Crescent Biopharma Inc美股招股说明书(2026-06-22版)

Ordinary SharesOffered by the Selling Securityholders This prospectus supplement updates, amends and supplements the prospectus dated March 3, 2026 (the “Prospectus”), relating tothe proposed resale or other disposition by the selling securityholders identified in the Prospectus of up to an aggregate of 19,580,843ordinary shares with a par value of US$0.001 per share (“Ordinary Shares”) of Crescent Biopharma, Inc. (the “Company”), consistingof (i) 13,534,837 outstanding Ordinary Shares issued pursuant to the Private Placement (as defined in the Prospectus), (ii) 131,434Ordinary Shares issuable upon the exercise of pre-funded warrants issued pursuant to the Private Placement and (iii) 1,387,866outstanding Ordinary Shares, 1,636,706 Ordinary Shares issuable upon the exercise of pre-funded warrants, and 2,890,000 OrdinaryShares issuable upon the conversion of Series A non-voting convertible preferred shares, in each case, held by Fairmount HealthcareFund II L.P. as of immediately prior to the closing of the Private Placement, which forms a part of our Registration Statement on FormS-1 (Registration No. 333-292600). This prospectus supplement is being filed to update, amend and supplement the Prospectus with the information contained in ourCurrent Report on Form 8-K, dated June 3, 2026, and Amendment No. 1 to our Quarterly Report on Form 10-Q for the quarterlyperiod ended March 31, 2026 filed with the Securities and Exchange Commission. This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be read in conjunctionwith the Prospectus, which is to be delivered with this prospectus supplement, and is qualified by reference thereto, except to theextent that the information in this prospectus supplement updates or supersedes the information contained in the Prospectus. Pleasekeep this prospectus supplement with your Prospectus for future reference. Our Ordinary Shares are listed on the Nasdaq Stock Market (“Nasdaq”) under the symbol “CBIO”. On June 18, 2026, the closingsale price of our Ordinary Shares was $17.69 per share. INVESTING IN OUR SECURITIES INVOLVES RISKS THAT ARE DESCRIBED IN THE “RISK FACTORS” SECTIONBEGINNING ON PAGE 9 OF THE PROSPECTUS. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved ofthese securities or passed upon the accuracy or adequacy of this prospectus supplement or the Prospectus. Any representationto the contrary is a criminal offense. The date of this prospectus supplement is June 22, 2026. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549________________________________________________________________________________________________ FORM 8-K CURRENT REPORTPursuant to Section 13 or 15(d)of the Securities Exchange Act of 1934Date of report (Date of earliest event reported): June 2, 2026________________________________________________________________________________________________ Crescent Biopharma, Inc.(Exact Name of Registrant as Specified in Charter) ________________________________________________________________________________________________ Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrantunder any of the following provisions: Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933(§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. Item 5.07Submission of Matters to a Vote of Security Holders. On June 2, 2026, Crescent Biopharma, Inc. (the “Company”) held its annual general meeting of shareholders (the “Annual Meeting”).At the close of business on April 7, 2026, the record date for the Annual Meeting (the “Record Date”), 27,571,935 ordinary shares, parvalue $0.001 per share (“Ordinary Shares”), were issued and outstanding, and 2,890 Series A non-voting convertible preferred shares,par value $0.001 per share (“Series A Preferred Shares”), were issued and outstanding. Each Ordinary Share was entitled to one voteper share for the election of Susan Moran, M.D., MSCE and one vote on each of proposals 3, 4 and 5. The holders of each