TuHURA生物科学公司美国存托凭证招股说明书（2025-10-31版）

Up to 4,570,629 Shares of Common StockUp to 4,750,916 Shares of Common Stock Issuable Upon Exercise ofWarrants________________________________________ This prospectus supplement supplements the prospectus dated September 26, 2025 (the “Prospectus”), which forms a partof our registration statement on Form S-1 (No. 333-289532) originally filed with the Securities and Exchange Commission (the“SEC”) on August 12, 2025 and declared effective by the SEC on September 26, 2025. This prospectus supplement is being filed to update and supplement the information in the Prospectus with the informationcontained in our Current Report on Form 8-K filed with the SEC on October 31, 2025 (the “Current Report”). Accordingly, wehave attached the Current Report to this prospectus supplement. The Prospectus and this prospectus supplement relate to the proposed offer and resale or other disposition from time totime by the selling stockholders identified in the Prospectus of up to an aggregate of up to (i) 4,570,629 shares of common stock,par value $0.001 per share, and (ii) 4,750,916 shares of common stock issuable upon the exercise of warrants. Our shares of Common Stock are currently listed on the Nasdaq Capital Market under the symbols “HURA”.The lastreported sale price of the common stock on October 30, 2025 was $2.48 per share. This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, andmay not be delivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto.This prospectus supplement should be read in conjunction with the Prospectus and if there is any inconsistency between theinformation in the Prospectus and this prospectus supplement, you should rely on the information in this prospectus supplement. Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertaintiesdescribed in the section titled “Risk Factors” beginning on page 5 of the Prospectus, and under similar headings in anyamendments or supplements to the Prospectus. Neither the Securities and Exchange Commission nor any state securitiescommission has approved or disapproved of the securities to be issued under the Prospectus and this prospectussupplement or determined if the Prospectus and this prospectus supplement is truthful or complete. Any representation tothe contrary is a criminal offense. The date of this prospectus supplement is October 31, 2025 UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 27, 2025 TUHURA BIOSCIENCES, INC. (Exact name of Registrant as Specified in Its Charter) Nevada(State or Other Jurisdictionof Incorporation) 99-0360497(IRS EmployerIdentification No.) 001-37823(Commission File Number) 10500 University Center Dr., Suite 110Tampa, Florida 33612(Address of Principal Executive Offices, including zip code) Registrant’s Telephone Number, Including Area Code:(813) 875-6600 N/A(Former Name or Former Address, if Changed Since Last Report) 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)) 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 1.01 Entry into a Material Definitive Agreement. Bridge Loan Transaction On October 27, 2025, TuHURA Biosciences, Inc. (the “Company”) entered into a Secured Promissory Note and Loan Agreement(the “Loan Agreement”) with the Matthew Nachtrab Revocable Trust dated 12/18/2014 (the “Lender”). Pursuant to the terms of theLoan Agreement, the Lender agreed to make loans to the Company in an aggregate principal amount of up to $3,000,000 (the“Loans”) during a 30-day availability period beginning on the date of the Loan Agreement. The Lender advanced the first loan tothe Company in the amount of $1,500,000 simultaneously with the execution of the Loan Agreement (the “Initial Advance”), andupon advance notice by