TABLE OF CONTENTS

Please read this prospectus carefully. It describes our business, financial condition, results of operations and prospects, among other things. We are responsible for the information contained in this prospectus and in any free-writing prospectus we have authorized. Neither we nor the underwriters have authorized anyone to provide you with different information, and neither we nor the underwriters take responsibility for any other information others may give you. Neither we nor the underwriters are making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. The information contained in this prospectus is accurate only as of the date on the front of this prospectus, regardless of the time of delivery of this prospectus or any sale of securities. You should not assume that the information contained in this prospectus is accurate as of any date other than its date.

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ABOUT THIS PROSPECTUS

Unless the context otherwise requires, references in this prospectus to “Company,” “TuHURA,” “we,” “us,” “our,” and “ours” refer to TuHURA Biosciences, Inc., and its subsidiaries where the context so requires.

This prospectus relates to the resale from time to time by the selling stockholders named in this prospectus of up to 9,518,618 shares of common stock. The exhibits to the registration statement of which this prospectus is a part contain the full text of certain contracts and other important documents that we have summarized in this prospectus. Since these summaries may not contain all the information that you may find important in deciding whether to acquire or purchase common stock offered by this prospectus, you should review the full text of these documents. The registration statement and the exhibits and other documents can be obtained from the SEC as indicated under the section entitled “Where You Can Find More Information.”

This prospectus only provides you with a general description of the common stock that the selling stockholders may offer, which is not meant to be a complete description of the common stock. Each time a selling stockholder sells common stock, such selling stockholder will provide a prospectus and any related prospectus supplement containing specific information about the terms of the applicable offering, as required by law. Such prospectus supplement may add, update or change information contained in this prospectus. If there is any inconsistency between the information in this prospectus and any prospectus supplement, you should rely on the information in the prospectus supplement. You should read carefully both this prospectus and any related prospectus supplement together with the additional information described under the section entitled “Where You Can Find More Information.”

The selling stockholders may offer the common stock directly or through one or more underwriters, broker-dealers or agents. A prospectus supplement may describe the terms of the plan of distribution and set forth the names of any underwriters involved in the sale of common stock. See “Plan of Distribution.”

You should rely only on the information contained in prospectus or in any related free writing prospectus filed by us with the Securities and Exchange Commission, or SEC. We and the selling stockholders have not authorized anyone to provide you with different information. This prospectus does not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in this prospectus or an offer to sell or the solicitation of an offer to buy such securities in any circumstances in which such offer or solicitation is unlawful. You should assume that the information appearing in this prospectus is only accurate as of the date hereof. Our business, financial condition, results of operations and prospects may have changed materially since such date.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus contains forward-looking statements. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplate,” “believe,” “estimate,” “predict,” “potential”, or “continue” or the negative of these terms or other similar expressions. In particular, statements about the markets in which we operate, including growth of our various markets, and our expectations, beliefs, plans, strategies, objectives, prospects, assumptions, or future events or performance contained in this prospectus under the headings “Prospectus Summary,” “Risk Factors,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and “Business” are forward-looking statements.

We have based these forward-looking statements on our current expectations, assumptions, estimates and projections. While we believe these expectations, assumptions, estimates, and projections are reasonable, such forward-looking statements are only predictions and involve known and unknown risks and uncertainties, many of which are beyond our control. These and other important factors, including those discussed in this prospectus under the headings “Prospectus Summary,” “Risk Factors,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and “Business,” may cause our actual results, performance, or achievements to differ materially from any future results, performance or achievements expressed or implied by these forward-looking statements, or could affect our share price. Important factors that could cause actual results or events to differ materially from those expressed in forward-looking statements include, but are not limited to, the following:

There are a number of important factors that could cause the actual results to differ materially from those expressed in any forward-looking statement made by us. These factors include, but are not limited to:

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Given the risks and uncertainties set forth in this prospectus, you are cautioned not to place undue reliance on such forward-looking statements. The forward-looking statements contained in this prospectus are not guarantees of future performance and our actual results of operations, financial condition, and liquidity, and the development of the industry in which we operate, may differ materially from the forward-looking statements contained in this prospectus. In addition, even if our results of operations, financial condition and liquidity, and events in the industry in which we operate, are consistent with the forward-looking statements contained in this prospectus, they may not be predictive of results or developments in future periods.

Any forward-looking statement that we make in this prospectus speaks only as of the date of such statement. Except as required by federal securities laws, we do not undertake any obligation to update or revise, or to publicly announce any update or revision to, any of the forward-looking statements, whether as a result of new information, future events or otherwise, after the date of this prospectus.

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PROSPECTUS SUMMARY

The following summary highlights selected information about our company and this offering that is included elsewhere in this prospectus in greater detail. It does not contain all of the information that you should consider before investing in our common stock. Before investing in our common stock, you should read this entire prospectus carefully, including the information presented under the heading “Risk Factors” and in our financial statements and notes thereto. Unless otherwise stated or the context otherwise indicates, references to “TuHURA,” the “Company,” “we,” “our,” “us,” or similar terms refer to TuHURA Biosciences, Inc. and our wholly-owned subsidiaries.

The Company

We are a clinical stage immuno-oncology company with three distinct technologies focused on the development of novel therapeutics designed to overcome primary and acquired resistance to cancer immunotherapies.

Our proprietary Immune Fx^TM technology platform, or IFx, is an innate immune agonist technology designed to “trick” the body’s immune system to attack tumor cells by making tumor cells look like bacteria. Our lead product candidate, IFx2.0, is an innate immune agonist designed to overcome primary resistance to checkpoint inhibitors. In June 2025, we initiated a single randomized placebo-controlled Phase 3 registration trial of IFx-2.0 administered as an adjunctive therapy to Keytruda^® (pembrolizumab) in first line treatment for patients with advanced or metastatic Merkel cell carcinoma who are checkpoint inhibitor naïve utilizing the FDA’s accelerated approval pathway.

In addition to our IFx technology platform, in June 2025 we acquired the rights to TBS-2025, a novel VISTA-inhibiting monoclonal antibody formerly known as KVA1213, through our acquisition of Kineta, Inc. (“Kineta”) on June 30, 2025. VISTA (otherwise referred to as V-domain Ig suppressor of T cell activation) is an immune checkpoint highly expressed on myeloid cells that is believed to be a strong driver of immunosuppression in the tumor microenvironment and is believed to be a primary mechanism by which leukemic blasts escape immune recognition contributing to low relapse rates and high rates of recurrence in acute myeloid leukemia, or AML. Following our acquisition of Kineta, we are currently planning on investigating TBS-2025 in a randomized Phase 2 trial in combination with a menin inhibitor vs menin inhibitor alone in mutated NPM1 (mutNPM1) AML.

In addition to our IFx and TBS-2025 technologies, we are leveraging our Delta Opioid Receptor technology to develop tumor microenvironment modulators in the form of first-in-class bi-specific antibody-peptide conjugates (“APCs”) and antibody-drug conjugates (“ADCs”) targeting Myeloid Derived Suppressor Cells (“MDSCs”). Our APCs and ADCs are being developed to inhibit the immune-suppressing effects of MDSCs on the tumor microenvironment to prevent T cell exhaustion and acquired resistance to checkpoint inhibitors and cellular therapies.

TuHURA’s principal executive offices are located at 10500 University Center Drive, Suite 110, Tampa, Florida 33612. TuHURA’s telephone number is (813) 875-6600. TuHURA’s principal website address is www.tuhurabio.com. The information contained on, or that can be accessed through, TuHURA’s website is deemed not to be incorporated in this prospectus or to be part of this prospectus. You should not consider information contained on its website to be part of this prospectus.

The Private Placement

On June 2, 2025, the Company and the selling stockholders (the “Purchasers”) entered into a securities purchase agreement (the “Securities Purchase Agreement”) pursuant to which the Company agreed to issue to the Purchasers, in a private placement (the “Offering”), an aggregate of 4,759,309 shares of common stock together

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with warrants to purchase an equal number of shares of common stock at an exercise price of $3.3125 (the “Warrants”), for an aggregate offering amount of approximately $12.6 million. The combined effective offering price for each share and accompanying Warrant in the Offering was $2.65.

Pursuant to the Securities Purchase Agreement, each Purchaser was obligated to purchase such Purchaser’s respective investment in the Offering in four equal tranches, as follows:

In addition to the approximately $8.9 million that was purchased in four equal tranches pursuant to the foregoing milestones, the remaining $3.7 million in the Offering is required to be purchased and funded by December 31, 2025 by certain Purchasers who agreed to invest an aggregate of $4.0 million or more in the Offering and who elected to defer the purchase of a portion of such Purchaser’s common stock and Warrants until such time.

The Company currently plans to use the net proceeds from the Offering for cash requirements to fund expenses acquired in connection with the acquisition of Kineta, to fund the initiation of the Phase 3 Trial for IFx-2.0, to fund the advancement of TBS-2025 to a Phase 2 trial and for other working capital needs.

The Warrants have an exercise price per share equal to $3.3125 and will expire on the fifth (5th) anniversary of December 3, 2025. The exercise price of the Warrants is subject to proportional adjustment for stock splits, reverse stock splits, and similar transactions.

The shares, Warrants and the shares of common stock issuable upon exercise of the Warrants were issued in a private placement and have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), and are instead being offered pursuant to the exemption provided in Section 4(a)(2) under the Securities Act and/or Rule 506(b) promulgated thereunder.

The Company agreed to file this registration statement to register the resale of the shares and shares of common stock underlying the Warrants no later than 60 calendar days following the date of the Initial Closing and to use reasonable efforts to cause such registration statement to become effective within 120 calendar days following the date of the Initial Closing.

Closing of Kineta Merger

On June 30, 2025, the Company completed the previously announced acquisition contemplated by the Agreement and Plan of Merger, dated December 11, 2024, and as amended by that certain First Amendment to Agreement and Plan of Merger, dated May 5, 2025 (as amended, the “TuHURA-Kineta Merger Agreement”), by and among the Company, Hura Merger Sub I, Inc., a Delaware corporation and a direct wholly-owned subsidiary of the Company (“Merger Sub I”), Hura Merger Sub II, LLC, a Delaware limited liability company and direct wholly-owned subsidiary of the Company (“Merger Sub II”), Kineta, and Craig Philips, solely in his capacity as

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the representative, agent and attorney-in-fact of the stockholders of Kineta. Pursuant to the terms of the TuHURA-Kineta Merger Agreement, among other things, Merger Sub I (a) merged with and into Kineta (the “First Merger”), with Kineta being the surviving corporation of the First Merger, also known as the “Surviving Entity” and (b) immediately following the First Merger, the Surviving Entity merged with and into Merger Sub II (the “Second Merger”, and together with the First Merger, the “Kineta Merger”), with Merger Sub II being the surviving company of the Second Merger.

Upon completion of the Kineta Merger, pursuant to the terms and conditions of the TuHURA-Kineta Merger Agreement, each share of Kineta common stock, par value $0.001 per share (each, a “Share”), issued and outstanding immediately prior to the First Merger, was converted into the right to receive 0.185298 shares of the Company’s common stock, par value $0.001 per share (“TuHURA common stock”), for an aggregate of approximately 2,868,169 shares of TuHURA common stock. Also pursuant to the terms and conditions of the TuHURA-Kineta Merger Agreement, each Share is also entitled to (i) its pro rata portion of approximately 1,129,885 shares of TuHURA common stock to be issued after six months following the closing of the Kineta Merger, subject to adjustment for losses incurred or accrued during the six month period from the closing of the Kineta Merger, and (ii) the right to its pro rata share of cash consideration received by Kineta pursuant to disposed asset payments related to legacy Kineta assets. Such payments, if any, will be made at a later date and in accordance with the terms of the TuHURA-Kineta Merger Agreement. In each case, in lieu of the issuance of any fractional shares of TuHURA common stock, we will pay an amount equal to the product of (A) such fractional share and (B) $5.7528.

Implications of Being a Smaller Reporting Company

We are a “smaller reporting company” as defined in Rule 10(f)(1) of Regulation S-K. Smaller reporting companies may take advantage of certain reduced disclosure obligations, including, among other things, providing only two years of audited financial statements. We will remain a smaller reporting company until the last day of the fiscal year in which (1) the market value of our common stock held by non-affiliates equals or exceeds $250 million as of the end of that year’s second fiscal quarter, or (2) our annual revenues equaled or exceeded $100 million during such completed fiscal year and the market value of our common stock held by non-affiliates equals or exceeds $700 million as of the end of that year’s second fiscal quarter.

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The Offering

The number of shares of common stock to be outstanding after the Offering is based on 50,046,926 shares of common stock outstanding at August 11, 2025 (assuming exercise by the selling stockholders of all warrants being offering), excludes the following as of August 11, 2025:

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RISK FACTORS

SUMMARY OF RISK FACTORS

The following is a summary of the principal risks and uncertainties that could materially adversely affect our business, results of operations, financial condition, cash flows, prospects and/or the price of our outstanding securities and make an investment in our securities speculative or risky. You should read this summary together with the more detailed description of each risk factor contained below.

Investing in shares of our common stock involves a high degree of risk. You should carefully consider the risks and uncertainties described below, the section of this prospectus entitled “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our financial statements and related notes included elsewhere in this prospectus before investing in shares of our common stock. The risks and uncertainties described below are not the only ones we face. Additional risks and uncertainties that we are unaware of, or that we currently believe are not material, may also become important factors that affect us. If any of the following risks occur, our business, operating results and prospects could be materially harmed. In that event, the price of our common stock could decline, and you could lose part or all of your investment

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Risks Relating to TuHURA’s Business and Industry

TuHURA is a clinical-stage company and has a limited operating history, which may make it difficult to evaluate TuHURA’s current business and predict its future performance.

TuHURA is a clinical-stage pharmaceutical and has no products approved for commercial sale. TuHURA employs a multi-indication immunomodulator platform (ImmuneFx) that utilizes both cell and gene therapies, together, to stimulate the immune system to recognize and combat tumor cells. Although there have been significant advances in cell and gene-based immunotherapies, TuHURA’s immunomodulatory platforms are new and largely unproven. TuHURA’s operations to date have been limited to organizing and staffing the company, business planning, raising capital, developing its technology, identifying potential product candidates, undertaking preclinical studies, and conducting clinical trials. If one of TuHURA’s product candidates received regulatory approval, TuHURA would need to transition from a company with a research and development focus to a company capable of supporting commercial activities. TuHURA may not be successful in such a transition. In addition, TuHURA’s limited operating history, particularly in light of the rapidly evolving cancer immunotherapy field, may make it difficult to evaluate its current business and predict its future performance. TuHURA will encounter risks and difficulties frequently experienced by early-stage companies in rapidly evolving fields. If it does not address these risks successfully, TuHURA’s business will suffer.

TuHURA has incurred significant losses since inception and expects to incur significant losses for the foreseeable future and may not be able to achieve or sustain profitability in the future.

TuHURA is not profitable and has incurred significant losses in each period since TuHURA’s inception, including net losses of $22.6 million and $29.3 million for the years ended December 31, 2024, and 2023, respectively, (which includes the expensing of the entire $16.2 million purchase price for the assets of TuHURA Biopharma, Inc., of which $15 million was paid in the form of common stock), and $6.7 million and $4.8 million for the three months ended March 31, 2025 and 2024, respectively. As of March 31, 2025, we had an accumulated deficit of $117.8 million. To date, TuHURA has financed its operations primarily through private placements of its preferred stock and convertible notes. TuHURA has not commercialized any products and has never generated any revenue from product sales. TuHURA expects these losses to increase as it continues to incur significant research and development and other expenses related to TuHURA’s ongoing operations, seeks regulatory approvals for TuHURA’s product candidates, scales-up manufacturing capabilities and hires additional personnel to support the development of its product candidates and to enhance its operational, financial and information management systems.

A critical aspect of TuHURA’s strategy is to invest significantly in its technology platform to improve the efficacy and safety of its product candidates. To become and remain profitable, TuHURA must develop and eventually commercialize products with significant market potential, which it may never achieve. Even if TuHURA succeeds in commercializing one or more of these product candidates, TuHURA will continue to incur losses for the foreseeable future relating to its substantial research and development expenditures to develop TuHURA’s technologies. TuHURA may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect its business. The size of TuHURA’s future net losses will depend, in part, on the rate of future growth of its expenses and its ability to generate revenue. TuHURA’s prior losses and expected future losses have had and will continue to have an adverse effect on its stockholders’ equity and working capital. Further, the net losses TuHURA incurs may fluctuate significantly from quarter to quarter and year to year, such that a period-to-period comparison of its results of operations may not be a good indication of TuHURA’s future performance. If TuHURA does not achieve profitability, it may not be able to sustain or increase profitability on a quarterly or annual basis. TuHURA’s failure to become and remain profitable would decrease the value of the company and could impair its ability to raise capital, maintain its discovery and preclinical and clinical development efforts, expand its business or continue its operations and may require TuHURA to raise additional capital that may dilute your ownership interest. A decline in the value of TuHURA could also cause you to lose all or part of your investment.

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TuHURA’s recurring losses from operations and financial condition raise substantial doubt about its ability to continue as a going concern.

TuHURA’s recurring losses from operations and financial condition raise substantial doubt about its ability to continue as a going concern. In TuHURA’s financial statements for the three months ended March 31, 2025, the year ended December 31, 2024 and 2023, TuHURA concluded that its recurring losses from operations and need for additional financing to fund future operations raise substantial doubt about TuHURA’s ability to continue as a going concern. Similarly, TuHURA’s independent registered public accounting firm included an explanatory paragraph in its report on TuHURA’s financial statements for the year ended December 31, 2024 with respect to this uncertainty. TuHURA’s ability to continue as a going concern will require it to obtain additional funding. If TuHURA is unable to obtain sufficient funding, its business, prospects, financial condition and results of operations will be materially and adversely affected, and TuHURA may be unable to continue as a going concern. If TuHURA is unable to raise capital when needed or on acceptable terms, it would be forced to delay, limit, reduce or terminate its product development or future commercialization efforts of one or more of its product candidates, or may be forced to reduce or terminate its operations. If TuHURA is unable to continue as a going concern, TuHURA may have to liquidate its assets and may receive less than the value at which those assets are carried on its audited financial statements, and it is likely that investors will lose all or part of their investment. If TuHURA seeks additional financing to fund its business activities in the future and there remains substantial doubt about its ability to continue as a going concern, investors and other financing sources may be unwilling to provide additional funding to it on commercially reasonable terms, if at all.

TuHURA has never generated any revenue from product sales for its human drug candidates and its ability to generate revenue from product sales and become profitable depends significantly on its success in numerous endeavors.

TuHURA has no products approved for commercial sale, has not generated any revenue from product sales, and does not anticipate generating any revenue from product sales until sometime after TuHURA has received regulatory approval for the commercial sale of a product candidate. TuHURA’s ability to generate revenue and achieve profitability depends significantly on its success in many endeavors, including:

Because of the numerous risks and uncertainties associated with biopharmaceutical product development, TuHURA is unable to accurately predict the timing or amount of increased expenses or when, or if, TuHURA

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will be able to achieve profitability. If TuHURA is required by the U.S. Food and Drug Administration (the “FDA”), or other regulatory agencies, domestic or foreign, or other comparable foreign authorities, to perform preclinical studies or clinical trials in addition to those TuHURA currently anticipates, or if there are any delays in completing its clinical trials or the development of any of its product candidates, TuHURA’s expenses could increase and revenue could be further delayed.

Even if one or more of the product candidates that TuHURA develops is approved for commercial sale, TuHURA anticipates incurring significant costs associated with commercializing any approved product candidate. TuHURA’s expenses could increase beyond expectations if TuHURA is required by the FDA or other regulatory agencies, domestic or foreign, to change its manufacturing processes or assays, or to perform clinical, nonclinical, or other types of studies in addition to those that TuHURA currently anticipates. If TuHURA is successful in obtaining regulatory approvals to market of one or more of its product candidates, its revenue will be dependent, in part, upon the size of the markets in the territories for which TuHURA gains regulatory approval, the accepted price for the product, the ability to get reimbursement at any price, and whether TuHURA owns the commercial rights for that territory. If the number of TuHURA’s addressable disease patients is not as significant as it estimates, the indication approved by regulatory authorities is narrower than it expects, or the reasonably accepted population for treatment is narrowed by competition, physician choice or treatment guidelines, TuHURA may not generate significant revenue from sales of such products, even if approved. If TuHURA is not able to generate revenue from the sale of any approved products, TuHURA may never become profitable.

TuHURA will require substantial additional capital to finance its operations in the future. If TuHURA fails to obtain additional financing on acceptable terms or at all, it may be unable to complete the development and commercialization of its product candidates.

TuHURA’s operations have required substantial amounts of cash since inception. TuHURA expects to continue to spend substantial amounts to continue the clinical development of its product candidates, particularly as TuHURA advances the development of its lead product candidate IFx-Hu2.0 as a potential treatment for patients with melanoma, bladder and cervical cancers. Additionally, as a result of the acquisition of Kineta in June 2025, TuHURA will require additional capital for the investigation of TBS-2025 in a Phase 2 trial with a menin inhibitor in NPM1 mutated AML. If TuHURA obtains orphan drug designation and marketing approval for IFx, TBS-2025 or any of TuHURA’s product candidates, TuHURA expects to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution.

As of March 31, 2025, TuHURA had cash and cash equivalents of $6.2 million. TuHURA will continue to incur costs associated with its operations, as well as additional costs associated with operating as a public company. Accordingly, TuHURA will require substantial additional funding to continue its operations. Based on its current operating plan, TuHURA believes that its existing cash, cash equivalents and short-term investments should be sufficient to fund its operations through late fourth quarter of 2025. This estimate is based on assumptions that may prove to be materially wrong, and TuHURA could use its available capital resources sooner than it currently expects because of circumstances beyond its control. TuHURA may require additional capital for the further development and commercialization of TuHURA’s product candidates and may need to raise additional funds sooner if TuHURA chooses to pursue additional indications or geographies for its product candidates or otherwise expand more rapidly than it presently anticipates. Any additional fundraising efforts may divert TuHURA’s management from their day-to-day activities, which may adversely affect TuHURA’s ability to develop and commercialize its product candidates.

TuHURA cannot be certain that additional funding will be available on acceptable terms, or at all. TuHURA’s ability to raise additional funding will depend on financial, economic and market conditions and other factors, over which TuHURA may have no or limited control. In addition, TuHURA’s ability to obtain future funding when needed through equity financings, debt financings or strategic collaborations may be particularly challenging in light of the uncertainties and circumstances resulting from the ongoing military conflict between Russian and Ukraine, as well as the ongoing conflict between Israel and Hamas, and the global impacts of such conflicts. TuHURA has no committed source of additional capital and if it is unable to raise

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additional capital in sufficient amounts or on terms acceptable to the company, TuHURA may have to significantly delay, scale back or discontinue the development or commercialization of its product candidates or other research and development initiatives. TuHURA’s license and collaboration agreements may also be terminated if it is unable to meet the payment obligations under the agreements. TuHURA could be required to seek collaborators for its product candidates at an earlier stage than otherwise would be desirable or on terms that are less favorable than might otherwise be available or relinquish or license on unfavorable terms TuHURA’s rights to its product candidates in markets where it otherwise would seek to pursue development or commercialization itself.

Any of the above events could significantly harm TuHURA’s business, prospects, financial condition, and results of operations and cause the price of shares of TuHURA common stock to decline.

The biotechnology and immunotherapy industries are characterized by rapid technological developments and a high degree of competition. TuHURA may be unable to compete with more substantial enterprises.

The biotechnology and biopharmaceutical industries are characterized by rapid technological developments and a high degree of competition. As a result, TuHURA’s actual or proposed immunotherapies could become obsolete before TuHURA recoups any portion of TuHURA’s related research and development and commercialization expenses. Competition in the biopharmaceutical industry is based significantly on scientific and technological factors. These factors include the availability of patent and other protection for technology and products, the ability to commercialize technological developments and the ability to obtain governmental approval for testing, manufacturing, and marketing. TuHURA competes with specialized biopharmaceutical firms in the United States, Europe and elsewhere, as well as a growing number of large pharmaceutical companies that are applying biotechnology to their operations. Many biopharmaceutical companies have focused their development efforts in the human therapeutics area, including cancer. Many major pharmaceutical companies have developed or acquired internal biotechnology capabilities or made commercial arrangements with other biopharmaceutical companies. These companies, as well as academic institutions, governmental agencies and private research organizations, also compete with TuHURA in recruiting and retaining highly qualified scientific personnel and consultants. TuHURA’s ability to compete successfully with other companies in the pharmaceutical field will also depend to a considerable degree on the continuing availability of capital to the company.

TuHURA is aware of certain investigational new drugs under development or approved products by competitors that are used for the prevention, diagnosis, or treatment of certain diseases TuHURA has targeted for drug development. Various companies are developing biopharmaceutical products that have the potential to directly compete with TuHURA’s immunotherapies even though their approach may be different. The competition comes from both biotechnology firms and from major pharmaceutical companies. Many of these companies have substantially greater financial, marketing, and human resources than TuHURA. TuHURA also experiences competition in the development of its immunotherapies from universities, other research institutions and others in acquiring technology from such universities and institutions.

In addition, certain of TuHURA’s immunotherapies may be subject to competition from investigational new drugs and/or products developed using other technologies, some of which have completed numerous clinical trials.

The successful development of immunotherapies is highly uncertain.

Successful development of biopharmaceuticals is highly uncertain and depends on numerous factors, many of which are beyond TuHURA’s control. Immunotherapies that appear promising in the early phases of development may fail to reach the market for several reasons including:

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Success in preclinical and early clinical studies does not ensure that large-scale clinical studies will be successful. Clinical results are frequently susceptible to varying interpretations that may delay, limit, or prevent regulatory approvals. The length of time necessary to complete clinical studies and to submit an application for marketing approval for a final decision by a regulatory authority varies significantly from one immunotherapy to the next and may be difficult to predict. The evidence of clinical response rates received to date for IFx-2.0, TuHURA’s principal product candidate, as well as the other clinical activity and results described in this prospectus, does not mean that IFx-2.0 or any other product candidate has demonstrated, or that such clinical response data will predict, sufficient clinical efficacy and prove the required level of safety in order to receive FDA approval or any other required regulatory approval.

In addition, we have entered into a Special Protocol Assessment (“SPA”) with the FDA for a single Phase 3 randomized placebo and injection controlled trial for IFx-2.0, our lead innate immune agonist, as an adjunctive therapy to pembrolizumab (Keytruda^®) in the first line treatment of patients with advanced or metastatic Merkel cell carcinoma, who are checkpoint inhibitor-naïve utilizing the FDA’s accelerated approval pathway. A Special Protocol Assessment agreement is a binding written agreement between the FDA and a trial sponsor that indicates the study’s design and analysis are adequate to support an application submission. A Special Protocol Assessment agreement does not increase the likelihood of marketing approval for the product and may not lead to a faster or less costly development, review, or approval process. We initiated the Phase 3 trial in June 2025.

Even if TuHURA is successful in getting market approval, commercial success of any of its product candidates will also depend in large part on the availability of coverage and adequate reimbursement from third-party payors, including government payors such as the Medicare and Medicaid programs and managed care organizations, which may be affected by existing and future health care reform measures designed to reduce the cost of health care. Third-party payors could require TuHURA to conduct additional studies, including post-marketing studies related to the cost effectiveness of a product, to qualify for reimbursement, which could be costly and divert TuHURA’s resources. If government and other health care payors were not to provide adequate coverage and reimbursement levels for any of TuHURA’s products once approved, market acceptance and commercial success would be reduced.

TuHURA’s technology platforms, including its proprietary, multi-indication immunomodulatory platform (ImmuneFx IFx, and Delta receptor targeting ADCs) technologies are a new approach to treat cancer and other immune-related diseases that present significant challenges.

TuHURA has concentrated its research and development efforts on advancing a new generation of immunotherapies based on the IFx and Delta receptor antibody drug conjugates (“ADC”) platforms, and its future success is highly dependent on the successful development of its product candidates, which target cancer and other immune-related diseases. TuHURA cannot be sure that its IFx or Delta receptor ADC platforms will yield satisfactory products that are safe and effective, scalable, or profitable.

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TuHURA’s technology could become subject to many of the challenges and risks that gene therapies face, including:

Moreover, public perception of therapy safety issues, including adoption of new therapeutics or novel approaches to treatment, may adversely influence the willingness of subjects to participate in clinical trials, or if approved, of physicians to subscribe to the novel treatment mechanics. Physicians, hospitals and third-party payors often are slow to adopt new products, technologies and treatment practices that require additional upfront costs and training. Physicians may not be willing to undergo training to adopt this novel and personalized therapy, may decide the therapy is too complex to adopt without appropriate training and may choose not to administer the therapy. Based on these and other factors, hospitals and payors may decide that the benefits of this new therapy do not or will not outweigh its costs.

TuHURA’s near-term ability to generate product revenue is dependent on the success of one or more of its product candidates, each of which are at an early stage of development and will require significant additional clinical testing before it can seek regulatory approval and begin commercial sales.

TuHURA’s near-term ability to generate product revenue is highly dependent on its ability to obtain regulatory approval of and successfully commercialize one or more of its product candidates. IFx-2.0 and IFx-Hu3.0 are in late and early stages, respectively, of development and will require additional clinical and nonclinical development, regulatory review, and approval in each jurisdiction in which TuHURA intends to market the products, substantial investment, access to sufficient commercial manufacturing capacity, and significant marketing efforts before it can generate any revenue from product sales. Additionally, TuHURA is investigating TBS-2025 in a randomized Phase 2 trial and will require additional capital before it can generate any revenue from product sales. Before obtaining marketing approval from regulatory authorities for the sale of TuHURA’s product candidates, TuHURA must conduct extensive clinical trials to demonstrate the safety, purity, and potency of the product candidates in humans. TuHURA cannot be certain that any of its product candidates will be successful in clinical trials and they may not receive regulatory approval even if they are successful in clinical trials.

Before TuHURA can generate any revenues from sales of its lead product candidates, it must complete the following activities for each of them, any one of which it may not be able to successfully complete:

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If TuHURA is unable to address one or more of these factors in a timely manner or at all, it could experience significant delays in the successful commercialization of, or an inability to successfully commercialize, TuHURA’s product candidates, which would materially harm its business. If TuHURA does not receive regulatory approvals for one or more of its product candidates, TuHURA may not be able to continue its operations. Even if TuHURA successfully obtains regulatory approvals to manufacture and market its product candidates, its revenues will be dependent, in part, upon the size of the markets in the territories for which it gains regulatory approval and has commercial rights. If the markets for patient subsets that TuHURA is targeting are not as significant as it estimates, TuHURA may not generate significant revenues from sales of such products, if approved.

TuHURA may encounter substantial delays in its clinical trials or may not be able to conduct its trials on the timelines it expects.

Clinical testing is expensive, time consuming, and subject to uncertainty. TuHURA cannot guarantee that any clinical trials will be conducted as planned or completed on schedule, if at all. A failure of one or more clinical trials can occur at any stage of testing, and TuHURA’s future clinical trials may not be successful. Events that may prevent successful or timely completion of clinical development include:

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For example, TuHURA’s IND for its planned Phase 3 trial for IFx-2.0 contemplated by its SPA agreement with the FDA was subject to a partial clinical trial hold as described in a January 2024 letter from the FDA that relates to certain CMC matters for the trial. The FDA lifted the partial clinical hold and TuHURA initiated the Phase 3 trial in June 2025. A partial clinical hold means that the FDA suspends part of the clinical work requested under an IND (i.e., a specific protocol or part of a protocol is not allowed to proceed). The partial hold requires TuHURA to provide additional CMC information from its contract manufacturers for the Phase 3 trial, complete and qualify a potency assay, and qualify the mixing process for IFx-2.0 at the clinical site prior to initiating the trial. Although TuHURA currently is working with its contract manufacturers to provide the additional required information, and has planned and is undertaking ongoing in vitro testing, development, and validation intended to address the other requirements, there is no assurance that TuHURA will be able to complete these requirements on a timely basis, which could delay TuHURA’s expected timetable to complete the trial, or if TuHURA is unable to complete these requirements, TuHURA will not be able to proceed with the trial.

Many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of marketing approval for TuHURA’s product candidates.

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Any inability to successfully complete preclinical and clinical development could result in additional costs to TuHURA or impair its ability to generate revenue. In addition, if TuHURA makes manufacturing or formulation changes to its product candidates, TuHURA may be required to, or it may elect to, conduct additional trials to bridge its modified product candidates to earlier versions. Clinical trial delays could also shorten any periods during which TuHURA’s products have patent protection and may allow its competitors to bring products to market before TuHURA does, which could impair its ability to successfully commercialize its product candidates and may harm its business and results of operations.

If TuHURA does not achieve its projected development and commercialization goals in accordance with its expected and announced timeframes, the commercialization of any of its product candidates may be delayed, and its business will be harmed.

TuHURA has provided timing estimates regarding the initiation of clinical trials and clinical development milestones, and the expected availability of data resulting from these trials for certain of TuHURA’s product candidates. TuHURA expects to continue to estimate the timing of these types of development milestones and its expected timing for the accomplishment of various other scientific, clinical, regulatory, and other product development objectives. From time to time, TuHURA may publicly announce the expected timing of some of these events. However, the achievement of many of these milestones and events may be outside of TuHURA’s control. These timing estimations are based on a variety of assumptions TuHURA makes, which may cause the actual timing of these events to differ from the timing it expects, including:

If TuHURA fails to timely achieve announced milestones, the commercialization of any of its product candidates may be delayed, and its business and results of operations may be harmed.

Failure to successfully identify, develop, and commercialize additional therapeutics or product candidates could impair TuHURA’s ability to grow.

Although a substantial amount of TuHURA’s efforts will focus on the continued preclinical and clinical testing and potential approval of the product candidates in the company’s current pipeline, TuHURA expects to continue to innovate and potentially expand its portfolio. Research programs to identify product candidates may require substantial additional technical, financial, and human resources and may not result in any new potential product candidates being identified. TuHURA’s success may depend, in part, upon its ability to identify, select, and develop promising product candidates and therapeutics. TuHURA may expend resources and ultimately fail to discover and generate additional product candidates suitable for further development. All product candidates are prone to risks of failure typical of biotechnology product development, including the possibility that a product

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candidate may not be suitable for clinical development due to its harmful side effects, limited efficacy, or other characteristics indicating that it is unlikely to receive approval by the FDA, the EMA, and other comparable foreign regulatory authorities and achieve market acceptance. If TuHURA does not successfully develop and commercialize new product candidates it has identified and explored, TuHURA’s business, prospects, financial condition, and results of operations could be adversely affected.

The FDA or comparable foreign regulatory authorities may disagree with TuHURA’s regulatory plans and TuHURA may fail to obtain regulatory approval of TuHURA’s product candidates.

The FDA standard for regular approval of a biologic generally requires two well-controlled Phase 3 studies or one large and robust, well-controlled Phase 3 study in the patient population being studied that provides substantial evidence that a biologic is safe and effective for its proposed indication. Phase 3 clinical trials typically involve hundreds of patients, have significant costs, and take years to complete. Product candidates studied for their safety and effectiveness in treating serious or life-threatening illnesses and that provide meaningful therapeutic benefit over existing treatments may be eligible for accelerated approval and may be approved on the basis of adequate and well-controlled clinical trials establishing that the product candidate has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity or prevalence of the condition and the availability or lack of alternative treatments. As a condition of accelerated approval, the FDA may require a sponsor of a drug or biologic receiving accelerated approval to perform post-marketing studies to verify and describe the predicted effect on irreversible morbidity or mortality or other clinical endpoint, and the drug or biologic may be subject to withdrawal procedures by the FDA that are more accelerated than those available for regular approvals. Recently, TuHURA entered into the SPA agreement with the FDA for a single Phase 3 randomized placebo and injection controlled trial for IFx-2.0. TuHURA initiated the Phase 3 trial in June 2025. If TuHURA’s efforts to obtain approval for IFx-2.0 or any other product candidate is not successful, then TuHURA may be required to conduct additional clinical trials beyond those it contemplates, which would likely result in a longer time period to potential approval and commercialization of such product candidate (if approved) and would likely increase the cost of development of such product candidate, all of which could harm the company’s competitive position in the marketplace and shorten the remaining term of applicable patent coverage after product approval.

As part of its marketing authorization process, the EMA may grant marketing authorizations on the basis of less complete data than is normally required, when, for certain categories of medicinal products, doing so may meet unmet medical needs of patients and serve the interest of public health. In such cases, it is possible for the Committee for Medicinal Products for Human Use (“CHMP”), to recommend the granting of a marketing authorization, subject to certain specific obligations to be reviewed annually, which is referred to as a conditional marketing authorization. This may apply to medicinal products for human use that fall under the jurisdiction of the EMA, including those that aim at the treatment, the prevention, or the medical diagnosis of seriously debilitating diseases or life-threatening diseases and those designated as orphan medicinal products.

A conditional marketing authorization may be granted when the CHMP finds that, although comprehensive clinical data referring to the safety and efficacy of the medicinal product have not been supplied, all the following requirements are met:

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The granting of a conditional marketing authorization is restricted to situations in which only the clinical part of the application is not yet fully complete. Incomplete nonclinical or quality data may only be accepted if duly justified and only in the case of a product intended to be used in emergency situations in response to public-health threats.

Conditional marketing authorizations are valid for one year, on a renewable basis. The holder will be required to complete ongoing studies or to conduct new studies with a view to confirming that the benefit-risk balance is positive. In addition, specific obligations may be imposed in relation to the collection of pharmacovigilance data.

The granting of a conditional marketing authorization will allow medicines to reach patients with unmet medical needs earlier than might otherwise be the case and will ensure that additional data on a product are generated, submitted, assessed, and acted upon. Although TuHURA may seek a conditional marketing authorization for one or more of TuHURA’s product candidates by the EMA, the EMA or CHMP may ultimately not agree that the requirements for such conditional marketing authorization have been satisfied.

TuHURA’s clinical trial results may also not support approval, whether accelerated approval, conditional marketing authorizations, or regular approval. The results of preclinical studies and clinical trials may not be predictive of the results of later-stage clinical trials, and product candidates in later stages of clinical trials may fail to show the desired safety and efficacy despite having progressed through preclinical studies and initial clinical trials. In addition, TuHURA’s product candidates could fail to receive regulatory approval for many reasons, including the following:

Further, failure to obtain approval for any of the above reasons may be made more likely due to the novel nature of TuHURA’s technology. Failure to obtain regulatory approval to market any of TuHURA’s product candidates would significantly harm its business, results of operations, and prospects.

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TuHURA’s clinical trials may fail to demonstrate adequately the safety and efficacy of its product candidates, which would prevent or delay regulatory approval and commercialization.

The clinical trials of TuHURA’s product candidates are, and the manufacturing and marketing of its products will be, subject to extensive and rigorous review and regulation by numerous government authorities in the United States and in other countries where TuHURA intends to test and market its product candidates. Before obtaining regulatory approvals for the commercial sale of any of its product candidates, TuHURA must demonstrate through lengthy, complex, and expensive preclinical testing and clinical trials that its product candidates are both safe and effective for use in each target indication. In particular, because its product candidates are subject to regulation as biological drug products, TuHURA will need to demonstrate that they are safe, pure, and potent for use in their target indications. Each product candidate must demonstrate an adequate risk versus benefit profile in its intended patient population and for its intended use. The risk/benefit profile required for product licensure will vary depending on these factors and may include not only the ability to show tumor shrinkage, but also adequate duration of response, a delay in the progression of the disease, and/or an improvement in survival. For example, response rates from the use of TuHURA’s product candidates may not be sufficient to obtain regulatory approval unless TuHURA can also show an adequate duration of response. Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. Failure can occur at any time during the clinical trial process. The results of preclinical studies and early clinical trials of TuHURA’s product candidates may not be predictive of the results of later-stage clinical trials. The results of studies in one set of patients or line of treatment may not be predictive of those obtained in another. TuHURA expects there may be greater variability in results for products processed and administered on a patient-by-patient basis, as anticipated for its product candidates, than for “off-the-shelf” products, like small molecule drugs which are not personalized for each patient. There is typically an extremely high rate of attrition from the failure of product candidates proceeding through clinical trials. Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy profile despite having progressed through preclinical studies and initial clinical trials. Many companies in the biopharmaceutical industry have suffered significant setbacks in advanced clinical trials due to lack of efficacy or unacceptable safety issues, notwithstanding promising results in earlier trials. Most product candidates that begin clinical trials are never approved by regulatory authorities for commercialization.

In addition, even if TuHURA’s clinical trials are successfully completed, TuHURA cannot guarantee that the FDA or foreign regulatory authorities will interpret the results as TuHURA does, and more trials could be required before TuHURA submits its product candidates for approval. To the extent that the results of the trials are not satisfactory to the FDA or foreign regulatory authorities for support of a marketing application, TuHURA may be required to expend significant resources, which may not be available to it, to conduct additional trials in support of potential approval of its product candidates.

TuHURA’s product candidates may cause undesirable side effects or have other properties that could halt their clinical development, prevent their regulatory approval, limit their commercial potential, or result in significant negative consequences.

As with most biological products, use of TuHURA’s product candidates could be associated with side effects or adverse events, which can vary in severity from minor reactions to death and in frequency from infrequent to prevalent. Undesirable side effects or unacceptable toxicities caused by TuHURA’s product candidates could cause TuHURA or regulatory authorities to interrupt, delay, or halt clinical trials.

The FDA or comparable foreign regulatory authorities could delay or deny approval of TuHURA’s product candidates for any or all targeted indications and negative side effects could result in a more restrictive label for any product that is approved. Side effects such as toxicity or other safety issues associated with the use of TuHURA’s product candidates could also require TuHURA or its collaborators to perform additional studies or halt development or sale of these product candidates.

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If one or more of TuHURA’s product candidates receives marketing approval, and TuHURA or others later identify undesirable side effects caused by such products, including during any long-term follow-up observation period recommended or required for patients who receive treatment using TuHURA’s products, many potentially significant negative consequences could result, including: