HBV infections to be a national priority which could impact the framework for available reimbursement or our ability to achieve a standard commercial return based on the value of our product, if approved.

We do not have any product candidates approved for sale in any jurisdiction, including international markets, and we do not have experience in obtaining marketing authorizations in international markets for our current or future product candidates.

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As a company that carries out extensive research and development activities, we seek to benefit from the U.K.

research and development tax relief programs, being the Small and Medium-sized Enterprises R&D tax relief program, or SME Program, and, to the extent that our projects are grant funded or relate to work subcontracted to us by third parties, the Research and Development Expenditure Credit program.

Under the SME Program, where available, we may be able to surrender some of our trading losses that arise from our qualifying research and development activities for cash or carry forward such losses for potential offset against future profits (subject to relevant restrictions).

The majority of our research, clinical trials management and manufacturing development activities are eligible for inclusion within these tax credit cash rebate claims.

Our eligibility to claim payable research and development tax credits may be limited or eliminated because we may no longer qualify as a small or medium-sized company.

In addition, the SME Program has been amended by the Finance Act 2021 which came into force in April 2021.

This legislation introduced a cap on claims under the SME Program to a multiple of payroll taxes (broadly, to a maximum payable credit equal to £20,000 plus three times the total PAYE and NICs liability of the company) subject to an exception which prevents the cap from applying.

That exception requires the company to be creating, taking steps to create or managing intellectual property, as well as having qualifying research and development expenditure in respect of connected parties which does not exceed 15% of the total claimed.

If such exception does not apply, this could restrict the amount of payable credit that we claim.

research and development tax relief programs.

From 2025, we benefit from the applicable United Kingdom research and development tax credit regime which is the merged scheme Research & Development expenditure credit ("RDEC") and enhanced R&D intensive support ("ERIS") that replaces the old RDEC and small and medium-sized enterprise ("SME") schemes for accounting periods beginning on or after April 1, 2024.

For expenditure under the merged scheme, the rate of Research and Development expenditure credit is 20%, which is the same as the rate under the old RDEC scheme for expenditure incurred on or after April 1, 2023.

For loss-makers and small profit-makers, a lower rate of notional tax restriction (currently 19%) applies at payment.

The amount of the Pay As You Earn ("PAYE") cap for claims under both the merged scheme and ERIS is £20,000 plus 300% of the company’s relevant PAYE and National Insurance contributions liabilities.

The PAYE cap (where applicable) will limit the amount of payable credit that can be received in the accounting period under consideration.

Any excess over the cap will be carried forward and treated as an amount of Research and Development expenditure credit to which the company will be entitled for the next accounting period.

Based on prior claims and the split of qualifying spend it is expected that the PAYE cap is unlikely to affect the net benefit.

Furthermore, legislation included in Finance Act 2024 restricts the extent to which payments to contractors for R&D, and externally provided workers can qualify for R&D relief where R&D activity takes place outside the U.K., which may restrict the ability to include cost incurred on externally provided workers based in the U.S.

A large portion of our research, clinical trials management and manufacturing development activities are eligible for inclusion within these tax credit cash rebate claims.

Our eligibility to claim payable research and development tax credits may be limited or eliminated because we may no longer qualify based on the eligibility criteria.

Unsurrendered U.K.

losses may be carried forward indefinitely to be offset against future taxable profits, subject to numerous utilization criteria and restrictions.

The amount that can be offset each year is limited to £5.0 million plus an incremental 50% of U.K.

taxable profits.

There was no tax loss restriction applied to the R&D tax credits in the U.K.

for the years ending December 31, 2025 and 2024.

Changes to the U.K.

R&D tax relief legislation that have been recently enacted, and which took effect from April 2023, reduce the R&D cash rebate rate under the SME Program.

For expenditure incurred on or after April 1, 2024, there are restrictions on relief that may be claimed for expenditure on sub-contracted R&D activity, broadly requiring either that workers carrying on such activity are subject to U.K.

PAYE or, where work is undertaken outside the U.K., that this must be due to geographical, environmental, social or other conditions that:

(i) are not present in the U.K.;

and (ii) it would be wholly unreasonable to replicate in the U.K.

These rate reductions and restrictions impact the quantum of R&D relief that we are able to claim.

In addition, this legislation also saw the introduction of a higher rate of relief for loss-making R&D-intensive small and medium enterprises, the SME Intensive Scheme.

Companies claiming under the existing SME Intensive Scheme tax relief will be eligible for a higher payable credit rate if they meet the definition for R&D intensity.

From the analysis performed, we have not and do not currently expect to claim under the loss-making R&D Intensive Scheme for SMEs primarily due to the proportion of total relevant expenditure occurring outside the United Kingdom.

Under both the current RDEC scheme and the historic SME scheme (which we relevant to us in prior tax years), a company qualifies as an R&D intensive business if R&D expenditure constitutes at least 30% of total expenditure.

From the analysis performed, we have not and do not currently expect to claim under the loss-making R&D intensive scheme criteria primarily due to the proportion of total relevant expenditure occurring outside the U.K.

We may benefit in the future from the U.K.’s “patent box” regime, which allows certain profits attributable to revenue from patented products (and other qualifying income) to be taxed at an effective rate of 10% by giving an additional tax deduction.

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• injunctions or the imposition of civil, criminal, or administrative penalties.

Additionally, under FDORA, sponsors of approved drugs and biologics must provide 6 months’ notice to the FDA of any changes in marketing status, such as the withdrawal of a drug, and failure to do so could result in the FDA placing the product on a list of discontinued products, which would revoke the product’s ability to be marketed.

The FDA’s and other regulatory authorities’ policies may change and additional government regulations may be enacted that could prevent, limit or delay marketing authorization of our product candidates.

Additionally, under FDORA, sponsors of approved drugs and biologics must provide 6 months’ notice to the FDA of any changes in marketing status, such as the withdrawal of a drug, and failure to do so could result in a letter citing such failure to comply and public posting of such letter and redacted company response, which could damage the company's reputation.

The FDA’s and other regulatory authorities’ policies may change and additional government regulations may be enacted

that could prevent, limit or delay marketing authorization of our product candidates.

We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the United States or abroad.

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If any such changes were to be imposed, they could adversely affect the operation of our business.

See the section entitled “Business – Government Regulation – Healthcare Reform and Legislative Changes.”

See the section titled “Business – Government Regulation – Healthcare Reform and Legislative Changes.

We expect that these and other healthcare reform measures that may be adopted in the future may result in more rigorous coverage criteria and in additional downward pressure on the price that we receive for any approved product candidate.

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Our business is heavily regulated and therefore involves significant interaction with public officials, including officials of non-United States governments.

Additionally, in many other countries, the healthcare providers who prescribe pharmaceuticals are employed by their government, and the purchasers of pharmaceuticals are government entities;

Additionally, in many other countries, the healthcare providers who prescribe

pharmaceuticals are employed by their government, and the purchasers of pharmaceuticals are government entities;

therefore, our dealings with these prescribers and purchasers will be subject to regulation under the FCPA.

Recently the Securities and Exchange Commission, or the SEC, and Department of Justice have increased their FCPA enforcement activities with respect to biotechnology and pharmaceutical companies.

There is no certainty that all of our employees, agents, suppliers, manufacturers, contractors, or collaborators, or those of our affiliates, will comply with all applicable

laws and regulations, particularly given the high level of complexity of these laws.

There is no certainty that all of our employees, agents, suppliers, manufacturers, contractors, or collaborators, or those of our affiliates, will comply with all applicable laws and regulations, particularly given the high level of complexity of these laws.

Violations of these laws and regulations could result in fines, criminal sanctions against us, our officers, or our employees, the closing down of facilities, including those of our suppliers and manufacturers, requirements to obtain export licenses, cessation of business activities in sanctioned countries, implementation of compliance programs, and prohibitions on the conduct of our business.

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Inadequate funding for the FDA, the SEC and other government agencies, including from government shutdowns, or other disruptions to these agencies’ operations, could hinder their ability to hire and retain key leadership and other personnel, prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

Currently, federal agencies in the U.S.

are operating under a continuing resolution that is set to expire on September 30, 2025.

Without appropriation of additional funding to federal agencies, our business operations related to our product development activities for the U.S.

Without appropriation of funding to federal agencies, our business operations related to our product development activities for the U.S.

market could be impacted.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory and policy changes.

Average review times at the agency have fluctuated in recent years as a result.

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In addition, government funding of the SEC and other government agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable.

For example, over the last several years the U.S.

Disruptions and personnel turnover, including as a result of leadership changes, staff reductions or otherwise, at the FDA and other agencies may also slow the time necessary for new drugs and biologics or modifications to approved drugs and biologics to be reviewed and/or approved by necessary government agencies, which would adversely affect our business.

Changes and cuts in FDA staffing also could result in delays in the FDA’s responsiveness or in its ability to review IND submissions or applications, issue regulations or guidance, or implement or enforce regulatory requirements in a timely fashion or at all.

Over the last several years the U.S.

government has shut down several times and certain regulatory authorities, such as the FDA and the SEC, have had to furlough critical FDA, SEC and other government employees and stop critical activities.

If a prolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business.

Further, future government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

In addition, the current U.S.

presidential administration has issued certain policies and Executive Orders directed towards reducing employee headcount and costs associated with U.S.

administrative agencies, including the FDA, and it remains unclear the degree to which these efforts may limit or otherwise adversely affect the FDA's ability to conduct routine activities.

If a prolonged government shutdown occurs, or if renewed global health concerns, funding shortages or staffing limitations hinder or prevent the FDA or other regulatory authorities from conducting their regular inspections, reviews, or other regulatory activities, including formal and informal interactions with product developers, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business.

Our business operations and current and future relationships with principal investigators, healthcare providers, including physicians, consultants, third-party payors and customers may be subject, directly or indirectly, to U.S.

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The risk of our being found in violation of these laws is increased by the fact that many of them have not been fully interpreted by applicable regulatory authorities or the courts, and their provisions are open to a variety of interpretations.

Efforts to ensure that our business arrangements with third parties will comply with applicable healthcare laws and

regulations will involve substantial costs.

Efforts to ensure that our business arrangements with third parties will comply with applicable healthcare laws and regulations will involve substantial costs.

Any action against us for violation of these laws, even if we successfully defend against it, could cause us to incur significant legal expenses and divert our management’s attention from the operation of our business.

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If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, including the imposition of significant civil, criminal and administrative penalties, including, without limitation, damages, fines, disgorgement, imprisonment, exclusion from participation in government healthcare programs, such as Medicare and Medicaid, additional reporting requirements and oversight if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance with these laws, and the curtailment or restructuring of our operations.

If we fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of our business.

If we fail to comply with data protection, privacy, and cybersecurity laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of our business.

We and our collaborators and third-party providers are subject to national, supranational, federal or state laws and regulations, regulatory guidance and industry standards relating to data protection, privacy and information security.

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Data Protection Act 2018).

The GDPR is wide-ranging in scope and impose numerous obligations on companies that process personal data, including imposing special requirements in respect of the processing of special categories of personal data (such as health data), requiring that consent of individuals to whom the personal data relates is obtained in certain circumstances, requiring additional disclosures to individuals regarding data processing activities, requiring that safeguards are implemented to protect the security and confidentiality of personal data, creating mandatory data breach notification requirements in certain circumstances, requiring data protection impact assessments for high risk processing and requiring that certain measures (including contractual requirements) are put in place when engaging third-party processors.

The GDPR is wide-ranging in scope and impose numerous obligations on companies that process personal data, including special requirements in respect of the processing of special categories of personal data (such as health data), requiring that

consent of individuals to whom the personal data relates is obtained in certain circumstances, requiring additional disclosures to individuals regarding data processing activities, requiring that safeguards are implemented to protect the security and confidentiality of personal data, creating mandatory data breach notification requirements in certain circumstances, requiring data protection impact assessments for high risk processing and requiring that certain measures (including contractual requirements) are put in place when engaging third-party processors.

The GDPR also provides individuals with various rights in respect of their personal data, including rights of access, erasure, portability, rectification, restriction and objection.

The GDPR defines personal data to include pseudonymized or coded data and require different informed consent practices and more detailed notices for clinical trial participants and investigators than applies to clinical trials conducted in the United States.

We are required to apply GDPR standards to any clinical trials that our EEA and U.K.

The GDPR defines personal data to include pseudonymized or coded data and requires different informed consent practices and more detailed notices for clinical trial participants and investigators than apply to clinical trials conducted in the United States.

We are required to apply GDPR standards to any clinical trials that recruit participants in the EEA and U.K.

as well as any clinical trials that our EEA and U.K.

established businesses carry out anywhere in the world.

The GDPR imposes strict rules on the transfer of personal data to countries outside the EEA and U.K., including the United States in certain circumstances, unless a derogation exists or we incorporate a GDPR transfer mechanism (such as the European Commission approved standard contractual clauses (“SCCs”) or the U.K.

International Data Transfer Addendum (“IDTA”)) into our agreements with third parties to govern such transfers of personal data and carry out transfer impact assessments to assess whether the data importer can ensure sufficient guarantees for safeguarding the personal information

under the GDPR, including an analysis of the laws in the recipient’s country.

Carrying out such restricted transfers, therefore, comes with a significant compliance burden, requiring significant effort and expense to overcome.

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While we have taken steps to comply with the GDPR, and implementing legislation in applicable EEA member states and the U.K., including by seeking to establish appropriate lawful bases for the various processing activities we carry out as a controller or joint controller, reviewing our security procedures and those of our vendors and collaborators, and entering into data processing agreements with relevant vendors and collaborators, we cannot be certain that our efforts to achieve and remain in compliance have been, and/or will continue to be, fully successful.

Given the breadth and depth of the applicable obligations, complying with the GDPR and similar data protection laws’ requirements are rigorous and time intensive and require significant resources and a review of our technologies, systems and practices, as well as those of any third-party collaborators, service providers, contractors or consultants that process or transfer personal data.

Given the breadth and depth of the applicable obligations, complying with the GDPR and similar data protection laws’ requirements is rigorous and time intensive and require significant resources and a review of our technologies, systems and practices, as well as those of any third-party collaborators, service providers, contractors or consultants that process or transfer personal data.

The U.K.’s data protection regime is independent from but aligned to the EU’s data protection regime.

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For example, the U.K.

has recently introduced a new Data (Use and Access) Bill (“U.K.

Bill”) into parliament.

If passed, the final version of the U.K.

Bill may have the effect of further altering the similarities between the U.K.

and EEA data protection regime and threaten the U.K.’s adequacy decision from the EC.

Data (Use and Access) Act 2025 (“U.K.

Act"), now in force, further alters the similarities between the U.K.

and EEA data protection regimes.

In December 2025, the European Commission adopted a decision determining that the UK continues to provide a level of data protection that is “essentially equivalent” to the EU standards and extended the validity of the UK adequacy decision for six years, through December 2031.

While this renewal reduces immediate adequacy concerns, uncertainty remains regarding how UK data protection laws will evolve in the medium to longer term.

This lack of clarity on future U.K.

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and any resulting divergence in laws could increase our risk profile and may require us to implement different compliance measures for the U.K.

In addition, EEA Member States have adopted national laws to implement the GDPR that may partially deviate from the GDPR.

Further, the competent authorities in the EEA Member States interpret GDPR obligations slightly differently from country to country (particularly in relation to the processing of health data) and therefore we do not expect to operate in a uniform legal landscape in the EEA.

Regulators and legislators in the U.S.

are increasingly scrutinizing and restricting certain personal data transfers and transactions involving foreign countries.

For example, the Department of Justice’s January 8, 2025, rule on “Preventing Access to U.S.

Sensitive Personal Data and Government-Related Data by Countries of Concern or Covered Persons,” prohibits data brokerage transactions involving certain sensitive personal data categories, including health data, genetic data, and biospecimens, to countries of concern, including China.

The regulations also restrict certain investment agreements, employment agreements and vendor agreements involving such data and countries of concern, absent specified

cybersecurity controls.

Actual or alleged violations of these regulations may be punishable by criminal and/or civil sanctions and may result in exclusion from participation in federal and state programs.

In the U.S., numerous federal and state laws and regulations, including federal health information privacy laws, state data breach notification laws, state health information privacy laws and federal and state consumer protection laws ( e.g.

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For example, the CCPA gives California residents expanded rights to access and delete their personal information, opt out of certain personal information sharing and receive detailed information about how their personal information is used.

The CCPA was recently amended to apply to certain sensitive personal information and created a new state agency vested with authority to implement and enforce the CCPA.

The CCPA applies to certain sensitive personal information and created a new state agency vested with authority to implement and enforce the CCPA.

The CCPA provides for civil penalties for violations, as well as a private right of action for data breaches that may lead to increased litigation.

states are constantly amending existing laws, requiring attention to frequently changing regulatory requirements, which may require us to modify our data collection or processing practices and policies and to incur substantial costs and expenses in an effort to comply with them.

We are conducting a clinical trial in California and therefore through our contract research organisation (CRO), we collect personal data on residents of California, therefore we are subject to the CCPA, and the CCPA imposes privacy compliance obligations on our business and will raise new risks for potential fines and class actions.

We are conducting a clinical trial in California, where the CCPA includes only a partial exemption for certain clinical trial data, and we may be subject to privacy compliance obligations on our business that raise new risks for potential fines and class actions.

Numerous other U.S.

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Any of these laws may broaden their scope in the future, and similar laws have been proposed on both a federal level and in more than half of the states in the United States.

While such state laws incorporate many similar concepts of the CCPA, there are also several key differences in the scope, application, and enforcement of the laws that will change the operational practices of regulated businesses.

The new laws will, among other things, impact how regulated businesses collect and process personal sensitive data, conduct data protection assessments, transfer personal data to affiliates, and respond to consumer rights requests.

State laws feature several key differences in scope, application, and enforcement, that collectively impact how regulated businesses collect and process personal sensitive data, conduct data protection assessments, transfer personal data to affiliates, and respond to consumer rights requests.

In addition to general privacy and data protection requirements, many jurisdictions around the world have adopted legislation that regulates how businesses operate online and enforces information security, including measures relating to privacy, cybersecurity, data security and data breaches.

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These laws are not consistent, and compliance in the event of a widespread data breach is costly and burdensome.

A growing number of legislators and regulators are adopting laws and regulations and have focused enforcement efforts on the adoption of artificial intelligence (“AI”) and use of such technologies in compliance with ethical standards and societal expectations.

These developments may increase our compliance burden and costs in connection with use of AI and lead to legal liability if we fail to meet evolving legal standards or if use of such technologies results in harms or other causes of action we did not predict.

We may use and integrate AI into our business processes both in our own development and implementation of AI and through the adoption of commercially available tools.

Use of this technology could pose cybersecurity, data privacy, IT, intellectual property, regulatory, legal, operational, competitive, reputational and other risks and challenges that could affect our business.

Specifically, risks related to accuracy, bias, artificial intelligence hallucinations, discrimination, harmful content, misinformation, fraud, scams, targeted attacks (including model poisoning or data poisoning), surveillance, data leakage, inequality, environmental harms, and other harms may flow from our development, use, or deployment of AI technologies.

The rapid evolution of AI will require the application of significant resources to design, develop, test and maintain such systems to help ensure that AI is implemented in accordance with applicable law and regulation and in a socially responsible manner and to minimize any real or perceived unintended harmful impacts.

If we enable or offer solutions that draw controversy due to perceived or actual negative societal impact, we may experience brand or reputational harm, competitive harm or legal liability.

In the U.S., the AI regulatory environment is complex and uncertain.

Over the past year, states have advanced, and in some cases passed, dozens of laws focusing on AI governance and regulation, including on deployment of AI in healthcare settings.

At the federal level, the Trump Administration has endorsed a federal moratorium on the enforcement of state AI laws, including through a December 11, 2025, executive order on “Ensuring a National Policy Framework for Artificial Intelligence.” So far, these efforts have not been successful at curtailing state action on AI regulation, contributing to a complicated legislative patchwork, which may be litigated in state and federal courts.

In Europe, the European Union began implementing the Artificial Intelligence Act (the “AI Act”) on August 1, 2024, with a significant part of the law scheduled to come into effect in August 2026.

As currently enacted, the AI Act, which may be amended as part of the EU’s Digital Omnibus, imposes significant obligations on providers and deployers of high-risk artificial intelligence systems, and encourages providers and deployers of artificial intelligence systems to account for EU ethical principles in their development and use of these systems.

The scope of requirements depends on judicial interpretations and forthcoming legislative amendments, and non-compliance can lead to significant fines.

In many jurisdictions, enforcement actions and consequences for non-compliance with protection, privacy and information security laws and regulations are rising.

In the EU and the U.K., data protection authorities may impose large penalties for violations of the data protection laws, including potential fines of up to €20 million (£17.5 million in the U.K.) or 4% of

annual global revenue, whichever is greater.

The authorities have shown a willingness to impose significant fines and issue orders preventing the processing of personal data on non-compliant businesses.

Data subjects also have a private right of action, as do consumer associations, to lodge complaints with supervisory authorities, seek judicial remedies, and obtain compensation for damages resulting from violations of applicable data protection laws.

In the United States, possible consequences for non-compliance include enforcement actions in response to rules and regulations promulgated under the authority of federal agencies and state attorneys general and legislatures and consumer protection agencies.

The risk of our being found in violation of these laws is increased by the fact that the interpretation and enforcement of them is not entirely clear.

Under the GDPR, data subjects also have a private right of action, as do consumer associations, to lodge complaints with supervisory authorities, seek judicial remedies, and obtain compensation for damages resulting from violations of applicable data protection laws.

The risk of our being found in violation of these laws is increased by their fact that the interpretation and enforcement is not entirely clear.

Efforts to ensure that our business arrangements with third parties will comply with applicable healthcare laws and regulations will involve substantial costs.

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regulatory environment, inflation and other areas.

For example, in September 2025, President Trump announced plans to impose 100% tariffs on imported branded or patented pharmaceuticals, unless the importing company is building U.S.

manufacturing capacity.

It is not yet clear whether these tariffs would apply to the importation of active pharmaceutical ingredients and possibly bulk drug products that are intended for use in clinical trials and not for commercial sale, which could increase the costs of materials for our clinical trials.

Any direct tariffs, if imposed on pharmaceutical products, may result in increased costs for raw materials and contract manufacturing services, reduced ability to source critical contract manufacturing organizations, and a delay in our development timelines.

Although we cannot predict the impact, if any, of these changes to our business, they could adversely affect our business.

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In addition, it is uncertain whether the World Trade Organization ("WTO") will waive certain intellectual property protections now or in the future on certain technologies.

unknown if such a waiver would be limited to patents, or would include other forms of intellectual property including trade secrets and confidential know-how.

It is unknown if such a waiver would be limited to patents, or would include other forms of intellectual property including trade secrets and confidential know-how.

We cannot be certain that any of our current or future product candidates or technologies would not be subject to an intellectual property waiver by the WTO.

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In addition, we may not have the right to control the preparation, filing, prosecution, maintenance, enforcement, and defense of patents and patent applications covering the technology that we license from third parties.

For example, we do not control the preparation, filing, prosecution or maintenance of patents in-licensed from OUI.

Therefore, we cannot be

certain that these patents and patent applications will be prepared, filed, prosecuted, maintained, enforced, and defended in a manner consistent with the best interests of our business.

Therefore, we cannot be certain that these patents and patent applications will be prepared, filed, prosecuted, maintained, enforced, and defended in a manner consistent with the best interests of our business.

If our licensors fail to prosecute, maintain, enforce, and defend such patents, or lose rights to those patents or patent applications, the rights we have licensed may be reduced or eliminated, and our right to develop and commercialize any of our products that are the subject of such licensed rights could be adversely affected.

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As the biotechnology and pharmaceutical industries expand and more patents are issued, the risk increases that our product candidates may give rise to claims of infringement of the patent rights of others.

Moreover, it is not always clear to industry participants, including us, which patents cover various types of viral vectors and vaccines or their methods of use or manufacture.

Thus, because of the large number of patents issued and patent applications filed in our fields, there may be a risk that third parties may allege they have patent rights encompassing our product candidates, technologies or methods.

For example, we are aware of third-party patents in the United States and Europe with claims which may be relevant to our VTP-300 and VTP-850 product candidates.

In the event that these patents were asserted against us in an infringement action, we may have to argue that the manufacture, use, sale or importation of our VTP-300 or VTP-850 product candidates in the United States and Europe do not infringe any valid claim of the asserted patents.

There is no assurance that a court would find in our favor on questions of infringement or validity.

If a third party (including any third party that controls the above referenced patents) claims that we infringe, misappropriate or otherwise violate its intellectual property rights (including the above referenced patents), we may face a number of risks, including, but not limited to:

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In addition to potential USPTO review proceedings, we may become a party to patent opposition proceedings in the EPO, or similar proceedings in other foreign patent offices, where our foreign patents are challenged.

For example, one of our in-licensed European patents relating to our now discontinued MVA influenza product candidate has been revoked in a European opposition proceeding.

This decision is currently on appeal, although there can be no assurance that any such appeal will be successful.

The costs of opposition or similar proceedings could be substantial, and may result in a loss of scope of some claims or a loss of the entire patent.

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The outcome following legal assertions of invalidity and unenforceability is unpredictable.

commercialize our product candidates or other technologies and compete directly with us, without payment to us, or result in our inability to manufacture or commercialize products without infringing third-party patent rights.

An adverse determination in any such submission, proceeding or litigation could reduce the scope of, or invalidate or render unenforceable, any rights we may have from our patent applications or any patents we in-license or may own in the future, allow third parties to commercialize our product candidates or other technologies and compete directly with us, without payment to us, or result in our inability to manufacture or commercialize products without infringing third-party patent rights.

Such proceedings also may result in substantial cost and require significant time from our scientists and management, even if the eventual outcome is favorable to us.

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Moreover, the applicable time period or the scope of patent protection afforded could be less than we request.

For biologics, separate non-patent exclusivity under the BPCIA may apply.

The FDA cannot make approval of a biosimilar effective until 12 years after the reference product’s first licensure, but policy changes could affect the scope or duration of this exclusivity, and competitors may nonetheless pursue full BLAs.

As a result, even with patents and any extensions, competition from biosimilars or other biologics could occur earlier than anticipated.

If we are unable to obtain patent term extension or the term of any such extension is shorter than what we request, our competitors or other third parties may obtain approval of competing products following expiration of any patents that issue from our patent applications, and our business, financial condition, results of operations, and prospects could be materially harmed.

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A successful invalidity challenge to a European patent under the UPC would result in loss of patent protection in those European countries.

Accordingly, a single proceeding under the UPC could result in the partial or

complete loss of patent protection in numerous European countries, rather than in each validated European country separately as such patents always have been adjudicated.

Accordingly, a single proceeding under the UPC could result in the partial or complete loss of patent protection in numerous European countries, rather than in each validated European country separately as such patents always have been adjudicated.

Such a loss of patent protection could have a material adverse impact on our business and our ability to commercialize our technology and product candidates and, resultantly, on our business, financial condition, prospects and results of operations.

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Many countries have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third parties.

As a result, in response to the COVID-19 pandemic, it is possible that certain countries may take steps to facilitate compulsory licenses that permit the distribution of a COVID-19 vaccine in those countries.

In addition, many countries limit the enforceability of patents against government agencies or government contractors.

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Third parties may use trademarks similar to our trademarks and any potential confusion as to the source of goods or services could have an adverse effect on our business.

For example, in April 2022, we received a letter asserting that our use of our “Vaccitech” trademark infringes a United Kingdom trademark held by a third party.

We timely responded rejecting the claims and we believe that such claims are without merit.

However, if such third party continues to assert its claims, we cannot provide any assurance whether we could reach a settlement relating to such claims or whether we would prevail in any litigation or action related to such claims.

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Litigation brought to protect and enforce our intellectual property rights could be costly, unpredictable, time-consuming and distracting to management, regardless of whether we are successful in such litigation.

If we are unable to obtain a registered trademark or establish name recognition based on our trademarks and trade names, we may not be able to compete effectively and our business, results of operations and financial condition may be adversely affected.

If we are unable to obtain a registered trademark or establish name recognition

based on our trademarks and trade names, we may not be able to compete effectively and our business, results of operations and financial condition may be adversely affected.

Numerous factors may limit any potential competitive advantage provided by the relevant patent rights.

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On January 10, 2025, we announced a restructuring plan that aims to prioritize our immune tolerance research and development programs, including a reduction in workforce.

We are planning to partner the further development of VTP-300 and plan to report the primary analysis data from HBV003 in the second quarter of 2025.

As of December 31, 2025, we had 14 full-time and part-time employees.

Despite our efforts, the pipeline prioritization and restructuring may be unsuccessful, lead to additional costs, disrupt our operations, create unintended problems in our workforce, and increase litigation risk, which could harm our business and results of operations.

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If we are unable to realize the expected operational efficiencies and cost savings from the pipeline prioritization and restructuring, our operating results and financial condition would be adversely affected.

Moreover, our decision to focus on the development of VTP-300 in CHB and VTP-1000 in celiac disease may cause us to fail to capitalize on viable commercial products or profitable market opportunities or limit the opportunities we are able to pursue.

Moreover, our decision to focus on the development of VTP-1000 in celiac disease may cause us to fail to capitalize on viable commercial products or profitable market opportunities or limit the opportunities we are able to pursue.

In addition, we may need to undertake additional workforce reductions or restructuring activities in the future.

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The loss of the services of any of our executive officers, other key employees and other scientific and medical advisors, and an inability to find suitable replacements could result in delays in product development and harm our business.

As previously announced on January 10, 2025, Graham Griffiths will step down from his role as Chief Operating Officer on June 30, 2025, and Gemma Brown will step down from her role as Chief Financial Officer on April 30, 2025.

We may experience changes in key leadership or key positions in the future.

The departure of key leadership personnel can result in loss of significant knowledge and experience from the company.

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Failure to attract and retain the right talent, or to smoothly manage the transition of responsibilities resulting from such turnover, would affect our ability to meet our challenges and may cause us to miss performance objectives or financial targets.

We conduct our operations at our facilities in Harwell, United Kingdom and Germantown, Maryland.

These regions are headquarters to many other biopharmaceutical companies and many academic and research institutions.

We conduct our operations at our facilities in Germantown, Maryland.

This region is the headquarters to many other biopharmaceutical companies and many academic and research institutions.

Competition for skilled personnel in these markets is intense and may limit our ability to hire and retain highly qualified personnel on acceptable terms, or at all.

Changes to U.K., U.S.

Changes to U.S.

or similar foreign immigration and work authorization laws and regulations, including those that restrain the flow of scientific and professional talent, can be significantly affected by political forces and levels of economic activity.

Our business may be materially adversely affected if legislative or administrative changes to the U.K.

(including, but not limited to, those that result as a direct or indirect consequence of Brexit), U.S.

Our business may be materially adversely affected if legislative or administrative changes to the U.S.

or similar foreign immigration or visa laws and regulations impair our hiring processes and goals or projects involving personnel who are not U.S.

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As of December 31, 2025, we had 14 full-time and part-time employees.

In connection with the restructuring announced in January 2025, we are planning a 65% reduction in force, but as our development and commercialization plans and strategies develop, we expect to need additional managerial, operational, technical, sales, marketing, financial and other personnel, as well as additional facilities to expand our operations.

As our development and commercialization plans and strategies develop, we expect to need additional managerial, operational, technical, sales, marketing, financial and other personnel, as well as additional facilities to expand our operations.

Future growth would impose significant added responsibilities on members of management, including:

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The risk of a security breach or disruption, particularly through cyberattacks or cyber intrusion, including by computer hackers, foreign governments, and cyber terrorists, has generally increased as the number, intensity and sophistication of attempted attacks and intrusions from around the world have increased.

Cyberattacks could include wrongful conduct by insider employees or vendors, hostile foreign governments, industrial espionage, wire fraud and other forms of cyber fraud, the deployment of harmful malware, including ransomware, denial-of-service, social engineering fraud, including phishing attacks, data breaches, or other means to threaten data security, confidentiality, integrity and availability.

Further, attempts to disrupt or gain unauthorized access to our and our third-party vendors’ information systems from malicious third-parties or insider threats may incorporate widely varying and frequently changing tactics, which may be enhanced or facilitated by AI.

If such an event were to occur, it could result in the theft or destruction of intellectual property, data or other misappropriation of assets, or otherwise compromise our confidential or proprietary information and result in a material disruption of our development programs and our business operations, such as the loss of clinical trial data from completed or future clinical trials.

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• our ability to effectively manage our growth;

• the size and growth of our initial cancer target markets;

• our ability to successfully treat additional types of cancers or at different stages;

• actual or anticipated variations in quarterly operating results;

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Broad market and industry factors may negatively affect the market price of our ADSs, regardless of our actual operating performance.

If we fail to regain compliance with the continued listing requirements of Nasdaq, our ADSs may be delisted and the price of our ADSs and our ability to access the capital markets could be negatively impacted.

On December 30, 2025, we received a deficiency letter from Nasdaq indicating that, for the last 30 consecutive business days, the bid price for our ADSs had closed below the minimum $1.00 per share requirement for continued inclusion on the Nasdaq Global Market, referred to as the minimum bid price rule.

In accordance with Nasdaq Listing Rules, we have an

initial period of 180 calendar days, or until June 29, 2026, to regain compliance with the minimum bid price rule.

If we do not regain compliance with the minimum bid price rule by June 29, 2026, we may be eligible for an additional 180 calendar day compliance period.

We intend to monitor the closing bid price of our ADSs and may, if appropriate, consider available options to regain compliance with the minimum bid price rule.

There are many factors that may adversely affect our ADS’ minimum bid price, including those described throughout this section titled “Item 1A.

Risk Factors.” Many of these factors are outside of our control.

As a result, we may not be able to sustain compliance with the minimum bid price rule in the long term.

Any potential delisting of our ADSs from the Nasdaq would likely result in decreased liquidity and increased volatility for our ADSs and would adversely affect our ability to raise additional capital or to enter into strategic transactions.

Any potential delisting of our ADSs from the Nasdaq would also make it more difficult for holders of our ADSs to sell our ADSs in the public market.

Holders of our ADSs are not treated as holders of our ordinary shares.

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If this jury trial waiver provision is not permitted by applicable law, an action could proceed under the terms of the deposit agreement with a jury trial.

If we or the depositary opposed a jury trial demand based on the waiver, the court would determine whether the waiver was enforceable based on the facts and circumstances of that case in accordance with the applicable state and federal law.

If we or the depositary opposed a jury trial demand based on the waiver, the court would

determine whether the waiver was enforceable based on the facts and circumstances of that case in accordance with the applicable state and federal law.

To our knowledge, the enforceability of a contractual pre-dispute jury trial waiver in connection with claims arising under the federal securities laws has not been finally adjudicated by the United States Supreme Court.

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We have elected to avail ourselves of this exemption and, therefore, we will not be subject to the same timing of adoption of new or revised accounting standards as other public companies that are not emerging growth companies.

Even after we no longer qualify as an emerging growth company, we may still qualify as a “smaller reporting company,” which may allow us to continue to take advantage of many of the same exemptions from disclosure requirements, including not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act and reduced disclosure obligations regarding executive compensation in this Annual Report and our periodic reports and proxy statements.

Even after we no longer qualify as an emerging growth company, we may still qualify as a “smaller reporting company,” which may allow us to continue to take advantage of many of the same exemptions from disclosure requirements, including reduced disclosure obligations regarding executive compensation in this Annual Report and our periodic reports and proxy statements.

We cannot predict if investors will find our ADSs less attractive because we may rely on these exemptions.

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(or the Channel Islands or the Isle of Man).

We believe that our place of central management and control is not in the United Kingdom (or the Channel Islands or the Isle of Man) for the purposes of the jurisdictional criteria of the Takeover Code.

We believe that our place of central management and control is not in the U.K.

(or the Channel Islands or the Isle of Man) for the purposes of the jurisdictional criteria of the Takeover Code.

Accordingly, we believe that we are not currently subject to the Takeover Code and, as a result, our shareholders are not currently entitled to the benefit of certain takeover offer protections provided under the Takeover Code, including the rules regarding mandatory takeover bids.

In the event that this changes, or if the interpretation and application of the Takeover Code by the Panel on Takeovers and Mergers, (the "Takeover Panel"), changes (including changes to the way in which the Takeover Panel assesses the application of the Takeover Code to English companies whose shares are listed outside of the United Kingdom), the Takeover Code may apply to us in the future.

In the event that this changes, or if the interpretation and application of the Takeover Code by the Panel on Takeovers and Mergers, (the "Takeover Panel"), changes (including changes to the way in which the Takeover Panel assesses the application of the Takeover Code to English companies whose shares are listed outside of the U.K.), the Takeover Code may apply to us in the future.

The Takeover Panel has confirmed that, from February 3, 2027, the location of the Company’s place of central management and control will no longer be relevant in determining whether the Takeover Code applies to the Company.

From February 3, 2027, the Takeover Code will only apply to the Company in the event that our securities are quoted on a UK regulated market (or U.K.

multilateral trading facility or certain exchanges in the Channel Islands or the Isle of Man).

The Takeover Code provides a framework within which takeovers of companies which are subject to the Takeover Code are regulated and conducted.

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(a) any derivative action or proceeding brought on our behalf;

(b) any action or proceeding asserting a claim of breach of fiduciary duty owed by any of our directors, officers or other employees to us;

(b) any action or proceeding asserting a claim of breach of fiduciary duty owed by any

of our directors, officers or other employees to us;

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The England and Wales Forum Provision will not apply to any causes of action arising under the Securities Act or the Exchange Act.

Our Articles further provide that unless we consent by ordinary resolution to the selection of an alternative forum, the United States District Court for the Southern District of New York shall be the exclusive forum for resolving any complaint

asserting a cause of action arising under the Securities Act or the Exchange Act (the “U.S.

Federal Forum Provision”).

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Treasury Department.

For example, the One Big Beautiful Bill Act (the “OBBBA”) was signed into law on July 4, 2025 and made significant changes to U.S.

federal tax law.

Changes to tax laws (which changes may have retroactive application) could adversely affect us or holders of our ordinary shares or ADSs.

We are evaluating the elections available under the OBBBA.

Based on our current assessment, we do not expect the changes to Section 174 under the OBBBA to have a material impact on our financial position or results of operations.

For example, under Section 174 of the Internal Revenue Code of 1986, as amended (the "Code"), in taxable years beginning after December 31, 2021, expenses that are incurred for research and development performed outside the U.S.

will be capitalized and amortized, which may have an adverse effect on our cash flow.

The OBBBA provides that for taxable years beginning after December 31, 2024, expenses that are incurred for research and development performed in the U.S.

may, at the taxpayer’s election, be immediately deducted or capitalized and amortized.

In addition, the OBBBA provides that for taxable years beginning after December 31, 2021 and before January 1, 2025, certain eligible taxpayers generally may elect to retroactively deduct expenses for research and development performed in the U.S.

in such taxable years by filing amended tax returns for such taxable years, and all other taxpayers that are not eligible to make such an election and that amortized expenses for research and development performed in the U.S.

in such taxable years generally may elect to accelerate and deduct the remaining unamortized amounts of such research and development expenses (i) in the first taxable year beginning after December 31, 2024, or (ii) ratably over the two-taxable year period beginning with the first taxable year beginning after December 31, 2024.

In recent years, many such changes have been made and changes are likely to continue to occur in the future.

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tax laws on an investment in our ordinary shares or ADSs.

We believe we were a passive foreign investment company ("PFIC"), for prior taxable years and we may be a PFIC in future taxable years, which could result in adverse U.S.

We believe we were a passive foreign investment company ("PFIC"), for prior taxable years and we may be a PFIC in the current or future taxable years, which could result in adverse U.S.

federal income tax consequences to U.S.

Under the Internal Revenue Code (the "Code"), we will be a passive foreign investment company, or PFIC, for any taxable year in which (i) 75% or more of our gross income consists of passive income or (ii) 50% or more of the average quarterly value of our assets consists of assets that produce, or are held for the production of, passive income.

Under the Code, we will be a PFIC, for any taxable year in which (i) 75% or more of our gross income consists of passive income or (ii) 50% or more of the average quarterly value of our assets consists of assets that produce, or are held for the production of, passive income.

For the purposes of these tests, passive income includes dividends, interest, gains from the sale or exchange of investment property and certain rents and royalties.

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Treasury Regulations.

Based on the current and expected composition of our income and the value of our assets, we were a PFIC for the year ended December 31, 2024 and expect to remain a PFIC for our current taxable year.

Based on the current and expected composition of our income and the value of our assets, we were a PFIC for the year ended December 31, 2025 and expect to remain a PFIC for our current taxable year (or the portion of our current taxable year ending on or prior to the consummation of the Scheme Transaction, as applicable).

No assurances regarding our PFIC status can be provided for the current taxable year or any future taxable years.

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Each “Ten Percent Shareholder” (as defined below) in a non-U.S.

corporation that is classified as a “controlled foreign corporation,” or a CFC, for U.S.

corporation that is classified as a “controlled foreign corporation (a “CFC”) for U.S.

federal income tax purposes generally is required to include in income for U.S.

federal tax purposes such Ten Percent Shareholder’s pro rata share of the CFC’s “Subpart F income,” “global intangible low-taxed income” and investment of earnings in U.S.

federal tax purposes such Ten Percent Shareholder’s pro rata share of the CFC’s “Subpart F income” and investment of earnings in U.S.

property, even if the CFC has made no distributions to its shareholders.

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corporation owns at least one U.S.

subsidiary, under current law, any current non-U.S.

subsidiary, under applicable law for taxable years ending before January 1, 2026, any current non-U.S.

subsidiaries and any future newly formed or acquired non-U.S.

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Subpart F income generally includes dividends, interest, rents, royalties, gains from the sale of securities and income from certain transactions with related parties.

Each Ten Percent Shareholder of a CFC is also required to include in income such Ten Percent Shareholder’s share of “global intangible low-taxed income” (for tax years beginning after December 31, 2017 and prior to January 1, 2026) and “net CFC tested income” (for tax years beginning after December 31, 2025) with respect to such CFC.

In addition, a Ten Percent Shareholder that realizes gain from the sale or exchange of shares in a CFC may be required to classify a portion of such gain as dividend income rather than capital gain.

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federal income tax purposes if Ten Percent Shareholders own, directly or indirectly, more than 50% of either the total combined voting power of all classes of stock of such corporation entitled to vote or of the total value of the stock of such corporation.

A “Ten Percent Shareholder” is a United States person (as defined by the Code) who owns or is considered to own 10% or more of the value or total combined voting power of all classes of stock entitled to vote of such corporation.

We do not believe that we were a CFC in 2024, and we do not expect to be a CFC in 2025.

A “Ten Percent Shareholder” is a United States person (as defined by the Code) who owns or is considered to own 10% or more of (1) the value of all classes of stock of such corporation or (2) the total combined voting power of all classes of stock entitled to vote of such corporation.

We do not believe that we were a CFC in 2025, and (prior to the consummation of the Scheme Transaction) we do not expect to be a CFC in 2026.

The determination of CFC status is complex and includes attribution rules, the application of which is not entirely certain.

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These changes may not, however, be effective in maintaining the adequacy of our internal controls, and any failure to maintain that adequacy, or consequent inability to produce accurate financial statements on a timely basis, could increase our operating costs and harm our business.

In addition, investors’ perceptions that our internal controls are inadequate or that we are unable to produce accurate financial statements on a timely basis may harm our stock price and make it more difficult for us to continue to discover and develop novel immunotherapeutics and vaccines for the treatment and prevention of infectious diseases, immunetolerance and cancer.

We could be subject to securities class action litigation .

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If we were to be sued, it could result in substantial costs and a diversion of management’s attention and resources, which could harm our business.

The United Kingdom’s withdrawal from the European Union could increase the regulatory burden of product development and authorization in the United Kingdom and European Union.

The United Kingdom formally left the European Union on 31 January 2020 (commonly referred to as Brexit).

The European Union and the United Kingdom have concluded a trade and cooperation agreement (“TCA”) which has been formally applicable since May 1, 2021.

The TCA includes specific provisions concerning pharmaceuticals, which include the mutual recognition of GMP, inspections of manufacturing facilities for medicinal products and GMP documents issued, but does not provide for wholesale mutual recognition of the United Kingdom and European Union pharmaceutical regulations.

As a result, a separate application must be made to conduct a clinical trial in the United Kingdom as well as the European Union and a separate U.K.

marketing authorization is required to commercialize a medicinal product in the United Kingdom as well as the European Union.

Obtaining such regulatory approvals is a lengthy and expensive process and this therefore adds time and expense to the conduct of our business in both the United Kingdom and European Union.

In addition, the United Kingdom is seeking to reform aspects of the medicines legislation following its departure from the European Union.

The U.K.'s withdrawal from the European Union could increase the regulatory burden of product development and authorization in the U.K.

and European Union.

formally left the European Union on 31 January 2020 (commonly referred to as Brexit).

The European Union and the U.K.

have concluded a trade and cooperation agreement (“TCA”) which has been formally applicable since May 1, 2021.

and European Union pharmaceutical regulations.

As a result, a separate application must be made to conduct a clinical trial in the U.K.

as well as the European Union and a separate U.K.

marketing authorization is required to commercialize a medicinal product in the U.K.

as well as the European Union.

Obtaining such regulatory approvals is a lengthy and expensive process and this therefore adds time and expense to the conduct of our business in both the U.K.

and European Union.

In addition, the U.K.

is seeking to reform aspects of the medicines legislation following its departure from the European Union.

For example, on December 12, 2024, the U.K.

government introduced a legislative proposal that, if implemented, will replace the current regulatory framework for clinical trials in the United Kingdom.

If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies governing clinical trials and the development of medicinal products in the United Kingdom and/or European Union, our development plans may be impacted.

government introduced a legislative proposal that, if implemented, will replace the current regulatory framework for clinical trials in the U.K.

If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies governing clinical trials and the development of medicinal products in the U.K.

and/or European Union, our development plans may be impacted.

If we fail to comply with the regulatory requirements, our target market will be reduced and our ability to realize the full market potential of our product candidates will be harmed and our business, financial condition, results of operations and prospects will be adversely affected.

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 1A. Risk Factors