Lexeo Therapeutics Inc美股招股说明书(2025-10-17版)

Our common stock is traded on the Nasdaq Global Market under the symbol “LXEO.” The last sale price of our common stock as reported on the Nasdaq Global Market on We are an emerging growth company and smaller reporting company as that term is used in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, and asmaller reporting company as defined underRule12b-2promulgated under the Securities Exchange Act of 1934, as amended, or the Exchange Act, and, as such, are subject tocertain reduced public company reporting requirements. See “Prospectus Supplement Summary—Implications of being an emerging growth company and a smaller reportingcompany.” Investing in our securities involves a high degree of risk. Before buying any securities, you should carefully read the discussion of the risks anduncertainties of investing in our securities described in the section titled “Risk Factors” beginning on pageS-10 of this prospectus supplement, page6 of theaccompanying prospectus and “Item 1A—Risk Factors” of our most recent report onForm10-Kor10-Qthat is incorporated by reference in this prospectussupplement. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon theadequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense. Underwriting discounts and commissions(1)Proceeds to Lexeo Therapeutics, Inc., before expenses (2) (2)Total gross proceeds from this offering and the concurrent private placement are $135.0million. Such proceeds less underwriting discounts and commissions, placement agentfees and estimated offering and private placement expenses are approximately $126.2million. On October16, 2025, we entered into a securities purchase agreement with Balyasny Asset Management, to issue and sell pre-funded warrants to purchase 1,250,015 sharesof our common stock, or the private placement warrants, for aggregate gross proceeds of approximately $10.0 million in a private offering, or the concurrent private placement, at aprice per private placement warrant of $7.9999. Neither this offering nor the concurrent private placement is conditioned upon the completion of the other offering. The concurrentprivate placement is exempt from registration under the Securities Act of 1933, as amended, or the Securities Act. Nothing contained herein shall constitute an offer to sell or thesolicitation of an offer to buy any private placement warrants. The private placement warrants are being offered pursuant to an exemption from the registration requirements of theSecurities Act provided in Section4(a)(2) of the Securities Act. We have granted the underwriters an option for a period of up to 30 days from the date of this prospectus supplement to purchase up to an additional 2,343,750 shares of ourcommon stock at the public offering price, less the underwriting discounts and commissions. Delivery of the securities is expected to be made on or about October20, 2025. Joint Book-running Managers Oppenheimer&Co. Table of Contents TABLE OF CONTENTS Prospectus Supplement About this Prospectus SupplementProspectus Supplement SummaryThe OfferingRisk FactorsSpecial Note Regarding Forward-Looking StatementsUse of ProceedsDividend PolicyDilutionMaterial U.S. Federal Income Tax Considerations For Non-U.S. Holders of Our Common StockUnderwritingLegal MattersExpertsWhere You Can Find More InformationIncorporation by Reference Prospectus About this ProspectusProspectus SummaryRisk FactorsSpecial Note Regarding Forward-Looking StatementsUse of ProceedsDescription of Capital StockDescription of Debt SecuritiesDescription of WarrantsDescription of Subscription RightsDescription of Purchase ContractsDescription of UnitsPlan of DistributionLegal MattersExpertsWhere You Can Find More InformationIncorporation by Reference Table of Contents ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement relates to the offering of our common stock. Before buying any of the common stock that we are offering, we urgeyou to carefully read this prospectus supplement, the accompanying prospectus, any free writing prospectus that we have authorized for use inconnection with this offering, and the information incorporated by reference as described in the sections titled “Where You Can Find More Information”and “Incorporation by Reference” in this prospectus supplement. These documents contain important information that you should consider when makingyour investment decision. Generally, when we refer to this “prospectus,” we are referring to the prospectus supplement and the accompanyingprospectus combined. This prospectus supplement describes the terms of this offering of common stock as well as the concurrent private placement and also adds to andupdates information contained in the documents incorporated by reference in this prospectus supplement. To the extent there is a