Seaport Therapeutics Inc美股招股说明书(2026-05-01版)

14,160,000Shares Common Stock This is an initial public offering of shares of common stock of Seaport Therapeutics, Inc. We are offering 14,160,000shares of our common stock. Prior to this offering, there has been no public market for our common stock. The initial public offering price is $18.00 per share. Our commonstock has been approved for listing on the Nasdaq Global Select Market under the symbol “SPTX.” We are an “emerging growth company” and “smaller reporting company” as defined under the U.S. federal securities laws and, as such, we haveelected to comply with certain reduced public company reporting requirements in this prospectus. For additional information, see the section titled“Prospectus Summary—Implications of Being an Emerging Growth Company and a Smaller Reporting Company.” Investing in our common stock involves a high degree of risk. See the section titled “Risk Factors” beginning on page 17 to read aboutfactors you should consider before deciding to invest in shares of our common stock. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities orpassed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense. PerShareTotalInitial public offering price$ 18.00$254,880,000Underwriting discounts and commissions(1)$1.26$17,841,600Proceeds, before expenses, to Seaport Therapeutics, Inc.$ 16.74$237,038,400 (1)For additional information regarding compensation payable to the underwriters, see the section titled “Underwriting.” We have granted the underwriters the option to purchase up to an additional 2,124,000shares of common stock from us, at the initial publicoffering price, less the underwriting discounts and commissions. We have received indications of interest from entities affiliated with General Atlantic to purchase up to $50million in shares of our common stockin this offering at the initial public offering price per share, on the same terms as the other purchasers in this offering. However, because indications ofinterest are not binding agreements or commitments to purchase shares, nor a commitment of the Company or the underwriters to allocate or sell shares,more, fewer or no shares may be sold to General Atlantic in this offering. The underwriters will receive the same underwriting discount andcommissions on these shares as they will on any other shares sold to the public in this offering. At our request, the underwriters have reserved up to 5% of the shares offered by this prospectus for sale, at the initial public offering price, to ourdirectors, officers, certain employees and certain other persons associated with us. See the section “Underwriting—Directed Share Program.” The underwriters expect to deliver the shares against payment on or about May4, 2026. GoldmanSachs&Co.LLC Table of Contents TABLE OF CONTENTSPagePROSPECTUS SUMMARY1RISK FACTORS17SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS101USE OF PROCEEDS103DIVIDEND POLICY104CAPITALIZATION105DILUTION107MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS110BUSINESS126MANAGEMENT182EXECUTIVE COMPENSATION193DIRECTOR COMPENSATION205CERTAIN RELATIONSHIPS AND RELATED PERSON TRANSACTIONS207PRINCIPAL STOCKHOLDERS212DESCRIPTION OF CAPITAL STOCK216SHARES ELIGIBLE FOR FUTURE SALE223MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES FOR NON-U.S. HOLDERS225UNDERWRITING229LEGAL MATTERS238EXPERTS238WHERE YOU CAN FIND ADDITIONAL INFORMATION238INDEX TO THE CONSOLIDATED FINANCIAL STATEMENTSF-1 Unless otherwise indicated, all references in this prospectus to “Seaport,” the “company,” “we,” “our,” “us,” or similar terms refer to SeaportTherapeutics, Inc. and its wholly owned subsidiaries, or either or all of them as the context may require. Neither we nor the underwriters have authorized anyone to provide you any information or make any representations other than those contained inthis prospectus or in any free writing prospectuses prepared by or on behalf of us or to which we have referred you. We and the underwriters take noresponsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We and the underwriters are notmaking an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing inthis prospectus or in any applicable free writing prospectus is current only as of its date, regardless of its time of delivery or any sale of shares of ourcommon stock. Our business, financial condition, results of operations, and prospects may have changed since that date. For investors outside of the United States: we have not, and the underwriters have not, done anything that would permit this offering or possessionor distribution of this prospectus in any jurisdiction where action for that purpose is required, other than the United States. Persons o