Organization and Description of Business	3 Months Ended
Mar. 31, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business Centessa Pharmaceuticals plc (“Centessa” or “the Company”) is a clinical-stage biotechnology company pioneering a new class of therapeutics in orexin-based neuroscience. We are developing a franchise of small molecule orexin receptor 2 (OX2R) agonists designed to address neuroscience diseases underpinned by dysregulation of wakefulness, attention, cognition, mood, and other symptoms, each grounded in the shared biology of the orexin pathway. Centessa was incorporated on October 26, 2020 as a limited liability company under the laws of England and Wales. In connection with the Company’s initial public offering, or IPO, the Company re-registered Centessa Pharmaceuticals Limited as an English public limited company and renamed it as Centessa Pharmaceuticals plc. The Proposed Lilly Transaction On March 31, 2026, we entered into a Transaction Agreement (the “Transaction Agreement”) with Eli Lilly and Company, an Indiana corporation (“Lilly” or “Parent”), and LDH XV Corporation, a Delaware corporation, and direct wholly owned subsidiary of Parent (“Purchaser”), pursuant to which Purchaser (and/or at Parent’s election its nominee(s)), will acquire our entire issued and to be issued share capital (including shares represented by our ADSs) pursuant to a court-sanctioned scheme of arrangement under Part 26 of the UK Companies Act 2006 (the “Scheme of Arrangement” and such acquisition, the “Transaction”), for $38.00 in cash per share, without interest, plus one non-transferable contingent value right entitling the holders to receive up to three contingent cash payments of up to an aggregate of $9.00 per share, contingent upon the achievement of specified milestones set forth in the Contingent Value Rights Agreement (the “CVR Agreement”), substantially in the form attached as Annex I to the Transaction Agreement (such contingent value rights, the “CVRs” and, together with the Cash Consideration, the “Transaction Consideration”). The Transaction is expected to close in the third quarter of 2026, subject to certain customary closing conditions, including the approval of the Scheme of Arrangement by our shareholders, the sanction of the Scheme of Arrangement by the High Court of Justice of England and Wales and receipt of the required regulatory approvals. See “Note 3 – Eli Lilly Agreement” in this Form 10-Q for additional information regarding the Transaction. Risks and Liquidity The Company is subject to risks common to other life science companies in various stages of development including, but not limited to, uncertainty of product development and commercialization, lack of marketing and sales history, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, product liability, protection of proprietary technology, ability to raise additional financing and compliance with government regulations in the markets in which the Company is seeking approvals, including U.S. Food and Drug Administration (“FDA”) regulations. If the Company does not successfully advance its programs, into and through human clinical trials and/or enter into collaborations for its programs and commercialize any of its product candidates, it may be unable to produce product revenue or achieve profitability. The Company has incurred losses and negative cash flows from operations since inception and the Company had an accumulated deficit of $1.27 billion as of March 31, 2026. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of the product candidates currently in development. Substantial additional capital will be needed by the Company to fund its operations and to develop its product candidates. The Company entered into a sales agreement, dated January 27, 2023 and amended and restated on November 24, 2025 (the “Sales Agreement”), by and between Centessa Pharmaceuticals plc and Leerink Partners LLC. As sales agent, Leerink Partners LLC provided for the issuance and sale by the Company of up to $250.0 million of its ordinary shares represented by American Depository Shares (“ADSs”) from time to time in “at-the-market” offerings (“ATM Program”). In the three months ended March 31, 2026, the Company has not sold any ordinary shares under the ATM Program. Since the inception of the ATM program in 2023, as of March 31, 2026, the Company sold 4,663,354 ordinary shares under the ATM Program, resulting in net proceeds of approximately $36.6 million under the Sales Agreement. In 2025, the Company completed an offering of its ordinary shares through the sale and issuance of a cumulative 13,372,093 ADSs. Each ADS represents one ordinary share with a nominal value of £0.002 per ordinary share. The completed offerings, which included the underwriters’ over-allotment option to purchase additional shares, was made pursuant to the Shelf registration. The net proceeds of these offerings, after deducting underwriting discounts and commissions and offering expenses, was approximately $269.2 million. The Company intends to use the net proceeds from the offerings, together with its existing cash, cash equivalents, and investments, to fund the continued development of its product candidates, as well as for general corporate purposes. The Company expects its existing cash, cash equivalents and investments as of March 31, 2026 of $533.7 million will be sufficient to fund its expected operating expenses and capital expenditure requirements for at least the next twelve months from the date of issuance of these unaudited interim consolidated financial statements. Emerging Growth Company and Smaller Reporting Company Status The Company is an emerging growth company, as defined in the JOBS Act. Under the JOBS Act, emerging growth companies can delay the adoption of new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. Other exemptions and reduced reporting requirements under the JOBS Act for emerging growth companies include presentation of only two years of audited financial statements in a registration statement for an initial public offering, an exemption from the requirement to provide an auditor’s report on internal controls over financial reporting pursuant to Section 404 of the Sarbanes-Oxley Act of 2002, as amended, an exemption from any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation and less extensive disclosure about our executive compensation arrangements. The Company has elected to use the extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that (i) it is no longer an emerging growth company or (ii) the Company affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. The Company will remain an emerging growth company until the earliest of (i) the last day of its first fiscal year in which it has total annual gross revenues of $1.235 billion or more, (ii) the last day of its first fiscal year following the fifth anniversary of the closing of its initial public offering, (iii) the date on which it is deemed to be a “large accelerated filer,” under the rules of the SEC, or (iv) the date on which we have issued more than $1.0 billion in non-convertible debt securities during the prior three-year period. As of January 1, 2026, the Company ceased to be a “smaller reporting company” (“SRC”) as defined in the Exchange Act. For the first fiscal quarter of 2026, the Company is no longer permitted to take advantage of scaled disclosure requirements for SRCs. The Company will retain its non-accelerated filer status for its filings due in the fiscal year 2026. The Company anticipates that it will have to comply with the auditor attestation requirements of Section 404(b) of the Sarbanes-Oxley Act for the year ended December 31, 2026, and its independent registered public accounting firm will have to evaluate and report on the effectiveness of internal control over financial reporting.

Centessa Pharmaceuticals plc (“Centessa” or “the Company”) is a clinical-stage biotechnology company pioneering a new class of therapeutics in orexin-based neuroscience. We are developing a franchise of small molecule orexin receptor 2 (OX2R) agonists designed to address neuroscience diseases underpinned by dysregulation of wakefulness, attention, cognition, mood, and other symptoms, each grounded in the shared biology of the orexin pathway. Centessa was incorporated on October 26, 2020 as a limited liability company under the laws of England and Wales. In connection with the Company’s initial public offering, or IPO, the Company re-registered Centessa Pharmaceuticals Limited as an English public limited company and renamed it as Centessa Pharmaceuticals plc.

On March 31, 2026, we entered into a Transaction Agreement (the “Transaction Agreement”) with Eli Lilly and Company, an Indiana corporation (“Lilly” or “Parent”), and LDH XV Corporation, a Delaware corporation, and direct wholly owned subsidiary of Parent (“Purchaser”), pursuant to which Purchaser (and/or at Parent’s election its nominee(s)), will acquire our entire issued and to be issued share capital (including shares represented by our ADSs) pursuant to a court-sanctioned scheme of arrangement under Part 26 of the UK Companies Act 2006 (the “Scheme of Arrangement” and such acquisition, the “Transaction”), for $38.00 in cash per share, without interest, plus one non-transferable contingent value right entitling the holders to receive up to three contingent cash payments of up to an aggregate of $9.00 per share, contingent upon the achievement of specified milestones set forth in the Contingent Value Rights Agreement (the “CVR Agreement”), substantially in the form attached as Annex I to the Transaction Agreement (such contingent value rights, the “CVRs” and, together with the Cash Consideration, the “Transaction Consideration”). The Transaction is expected to close in the third quarter of 2026, subject to certain customary closing conditions, including the approval of the Scheme of Arrangement by our shareholders, the sanction of the Scheme of Arrangement by the High Court of Justice of England and Wales and receipt of the required regulatory approvals. See “Note 3 – Eli Lilly Agreement” in this Form 10-Q for additional information regarding the Transaction.

The Company is subject to risks common to other life science companies in various stages of development including, but not limited to, uncertainty of product development and commercialization, lack of marketing and sales history, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, product liability, protection of proprietary technology, ability to raise additional financing and compliance with government regulations in the markets in which the Company is seeking approvals, including U.S. Food and Drug Administration (“FDA”) regulations. If the Company does not successfully advance its programs, into and through human clinical trials and/or enter into collaborations for its programs and commercialize any of its product candidates, it may be unable to produce product revenue or achieve profitability.

The Company has incurred losses and negative cash flows from operations since inception and the Company had an accumulated deficit of $1.27 billion as of March 31, 2026. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of the product candidates currently in development. Substantial additional capital will be needed by the Company to fund its operations and to develop its product candidates.

The Company entered into a sales agreement, dated January 27, 2023 and amended and restated on November 24, 2025 (the “Sales Agreement”), by and between Centessa Pharmaceuticals plc and Leerink Partners LLC. As sales agent, Leerink Partners LLC provided for the issuance and sale by the Company of up to $250.0 million of its ordinary shares represented by American Depository Shares (“ADSs”) from time to time in “at-the-market” offerings (“ATM Program”). In the three months ended March 31, 2026, the Company has not sold any ordinary shares under the ATM Program. Since the inception of the ATM program in 2023, as of March 31, 2026, the Company sold 4,663,354 ordinary shares under the ATM Program, resulting in net proceeds of approximately $36.6 million under the Sales Agreement.

In 2025, the Company completed an offering of its ordinary shares through the sale and issuance of a cumulative 13,372,093 ADSs. Each ADS represents one ordinary share with a nominal value of £0.002 per ordinary share. The completed offerings, which included the underwriters’ over-allotment option to purchase additional shares, was made pursuant to the Shelf registration. The net proceeds of these offerings, after deducting underwriting discounts and commissions and offering expenses, was approximately $269.2 million. The Company intends to use the net proceeds from the offerings, together with its

The Company expects its existing cash, cash equivalents and investments as of March 31, 2026 of $533.7 million will be sufficient to fund its expected operating expenses and capital expenditure requirements for at least the next twelve months from the date of issuance of these unaudited interim consolidated financial statements.

The Company is an emerging growth company, as defined in the JOBS Act. Under the JOBS Act, emerging growth companies can delay the adoption of new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. Other exemptions and reduced reporting requirements under the JOBS Act for emerging growth companies include presentation of only two years of audited financial statements in a registration statement for an initial public offering, an exemption from the requirement to provide an auditor’s report on internal controls over financial reporting pursuant to Section 404 of the Sarbanes-Oxley Act of 2002, as amended, an exemption from any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation and less extensive disclosure about our executive compensation arrangements. The Company has elected to use the extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that (i) it is no longer an emerging growth company or (ii) the Company affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act.

The Company will remain an emerging growth company until the earliest of (i) the last day of its first fiscal year in which it has total annual gross revenues of $1.235 billion or more, (ii) the last day of its first fiscal year following the fifth anniversary of the closing of its initial public offering, (iii) the date on which it is deemed to be a “large accelerated filer,” under the rules of the SEC, or (iv) the date on which we have issued more than $1.0 billion in non-convertible debt securities during the prior three-year period.

As of January 1, 2026, the Company ceased to be a “smaller reporting company” (“SRC”) as defined in the Exchange Act. For the first fiscal quarter of 2026, the Company is no longer permitted to take advantage of scaled disclosure requirements for SRCs. The Company will retain its non-accelerated filer status for its filings due in the fiscal year 2026. The Company anticipates that it will have to comply with the auditor attestation requirements of Section 404(b) of the Sarbanes-Oxley Act for the year ended December 31, 2026, and its independent registered public accounting firm will have to evaluate and report on the effectiveness of internal control over financial reporting.