Nature of Business and Basis of Presentation	6 Months Ended
Nature of Business and Basis of Presentation	Jun. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	Nature of Business and Basis of Presentation Barinthus Biotherapeutics plc is a public limited company incorporated pursuant to the laws of England and Wales in March 2021. Barinthus Biotherapeutics plc and its direct and indirect subsidiaries, Barinthus Biotherapeutics (UK) Limited, Barinthus Biotherapeutics North America, Vaccitech Oncology Limited (“VOLT”), Barinthus Biotherapeutics Pty Limited, Barinthus Biotherapeutics Switzerland GmbH, are collectively referred to as the “Company” or “Barinthus Bio.” During the quarterly period ended September 30, 2025, the Company incorporated two new subsidiaries, Beacon Topco, Inc. (“Topco”) and Cdog Merger Sub, Inc. (“Merger Sub”), for the purpose of the transactions contemplated by the recently announced merger agreement with Clywedog Therapeutics, Inc. ("Clywedog"). These entities are not material to the Company's condensed consolidated financial position or results of operations. The Company is a clinical-stage biopharmaceutical company focused on developing novel immunotherapeutic drug candidates for treating autoimmune and inflammatory diseases within the immunology and inflammation (“I&I”) space enabled by the proprietary and highly differentiated platform for promoting immune tolerance, referred to as SNAP-TI. The Company's 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. The Company occupies laboratory and office space in Germantown, Maryland, United States. The Company operates in an environment of rapid technological change and substantial competition from pharmaceutical and biotechnology companies. The Company is subject to risks common to companies in the biopharmaceutical industry that are also in a similar stage of its life cycle including, but not limited to, the need to obtain adequate additional funding, possible failure of preclinical testing or clinical trials, the need to obtain marketing approval for its product candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of any of its products that are approved, and protection of proprietary technology. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain required regulatory approval or that any approved products will be commercially viable. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will generate significant product sales. If the Company does not successfully commercialize any of its products or mitigate any of these other risks, it will be unable to generate revenue or achieve profitability. Merger Agreement with Clywedog On September 29, 2025, the Company entered into an Agreement and Plan of Merger (the “Original Merger Agreement”) by and among the Company, Topco, Merger Sub and Clywedog, as amended by that certain Amendment to the Original Merger Agreement, dated as of February 22, 2026 (the “Merger Agreement Amendment,” together with the Original Merger Agreement, the “Merger Agreement”). The Merger Agreement provides that, among other things, upon the terms and subject to the conditions set forth therein: (i) Topco will acquire the entire issued and to be issued share capital of the Company pursuant to (1) a scheme of arrangement (subject to any modification, addition or condition which (a) the Company, Topco and Clywedog mutually agree and which (if required) is approved by the High Court of Justice of England and Wales (the “Court”) or (b) is otherwise imposed by the Court and mutually acceptable to the Company, Topco and Clywedog, each acting reasonably and in good faith, in each case in accordance with the Part 26 of the United Kingdom Companies Act 2006 (the “Scheme of Arrangement”), (2) a share purchase agreement pursuant to which the deferred A shares in the capital of the Company will be acquired by Topco subject to and upon effectiveness of the Scheme of Arrangement, and (3) the Merger Agreement (such transaction, together with the Scheme of Arrangement the “Scheme Transaction”), resulting in the Company becoming a direct wholly owned subsidiary of Topco, and (ii) Merger Sub will merge with and into Clywedog, with Clywedog continuing as the surviving corporation and a direct wholly owned subsidiary of Topco in accordance with the Delaware General Corporations Law (the “Merger” and, together with the Scheme Transaction, the “Combinations”, and, together with such other transactions contemplated by the Merger Agreement, the “Contemplated Transactions”). The Scheme Transaction will be consummated prior to the Merger. At the effective time of the Scheme Transaction (the “Scheme Effective Time”), upon the terms and subject to the conditions set forth in the Merger Agreement, Topco will acquire each outstanding ordinary share of the Company, with a par value £0.000025 per ordinary share (each such acquired ordinary share, a “Scheme Share”), which, for the avoidance of doubt, will include ordinary shares held by The Bank of New York Mellon (the “Depositary”) (or to the extent that the Depositary is not itself the registered holder of such shares that underly the Company’s American Depositary Shares (the “ADSs”), each representing one (1) ordinary share, whichever nominee, custodian or other entity is the registered holder under the terms of the Deposit Agreement, dated as of April 29, 2021, among the Company, the Depositary, and all holders from time to time of the ADSs, as may be amended from time to time), from the holders of Scheme Shares whose names appear in the register of members of the Company at the Scheme Effective Time) in accordance with the provisions of the Scheme of Arrangement, and each Scheme Share will be converted into the right to receive (i) between 0.1 and 0.166667, as finally determined by the Company’s board of directors (or a duly appointed committee thereof) in its sole discretion prior to the Scheme Effective Time, shares of common stock, $0.0001 par value per share, of Topco (the “Topco Common Stock”) rounded down to the nearest whole share, plus (ii) cash in lieu of any fraction of a real share, each subject to and strictly in accordance with the terms of the Scheme of Arrangement. Following the Scheme Effective Time, Topco may in its discretion elect to commence a self-tender offer (“Self-Tender Offer”) to purchase up to $27.0 million in shares of Topco Common Stock then issued and outstanding, which Self-Tender Offer, if elected, will be consummated prior to the Merger. At the effective time of the Merger (the “Merger Effective Time”), subject to adjustment in accordance with the terms of the Merger Agreement, each share of common stock, $0.0001 par value per share, of Clywedog (the “Clywedog Common Stock”) and each share of Series Seed Preferred Stock, $0.0001 par value per share, of Clywedog (the “Clywedog Preferred Stock”, and together with the Clywedog Common Stock, the “Clywedog Capital Stock”), other than Clywedog Capital Stock held as treasury stock or owned by Topco or Merger Sub immediately prior to the Merger Effective Time, will be converted solely into the right to receive (i) between 0.000305 and 0.000508, as finally determined by Clywedog and the Company, of shares of Topco Common Stock rounded down to the nearest whole share plus (ii) cash in lieu of any fraction of a share. The closing of the Contemplated Transactions is subject to the satisfaction or waiver of certain customary conditions, including, among other things: (i) the effectiveness of a registration statement (the “Registration Statement”) to register the shares of Topco Common Stock to be issued in connection with the Combinations; (ii) approvals by the Company’s shareholders of the Scheme Transaction and certain related matters, and sanction by the Court of the Scheme Transaction; (iii) approval by Clywedog’s stockholders of the Merger Agreement, the Merger and Contemplated Transactions; (iv) the approval for listing by the Nasdaq Stock Market of the shares of Topco Common Stock issuable in the Combinations, subject to official notice of issuance; (v) the completion of the Self-Tender Offer to the extent that Topco elects to commence the Self-Tender Offer; (vi) minimum cash requirements for each party. The Merger Agreement may be terminated and the transactions contemplated thereby abandoned at any time prior to the closing under certain specified circumstances. Either the Company or Clywedog may terminate the Merger Agreement if, among other things: (i) the closing date will not have occurred by September 30, 2026, subject to up to a 60 day extension if the U.S. Securities and Exchange Commission (the “SEC”) has not declared effective the Registration Statement by July 31, 2026, (ii) a governmental authority of competent jurisdiction has issued a final, non-appealable order prohibiting the Contemplated Transactions, (iii) the required Company shareholder approval or Clywedog shareholder approval is not obtained in accordance with the Merger Agreement, (iv) the Scheme of Arrangement is not sanctioned by the Court, or (v) another party breaches or fails to perform in any material respect any of its covenants or any of the other party’s representations or warranties are inaccurate and such breach, failure to perform or inaccuracy would result in certain of the closing conditions not being satisfied, subject to a cure period. Basis of presentation The Company’s unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (the "SEC") for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Certain notes or other information that are normally required by GAAP have been omitted if they substantially duplicate the disclosures contained in the Company’s annual audited consolidated financial statements. Accordingly, the unaudited condensed consolidated financial statements should be read in connection with the Company’s audited consolidated financial statements and related notes as of and for the year ended December 31, 2025. The condensed consolidated balance sheet as of December 31, 2025, was derived from the audited financial statements but does not contain all of the footnote disclosures from the annual financial statements. As of June 30, 2026, the Company had cash, cash equivalents and restricted cash of $59.6 million and an accumulated deficit of $320.2 million, and the Company expects to incur losses for the foreseeable future as it continues to pursue its activities, including the commercialization of its research and development. The Company expects to continue to incur costs and expenditures in connection with the Contemplated Transactions. In connection with the Contemplated Transactions, the Company may pay up to $27.0 million to existing shareholders under a self tender offer. If the Contemplated Transactions are consummated, any additional funding will be sought by the combined company. However, as the transaction is not yet consummated, when performing the going concern assessment, management have assessed the Company on a standalone basis and expects that its cash, cash equivalents and restricted cash will be sufficient to fund current operations for at least the next 12 months from the issuance of these condensed consolidated financial statements. In the future the Company will need additional cash inflows to pursue its activities, including the commercialization of its research and development. There is no assurance that the Company will be successful in obtaining sufficient cash inflows on terms acceptable to the Company to fund continuing operations, if at all. The condensed consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates, among other things, the realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. The unaudited condensed consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates, among other things, the realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Unaudited Condensed Consolidated Financial Information The accompanying Condensed Consolidated Balance Sheets as of June 30, 2026, and December 31, 2025, the Condensed Consolidated Statements of Operations and Comprehensive Loss, Condensed Consolidated Statements of Changes in Stockholders’ Equity and the Condensed Consolidated Statements of Cash Flows for the three and six months ended June 30, 2026 and 2025 are unaudited. These unaudited condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, filed with the Securities Exchange Commission (the “Annual Report”) on March 13, 2026. In the Company's opinion, the unaudited condensed consolidated financial statements include all adjustments of a normal recurring nature necessary for the fair statement of its financial position as of June 30, 2026, its results of operations for the three and six months ended June 30, 2026, and 2025, and its cash flows for the six months ended June 30, 2026, and 2025. The results of operations for the three and six months ended June 30, 2026, are not necessarily indicative of the results to be expected for the year ending December 31, 2026, or any other interim periods.