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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2024

Commission file number: 001-40367

BARINTHUS BIOTHERAPEUTICS PLC

(Exact name of registrant as specified in its charter)

England and Wales Not Applicable

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: +44 (0)1865 818 808

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

Title of each class Trading Symbol(s) Name of each exchange on which registered

American Depositary Shares* BRNS The Nasdaq Global Market

Ordinary shares, nominal value £0.000025 per share**

*American Depositary Shares may be evidenced by American Depositary Receipts. Each American Depositary Share represents one (1) ordinary share.

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

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

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes oNox

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes oNox

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yesx No o

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yesx No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. o

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. o

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). o

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes o No x

As of the last business day of the registrant’s most recently completed second fiscal quarter, the aggregate market value of the registrant’s ordinary shares, nominal value £0.000025 per share, in the form of American Depositary Shares, held by non-affiliates was approximately $31.1 million.

The number of shares outstanding of the registrant’s ordinary shares, nominal value £0.000025 per share, as of March 14, 2025: 40,339,395 shares.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s definitive proxy statement to be filed with the Securities and Exchange Commission relative to the registrant’s 2025 Annual Meeting of Shareholders are incorporated by reference into Items 10, 11, 12, 13 and 14 of Part III of this Annual Report on Form 10-K.

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BARINTHUS BIOTHERAPEUTICS PLC

ANNUAL REPORT ON FORM 10-K

FOR THE FISCAL YEAR ENDED DECEMBER 31, 2024

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PART I

Item 1. Business 8

Item 1A. Risk Factors 51

Item 1B. Unresolved Staff Comments 109

Item 1C. Cybersecurity 109

Item 2. Properties 110

Item 3. Legal Proceedings 110

Item 4. Mine Safety Disclosures 110

PART II

Item 6. [Reserved] 114

Item 7A. Quantitative and Qualitative Disclosures About Market Risk 127

Item 8. Financial Statements and Supplementary Data 127

Item 9A. Controls and Procedures 127

Item 9B. Other Information 128

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections 128

PART III

Item 10. Directors, Executive Officers and Corporate Governance 129

Item 11. Executive Compensation 129

Item 14. Principal Accounting Fees and Services 129

PART IV

Item 15. Exhibits, Financial Statement Schedules 130

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We own the registered trademark BARINTHUS in the United Kingdom, and we have filed applications at the U.K. Intellectual Property Office and other intellectual properties to register trademarks for BARINTHUS, SNAP-TI, SNAP-CI and a design logo globally.We also own various trademark registrations and applications, and unregistered trademarks, including the registered trademark VACCITECH, and trademarks relating to the technologies acquired as part of our acquisition of Avidea Technologies, Inc. in December 2021 including the registered trademarks SNAPVAX and SYNTHOLYTIC. All other trade names, trademarks and service marks of other companies appearing in this Annual Report on Form 10-K ("Annual Report") are the property of their respective holders. Solely for convenience, the trademarks and trade names in this Annual Report may be referred to without the ® and TM symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto. We do not intend to use or display other companies’ trademarks and trade names to imply a relationship with, or endorsement or sponsorship of us by, any other companies.

From time to time, we may use our website, our X (formerly known as Twitter) account at @Barinthusbio and our LinkedIn account at linkedin.com/company/barinthus-bio to distribute material information about us and for complying with our disclosure obligations under Regulation FD. Our financial and other material information is routinely posted to and accessible on the Investors section of our website, available at www.barinthusbio.com. Investors are encouraged to review the Investors section of our website because we may post material information on that site that is not otherwise disseminated by us. Information that is contained in and can be accessed through our website, our X (formerly known as Twitter) posts and our LinkedIn posts are not incorporated into, and does not form a part of, this Annual Report.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report contains express or implied forward-looking statements that involve substantial risks and uncertainties. In some cases, you can identify forward-looking statements by the words “may,” “might,” “will,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “objective,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “continue,” “ongoing,” or the negative of these terms, or other comparable terminology intended to identify statements about the future. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. The forward-looking statements and opinions contained in this Annual Report are based upon information available to our management as of the date of this Annual Report and, while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. Forward-looking statements contained in this Annual Report include, but are not limited to, statements about:

•the success, cost and timing of our product development activities and clinical trials;

•the timing, scope or likelihood of regulatory filings and approvals, including timing of Investigational New Drug Application ("IND"), New Drug Application ("NDA"), and Biologics License Application ("BLA") filings for our current and future product candidates, and final U.S. Food and Drug Administration ("FDA"), European Medicines Agency ("EMA"), United Kingdom Medicines and Healthcare products Regulatory Agency ("MHRA"), or other foreign regulatory authority approvals relating to our current and future product candidates;

•our future expectations, plans and prospects, including the estimates of costs that we expect to incur in connection with the restructuring and the timing thereof;

•our ability to develop and advance our current and future product candidates and programs into, and successfully complete, clinical trials;

•our ability to establish future or maintain current collaborations or strategic relationships;

•the rate and degree of market acceptance and clinical utility of our current and future product candidates;

•any expectations surrounding the payments we could potentially receive pursuant to our collaborations and license agreements;

•the ability and willingness of our third-party collaborators to continue research and development activities relating to our product candidates;

•our ability to obtain, maintain, defend and enforce our intellectual property protection for our product candidates, and the scope of such protection;

•our manufacturing, commercialization and marketing capabilities and strategy;

•future agreements with third parties in connection with the commercialization of our product candidates, if approved, and any other approved products;

•regulatory developments in the United States and foreign countries;

•competitive companies, technologies and our industry and the success of competing therapies that are or may become available;

•our ability to attract and retain key scientific or management personnel;

•our ability to obtain funding for our operations, including funding necessary to complete further development and commercialization of our product candidates;

•the accuracy of our estimates of our annual total addressable markets, future revenue, expenses, capital requirements and needs for additional financing;

•our expectations about market trends;

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•our ability to anticipate and overcome challenges posed to the conduct of our business in the event of a global pandemic or similar event;

•the impact of global economic and political developments on our business, including inflationary pressures, volatile interest rates, or intensified disruptions in the global financial markets, the change in the U.S. presidential administration, the conflict in Ukraine, the conflict in Israel and Gaza, disruptions in the banking industry, economic sanctions and economic slowdowns or recessions that may result from such developments; and

•our expectations regarding the period during which we qualify as an emerging growth company under the Jumpstart Our Business Startups Act of 2012, as amended ("JOBS Act").

You should refer to the section titled “Risk Factors” for a discussion of important factors that may cause our actual results to differ materially from those expressed or implied by our forward-looking statements. As a result of these factors, we cannot assure you that the forward-looking statements in this Annual Report will prove to be accurate. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. In light of the significant uncertainties in these forward-looking statements, you should not regard these statements as a representation or warranty by us or any other person that we will achieve our objectives and plans in any specified time frame, or at all. We undertake no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. You should read this Annual Report and the documents that we reference in this Annual Report with the understanding that our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements in this Annual Report by these cautionary statements.

This Annual Report contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Unless the context otherwise requires, reference in this Annual Report to the terms “Barinthus Bio,” “the Company,” “we,” “us,” “our,” and similar designations refer to Barinthus Biotherapeutics plc and, where appropriate, our majority-owned subsidiaries.

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SUMMARY OF THE MATERIAL RISKS ASSOCIATED WITH OUR BUSINESS

•We are a clinical-stage biopharmaceutical company with a limited operating history. We have incurred significant losses since inception. We expect to incur losses for at least the next several years and may never achieve or maintain profitability.

•We have not yet generated any material revenue from our product candidates.

•If we engage in further acquisitions or future strategic partnerships, this may increase our capital requirements, dilute our shareholders, cause us to incur debt or assume contingent liabilities, and subject us to other risks.

•Our limited operating history may make it difficult for you to evaluate the success of our business to date and to assess our future viability.

•Raising additional capital may cause dilution to our existing shareholders, restrict our operations or require us to relinquish rights to our technologies or product candidates.

•We may require substantial additional funding in the future. If we are unable to raise capital when needed, we would be compelled to delay, reduce or eliminate our product development programs or commercialization efforts.

•If we are unable to advance our current or future product candidates into and through clinical trials, obtain marketing approval or reimbursement and ultimately commercialize any product candidates we develop, or experience significant delays in doing so, our business will be materially harmed.

•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. We may encounter substantial delays in clinical trials, or may not be able to conduct or complete clinical trials on the expected timelines, if at all. If our preclinical studies and clinical trials are not sufficient to support marketing authorization of any of our product candidates, we may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development of such product candidate.

•Interim, “topline,” and preliminary data from our clinical trials that we announce or publish from time to time may change as more participant data become available and are subject to audit and verification procedures that could result in material changes in the final data.

•Our product candidates are based on novel approaches to the treatment of diseases, which makes it difficult to predict the time and cost of product candidate development.

•Our product candidates may cause serious adverse events, serious side effects or have other properties that could halt their clinical development, prevent their marketing authorization, require expansion of the trial size, limit their commercial potential or result in significant negative consequences.

•The market opportunities for certain of our oncology product candidates may be relatively small as it may be limited to those patients who are ineligible for or have failed prior treatments and our estimates of the prevalence of our target patient populations may be inaccurate.

•We may form or seek additional collaborations or strategic alliances or enter into additional licensing arrangements in the future, and we may not realize the benefits of such collaborations, alliances or licensing arrangements.

•The marketing authorization processes of the FDA, the EMA, MHRA and other comparable foreign regulatory authorities are lengthy, time-consuming and inherently unpredictable, and if we are ultimately unable to obtain marketing authorizations for our product candidates, or the marketing authorization is for a narrower indication than we seek, our business will be substantially harmed.

•Even if we receive marketing authorization for our product candidates, we will be subject to ongoing regulatory obligations and continued regulatory review, which may result in significant additional expenses and we may be subject to penalties if we fail to comply with regulatory requirements or experience unanticipated problems with our product candidates.

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•If we are unable to obtain and maintain patent protection for any products we develop and for our technology, or if the scope of the patent protection obtained is not sufficiently broad, our competitors could develop and commercialize products and technology similar or identical to ours, and our ability to successfully commercialize any product candidates we may develop and our technology may be adversely affected.

•Our rights to develop and commercialize our technology and product candidates are subject, in part, to the terms and conditions of licenses granted to us by others and if we fail to comply with our current or future obligations in any agreements under which we license intellectual property rights from third parties or otherwise experience disruptions to our business relationships with our licensors, we could lose license rights that are important to our business.

•The pipeline prioritization and restructuring may be unsuccessful, lead to additional costs, disrupt our operations, create unintended problems in our workforce, or increase litigation, in which case our business could be harmed.

•We are highly dependent on our key personnel, and if we are not successful in attracting and retaining highly qualified personnel, we may not be able to successfully implement our business strategy.

•We will need to grow the size of our organization and we may experience difficulties in managing this growth.

•If we were classified as a passive foreign investment company, it would result in adverse U.S. federal income tax consequences to U.S. Holders (as defined below).

•A variety of risks associated with operating our business internationally could materially adversely affect our business.

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PART I

Item 1. Business

Overview

We are a clinical-stage biopharmaceutical company focused on developing novel immunotherapeutic drug candidates for treating auto-immune and inflammatory diseases within the immunology and inflammation ("I&I") space. Helping patients and their families is the guiding principle at the heart of Barinthus Bio. We aim to achieve this by developing truly transformational and highly disease-specific immunotherapies.

We are prioritizing the development of a pipeline for I&I indications enabled by our proprietary and highly differentiated platform for promoting immune tolerance, referred to as SNAP-TI, that are designed to guide patient's T cells to reduce inflammation and restore the natural state of immune non-responsiveness to healthy tissue. Our lead candidate, VTP-1000, is designed to restore immune non-responsiveness to gluten in patients with celiac disease, and is currently being assessed in a Phase 1 clinical trial. Based on encouraging preclinical data, we believe that the SNAP-TI platform has the potential to impact multiple other I&I indications.

We are also evaluating two product candidates to treat infectious diseases and cancer that harness our proprietary viral vector platform technologies, consisting of ChAdOx and MVA; these technologies are designed to increase disease-specific CD8+ T cells. These include: VTP-300, a Phase 2 immunotherapeutic treatment modality that is a component of a treatment regimen to establish functional cure in patients who are chronically infected by the hepatitis B virus, and VTP-850, a second-generation immunotherapeutic candidate for the prevention of recurrence of prostate cancer. VTP-850 is being tested in patients in a Phase 1 clinical trial in prostate cancer after surgical resection. We intend to progress the development of these product candidates by completing the ongoing clinical trials, and seek a partner or collaborator for continuing development.

Alongside these proprietary programs, we have partnerships in place to advance additional prophylactic and therapeutic product candidates utilizing our viral vector platforms, including VTP-500 for Middle East Respiratory Syndrome, or MERS, VTP-400 for Herpes Zoster infections, and VTP-600 with potential for multiple cancer indications, including Non-Small Cell Lung Cancer ("NSCLC"), and Squamous Esophageal Cancer. We also co-invented a COVID-19 vaccine with the University of Oxford, which was exclusively licensed worldwide to AstraZeneca U.K. Limited ("AstraZeneca").

We believe our core capabilities at the intersection of T cell immunology and immunotherapeutic technology platforms combined with our track record of successfully executing development path activities uniquely position us to navigate towards delivering promising new treatments for patients with auto-immune and inflammatory diseases and building value for shareholders.

Our Approach

We are leveraging the latest understanding of how the immune system's T cells naturally function to control disease. Research has shown that T cells are key to our body’s ability to identify and respond to threats through recognition of antigens. Disease can occur when the T cell response is either inappropriate, as occurs in auto-immunity, or inadequate, as often occurs in chronic viral infections or cancer.

Many auto-immune and inflammatory diseases are characterized by an inappropriate or overactive immune response caused by an imbalance in the T cell population. T effector ("Teff") cells that normally fight infections and cancer can inappropriately attack the body and overwhelm the regulatory T ("Treg") cells that are meant to prevent inflammation. While there has been incredible progress in the treatment options over the last two decades, current therapies still rely heavily on the use of non-specific immunosuppressive agents and supportive therapies. These may efficiently dampen inflammation and slow disease progression, but they often require lifelong treatment and their lack of specificity for the pathogenic mechanism can lead to several, sometimes life-threatening, side effects. Therefore, there remains a need for more targeted, curative therapies that directly address the T cell (Treg/Teff) imbalance underlying many auto-immune and inflammatory diseases. Fortunately, improved understanding of the cause of inflammatory diseases is allowing the identification of the specific antigens that Teff cells are attacking. In auto-immunity, Teff cells recognize and attack tissues harboring self-antigens, such as pancreatic beta islet cell associated antigens in type-1 diabetes. Knowledge of the problematic antigens that the Teff cells are responding to allows for the development of highly specific treatments that only target the T cells involved in the disease and may provide a less aggressive and potentially curative approach.

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We aim to directly address the disease process underlying auto-immunity and other inflammatory diseases by developing antigen-specific immune tolerance ("ASIT") therapies based on our proprietary SNAP-TI technology platform. Our approach is to use SNAP-TI to provide the immune system with problematic antigens within an appropriate tolerogenic context that promotes a reduction in Teff cells and increase in Treg cells, aiming to restore the natural state of immune tolerance and control over disease. Properties that differentiate SNAP-TI from other ASIT therapies are the use of synthetic, self-assembling nanoparticles to improve manufacturability of multiple antigen compositions; ability to administer by preferred intramuscular or subcutaneous routes; and use of an immunomodulator that aims to improve the Treg/Teff ratio and prevent unwanted inflammation associated with the treatment.

For chronic viral infections and cancer, we use a different platform and approach but still leverage T cells. Our viral vector platforms are designed to stimulate the production of very high levels of Teff cells, such as CD8+ T cells that can recognize viral antigens or tumor antigens. Over the past three decades, hundreds of trials have examined a wide variety of approaches that induce the production of CD8+ T cells against infected and cancerous cells. These trials have demonstrated that different approaches induce different breadths and magnitudes of immune responses. While there have been many successes, certain diseases requiring a robust CD8+ T cell response have remained resistant possibly due to limitations of existing approaches. Our approach for treating chronic viral infections or cancers is to attempt to elicit a strong and specific immune response against key viral or tumor antigens, respectively, using a combination of two proprietary platforms encoded with the target antigens, each administered one month apart. We employ unique antigen design strategies intended to optimize antigen presentation to the immune system and maximize the desired type of immune response we are seeking to induce. This specific combination approach has been shown to provide a very high magnitude and durable CD8+ T cell response induced in humans. Our viral platforms are further differentiated by their flexibility, applicability across diseases, favorable tolerability profile and proven rapid production on a large scale.

In 2024, we achieved a number of strategic, operational, and financial objectives, which we believe position us to deliver on our long-term plans:

•In April 2024, we received clearance from the FDA on an Investigational New Drug ("IND") application, as well as from the Australian regulatory authorities, to progress VTP-1000 in a first in human clinical trial in celiac disease. AVALON is a randomized, placebo-controlled Phase 1 trial with a controlled gluten challenge to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of VTP-1000 in adults with celiac disease. The primary endpoint is assessment of the safety and tolerability of single and multiple dosing, and determination of a dose and schedule for further investigation. The trial also aims to demonstrate proof-of-principle of induction of immune tolerance and early proof-of-concept for VTP-1000, as a potential treatment for celiac disease, based on assessment of pharmacodynamics and preliminary efficacy determined by means of a controlled gluten challenge.

•In April 2024, we announced top-line final data from the APOLLO trial (also known as HPV001), a Phase 1b/2 randomized, placebo-controlled, multi-center dose-ranging trial of VTP-200 in 108 participants across the U.K. and EU evaluating the safety, tolerability and immunogenicity of VTP-200 in women aged 25-55 with persistent high-risk human papillomavirus ("hrHPV") infections and low-grade cervical lesions. The trial was designed to assess the effect of VTP-200 on clearance of hrHPV infection and cervical lesion(s), as well as defining select appropriate doses for further development.

•In May 2024, we appointed Dr. Leon Hooftman, M.D., as our Chief Medical Officer, effective as of June 2, 2024. Dr. Hooftman brings significant drug development expertise across a broad array of therapeutic areas including oncology, infectious diseases, and inflammation.

•In June 2024, we presented interim data on two Phase 2 trials of VTP-300. Across both studies, 19% of participants had undetectable HBsAg levels. The majority of patients who were assessed reached very low levels of HBsAg and eligibility for NUC discontinuation. Management believe these data are further evidence that VTP-300 could be a critical component of a functional cure regimen.

•In June 2024, we announced a strategic pipeline prioritization following positive interim data from VTP-300 in Chronic Hepatitis B virus infections, prioritizing the development of VTP-300 in chronic Hepatitis B, and VTP-1000 in celiac disease.

•In September 2024, we announced that the first patient/participant was entered into the Phase 1 AVALON clinical trial for VTP-1000 in celiac disease. The AVALON trial aims to enroll 42 participants with celiac disease and will be conducted in two parts: a randomized double-blind placebo controlled single ascending dose ("SAD") part,

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followed by a randomized double-blind placebo-controlled multiple ascending dose part, incorporating a controlled gluten challenge to assess the impact of VTP-1000 administration on patients’ exposure to gluten.

•In October 2024, we announced that enrollment had completed in the Phase 2b HBV003 clinical trial for VTP-300 in chronic hepatitis B as well as the Phase 1 PCA001 clinical trial for VTP-850 in prostate cancer, respectively. The Phase 2b trial with VTP 300 enrolled 121 adult participants and is designed to obtain critical dosing information for a potential functional cure regimen for chronic hepatitis B, with participants receiving VTP-300 and low-dose ("LD") nivolumab. The Phase 1 PCA001 clinical trial enrolled 22 participants and is designed to determine the recommended Phase 2 dosing regimen of VTP-850 as well as evaluate safety and efficacy, as measured by PSA and T cell responses.

•In November 2024, we presented positive updated interim data from the Phase 2b HBV003 clinical trial for VTP-300. The new data showed that as of the data cut off date of September 30, 2024, eight participants demonstrated complete HBsAg loss (defined as HBsAg levels below the lower limit of quantitation [<LLOQ, 0.05 IU/mL]) and two participants met the criteria for functional cure. Uniquely, two of the eight participants with HBsAg loss, became positive for anti-hepatitis B antibodies ("HBsAb", so called seroconversion) that they did not have before, including one of those who met functional cure criteria.

•In November 2024, we presented interim data from Group C of the Phase 2a IM-PROVE II clinical trial in collaboration with Arbutus Biopharma Corporation ("Arbutus") (NASDAQ: ABUS), in people with chronic hepatitis B receiving imdusiran followed by VTP-300 and low-dose nivolumab. The data indicated that Group C participants receiving nivolumab and VTP-300 experienced increased rates of HBsAg loss at Week 48 (3/13) compared to Group A and B participants who received imdusiran and VTP-300 or placebo.

•In November 2024, we announced the promotion of Geoffrey Lynn, M.D., Ph.D., to Chief Scientific Officer, effective as of December 1, 2024, following the departure of Nadège Pelletier, Ph.D. Dr. Lynn is a seasoned biotech innovator and executive with over 15 years of experience leading immunotherapeutic R&D from discovery through early development.

The Key Elements of Our Immunotherapy Platforms

We have two distinct technology platforms that are designed to either promote immune tolerance for treating auto-immunity and inflammatory diseases or induce CD8+ T cells to fight chronic viral infectious disease and cancer. Our immune tolerance platform, SNAP-TI, is designed to restore immune tolerance by a mechanism of action that includes the induction of Treg cells and/or decrease of Teff cells to specifically restore a beneficial Treg/Teff ratio. Our viral vector platforms (ChAdOx and MVA) by contrast allow us to develop product candidates designed to induce high and durable levels of antigen-specific polyfunctional T cells, particularly CD8+ T cells, and B cells to prevent and treat infectious diseases and cancer.

Key elements of SNAP-TI:

•Self-assembling nanoparticles based on amphiphilic peptides as a tolerance immunotherapy ("SNAP-TI") is a synthetic platform that leverages self-assembly to co-deliver multiple disease-specific peptide antigens and immunomodulators in nanoparticles of uniform size (~20 nm) and composition that are designed to access immune cells that promote tolerance following intramuscular or subcutaneous routes of administration.

•Use of self-assembly is a key differentiator of SNAP-TI that allows for co-delivery of multiple antigens and an immunomodulator at up to about 50% loading by particle mass. This relatively high loading enables dosing by intramuscular or subcutaneous routes. The small size of SNAP-TI particles allows them to enter different lymphoid organs and promote uptake by the key immune cells that help to promote immune tolerance. Importantly, the co-delivered immunomodulator provides a tolerogenic context to prevent any unwanted inflammation and to promote an increased Treg/Teff ratio.

•SNAP-TI has shown promising data on protection from disease in multiple mouse models of autoimmunity and is now being assessed in clinical studies as a product candidate (VTP-1000) for treating celiac disease. We expect that the modularity of the SNAP-TI platform could allow for a growing pipeline of candidates for I&I indications.

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Antigen selection and design for SNAP-TI candidates:

•We are prioritizing the research and development of candidates for treating autoimmune and inflammatory diseases that are at least in part driven by Teff cells and preferably have a known human leukocyte antigen ("HLA") association. This focus allows us to select specific I&I indications and patients who are most likely to benefit from therapy with SNAP-TI. For each indication, we undertake a rigorous antigen selection process to identify key antigens that are recognized by Teff cells involved in disease pathology or present in disease tissue that may be helpful for inducing bystander Tregs. Our pipeline integrates clinical precedent, in silico bioinformatics and ex vivo screening of candidate antigens with patient derived Teff cells. The result of this screening process is the selection of antigens to include in SNAP-TI with the aim of inducing antigen-specific immune tolerance tailored to the specific disease indication.

The key elements of our viral vector platforms, which include ChAdOx and MVA, are:

•Proprietary simian vectors: ChAdOx1 and ChAdOx2 are modified simian adenoviral vectors which deliver target antigens into cells to generate a specific immune response. These viruses were originally isolated from chimpanzees to avoid pre-existing immunity issues affecting the use of human adenovirus vectors. Researchers at the Jenner Institute modified the ChAdOx viruses to be non-replicating and to have an increased antigen-carrying capacity. To date, we have developed several candidates with the ChAdOx vectors, each carrying antigens that are specific to the targeted pathogens and diseases. Adenoviral vectors have demonstrable safety profiles and have induced the desired immune responses in all age groups evaluated to date.

•Well-validated follow-up vector: MVA is a highly attenuated vaccinia virus used to deliver target antigens into cells to generate de novo or amplify an existing immune response. MVA has a large antigen-carrying capacity and generates a particularly strong immune response when used secondarily, in sequential combination, to an alternative viral vector carrying the same antigen load (ChAdOx in this case). MVA is replication-deficient and has a well-documented safety profile in hundreds of thousands of people, and is licensed as a smallpox vaccine in both Europe and the U.S.

•Proprietary promoters and enhancers: Promoters and molecular enhancers are genetic codes that influence antigen expression. For our adenoviral vectors, we use a proprietary promoter that is modified from cytomegalovirus. The use of this modified promoter has been shown to increase both antigen expression and the associated immune response. For our MVA vector, we use a proprietary promoter to control expression of recombinant antigens and thereby further enhance T cell induction levels. We may use molecular adjuvants to enhance the CD8+ T cell response.

•Rapid vector generation and manufacturing: We employ manipulation of adenovirus genomes to enable rapid generation of recombinant adenoviral vectors to meet GMP standards. We believe our sequencing techniques have the potential to result in safer, more stable, product candidates. We believe that our adenovirus product candidates can be manufactured quickly and to significant scale, as demonstrated by Vaxzevria, a prophylactic vaccine for the prevention of COVID-19 infection. Vaxzevria, which is based on the ChAdOx1 vector, was designed, constructed and manufactured for human use within three months. Normal GMP production processes typically take six to ten months each for adenovirus and for MVA.

Antigen selection and design for our viral vectors:

•We select full-length and/or subunit antigen sequences involved in or associated with targeted infectious disease or cancer. We employ unique antigen design strategies to optimize in vivo antigen presentation and maximize the desired type of immune responses while maintaining the desired tolerability profile. For example, some targeted diseases may require a greater CD8+ T cell-mediated response, whereas others may require a more balanced T and B cell response. We use cutting-edge bioinformatics methods to design and optimize our antigen load. For example, to select antigen targets for pathogens, we use databases to rank options based on factors including global distribution of genetic strains, evolutionary competitive advantage, known pathogenicity and sequence upload bias; and design our final antigens to achieve maximal antigen presenting cell processing to elicit CD8+ T cells.

We have several product candidates in our pipeline focusing on I&I indications, infectious diseases, and oncology.

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Our Proprietary I&I Pipeline:

The chart below provides key information about our program using the SNAP-TI platform.

*We have worldwide rights for this product candidate.

1Based on Management's current estimates on expected clinical data milestones.

VTP-1000: Antigen-specific Immune Tolerance Candidate for Celiac Disease

Patients with celiac disease have an unwanted immune response against gluten proteins and can become severely ill following exposure to gluten found in various cereal grains, especially wheat.

VTP-1000 is designed to suppress the unwanted immune response to gluten by restoring a beneficial regulatory T cell to effector T cell ratio. It is based on SNAP-TI and comprises multiple gluten antigens (representing the key antigens linked to celiac disease) and an immunomodulator co-delivered in nanoparticles of precise size and composition that are optimized to target the appropriate immune cells that promote tolerance. The immunomodulator is a key component of VTP-1000 and is intended to drive regulatory T cell expansion and prevent pro-inflammatory responses.

Clinical Development

AVALON - Currently enrolling, ongoing Phase 1

The AVALON clinical trial is designed to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of VTP-1000. The trial aims to enroll 42 participants with celiac disease and will be conducted in two parts: a randomized double-blind placebo-controlled single ascending dose ("SAD") part, followed by a randomized double-blind placebo-controlled multiple ascending dose ("MAD") part, incorporating a controlled gluten challenge to assess the impact of VTP-1000 administration on patients’ exposure to gluten. In the AVALON trial, we are enrolling adults with celiac disease in the two-part trial, as described in the table below.

Future Development

As VTP-1000 is our first product candidate directed towards the treatment of an inflammatory disease, we believe demonstration of T regulatory cell induction and/or suppression of unwanted immune responses to gluten would pave the way for other therapeutic candidates based on SNAP-TI, including alternative autoimmune disease indications.

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Our Proprietary Infectious Disease and Oncology Pipeline:

*We have worldwide rights for all product candidates, except where indicated.

†Based on Management's current estimates on expected clinical data milestones.

VTP-300: An Immunotherapeutic Targeting Chronic HBV Infection

Patients with chronic hepatitis B infection live with the disease in the absence of symptoms for decades after initial infection. However, as the disease progresses and symptoms occur, it can cause serious health problems, including development of hepatocellular carcinoma or liver cirrhosis, especially if left untreated. There is an urgent need to develop an effective therapeutic strategy for chronic hepatitis B infection as less than 10% of patients achieve a functional cure with existing therapies. Experts agree that achieving functional cure in chronic Hepatitis B patients will likely require a combination of agents with complementary mechanisms of action. VTP-300 has been designed to be one of those components by stimulating a highly potent and polyfunctional disease-specific immune response, mostly led by disease-specific effector T-cells.

VTP-300 is composed of two viral vectors (ChAdOx and MVA), both encoding the same antigen sequence based on HBV genotype C antigen sequences that are administered intramuscularly one month apart, with the potential for additional administrations subsequently, depending upon outcome.

Clinical Development

HBV002 – Completed Phase 1b/2a Trial

In June 2023, we announced positive final safety and efficacy data from the HBV002 trial (NCT04778904). VTP-300 as a monotherapy and in combination with low-dose nivolumab was administered with no treatment-related serious adverse events. Meaningful, durable reductions of HBsAg were seen in Group 2 (receiving VTP-300 monotherapy, N=18) and Group 3 (receiving VTP-300 followed by a single low dose of nivolumab together with MVA, N=18). In Group 3, two participants developed non-detectable HBsAg levels, which continued eight months after last dose.

Importantly, VTP-300, based on HBV genotype C sequences, was observed to lead to a decline in HBsAg in both genotype B- and C-infected CHB patients. Additionally, T cell responses to HBV core protein induced by VTP-300 in healthy subjects were shown to cross-react with other prevalent genotypes (A to E). Together, these results highlighted that T cell responses induced by VTP-300, based on genotype C, were cross-reactive to other common HBV genotypes.

HBV003 – Fully Enrolled, Ongoing Phase 2b Trial

HBV003 is designed to obtain critical information on treatment dosing regimens in patients receiving VTP-300 and low-dose nivolumab. Participant enrollment was completed in October 2024. In the HBV003 trial, we enrolled CHB patients in three treatment groups as described in the table below. The trial design directly builds on HBV002 to evaluate PD-1 inhibition timing, and includes criteria for discontinuation of maintenance therapy with standard-of-care nucleos(t)ide reverse transcriptase inhibitors ("NUC") to obtain information on the durability of the response in the absence of such treatment.

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Interim Data from the HBV003 Trial

In November 2024, we reported updated data with another interim analysis of the ongoing HBV003 trial (NCT05343481) (with data as of September 30, 2024, for laboratory data and October 8, 2024, for clinical data). One hundred and twenty-one virally suppressed CHB patients on stable NUC therapy have been enrolled in the fully recruited trial, and this interim analysis focused on the 69 virally-suppressed participants who had entered the trial with HBsAg levels below 200 IU/mL.

These most recent data showed that as of data cut off date of September 30, 2024, eight participants demonstrated complete HBsAg loss (defined as HBsAg levels below the lower limit of quantitation [<LLOQ, 0.05 IU/mL]). Among these eight participants, three discontinued their NUC treatment, of which two met the criteria for functional cure, defined as undetectable HBV DNA and undetectable HBsAg for at least six months post-NUC treatment discontinuation. Uniquely, two of the eight participants with HBsAg loss, seroconverted to anti-HBsAb, including one of those who met functional cure criteria. The data from this ongoing trial indicate that stronger responses may happen in participants treated with the combination of VTP-300 and a low dose of the anti-PD1 antibody nivolumab given simultaneously (Groups 1 and 2) rather than separately (Group 3). VTP-300 in combination with nivolumab led to durable HBsAg declines in all treatment groups (as shown in graphs below).

1 The curves shown herewith are derived from the interim intent to treat ("ITT") comparison of the 3 treatment groups in HBV003.

Preliminary safety data indicated that VTP-300 in combination with low-dose nivolumab was generally well tolerated with no treatment-related SAEs observed or reported as of the data cut off date of September 30, 2024.

IM-PROVE II – Fully Enrolled, Ongoing Phase 2a Trial in Collaboration with Arbutus

IM-PROVE II, or AB-729-202, is an ongoing Phase 2a clinical trial in collaboration with Arbutus to evaluate Arbutus’ RNAi therapeutic candidate, imdusiran or AB-729, in combination with VTP-300 for the treatment of patients with chronic HBV infection. The clinical trial is designed to evaluate whether decreasing HBsAg levels following imdusiran but prior to VTP-300 treatment, lead to a more sustained HBsAg reduction compared to treatment with imdusiran alone, for CHB patients. Primary endpoints are evaluating the safety, antiviral activity and T cell activity of VTP-300 administered post imdusiran treatment. The trial is designed to enroll 60 CHB patients as shown in the table below. All patients receive imdusiran (60mg every 8 weeks) plus NUC therapy for 24 weeks. At week 24, treatment with imdusiran stops and patients

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are randomized to receive either placebo (Group B) or VTP-300 (Groups A & C) at week 26 and 30 (and conditionally at week 38 if they experienced a >0.5log10 decline in HBsAg between week 26 and 34). Group C receives in addition to the above a low dose nivolumab concomitantly with their MVA dose. At week 48 all participants are evaluated for eligibility to either discontinue or remain on NUC therapy.

Interim Data from the IM-PROVE II Trial

In November 2024, we announced new interim data from Group C of the IM-PROVE II trial (ACTRN12622000317796). Group C enrolled a total of 22 non-cirrhotic, virally suppressed cHBV participants with HBsAg ≥100 to <5,000 IU/mL at screening.

The data indicated that Group C participants receiving nivolumab experienced increased rates of HBsAg loss (defined as HBsAg <LLOQ [0.05 IU/mL]) compared to Group A and B participants who received imdusiran and VTP-300 or placebo.

The preliminary data from Group C included data to Week 48 (20/22 participants) and, as shown in the graph below, showed that imdusiran lead-in treatment led to a mean decline from baseline in HBsAg consistent with data from Groups A and B. Significantly greater mean declines in HBsAg levels (p <0.017) were seen in Group C participants, who received imdusiran and VTP-300 with nivolumab, at Week 48 compared with Groups A and B and Group C without nivolumab. 23% of participants (3/13) in the group receiving imdusiran, VTP-300 and low-dose nivolumab achieved HBsAg loss by Week 48. Increases in soluble immune biomarkers associated with immune checkpoint proteins, inflammation, and T-cell activation were observed in participants who had HBsAg loss at any point through Week 48.

The Group C treatment regimen with nivolumab was generally well tolerated and did not result in any immune-related adverse events.

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Future Development

We believe that the interim analysis from the HBV003 Phase 2b and the IM-PROVE II Phase 2a studies suggest that VTP-300 contributes to HBsAg loss, and could become part of a regimen that can attain and maintain functional cure.

We are actively seeking a partner to take advantage of VTP-300's differentiated ability to achieve sustained HBsAg loss and functional cure in patients with low levels of HBsAg. We expect to report out more definitive data of a complete primary analysis of both the HBV003 trial and the IM-PROVE II combination trial with Arbutus in the second quarter of 2025.

VTP-200: A Potential Non-Invasive Treatment for Persistent High-Risk HPV (hr-HPV)

VTP-200 is a potential curative treatment for persistent hrHPV infection and associated pre-cancerous lesions. An estimated 291 million women worldwide are carriers of human papillomavirus ("HPV") DNA, which can progress to pre-cancerous cervical lesions if untreated. The last clinical visit of the final patient in our Phase 1b/2 APOLLO (HPV001) clinical trial of VTP-200, (NCT04607850), took place in January 2024. VTP-200 is composed of two viral vectors (ChAdOx1 and MVA), both encoding the same HPV antigens (i.e.,: E1, E2, E4, E5, E6, E7), designed to elicit an antigen-specific T cell immune response to HPV. Both vectors are administered intramuscularly and sequentially, one month apart.

Clinical Development

APOLLO (HPV001) - Completed Phase 1b/2 Trial

Our Phase 1b/2 APOLLO clinical trial was designed to assess the safety and efficacy of VTP-200 and determine the optimal dosing regimen. We enrolled a total of 108 healthy women with low grade lesions who had persistent hrHPV for at least six months. Patients with high-grade squamous intraepithelial lesions ("HSIL") or early cancer were excluded. The trial was conducted in the United Kingdom and the European Union. The diagram below provides an overview of the Phase 1b/2 clinical trial design.

The primary objective of the trial was to evaluate the safety and tolerability of VTP-200. The secondary objective of this trial was to determine the optimal dose and to evaluate the efficacy of HPV001 on the clearance of hrHPV infection and on the cervical intraepithelial neoplasia ("CIN").

In April 2024, we announced topline data from 108 participants with low grade lesions who had persistent hrHPV for at least six months. The APOLLO trial met its primary safety endpoint, demonstrating that VTP-200 was generally well-tolerated and was administered with no treatment-related grade 3 or higher unsolicited AEs and no treatment-related SAEs.

The highest hrHPV clearance rate of 60% at Month 12 was observed in Group 2, which included the highest dose of ChAdOx, compared to a 33% clearance rate in the placebo group. Groups 1, 3, 4 and 5 showed 12%, 11%, 33% and 36% hrHPV clearance rates, respectively.

The trial also evaluated cervical lesion clearance rates in participants with both reported lesions at screening and visualization of the cervical transformation zone at 12 months (n=57). The highest cervical lesion clearance rate of 67% was observed in Group 2 and Group 5, both received the highest dose of ChAdOx, compared to 39% in the placebo group. Groups 1, 3 and 4 showed 40%, 20% and 33% cervical lesion clearance rates, respectively.

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Pooled data from the five active dose groups showed no significant improvement in hrHPV clearance or cervical lesion clearance rates in comparison to the placebo group.

Future Development

The clinical development of VTP-200 is expected to be progressed by external parties via licensing or partnership, if a partner can be identified. We will not continue to develop this product candidate.

VTP-850: Our Next-Generation Immunotherapeutic Candidate for Prostate Cancer

We are developing VTP-850, our next-generation prostate cancer product candidate, to improve upon VTP-800. Both VTP-800 and VTP-850 are composed of two viral vectors (ChAdOx1 and MVA, both encoding the same antigen sequences); however, VTP-800 encodes only one antigen, 5T4, while VTP-850 encodes four antigens, PSA, PAP, STEAP1 and 5T4. We designed VTP-850 to induce a broader immune response by encoding multiple antigens to reduce the ability of cancer cells to evade the immune response by mutating or losing expression of any one antigen. The antigens we encode in VTP-850 are expressed in most prostate cancers but have little or no expression on healthy tissues other than prostate.

Clinical Development

Phase 1 (VANCE) and Phase 2 (ADVANCE) clinical trials of VTP-800 were sponsored and conducted by the University of Oxford in the United Kingdom.

VANCE - Completed Phase 1

VANCE was a first-in-human, open label, randomized, Phase 1 clinical trial designed to evaluate the safety and immunological response of VTP-800 with and without low dose cyclophosphamide in localized prostate cancer. Thirty-nine patients with early stage localized, castration-sensitive prostate cancer were treated. Thirty-three patients received sequential administration of ChAdOx1-5T4 and MVA-5T4, one month apart, while six patients received MVA-5T4 alone. Patients received both regimens alone or with cyclophosphamide preconditioning. VTP-800 was generally well tolerated, with side effects of local injection site pain, fatigue, feverishness, and myalgia, which are consistent with those observed for these vectors in other clinical trials. There were no reported treatment-related serious adverse events. Data showed that 59% of participants had no detectable T cell response at baseline and developed a 5T4-specific T cell response de novo. Two patients had a baseline response, and the frequency of 5T4-specific T cells was observed to increase following administration. T cell infiltration into the resected prostate was also observed.

ADVANCE - Completed Phase 2

ADVANCE was an open-label, non-randomized Phase 2 clinical trial of VTP-800 in combination with anti-PD-1 checkpoint inhibitor, nivolumab, in 23 patients with metastatic prostate cancer. The primary objectives of the ADVANCE trial were to assess the safety and response rate of VTP-800 when administered in combination with nivolumab. The secondary objectives were to assess the immune responses in peripheral blood and to evaluate radiographic progression-free survival and overall survival. Patients received sequential administration of ChAdOx1-5T4 followed by MVA-5T4 one month later. Nivolumab was administered at months one, two and three. In most patients, VTP-800 was also given at months three and four. All patients received 2.5 x 10˄10 vp of ChAdOx1-5T4, 2.0 x 10˄10 pfu of MVA-5T4 and 480mg of nivolumab. VTP-800 was generally well tolerated. The most common treatment emergent adverse events were bone pain, injection site pain, muscle pain, stomatitis, and constipation, and most were mild and grade 1 or 2. The only grade 3 adverse event was a chest infection, which was not related to trial drug. There were no grade 4 or 5 treatment-related adverse events. Data showed that three of eight patients with measurable disease had partial tumor responses. Five of 23, or 22%, of enrolled patients had greater than 50% reduction of prostate specific antigen ("PSA") at any timepoint.

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PSA Reduction in Patients from ADVANCE Phase 2 Clinical Trial

PCA001 - Fully Enrolled, Phase 1 Trial

In October 2024, we announced enrollment was complete for PCA001 (NCT05617040), our ongoing Phase 1 clinical trial designed to determine the recommended dosing regimen of VTP-850 as well as evaluate safety and efficacy, as measured by prostate-specific antigen (PSA), and induced T cell response of VTP-850 monotherapy in men with rising PSA after definitive local therapy for their disease (i.e., biochemical recurrence). PCA001 builds on the previous promising data from the University of Oxford Phase 1 VANCE and Phase 1/2 ADVANCE clinical trials of VTP-800.

The trial involves a Phase 1 dose finding stage testing 2 doses of ChAdOx-PCA with follow-up MVA-PCA dose administered either intramuscularly or intravenously to determine potential Phase 2 recommended dose and route of administration. The diagram below provides an overview of the Phase 1 clinical trial design for PCA001.

Future Development

We expect to announce topline data from the PCA001 clinical trial in the second quarter of 2025. The future clinical development of VTP-850 is expected to be progressed by external parties via licensing or partnership, if a partner can be identified.

VTP-600: Our Immunotherapeutic Candidate Targeting MAGE-A3 and NY-ESO1 Antigens

VTP-600 is an immunotherapy candidate encoding the tumor-associated antigens MAGE-A3 and NY-ESO1, initially as a potential first line treatment of NSCLC in combination with standard of care treatment, chemotherapy and pembrolizumab. Lung cancer is the most common cancer diagnosis and cause of cancer death worldwide, with 85% of cases classified as NSCLC. About 25% to 30% of NSCLC patients have squamous histology and the remainder have non-squamous histology. MAGE-A3 is expressed in 48% of squamous NSCLC and 24% of non- squamous NSCLC. NY-ESO1 has been shown to have an expression rate of 27% across all NSCLC types. We initiated a first-in-human Phase 1/2a trial in collaboration with Cancer Research U.K. ("CRUK"), who are sponsoring and funding this trial.

In 2024, CRUK opened a squamous esophageal cancer cohort with the intention of recruiting up to 17 participants. As squamous esophageal cancer is suitable for biopsy, we believed that the trial in this cohort could enable the observation of

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changes in T cell immunity both in the periphery and in the tumor micro-environment between pre- and post-VTP-600 treatment. Recruitment into both the NSCLC and squamous esophageal arms stopped in September 2024 and patients are in follow-up. No toxicity was observed during the trial and safety was not a factor in deciding to stop the trial.

Together with our strategic collaborators, Ludwig Institute for Cancer Research (the "Ludwig Institute"), and CRUK, we are looking for other routes to continue development of VTP-600.

VTP-500: A Prophylactic Vaccine Candidate to Prevent MERS

We are developing VTP-500 as a vaccine product candidate to prevent infection and subsequent disease caused by the MERS coronavirus. Although human-to-human transmission appears to be rare, MERS coronavirus has the potential to cause epidemics, infecting hundreds of thousands of people and causing significant morbidity and mortality in 34% of infected individuals. Clinical efficacy trials to prevent MERS are challenging to execute due to the sporadic nature of infection, however studies have demonstrated positive Phase 1 safety and immunogenicity data. In November 2021, VTP-500 results from the Saudi Arabia Phase 1 trial were published in The Lancet Microbe. The Phase 1 data showed that VTP-500 was generally well tolerated in patients, and further development of the product candidate is planned by our non-exclusive licensee, the University of Oxford.

On December 21, 2023, we announced a project with Coalition for Epidemic Preparedness Innovations ("CEPI") and the University of Oxford, aiming to fast-track the development of VTP-500 for the prevention of MERS. The project includes CEPI contributing funding of up to $34.8 million to Barinthus Bio, in addition to funds previously committed to the University of Oxford to develop and stockpile a ready reserve of emergency MERS vaccine candidate, VTP-500.

Due to VTP-500’s potential in significantly addressing the unmet need for MERS, the EMA confirmed support for the program through PRIME designation in December 2023. The EMA’s PRIME designation enhances support for the development of medicines that target an unmet medical need, offering early and proactive support to medicine developers to optimize the generation of robust data on a medicine's benefits and risks and enable accelerated assessment of medicines applications.

VTP-400: A Prophylactic Vaccine Candidate for Shingles (Herpes Zoster)

VTP-400 is our vaccine candidate in development to prevent shingles in adults aged 50 years and older. There are an estimated 140 million cases globally of shingles each year, which can result in significant post-infection pain, known as post-herpetic neuralgia, or even death. Our regional partner in China and Southeast Asia, CanSino, initiated a Phase 1 clinical trial of VTP-400 in Canada in November 2023 to evaluate both T cell-mediated and B cell-mediated immune responses resulting from VTP-400.

Vaxzevria: A Prophylactic Vaccine for the Prevention of COVID-19 Infection

The speed of the development of Vaxzevria (formerly VTP-900 and AZD1222) for the prevention of COVID-19, which entered the clinic within three months from initial antigen design, demonstrated that our ChAdOx platform enables rapid development of product candidates. We co-invented VTP-900 in partnership with the University of Oxford’s Jenner Institute, which we assigned to Oxford University Innovation ("OUI") to facilitate the licensing of those rights by OUI to AstraZeneca. It has been estimated that over 6.5 million lives have been saved worldwide, and between 37.7 and 122.4 million hospitalizations were prevented. We are eligible to receive a share of royalties and other revenue received by OUI pursuant to its agreement with AstraZeneca for Vaxzevria. In May 2024, AstraZeneca announced it had made the strategic decision to initiate the withdrawal of marketing authorization for Vaxzevria within Europe, citing decline in demand as the reason for the decision. In October 2024, we were informed of $15.0 million due to the Company from OUI in relation to the Company's share of royalties received by OUI as a result of prior commercial sales of Vaxzevria by AstraZeneca. We do not expect to receive any further payments relating to future commercial sales of Vaxzevria.

Our History and Team

We were founded in May 2016 as a spin-out from a leading institution in the United Kingdom, the Jenner Institute at the University of Oxford, with the aim of developing and commercializing innovative immunotherapeutics and vaccines to treat and prevent infectious diseases and cancer. The ChAdOx1 and MVA platforms use technologies that were developed at the Jenner Institute over 15 years and through clinical trials involving thousands of participants. Our scientific founders, Professor Adrian Hill KBE, FRCP, FRS and Professor Dame Sarah Gilbert DBE, are leaders in the fields of infectious

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diseases, immunology, vaccine development and viral vectors. Professor Hill is the founding Director of the Jenner Institute at the University of Oxford and is also the Lakshmi Mittal and Family Professor of Vaccinology at the University of Oxford. Professor Gilbert is Professor of Vaccinology at the University of Oxford and leads programs on the development of vaccines against multiple emerging viral pathogens as well as research into vaccine manufacturing. She was the Oxford Project Lead for the Oxford/AstraZeneca COVID-19 vaccine project. Our strategic trajectory has grown with the acquisition of Avidea Technologies, Inc. ("Avidea") and the SNAP-TI platform in 2021, expanding our product candidate pipeline and strengthening our scientific leadership in immunotherapies and the autoimmune space.

We have assembled a management team with extensive expertise in building and operating biopharmaceutical organizations that have discovered, developed and delivered innovative medicines to patients. Our management team has broad experience and successful track records in biopharmaceutical drug discovery, clinical development, regulatory affairs, manufacturing and commercialization, as well as in business, operations, and finance. Our management team’s experience was gained at leading institutions that include Agalimmune, Altimmune, Celltech, Ernst & Young, GenVec and Roche.

Our board of directors has extensive expertise in the fields of science, business, and finance. Our scientific advisory board ("SAB") works with our management team in the planning and development of scientific, clinical, and research and development initiatives and strategies. The SAB is composed of scientific and clinical thought leaders in the fields of immunotherapy, vaccine development, immunology, infectious diseases, immune tolerance and oncology.

Our Collaboration and License Agreements

2016 License Agreement with OUI

In March 2016, we entered into a license agreement (the "2016 OUI License Agreement") (as amended in January 2019 and April 2020), with OUI (previously known as Isis Innovation Limited) for the development and commercialization of vaccines for influenza, cancer (including therapeutic and prophylactic vaccines and including cancer associated with viral infections), varicella zoster and MERS. We refer to these areas together as the “Field.”

Pursuant to the 2016 OUI License Agreement, OUI granted us a worldwide license under certain patent rights of OUI, including rights related to the use of ChAdOx1, ChAdOx2, adenoviral and MVA promoters and influenza product candidates, among other rights (the "2016 Licensed Technology") to develop, manufacture, use and commercialize licensed products. The rights are exclusive in certain fields and non-exclusive in others. Our license to certain patents and applications relating to certain adenoviral vectors encoding a pathogen or tumor antigen and certain pox virus expression systems is exclusive within the Field, non- exclusive in all other fields, and excludes veterinary applications. Our license to certain patents and applications relating to certain compositions and methods is exclusive in all fields and excludes veterinary applications. Our license for the use of the ChAdOx1 vector under certain patents and applications relating to certain simian adenovirus and hybrid adenoviral vectors is exclusive in the Field, non-exclusive in all other fields, and excludes veterinary applications (apart from MERS) and certain specified indications. Furthermore, our license with respect to the use of the ChAdOx2 vector under certain patents and applications relating to certain adenoviral vectors is exclusive in certain vaccine-related fields, non- exclusive in all other fields, and excludes all veterinary applications (apart from MERS) and certain other specified indications. In addition, we also obtained a license to certain clinical data generated from OUI projects and related confidential know-how to develop, manufacture, use and commercialize licensed products, and such license is exclusive in the Field, other than with respect to know-how related to ChAdOx2, which is licensed non-exclusively. The 2016 Licensed Technology is sublicensable subject to obtaining OUI’s prior written consent (such consent not to be unreasonably withheld, conditioned or delayed) and inclusion in any sublicense agreement of restrictions on further sub-licensing, among other terms and conditions.

Pursuant to the 2016 OUI License Agreement, all intellectual property rights resulting from improvements made prior to the second anniversary of the agreement (i) to the licensed patent rights by the inventor belong to OUI, and (ii) to the 2016 Licensed Technology by us belong to us. OUI retains the right for the University of Oxford and any person who works or has worked on the 2016 Licensed Technology to use the 2016 Licensed Technology, as well as any improvements that we made to that technology during the first two years of the license, for education, research and limited clinical patient care. Furthermore, the University of Oxford may publish the 2016 Licensed Technology and those improvements without our consent provided that they have first given us advance notice and delayed the publication if necessary for us to obtain patent protection. In addition, OUI retains the right to grant academic and research licenses to any third parties under the 2016 Licensed Technology to encourage basic research for education and limited clinical patient care but may not grant licenses for commercialization of the 2016 Licensed Technology that is exclusively licensed to us, nor for development or marketing or products or services that are produced or supplied using the 2016 Licensed Technology.

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Upon execution of the 2016 OUI License Agreement, we paid OUI a one-time upfront fee of £100,000. We are obligated to pay OUI a low single-digit royalty (that varies based on the indication) on net sales of any product or process produced by or using the 2016 Licensed Technology. If we sublicense the 2016 Licensed Technology, we will be required to pay OUI a mid-single-digit royalty on any royalties paid to us by the sublicensee and a high single-digit royalty on non-royalty sublicensing income (excluding milestone payment income overlapping with milestone payments paid to OUI and income used to fund research and development). In the event that the royalties (excluding the royalty on sublicensing income) owed to OUI do not amount to a specified minimum ranging from the mid five figures to low six figures based on the license year in each year following March 2020, we must also pay OUI the difference between the royalty paid and the applicable minimum sum payable. In 2024, we paid £100,000 to OUI, representing the difference between royalties paid and the minimum sum payable. In addition, we are required to pay OUI milestone payments of up to an aggregate of £14.8 million upon the achievement of specified development, regulatory and commercial milestones.

Unless earlier terminated, the 2016 OUI License Agreement will continue until the later of the expiration of the last claim of a licensed patent or 20 years from the date of the agreement. The last patent under the 2016 OUI License Agreement, if granted, is expected to expire in November 2039, without giving effect to any potential patent term extensions or patent term adjustments. Either party may terminate for the uncured breach of the other party. We may terminate the agreement at any time upon three months’ prior written notice. OUI may terminate the agreement upon us filing for bankruptcy or in the event of liquidation or receivership proceedings, or upon 30 days’ prior written notice upon the occurrence of certain other events. Upon termination of the 2016 OUI License Agreement, we are required to, among other things, grant to OUI an irrevocable, transferable, non-exclusive license to develop, make and use any improvements to the 2016 Licensed Technology which we made prior to the second anniversary of the date of the agreement.

2017 License Agreement with OUI (Barinthus Biotherapeutics (U.K.) Limited)

In September 2017, we entered into a further license agreement with OUI (the "2017 OUI License Agreement") for the development and commercialization of immunotherapies for HBV and HPV.

Pursuant to the 2017 OUI License Agreement, we acquired a worldwide license under certain additional patent rights of OUI, including rights related to the use of HBV immunotherapy product candidates, HPV immunotherapy product candidates and shark invariant chain polypeptides, among other rights (the "2017 Licensed Technology"), to develop, manufacture, use and commercialize licensed products. The rights are exclusive in some fields and non-exclusive in others. Our license to certain patents and applications relating to certain HBV and HPV vaccines is exclusive in all fields. Our license to certain patents and applications relating to molecular adjuvants is non-exclusive in the field of HBV. Our license to certain patents and applications relating to certain simian and hybrid adenoviral vectors is exclusive in the fields of HPV associated diseases and HBV. Further, our license to certain patents and applications relating to certain other vectors is exclusive in the field of HBV.

Pursuant to the 2017 OUI License Agreement, we also obtained a non-exclusive license under related know- how to develop, manufacture, use and commercialize licensed products in all fields. The 2017 Licensed Technology is sublicensable subject to obtaining OUI’s prior written consent (such consent not to be unreasonably withheld, conditioned or delayed) and inclusion in any sublicense agreement of restrictions on further sub-licensing, among other terms.

Pursuant to the 2017 OUI License Agreement, all intellectual property rights resulting from improvements made prior to the second anniversary of the agreement (i) to the licensed patent rights by the inventor belong to OUI, and (ii) to the 2017 Licensed Technology by us belong to us. OUI retains the right for the University of Oxford and any person who works or has worked on the 2017 Licensed Technology to use the 2017 Licensed Technology, as well as any improvements that we made to that technology during the first two years of the license, for education, research and limited clinical patient care. Furthermore, the University of Oxford may publish the 2017 Licensed Technology and those improvements without our consent provided that they have first given us advance notice and delayed the publication if necessary for us to obtain patent protection. In addition, OUI retains the right to grant academic and research licenses to any third parties under the 2017 Licensed Technology to encourage basic research for education and limited clinical patient care but may not grant licenses for commercialization of the 2017 Licensed Technology that is exclusively licensed to us, nor for development or marketing or products or services that are produced or supplied using the 2017 Licensed Technology.

Upon execution of the 2017 OUI License Agreement, we paid OUI a one-time upfront fee of £50,000. We are obligated to pay OUI a low single-digit royalty (that varies based on the indication) on net sales made by us or our sublicensees of any product or process produced by or using the 2017 Licensed Technology. In the event that such sales royalties owed to OUI do not amount to a specified minimum ranging from the mid five figures to low six figures based on the license year in each year following September 2020, we must also pay OUI the difference between the royalty paid and the applicable minimum sum payable. In 2024, we paid £100,000 to OUI, representing the difference between royalties paid and the

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minimum sum payable. If we sublicense the 2017 Licensed Technology, we will be required to pay OUI a mid-single-digit royalty on non- royalty sublicensing income (excluding milestone payment income overlapping with milestone payments paid to OUI and income used to fund research and development). In addition, we are required to pay OUI milestone payments of up to an aggregate of £9.85 million upon the achievement of specified development, regulatory and commercial milestones.

Unless earlier terminated, the 2017 OUI License Agreement will continue until the later of the expiration of the last claim of a licensed patent or 20 years from the date of the agreement. The last patent under the 2017 OUI License Agreement, if granted, is expected to expire in August 2038, without giving effect to any potential patent term extensions or patent term adjustments. Either party may terminate for the uncured breach of the other party. We may terminate the agreement at any time upon three months’ prior written notice. OUI may terminate the agreement upon us filing for bankruptcy or in the event of liquidation or receivership proceedings, or upon 30 days’ prior written notice upon the occurrence of certain other events. Upon termination of the 2017 OUI License Agreement, we are required to, among other things, grant to OUI an irrevocable, transferable, non-exclusive license to develop, make and use any improvements to the 2017 Licensed Technology which we made prior to the second anniversary of the date of the agreement.

2017 License Agreement with OUI (Barinthus Biotherapeutics North America, Inc.)

In March 2017, Avidea entered into a license agreement with OUI (the "March 2017 OUI License Agreement") for the development and commercialization of products comprising thermo-responsive adjuvant scaffolds for use in all indications. All of Avidea’s rights, duties and obligations under this March 2017 OUI License Agreement were assumed by Barinthus Bio NA following the acquisition of Avidea by Barinthus Biotherapeutics plc on December 10, 2021.

Pursuant to the March 2017 OUI License Agreement, OUI granted us a worldwide license under certain patent rights of OUI related to the use of thermo-responsive adjuvant scaffolds, among other rights (the "March 2017 Licensed Technology"), to develop, manufacture, use and commercialize licensed products. The license to patent rights are exclusive in all fields, and the license to know how is non-exclusive. The March 2017 Licensed Technology is sublicensable subject to obtaining OUI’s prior written consent (such consent not to be unreasonably withheld, conditioned or delayed) and inclusion in any sublicense agreement of restrictions on further sub-licensing, among other terms and conditions.

Pursuant to the March 2017 OUI License Agreement, all intellectual property rights resulting from improvements made by us belong to us. OUI retains the right for the University of Oxford, the U.S. National Institutes of Allergy and Infectious Diseases (“NIAID”), the Institute of Macromolecular Chemistry of the Czech Republic (“IMC”) and any person who works or has worked on the March 2017 Licensed Technology to use the March 2017 Licensed Technology and any licensee improvements for non-commercial use. Furthermore, the University of Oxford, NIAID or IMC may publish the March 2017 Licensed Technology and those improvements without our consent provided that they have first given us advance notice and delayed the publication if necessary for us to obtain patent protection. In addition, OUI retains the right to grant academic and research licenses to any third parties under the March 2017 Licensed Technology to encourage basic research for education and limited clinical patient care but may not grant licenses for commercialization of the March 2017 Licensed Technology that is exclusively licensed to us, nor for development or marketing or products or services that are produced or supplied using the March 2017 Licensed Technology.

Upon execution of the March 2017 OUI License Agreement, we paid OUI a one-time upfront fee of £3,000. We are obligated to pay OUI a low single-digit royalty on net sales of any product or process produced by or using the March 2017 Licensed Technology. If we sublicense the March 2017 Licensed Technology, we will be required to pay OUI a mid-single-digit royalty on any non-royalty sublicensing income. As of March 14, 2025, OUI has not been paid any royalties under the 2017 OUI License Agreement. In the event that the royalties (excluding the royalty on sublicensing income) owed to OUI do not amount to a specified minimum ranging from the low to mid five figures based on the license year in each year following March 2020, the licensee must also pay OUI the difference between the royalty paid and the applicable minimum sum payable. In 2024, we paid £55,000 to OUI, representing the difference between royalties paid and the minimum sum payable. In addition, we are required to pay OUI milestone payments of up to an aggregate of £2.43 million upon the achievement of specified development, regulatory and commercial milestones.

Unless earlier terminated, the 2017 OUI License Agreement will continue for as long as anything within the definition of the licensed patent remains in effect or 20 years from the date of the agreement. The patent licensed under the March 2017 OUI License Agreement, if granted, is expected to expire in October 2035, without giving effect to any potential patent term extensions or patent term adjustments. Either party may terminate for the uncured breach of the other party. We may terminate the agreement at any time upon six months’ prior written notice. OUI may terminate the agreement upon us filing for bankruptcy or in the event of liquidation or receivership proceedings, or upon 30 days’ prior written notice upon the occurrence of certain other events. Upon termination of the March 2017 OUI License Agreement, we are required to,

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among other things, grant to OUI an irrevocable, transferable, non-exclusive license to develop, make and use any improvements to the March 2017 Licensed Technology which we made prior to the second anniversary of the date of the agreement.

2017 Cooperative Research and Development Agreement with NIH (Barinthus Biotherapeutics NA)

In February 2017, Avidea entered into a Cooperative Research and Development Agreement (“CRADA”) with the U.S. National Institutes of Health (“NIH”) to carry out collaborative research for the evaluation of Avidea’s synthetic, polymer-based vaccine technology, “Immunotherapeutic Nanoscaffolds” (IMNs) for infectious disease prevention and cancer treatment in animal models. Under this CRADA Avidea committed to providing scientific staff together with materials for use in experiments to evaluate their performance in various animal models of infectious disease and cancer. Under this CRADA NIH committed to evaluating Avidea materials in animal models and to perform comprehensive immune analysis. No funding was exchanged under this CRADA.

In October 2019, the CRADA was amended (“1st CRADA Amendment”) to expand the scope of the collaborative research to evaluate the therapeutic potential of Avidea’s polymer-based vaccine technology, “Immunotherapeutic Nanoscaffolds” (IMNs), including Star polymers and self-assembling nanoparticles based on amphiphilic polymers (SNAP), in preclinical animal models for cancer, infectious and inflammatory diseases. Under this 1st CRADA Amendment Avidea committed to increase its scientific staffing contribution and to provide funding of $22,500 by October 15, 2019 and a further $62,500 by October 15, 2020.

In October 2020, the CRADA was further amended (“2nd CRADA Amendment”) to defer payment of Avidea’s October 2020 funding contribution of the 1st CRADA Amendment to April 15, 2021.

In May 2021, the CRADA was further amended (“3rd CRADA Amendment”) to extend the term of the CRADA by 2 additional years and to defer payment of Avidea’s April 2021 funding contribution of the 2nd CRADA Amendment to October 31, 2021.

In November 2021, the CRADA was further amended (“4th CRADA Amendment”) to expand the scope of the collaborative research to evaluate the therapeutic potential of Avidea’s polymer-based vaccine technology, “Immunotherapeutic Nanoscaffolds” (IMNs), including Star polymers and self-assembling nanoparticles based on amphiphilic polymers (SNAP), in preclinical animal models for cancer, infectious and inflammatory diseases (e.g., induction of suppression and/or tolerance for treating or preventing allergies, autoimmunity, and transplant rejection).

In October 2022, the CRADA was further amended (“5th CRADA Amendment”) to acknowledge that all of Avidea’s rights, duties and obligations under the CRADA were assumed by Barinthus Bio NA following the acquisition of Avidea by Barinthus Biotherapeutics plc on December 10, 2021.

Under the CRADA as amended we own inventions made solely by our staff, and we have an option to enter an exclusive or nonexclusive license to any inventions made solely by NIH staff or made jointly by our staff and NIH under the CRADA (the "CRADA Licensed Technology"). NIH retains rights on behalf of the U.S. Government in the CRADA Licensed Technology as required by statute and NIH policy. The CRADA gave us the option to exclusively license any further inventions made under the CRADA. The CRADA expired on February 23, 2025.

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2019 License Agreement with NIH (Barinthus Bio NA)

In September 2019, Avidea entered into a license agreement with the NIH for the commercial development of products and processes for the prevention and/or treatment of cancer and infectious diseases within the scope of Licensed Patent rights that had been developed under a CRADA entered into by NIH and Avidea in February 2017 and amended in March 2019, December 2020, May 2021, November 2021 and October 2022. We are co-owners of all the Licensed Patents under this agreement, and we have an option to exclusively license NIH rights in all inventions made under this CRADA.

All of Avidea’s rights, duties and obligations under the 2019 License Agreement with NIH were assumed by Barinthus Bio NA following the acquisition of Avidea by Barinthus Biotherapeutics plc on December 10, 2021. The 2019 License Agreement with NIH was amended in September 2022 to note Barinthus Bio NA’s rights, duties and obligations and also to include newly filed patents developed under the 2017 CRADA as amended.

Pursuant to the 2019 License Agreement with NIH, NIH granted us a worldwide exclusive license under certain patent rights co-owned by us and NIH related to the use of the SNAP-TI and SNAP-CI platforms, among other rights (the "2019 Licensed Technology"), to develop, manufacture, use and commercialize licensed products. The license to patent rights are exclusive in all fields. The 2019 Licensed Technology is sublicensable subject to obtaining NIH’s prior written consent (such consent not to be unreasonably withheld) and inclusion of other customary provisions. NIH retains rights on behalf of the U.S. Government in the 2019 Licensed Technology as required by statute and NIH policy.

Upon execution of the 2019 License Agreement with NIH, we paid NIH a one-time upfront fee of $20,000. We are obligated to pay NIH a low single-digit royalty on net sales of any product or process produced by or using the 2019 Licensed Technology. If we sublicense the 2019 Licensed Technology, we will be required to pay NIH a low-single-digit royalty on any non-royalty sublicensing income. As of March 23, 2023, NIH has not been paid any royalties under the 2019 License Agreement with NIH. In the event that the royalties (excluding the royalty on sublicensing income) owed to NIH do not amount to a specified minimum ranging from the low to mid five figures based on the license year in each year following September 2019, the licensee must also pay NIH the difference between the royalty paid and the applicable minimum royalty payment. In 2024, we paid $20,000 to NIH, representing the difference between royalties paid and the minimum sum payable. In addition, we are required to pay NIH milestone payments of up to an aggregate of $3.24 million upon the achievement of specified development, regulatory and commercial milestones for each Licensed Product.

Unless earlier terminated, the 2019 License Agreement with NIH will continue until expiry of the last to expire Licensed Patent. 5 patent families licensed under the 2019 License Agreement with NIH that cover the SNAP-TI and SNAP-CI platforms, if granted, are expected to expire in April 2038, in May 2039, in October 2039, in February 2042 and in June 2042, without giving effect to any potential patent term extensions or patent term adjustments. Two patent families licensed under the 2019 License Agreement with NIH that cover the syntholytic platform, if granted, are expected to expire in April 2040 and in October 2041, without giving effect to any potential patent term extensions or patent term adjustments. Either party may terminate for the uncured breach of the other party. We may terminate the agreement at any time upon 60 days’ prior written notice. NIH may terminate the agreement upon the occurrence of certain events.

2017 Research Collaboration Agreement (“RCA”) with Institute of Macromolecular Chemistry, Prague (Barinthus Biotherapeutics NA)

In September 2017, Avidea entered into a RCA with the IMC to carry out collaborative research for the development of polymer-based immunotherapies for cancer treatment, HIV prevention and recombinant protein delivery. Under this RCA Avidea committed to providing bioactive molecules and to developing and deploying animal models for evaluating immunotherapies. Under this RCA IMC committed to synthesizing various polymers and bioactive molecules and to linking such polymers and bioactive molecules for use in experiments to characterize their physicochemical properties. No funding was exchanged under this RCA. All of Avidea’s rights, duties and obligations under the 2017 RCA with IMC were assumed by Barinthus Bio NA following the acquisition of Avidea by Barinthus Biotherapeutics plc on December 10, 2021.

Under the RCA we own inventions made solely by our staff, and we have an exclusive option to enter an exclusive or nonexclusive license to any inventions made solely by IMC staff or made jointly by our staff and IMC under the RCA. We have secured exclusive rights in two patent families that we co-own with IMC under the 2022 License Agreement with IMC as described below. We have an exclusive option to exclusively license any further inventions made under the RCA. The RCA expired on September 18, 2022. Our rights in inventions made under the RCA survive expiry of the RCA.

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2022 License Agreement with IMC (Barinthus Bio NA)

In April 2022, we entered into an exclusive license agreement with the IMC for the exploitation, development and commercialization of technologies and products within the scope of Licensed Patent rights that had been developed under a RCA entered into by IMC and Avidea in September 2017. We are co-owners of all the Licensed Patents under this agreement, and we have an option to exclusively license IMC rights in all inventions made under this RCA.

Pursuant to the 2022 License Agreement with IMC, IMC granted us a worldwide, exclusive license under certain patent rights co-owned by us and IMC related to the use of polymer-based immunotherapies, among other rights (the "2022 Licensed Technology"), to develop, manufacture, use and commercialize licensed products. The license to patent rights is exclusive in all fields. The 2022 Licensed Technology is sublicensable.

We are obligated to pay IMC a low single-digit royalty on net sales of any product or process produced by or using the 2022 Licensed Technology. If we sublicense the 2022 Licensed Technology, we will be required to pay IMC a low-single-digit royalty on any non-royalty sublicensing income. As of March 14, 2025, IMC has not been paid any royalties under the 2022 License Agreement with IMC. In addition, we are required to pay IMC milestone payments of up to an aggregate of $820,000 upon the achievement of specified development, regulatory and commercial milestones for each Licensed Product.

Unless earlier terminated, the 2022 License Agreement with IMC will continue until expiry of the last valid claim of the Licensed Patents. One patent family licensed under the 2022 License Agreement with IMC that covers the SNAP-TI and SNAP-CI platforms, if granted, is expected to expire in September 2041, without giving effect to any potential patent term extensions or patent term adjustments. One patent family licensed under the 2022 License Agreement with IMC that covers the syntholytic platform, if granted, is expected to expire in April 2040, without giving effect to any potential patent term extensions or patent term adjustments. Either party may terminate for the uncured breach or insolvency of the other party. We may terminate the agreement at any time upon 3 months’ prior written notice.

2019 License Agreement with OUI

In January 2019, we entered into an additional license agreement with OUI (the "2019 OUI License Agreement"). Pursuant to the 2019 OUI License Agreement, OUI granted us a worldwide, license under an additional patent application of OUI related to the rapid production of recombinant adenovirus constructs, to be used as personalized cancer vaccines or emerging pathogen vaccines, and related confidential know-how (the "2019 OUI Licensed Technology") to develop, manufacture, use and commercialize licensed products.

Upon execution of the 2019 OUI License Agreement, we paid OUI a nominal upfront fee. The 2019 OUI License set out various royalty payments due in certain circumstances and a minimum sum that would be payable based on the license year in each year following January 2022. In 2024, we paid £100,000 to OUI, representing the difference between royalties paid and the minimum sum payable.

In September 2024, we provided notice of termination of the 2019 OUI License Agreement to OUI. Termination took effect on December 26, 2024. No improvements had been made to this technology prior to the second anniversary of the agreement, and consequently no license was granted to OUI on termination. No further payments are due to OUI under or in relation to the 2019 OUI License Agreement.

2018 License Agreement with OUI and Oxford

In September 2018, we entered into a license agreement (the "2018 License Agreement") with The Chancellor, Masters and Scholars of the University of Oxford, or Oxford, and OUI. Pursuant to the 2016 OUI License Agreement, OUI had granted us certain exclusive rights related to the Licensed Technology, as defined in the 2016 OUI License Agreement, in the field of diagnosis, prevention and treatment of MERS. The 2018 License Agreement enables Oxford to grant a further sublicense to CEPI in the field of MERS (the "Field") and to enable Oxford to conduct related activities.

Pursuant to the 2018 License Agreement, we agreed to grant to Oxford a fully-paid-up, worldwide, non- exclusive license under the Licensed Technology, as defined in the 2016 OUI License Agreement, and developments and improvements to such technology controlled by us during the term of the 2016 OUI License Agreement (the "MERS Technology") in the Field solely for the purpose of enabling Oxford to develop any product or process which uses or is within the scope of the MERS Technology ("Licensed Product"). This license includes the right to generate investigational stockpiles, but excludes any commercial use or sale of Licensed Products and is sublicensable by Oxford solely to its collaborators under the framework agreement entered into on or about the same date as the 2018 License Agreement between Oxford, CEPI and

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Janssen Vaccines & Prevention B.V. Furthermore, we agreed that the rights retained by OUI under the 2016 OUI License Agreement include the right to allow Oxford to use the MERS Technology to carry out research activities (including in collaboration with other parties) up to and including the performance of Phase 1/2 clinical trials and related activities, and the generation of Licensed Product for research use (but excluding any commercial use or sale of such Licensed Product). We have been informed by Oxford that Janssen Vaccines & Prevention B.V. is no longer a party to that framework agreement.

In addition, we agreed to grant to Oxford a fully-paid-up, worldwide, non-exclusive license under the MERS Technology in the Field solely for the purpose of enabling Oxford to grant a sublicense to CEPI in order to address (i) circumstances in which CEPI determines there to be a heightened need for the Licensed Product and that steps should be taken to prepare for such need; and/or (ii) material increases in the number of cases of people infected with MERS in particular geographical areas that are declared a public health emergency. Oxford is permitted to grant CEPI a fully-paid-up, worldwide, non-exclusive sublicense under the MERS Technology to develop, manufacture and commercialize the Licensed Product in the Field anywhere in the world, provided that all end users (i) are in a relevant affected territory, or (ii) are healthcare workers going to an affected territory under the direction of one or more governments or recognized not-for-profit organizations, or Public Sector Agencies, in order to help address a public healthcare issue. However, the sublicense must exclude the right for CEPI to (i) apply for or obtain any marketing approval or conduct any post-marketing activities, (ii) sell Licensed Product other than to Public Sector Agencies on a “cost plus” basis, where “cost plus” means the cost of manufacturing and supply plus a margin of 10% percent on such cost, or (iii) further sublicense its rights other than to its affiliates and/or to Public Sector Agencies and their appointees for the sole purpose of accelerating epidemic preparedness for public health applications.

Pursuant to the 2018 License Agreement, OUI agreed that, notwithstanding our payment obligations under the 2016 OUI License Agreement, we are not obligated to make any payment to OUI in connection with the 2018 License Agreement.

On February 2, 2024, following the entry by Barinthus Biotherapeutics (U.K.) Limited and Oxford into a funding agreement with CEPI (described below), Oxford, OUI and Barinthus Biotherapeutics (U.K.) Limited entered into a termination agreement, pursuant to which the 2018 License Agreement was terminated other than obligations that have accrued prior to the termination or were expressly intended to survive, including certain confidentiality obligations.

OUI License Agreement Amendment

In April 2020, we entered into an amendment, assignment and revenue share agreement (the "OUI License Agreement Amendment") with OUI to amend the 2016 OUI License Agreement. Pursuant to the 2016 OUI License Agreement and among other rights and obligations, OUI granted to us a non-exclusive license to certain patent applications relating to its ChAdOx1 and ChAdOx2 vaccine vectors and the adenovirus long promoter for use in certain fields, or the Field, including SARS-CoV2, which is the virus known to cause COVID 19. The OUI License Agreement Amendment was entered into to enable a single exclusive license agreement for a COVID 19 vaccine co-developed by us and the University of Oxford’s Jenner Institute to be negotiated with a suitable pharmaceutical partner.

Under the OUI License Agreement Amendment, we agreed to exclude SARS-CoV2 from the Field and to cease use of the ChAdOx1 vector, ChAdOx2 vector and the adenovirus long promoter in SARS-CoV2. In addition, we assigned to OUI our rights to a jointly owned U.K. patent application relating to the composition of matter related to a ChAdOx1 vector-based or a ChAdOx2 vector-based vaccine to prevent COVID 19 (the "Assigned Patent Application"), as well as certain other intellectual property rights related to any ChAdOx1 vector-based or ChAdOx2 vector-based COVID 19 vaccine covered by the Assigned Patent Application and its manufacture, including rights to the variations, improvements and modifications thereof, whether existing at or arising after the date of the OUI License Agreement Amendment. In consideration of the rights granted by us, OUI agreed to pay us approximately 24% of payments, including royalties and milestones, received by OUI in connection with the commercialization of any ChAdOx1 vector-based or ChAdOx2 vector-based vaccine in the field of SARS-CoV2 covered by or disclosed in the Assigned Patent Application. The last patent under the OUI License Agreement Amendment, which is owned by OUI, if granted, is expected to expire in March 2041, without giving effect to any potential patent term extensions or patent term adjustments.

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Impact of OUI’s Agreement with AstraZeneca

OUI has entered into an exclusive research collaboration and worldwide license agreement (the "AstraZeneca License Agreement") with AstraZeneca. The following description of the impact of AstraZeneca License Agreement with respect to our rights under the OUI License Agreement Amendment is based solely on an extract of the AstraZeneca License Agreement provided by the parties to that agreement. We are not a party to the AstraZeneca License Agreement and do not have access to a copy of that agreement to verify the accuracy of such extract. In addition, no party to the AstraZeneca License Agreement has confirmed that there are no material terms in that agreement that are not included in the description below that could adversely impact the economic and other terms of the AstraZeneca License Agreement described below. Moreover, there can be no assurance that the AstraZeneca License Agreement is an enforceable agreement, that the parties thereto will comply with their obligations under that agreement (including any obligations of AstraZeneca to make milestone or royalty payments to OUI), or that the terms of that agreement (including royalty rates and other economic terms) will not be modified by the parties in the future.

The AstraZeneca License Agreement allows AstraZeneca to pursue, among other things, the commercialization of a vaccine product candidate for the prevention of COVID 19 containing one or more of the ChAdOx1 or ChAdOx2 vectors or their derivatives. AstraZeneca announced that as of January 13, 2022, the vaccine had been granted a conditional marketing authorization or emergency use in more than 90 countries. It also had Emergency Use Listing from the World Health Organization, which accelerated the pathway to access in up to 144 countries through the COVAX Facility. In May 2024, AstraZeneca withdrew the marketing authorization for Vaxzevria within Europe, citing decline in demand as the reason for the decision.

Pursuant to the OUI License Agreement Amendment, we received $2.4 million in July 2020 as our share of the upfront fee paid by AstraZeneca. We were also entitled to receive a share of certain regulatory and sales milestones and royalties on net sales of Vaxzevria, as well as a portion of any sublicensing income payable by AstraZeneca. Our share of the royalties on net sales of Vaxzevria is approximately 1.4%.

Our understanding is that we were not entitled to receive any royalties or payments from sub-licensees from the commercialization of Vaxzevria until after the pandemic period, which was defined as a period that would end on July 1, 2021 (or such later date when AstraZeneca, in good faith, determines that the COVID-19 pandemic is over). However, our understanding was that we were entitled to receive our share of any regulatory milestone payments during the pandemic period. The royalty term for net sales of Vaxzevria commenced in 2022 and continues, on a country-by-country basis, until the later of (i) the date upon which the vaccine is no longer subject to patent protection in such country, (ii) expiration of regulatory exclusivity for the vaccine in such country or (iii) ten years from the first commercial sale of the vaccine in such country. In May 2024, AstraZeneca announced the initiation of withdrawal of marketing authorization for Vaxzevria in Europe as demand had declined, and therefore we do not expect to receive any further payments relating to future commercial sales of Vaxzevria and, if such payments are due, that we will be notified of such payments in a timely manner.

2018 ChAdOx Zoster Project Agreement (under the CanSino Agreement)

Pursuant to the CanSino Agreement, we entered into a project agreement in September 2018 with CanSino (the "ChAdOx Zoster Project Agreement") with the goal of developing a Zoster vaccine to become a competitor to Shingrix. Under the ChAdOx Zoster Project Agreement, we are responsible for funding and undertaking various development tasks, including (subject to availability of funding) conducting a Phase 1 clinical trial in the U.K. CanSino was responsible for funding and undertaking various development tasks, including conducting a Phase 1 clinical trial in China. The ChAdOx Zoster Project Agreement was amended on August 31, 2023 following the parties’ agreement that the Phase 1 clinical trial to be conducted by CanSino as Sponsor should be carried out in Canada (rather than China). It was also agreed that the parties would each be responsible for 50% of the budgeted cost of the Phase 1 clinical trial (rather than each being responsible for funding or securing funding for any Phase 1 clinical trial in its respective country). The amendment further expanded the scope of the ChAdOx Zoster Project Agreement to cover potential administration of the product by inhalation.

The parties’ rights and responsibilities in relation to Phase 2 and 3 clinical trials are pending, subject to further negotiation. In addition, the parties agreed to use all reasonable efforts to enter into a separate supply agreement pursuant to which CanSino will manufacture all product necessary for clinical trials and commercialization under the project agreement. If the parties cannot agree upon such supply agreement, they must follow a specified dispute resolution process set forth in the CanSino Agreement. For all products manufactured by CanSino under a supply agreement that we wish to sell in the Barinthus Bio Territory, we have agreed to pay the costs incurred by CanSino to manufacture the products plus 20% of such costs.

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We received an upfront payment of £50,000 under this project agreement. We will also receive milestone payments of up to an aggregate of £1.125 million based on successful conduct of clinical trials and commercialization of the product. We will receive mid-single-digit royalties on the net sales of the product by or on behalf of CanSino or its sub-licensees in the CanSino Territory. If CanSino sublicense their rights in the product to a non-affiliate third party, we are also entitled to receive a mid-teens royalty on the transaction value (excluding royalties). We must pay to CanSino mid-single-digit royalties on the net sales of the product by or on behalf of us or our sub-licensees in the Barinthus Bio Territory. A party will benefit from a reduction of its royalties (in the low single digits) where it requires a license from a third party to sell the product in its territory.

Unless earlier terminated, the term of the ChAdOx Zoster Project Agreement will expire upon the later of expiry of all registered patents in the New IP developed under the project, or ten years from first commercial sale of the product. The last patent under the ChAdOx Zoster Project Agreement, if granted, is expected to expire in November 2039, without giving effect to any potential patent term extensions or patent term adjustments. A party may terminate the ChAdOx Zoster Project Agreement by written notice if the other party unreasonably delays the performance of its obligations. Upon the expiration of the term, we agreed to grant CanSino a royalty-free, perpetual, sub-licensable, non-exclusive license to use our Background IPR and our New IPR used to develop, incorporated in, or referenced in any products that are the subject of the project agreement to the extent necessary for CanSino to undertake research, develop, manufacture and commercialize such products in the CanSino Territory. Pursuant to the CanSino Agreement, upon the expiration or earlier termination of the project agreement, except for termination by CanSino for our breach, CanSino agreed to grant us a royalty-free, perpetual, sub-licensable, non-exclusive license to use their Background IPR and New IPR used to develop, incorporated in, or referenced in any products that are the subject of the project agreement to the extent necessary for us to undertake research, develop, manufacture and commercialize such products in the Barinthus Bio Territory. Unless we terminate the project agreement early for CanSino’s breach, upon early termination after completion of a Phase 1 trial, we will continue to pay CanSino a low single-digit royalty on net sales of the product by us or our sub-licensees in the Barinthus Bio Territory, for the remainder of the Term. If such early termination is after completion of a Phase 2 trial, the royalty we must pay rises to mid-single digit.

Clinical Trial and Option Agreement with CRUK

In December 2019, Vaccitech Oncology Limited ("VOLT"), entered into a clinical trial and option agreement (the "Clinical Trial Agreement") with CRUK and CRUK’s subsidiary, Cancer Research Technology Limited ("CRT"), relating to the conduct of a Phase 1/2a clinical trial of VOLT’s VTP 600 immunotherapy product in patients with non-small cell lung cancer, or the Clinical Trial. The trial opened in the first quarter of 2022 across multiple clinical sites in the U.K.

VOLT is our oncology focused strategic collaboration with the Ludwig Institute for Cancer Research, an international non-profit organization that conducts innovative cancer research and is looking to enable the clinical development of new treatments that induce and harness CD8+ T cells of the immune system to fight cancer. VOLT has a license to our proprietary CD8+ T cell induction platform and research by Benoit Van den Eynde’s group at the Ludwig Oxford Branch.

Pursuant to the Clinical Trial Agreement, CRUK is responsible for, among other things, designing, preparing, carrying out and sponsoring the Clinical Trial, at its cost, and VOLT has granted to CRUK a license under its intellectual property to enable CRUK to perform such activities. VOLT is responsible for supplying agreed quantities of its VTP 600 immunotherapy product. VOLT retains the right to continue the development of the product during the Clinical Trial, provided that the parties have first agreed appropriate terms for sharing of safety data. CRUK owns all results, including all intellectual property therein, generated in the performance of the Clinical Trial. Upon the completion of the Clinical Trial, VOLT has the option to obtain a license to use such results (the "VTP 600 License"). The terms of the VTP 600 License have been pre-agreed and are set out in the Clinical Trial Agreement.

If VOLT exercises the option to take the VTP 600 License, CRT agrees to grant VOLT an exclusive license under the results of the Clinical Trial that exclusively relate to the VTP 600 immunotherapy product (the "Exclusive Results") and a non-exclusive license under any results that are not Exclusive Results, in each case, to develop and commercialize any product which makes use of the results of the Clinical Trial in an application for regulatory authorization, contains the relevant active ingredients, or is covered by the patent application PCT/EP2019/070555 (the "Product"). The rights under the VTP 600 License are sublicensable (except to a tobacco company). The exclusive rights granted under the VTP 600 License are subject to the right of certain third-party contributors associated with the Clinical Trial, CRUK and scientists funded or employed by CRUK to use the Exclusive Results for non-commercial scientific or clinical research purposes and to publish the Exclusive Results and the results of non-commercial research performed using the Exclusive Results (subject to the publication process set out in the Clinical Trial Agreement). Upon exercise of the option, VOLT is required to pay a

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one-time upfront fee of an amount in pounds Sterling in the high six-digits. VOLT is also obligated to make future milestone payments upon the achievement of development, regulatory and commercial milestones, with an aggregate total value of £40.8 million. VOLT is required to pay to CRT a low single-digit royalty on net sales of Products sold by VOLT or its sublicensees. If VOLT sublicenses the right to sell Products, VOLT will also be required to pay to CRT a royalty of between 5% and 20% on non-royalty amounts due to VOLT from a sublicensee, with the precise rate depending on the stage in development at which such sublicense was granted. VOLT is obligated to use commercially reasonable efforts to meet certain development, regulatory and commercialization obligations, including commencement of a Phase 2 clinical trial of a Product in an oncology indication before the second anniversary of the date of the VTP 600 License. CRT may terminate the VTP 600 License in respect of any given Product if VOLT is not actively developing it or fails to launch it after receiving marketing authorization. CRT may also terminate the VTP 600 License as a whole if no Product is being actively developed or commercialized.

If VOLT does not exercise the option to take the VTP 600 License, or if the VTP 600 License or Clinical Trial Agreement is subsequently terminated by CRUK (as described below) VOLT will enter into a step-in agreement with CRT (the "Step-In Agreement"). Pursuant to the Step-In Agreement, the terms of which have been pre-agreed and are set out in the Clinical Trial Agreement, VOLT will assign to CRT certain know- how and materials owned or controlled by VOLT. In addition, we agreed to grant to CRT an exclusive sub-license to a third-party patent family relating to viral vectors and methods for the prevention or treatment of cancer and non-exclusive sub-licenses to the HEK293 TetR Cell Line as well as certain third party patents and patent applications relating to certain adenovirus vectors and poxvirus expression systems, in each case, to develop and commercialize the Products on a revenue sharing basis. VOLT will receive a share of between 55% and 80% of the net revenue received by CRT for commercialization of the Product, with the precise share depending on the stage in development at which such Step-In Agreement is entered into.

The term of the Clinical Trial Agreement continues until it is otherwise terminated by the parties or, if the option is not exercised, upon the execution of the Step-In Agreement. The Clinical Trial Agreement can be terminated by either party upon an insolvency event in respect of the other party, for material breach of the other party, or upon a change of control of the other party (if the new controlling entity generates its revenue from the sale of tobacco products). If the Clinical Trial Agreement is terminated by CRUK for such causes prior to VOLT’s exercise of its option, VOLT will reimburse CRUK for all costs incurred or committed in connection with the Clinical Trial. In addition, CRUK may terminate the Clinical Trial Agreement at any time before the last cycle of treatment under the Clinical Trial is complete, in which case, upon VOLT’s request, CRT will grant the VTP 600 License to VOLT with appropriately reduced payments, to reflect the stage of the Clinical Trial at the date of termination. If the Clinical Trial Agreement is terminated for any reason after VOLT’s exercise of its option, VOLT may for three months following such termination continue to manufacture Products to the extent necessary to satisfy orders for Products accepted before such termination, and sell, use or otherwise dispose of Product inventory.

VOLT License Agreement

In November 2018, we entered into a license agreement (the "VOLT License Agreement") with VOLT. Pursuant to the VOLT License Agreement, we granted to VOLT a non-exclusive worldwide license under certain patent rights, know-how and materials related to the use of ChAdOx1, ChAdOx2, adenoviral and MVA promoters, and the TR293 Tet-Repressed Cell Line (the "VOLT Licensed Technology"), to manufacture, use and commercialize any product which uses or is within the scope of the VOLT Licensed Technology (the "VOLT Licensed Product"). In part, the rights granted are a sublicense of rights granted to us by OUI under the 2016 OUI License Agreement. The license is sublicensable subject to obtaining OUI’s prior consent with respect to sublicensing of any of the VOLT Licensed Technology licensed to us by OUI (with such consent not to be unreasonably withheld).

Pursuant to the VOLT License Agreement, we are required to make available to VOLT such further know- how relating to the manufacture of VOLT Licensed Products as we consider to be reasonably necessary or useful. We are also required to notify VOLT on a confidential basis of any improvements to the VOLT Licensed Technology that we develop or acquire rights in, and such improvements will be included within the scope of the license.

Unless earlier terminated, the VOLT License Agreement will continue until the later of the expiration of all patents included in the VOLT Licensed Technology or the know-how included in the VOLT Licensed Technology ceasing to be secret and substantial. The last patent under the VOLT License Agreement, if granted, is expected to expire in July 2039, without giving effect to any potential patent term extensions or patent term adjustments. Either party may terminate for the uncured material breach or insolvency of the other party. In the event of termination of the 2016 OUI License Agreement, we may terminate the VOLT License Agreement in respect of any of the VOLT Licensed Technology that is licensed to us

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by OUI, and VOLT and OUI shall enter into a direct license containing the same obligations and liabilities as set forth in the VOLT License Agreement.

The VOLT License Agreement was subsequently amended in July 2019 by two separate agreements for the research, development, and commercialization of cancer immunotherapy targeting MAGE-A3 and NY-ESO-1 for the treatment of various forms of cancer under the VOLT Licensed Technology. Such amendments further elaborated on the parties’ respective rights and obligations, including with respect to VOLT’s payment obligations to us.

2023 CEPI Funding Agreement

On December 20, 2023, we, the Chancellors, Masters and Scholars of the University of Oxford (“Oxford,” together with us, the “Partners”) and CEPI entered into a Funding Agreement (the “Funding Agreement”) pursuant to which CEPI will provide funding of up to $34.8 million to us to advance the development of VTP-500, our vaccine candidate against MERS (such development activities, the “Project”). In December 2023, VTP-500 received PRIority MEdicines (“PRIME”) designation by the EMA. Under the Funding Agreement, the Partners have agreed to use reasonable endeavors to achieve the deliverables, milestones and timelines for the vaccine development activities under discrete “Work Packages” mutually agreed to by the parties from time to time.

Under the initial Work Package, we have agreed, subject to the achievement of certain milestones, including a successful Phase 2 clinical trial of VTP-500, that it will manufacture or have manufactured an investigational ready reserve of 100,000 doses of VTP-500 to be rapidly deployed for a clinical trial in the event of a substantial outbreak of MERS. During the Term (as defined below), we have also agreed to certain collaboration obligations in the event of a regional or national public health emergency or preparation need for an impending outbreak of MERS.

Pursuant to the Funding Agreement, we will retain ownership of its intellectual property owned or controlled throughout the term of the Funding Agreement, subject to the rights of CEPI under the Funding Agreement. We will also own any intellectual property invented by or on behalf of us in connection with the activities contemplated by the Funding Agreement, as well as all tangible materials and results made or developed by or on behalf of us in connection with the Funding Agreement.

Any amounts funded by CEPI to the Partners under the Funding Agreement in accordance with each Work Package will be paid in tranches covering six-month periods based on mutually agreed project-based budgets and subject to certain conditions as set forth in the Funding Agreement including the achievement of identified milestones.

Pursuant to the Funding Agreement, we have agreed to pay CEPI on a country-by-country basis increasing mid-single digit percentage royalties of net sales and net income with respect to future cash sales of VTP-500, less certain deductions, for a period starting on December 20, 2023 (“Effective Date”) and ending the later of: (i) the expiration of the last valid patent claim included in intellectual property developed under the Project covering VTP-500 in such country, (ii) the expiration of Regulatory Exclusivity (as defined in the Funding Agreement) for VTP-500 in such country, and (iii) the tenth (10th) anniversary of the first commercial sale of VTP-500 (the “Royalty Term”). We shall also pay CEPI a mid-double digit percentage of net revenue earned on VTP-500 until CEPI has received payments from us under the Funding Agreement equaling the total amount of funding paid by CEPI to us and a low double-digit percentage of such net revenue thereafter. Sales for the benefit of end users in specified low and middle income countries (“LMICs”) and upper and middle income countries (“UMICs”) are excluded from the calculations of net sales and net revenue. Sales of product for the benefit of end users in LMICs and UMICs are subject to tiered discounted pricing requirements under the Funding Agreement. We are further required to pay a mid-double digit percentage of any proceeds earned on any priority review voucher related to VTP-500 during the Royalty Period.

The Funding Agreement will commence on the Effective Date and will continue until the fifth (5th) anniversary of the Effective Date, unless the parties agree to extend the Funding Agreement for a period of up to twenty-four (24) months unless all activities under the Funding Agreement have been completed (“Term”). Either Partner or CEPI can terminate the Funding Agreement following an insolvency event or material breach by the other party that is not cured within forty-five (45) business days, in the event of termination by a Partner, or thirty (30) business days, in the event of termination by CEPI. Pursuant to the Funding Agreement, CEPI also has certain discretionary termination rights, including if CEPI determines that we are involved in material safety, regulatory, scientific misconduct, or ethical issues or is no longer able to fulfill its obligations under the Funding Agreement.

Neither CEPI, us nor Oxford may assign its rights or obligations under the Funding Agreement without the other parties’ consent; provided that CEPI may do so to an organization of equivalent charitable mission and technical capabilities.

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Intellectual Property

Our success depends, in part, on our ability to obtain and maintain intellectual property protection for our product candidates, technology and know-how, to defend and enforce our intellectual property rights, in particular, our patent rights, to preserve the confidentiality of our know-how and trade secrets, and to operate without infringing the proprietary rights of others. We seek to protect our product candidates and technologies by, among other methods, filing U.S. and foreign patent applications related to our proprietary technology, inventions and improvements that are important to the development of our business. We also rely on trade secrets, know-how, continuing technological innovation and in-licensing of third-party intellectual property to develop and maintain our proprietary position. We, or our licensors, file patent applications directed to our key product candidates in an effort to establish intellectual property positions to protect our product candidates as well as uses of our product candidates for the prevention and/or treatment of diseases.

As of March 14, 2025, we control a patent portfolio comprising in-licensed and co-owned patent families relating to our key SNAP-TI, SNAP-CI and syntholytic technology platforms and product candidates, including 10 pending U.S. patent applications, six issued foreign patents, 50 pending foreign patent applications and two pending PCT patent applications. We also own a patent family relating to our novel prime-boost regimens that includes one pending U.S. patent application and one pending foreign patent application together with one pending Patent Cooperation Treaty ("PCT") patent application relating to our novel viral vectored products. In addition, we have in-licensed certain patent families relating to our viral vectored technology platforms and product candidates, including 13 issued U.S. patents, six pending U.S. patent applications, at least 30 issued foreign patents and at least 60 pending foreign patent applications.

Universal Vector Technology Platforms

ChAdOx 1 Expression Vector

As of March 14, 2025, with regard to our ChAdOx1 expression vector, we in-license from OUI a patent family that includes three issued U.S. patents with claims directed to the composition of matter of the ChAdOx1 adenovirus vector and methods of using such a vector, and 9 issued foreign patents granted in such jurisdictions as Australia, Canada, China, Europe (validated in 12 countries including Denmark, France, Germany, Italy, Spain, and Great Britain), India, Japan, Singapore and South Africa. A second granted European patent with further claims directed to the composition of matter of ChAdOx adenovirus vector is validated in France, Germany and Great Britain. This patent family also includes a pending U.S. patent application. The granted patents and pending applications, if issued, are expected to expire in 2032, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees.

Adenoviral Promoter

Certain of our ChAdOx1 vectors incorporate a proprietary adenoviral promoter, which is covered by a patent family that we in-license from OUI. As of March 14, 2025, the patent family includes two issued U.S. patents and one granted patent in Europe (validated in 7 countries including France, Germany, Italy, Spain, and Great Britain). The patents in this family are expected to expire in 2028, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees.

MVA-poxvirus Promoter

Our MVA vector incorporates a proprietary poxvirus promoter ("MVA-poxvirus promoter") which is covered by a patent family that we in-license from OUI. As of March 14, 2025, the patent family includes two issued U.S. patents and one granted European patent (validated in 9 countries including Denmark, France, Germany, Italy, Spain, and Great Britain) that are expected to expire in 2031, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees.

Synthetic SNAP platform (SNAP-TITM and SNAP-CITM)

Our proprietary synthetic SNAP platform is covered by a patent portfolio that includes one patent family we own, eight patent families that we co-own and one patent family that we in-license from OUI. As of March 14, 2025, we in-license a patent family from OUI that includes one pending U.S. patent application and one pending European patent application that are expected to expire in 2035, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. As of March 14, 2025, we own a patent family that includes four issued foreign patents that are expected to expire in 2030, without giving effect

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to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. As of March 14, 2025, we co-own a patent family that includes two issued foreign patents, one pending U.S. patent application, one pending European patent application and at least 10 pending foreign patent applications that are expected to expire in 2038, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have exclusively licensed rights in this patent family, which resulted from work carried out under a CRADA with the NIH. As of March 14, 2025, we co-own a patent family that includes one pending U.S. patent application, one pending European patent application and a further 5 pending foreign patent applications that are expected to expire in 2039, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have exclusively licensed rights in this patent family, which resulted from work carried out under a CRADA with the NIH. As of March 14, 2025, we co-own a patent family that includes one pending U.S. patent application, one pending European patent application and a further 2 pending foreign patent applications that are expected to expire in 2039, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have exclusive rights in this patent family, which resulted from work carried out under a CRADA with the NIH. As of March 14, 2025, we co-own a patent family that includes one pending U.S. patent application, one pending European patent application and a further nine pending foreign patent applications that are expected to expire in 2042, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have exclusive rights in this patent family, which resulted from work carried out under a CRADA with the NIH. As of March 14, 2025, we co-own a patent family that includes one pending U.S. patent application, one pending European patent application and a further three pending foreign patent applications that are expected to expire in 2042, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have exclusive rights in this patent family, which resulted from work carried out under a CRADA with the NIH. As of March 14, 2025, we co-own a patent family that includes one pending U.S. patent application, one pending European patent application and a further two pending foreign patent applications that are expected to expire in 2041, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have licensed exclusive rights in this patent family, which resulted from work carried out under a RCA with the IMC. As of March 14, 2025, we co-own a patent family that includes one pending U.S. patent application and one pending international PCT patent application that are expected to expire in 2043, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have exclusive rights in this patent family, which resulted from work carried out under a CRADA with the NIH. As of March 14, 2025, we co-own a patent family that includes one pending international PCT patent application that is expected to expire in 2043, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have exclusive rights in this patent family, which resulted from work carried out under a CRADA with the NIH.

Syntholytic

Our proprietary Syntholytic technology is covered by a patent portfolio that includes one patent family we own, 2 patent families that we co-own and one patent family that we in-license from OUI. As of March 14, 2025, we in-license a patent family from OUI that includes one pending U.S. patent application and one pending European patent application that are expected to expire in 2035, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. As of March 14, 2025, we own a patent family that includes four issued foreign patents that are expected to expire in 2030, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. As of March 14, 2025, we co-own a patent family that includes one pending U.S. patent application, one pending European patent application and a further seven pending foreign patent applications that are expected to expire in 2040, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have exclusive rights in this patent family, which resulted from work carried out under a CRADA with the NIH, and we have licensed exclusive rights in this patent family, which resulted from work carried out under a RCA with the IMC, Prague. As of March 14, 2025, we co-own a patent family that includes one pending U.S. patent application, one pending European patent application and a further two pending foreign patent applications that are expected to expire in 2041, without giving effect to any potential patent term extensions and patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have licensed exclusive rights in this patent family, which resulted from work carried out under a RCA with the IMC.

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Product Candidates

Our VTP-200 product candidate comprises a ChAdOx1HPV vector and a MVA-HPV vector, where each vector incorporates an engineered HPV antigen. We in-license from OUI a patent family directed to the HPV antigen with claims directed to a nucleic acid encoding a polypeptide comprising certain peptide sequences based on certain HPV proteins. As of March 14, 2025, the patent family includes two issued U.S. patents, three issued foreign patents and seven foreign patent applications pending in jurisdictions including Europe, Australia, Canada, and Japan. If patents were to issue from such patent applications, they would be expected to expire in 2038, without giving effect to any potential patent term extensions or patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. In addition, we also rely on patent protection afforded by the patent family directed to the ChAdOx1 expression vector, which is expected to expire in 2032, and the patent family directed to our MVA-poxvirus promoter, which is expected to expire in 2031, as discussed above.

Our VTP-300 product candidate comprises a ChAdOx1-HBV vector and a MVA-HBV vector, where each vector incorporates an engineered HBV antigen. As of March 14, 2025, we in-license from OUI a patent family with claims directed to a multi-HBV immunogen viral vector vaccine that includes five issued foreign patents, one pending U.S. patent application and 12 foreign patent applications pending in jurisdictions including Europe, Australia, Canada and China. If patents were to issue from such patent applications, they would be expected to expire in 2038, without giving effect to any potential patent term extensions or patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. In addition, we also rely on patent protection afforded by the patent family directed to the ChAdOx1 expression vector, which is expected to expire in 2032, and the patent family directed to our MVA-poxvirus promoter, which is expected to expire in 2031, as discussed above.

Our VTP-600 product candidate comprises a ChAdOx1MAGE-NYESO vector, a MVA-MAGE vector, and a MVA-NYESO vector. We in-license from Ludwig Institute a patent family with claims directed to a chimpanzee adenovirus vector encapsulating a nucleic acid molecule encoding a MAGE antigen, a NY- ESO1 antigen or both a MAGE antigen and a NY-ESO1 antigen. As of March 14, 2025, the patent family includes one granted U.S. patent and 11 foreign patent applications pending in jurisdictions including Europe, Australia, Canada, China, and Japan. If a patent were to issue from such patent applications, it would be expected to expire in 2039, without giving effect to any potential patent term extensions or patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. In addition, we also rely on patent protection afforded by the patent family directed to the ChAdOx1 expression vector, which is expected to expire in 2032, the patent family directed to our adenoviral promotor, which is expected to expire in 2028, and the patent family directed to our MVA-poxvirus promoter, which is expected to expire in 2031, as discussed above.

Our VTP-800 and VTP-850 product candidates comprise a ChAdOx15T4 vector and a MVA5T4 vector, where each vector incorporates an engineered 5T4 antigen and in VTP-850 the 5T4 antigen is also in combination with additional antigens. We in-license from OUI a patent family with claims directed to a composition for inducing a T Cell response comprising a MVA vector expressing the 5T4 antigen polypeptide. As of March 14, 2025, the patent family includes one granted foreign patent, one pending U.S. patent application and 10 foreign patent applications pending in jurisdictions including Europe, Australia, Canada, China, and Japan. If a patent were to issue from a patent application claiming the benefit of this PCT application, such a patent would be expected to expire in 2039, without giving effect to any potential patent term extensions or patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. In addition, we also rely on patent protection afforded by the patent family directed to the ChAdOx1 expression vector, which is expected to expire in 2032, the patent family directed to our adenoviral promotor, which is expected to expire in 2028, and the patent family directed to our MVA-poxvirus promoter, which is expected to expire in 2031, as discussed above.

Our VTP-500 product candidate comprises a ChAdOx1MERS vector that incorporates an engineered MERS antigen. We rely on patent protection afforded by the patent family directed to the ChAdOx1 expression vector, which is expected to expire in 2032 and the patent family directed to our adenoviral promotor, which is expected to expire in 2028, as discussed above.

Our VTP-400 product candidate comprises a ChAdOx1VZVgE vector that incorporates an engineered VZVgE antigen. We in-license from OUI a patent family with claims directed to an adenoviral vector comprising a nucleic acid encoding the varicella-zoster virus antigen. As of March 14, 2025, the patent family includes one granted foreign patent, one pending U.S. patent application and 12 foreign patent applications pending in jurisdictions including Europe, Australia, Canada, China, and Japan. If a patent were to issue from a patent application claiming the benefit of this PCT application, such a patent would be expected to expire in 2039, without giving effect to any potential patent term extensions or patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We also

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rely on patent protection afforded by the patent family directed to the ChAdOx1 expression vector, which is expected to expire in 2032 and the patent family directed to our adenoviral promotor, which is expected to expire in 2028, as discussed above.

Our VTP-1100 product candidate includes SNAP-CI platform technology to target HPV16+ cancers. We co-own a patent family with claims directed to methods of treating cancers using SNAP-CI compositions. As of March 14, 2025, the patent family includes one pending international PCT patent application. If a patent were to issue from a patent application claiming the benefit of this PCT application, such a patent would be expected to expire in 2043, without giving effect to any potential patent term extensions or patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. We have exclusive rights in this patent family, which resulted from work carried out under a CRADA between Barinthus Bio and the NIH. In addition, we rely on patent protection afforded by the patent families directed to the SNAP technology platforms, which are expected to expire between 2030 and 2042, as discussed above.

Our VTP-1000 product candidate includes SNAP-TI platform technology to provide tolerizing immunotherapy for celiac disease. We co-own a patent family with claims directed to compositions and methods for treating celiac disease. As of March 14, 2025, the patent family includes one pending U.S. patent application and one pending international PCT patent application. If a patent were to issue from either of these pending applications or from a patent application claiming the benefit of either of these applications, such a patent would be expected to expire in 2043, without giving effect to any potential patent term extensions or patent term adjustments and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees. In addition, we rely on patent protection afforded by the patent families directed to the SNAP technology platforms, which are expected to expire between 2030 and 2042, as discussed above.

Individual patents have terms for varying periods depending on the date of filing of the patent application or the date of patent issuance and the legal term of patents in the countries in which they are obtained. Generally, utility patents issued for applications filed in the United States are granted a term of 20 years from the earliest effective filing date of a non-provisional patent application. The duration of foreign patents varies in accordance with provisions of applicable local law, but typically is also 20 years from the earliest effective filing date. All taxes, annuities or maintenance fees for a patent, as required by the USPTO and certain foreign jurisdictions, must be timely paid in order for the patent to remain in force during this period of time.

The actual protection afforded by a patent may vary on a product by product basis, from country to country and can depend upon many factors, including the type of patent, the scope of its coverage, the availability of regulatory-related extensions and the availability of legal remedies in a particular country and the validity and enforceability of the patent. Our patents and patent applications may be subject to procedural or legal challenges by others. We may be unable to obtain, maintain and protect the intellectual property rights necessary to conduct our business, and we may be subject to claims that we infringe or otherwise violate the intellectual property rights of others, which could materially harm our business. For more information about the risks associated with our efforts to obtain adequate intellectual property protection for our product candidates, and the enforcement of such intellectual property rights, as well as the risks associated with third party intellectual property rights, see the section titled “Risk Factors — Risks Related to Our Intellectual Property.” With regard to our VTP-300 and VTP-850 product candidates, we are aware of third-party patents in the United States with claims which may be relevant to these product candidates. See “Risk Factors — Risks Related to Intellectual Property — The intellectual property landscape around immunotherapeutics and viral-vector based vaccines is crowded and dynamic, and third parties may initiate legal proceedings alleging that we are infringing, misappropriating or otherwise violating their intellectual property rights and such claims may be costly and time-consuming and may prevent or delay our product discovery and development efforts.”

Government Regulation

In the United States, the FDA regulates drugs under the Federal Food, Drug, and Cosmetic Act (the "FD&C Act") and biological products under the FD&C Act and the Public Health Service Act (the “PHS Act”), and other federal, state, and local statutes and regulations. Both the FD&C Act and the PHS Act and their corresponding regulations govern, among other things, the research, development, testing, manufacturing, quality control, approval, safety, efficacy, labeling, packaging, storage, record keeping, distribution, reporting, marketing, promotion, export and import, advertising, post-approval monitoring, and post-approval reporting involving drugs and biological products. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state, local and foreign statutes and

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regulations, and international guidelines require the expenditure of substantial time and financial resources and we may not be able to obtain the required regulatory approvals.

Further, even if we obtain the required regulatory approvals for our products, pharmaceutical companies are subject to myriad federal, state, and foreign healthcare laws, rules, and regulations governing all aspects of our operations, including, but not limited to, our relationships with healthcare professionals, healthcare institutions, distributors of our products, and sales and marketing personnel; governmental and other third-party payor coverage and reimbursement of our products; and data privacy and security. Such laws, rules, and regulations are complex, continuously evolving, and, in many cases, have not been subject to extensive interpretation by applicable regulatory agencies or the courts. We are required to invest significant time and financial resources in policies, procedures, processes, and systems to ensure compliance with these laws, rules, and regulations, and our failure to do so may result in the imposition of substantial monetary or other penalties by federal or state regulatory agencies, give rise to reputational harm, or otherwise have a material adverse effect on our results of operations and financial condition.

U.S. Drug and Biological Products Development Process

In the United States, the FDA is responsible for enforcing the laws in place to protect public health by ensuring the safety, efficacy, and security of drugs and biological products. The process required by the FDA before a product may be marketed in the United States generally involves the following:

•completion of extensive preclinical laboratory tests and animal studies performed in accordance with applicable regulations, including the FDA’s Good Laboratory Practices (GLPs), regulations and standards;

•submission to the FDA of an IND, which must become effective before clinical trials may begin;

•approval by an independent institutional review board ("IRB") or ethics committee representing each clinical site before the trial is commenced;

•performance of adequate and well-controlled human clinical trials in accordance with applicable IND regulations, Good Clinical Practices ("GCPs"), and other clinical trial-related regulations to establish the safety, purity and potency of the proposed product candidate for its intended purpose;

•preparation of and submission to the FDA of an NDA or BLA, which includes not only the results of the clinical trials, but also, detailed information on the chemistry, manufacture and quality controls for the product candidate and proposed labeling;

•payment of user fees for FDA review of the NDA or BLA (unless a fee waiver applies);

•a determination by the FDA within 60 days of its receipt of a NDA or BLA to file the application for review;

•satisfactory completion of an FDA pre-approval inspection of the manufacturing facility or facilities at which the proposed product is produced to assess compliance with current Good Manufacturing Practice requirements ("cGMPs") and to assure that the facilities, methods and controls are adequate to preserve the investigational product’s identity, strength, quality and purity, and of selected clinical trial sites that generated the data in support of the application to assess compliance with the FDA’s GCPs;

•satisfactory completion of an FDA Advisory Committee review, if applicable; and

•FDA review and approval, or licensure, of an NDA or BLA to permit commercial marketing of the product for particular indications for use in the United States.

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