Kazia Therapeutics Ltd ADR美国存托凭证招股说明书（2026年5月26日版）

PROSPECTUS SUPPLEMENT(to Prospectus dated December 23, 2025) Kazia Therapeutics Limited This prospectus supplement is being filed to update and supplement the information contained in the prospectus dated December 23,2025 (the “Prospectus”), which forms a part of our Registration Statement on Form F-1 (Registration No. 333-292303), with theinformation contained in our current report on Form 6-K, furnished to the Securities and Exchange Commission on May 26, 2026 (the This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not bedelivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectussupplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in the The ADSs are listed on The Nasdaq Capital Market (“Nasdaq”) under the symbol “KZIA.” On May 22, 2026, the last reported saleprice of the ADSs on Nasdaq was $13.66 per ADS. Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page 9 of the Prospectus and the“Risk Factors” in “Item 3. Key Information-D. Risk Factors” of our most recent Annual Report on Form 20-F, which is Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or passed upon the adequacy or accuracy of the Prospectus or this prospectus supplement. Any representation to the The date of this prospectus supplement is May 26, 2026 INFORMATION CONTAINED IN THIS FORM 6-K REPORT Press Release On May 26, 2026, Kazia Therapeutics Limited (the “Company”) issued a press release titled “Kazia Therapeutics Expands OngoingPhase 1b Trial of Paxalisib in Advanced Breast Cancer”. A copy of this press release is attached hereto as Exhibit 99.1 and is Incorporation by Reference The Company hereby incorporates by reference the information contained herein, including 99.1, except for the quotes of Dr. JohnFriend, Chief Executive Officer of the Company, contained in Exhibit 99.1, into the Company’s registration statements on Form F-3 EXHIBIT INDEX SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on itsbehalf by the undersigned, thereunto duly authorized. Kazia Therapeutics Limited. By:/s/ John FriendName:John FriendTitle: Chief Executive Officer Kazia Therapeutics Expands Ongoing Phase 1b Trial of Paxalisib in Advanced Breast Cancer Planned Enrollment to Increase from 12 to 36 Patients Following Continued Encouraging Safety and Tolerability Data SYDNEY, Australia, May 26, 2026 –Kazia Therapeutics Limited (NASDAQ: KZIA) (“Kazia” or the “Company”), a clinical-stageoncology company advancing therapies designed to reprogram cancer biology and overcome treatment resistance, today announcedplans to expand its ongoing Phase 1b clinical trial evaluating lead assetpaxalisib in combination with standard-of-care therapies inpatients with advanced triple negative breast cancer (“TNBC”). Based on continued encouraging safety, tolerability and clinical The expansion is intended to further evaluate the safety, tolerability, dose optimization and preliminary efficacy of the paxalisib-basedcombination regimen with pembrolizumab and chemotherapy. The expanded dataset is expected to provide a more meaningfulassessment of objective response rate (“ORR”), progression-free survival (“PFS”) and translational biomarkers. Additional clinical “We remain encouraged by the safety and tolerability data observed to date, and expanding enrollment allows us to generate a broaderclinical and translational dataset as we advance paxalisib in difficult-to-treat advanced breast cancer, such as TNBC,” said Dr. JohnFriend, CEO, Kazia Therapeutics. “Paxalisib’s mechanism, modulating key resistance and immune-related pathways, addresses thevery reasons that current therapies fail, and we believe it holds meaningful potential for an underserved patient population. While weplanned to present scientific progress at ASCO 2026, we made the decision to withdraw our abstracts solely to protect our intellectual The Phase 1b study is evaluating paxalisib in combination with established breast cancer regimens across multiple dose cohorts. Thetrial expansion is supported by a recently publishedpreclinical study inMolecular Cancer Therapeutics, a journal of the AmericanAssociation for Cancer Research (“AACR”), demonstrating that dual PI3K/mTOR inhibition with paxalisib altered tumor cell stateand immune signaling in preclinical TNBC models. TNBC accounts for approximately 15 to 20 percent of all breast cancer diagnoses About Kazia Therapeutics Kazia Therapeutics (NASDAQ: KZIA) is an oncology-focused drug development company, based in Sydney, Australia. TheCompany’s lead asset, paxalisib, is an investigational brain penetrant inhibitor of the PI3K/Akt /mTOR