TuHURA Biosciences Receives Key U.S. Patent for its Groundbreaking Delta Opioid Receptor (DOR) Antibody Drug Conjugate (ADC) Technology

Patent discloses uses beyond ADCs, including autologous or allogeneic adoptive cellular immunotherapies like CAR-T,  Tregs or TIL cell therapies

TAMPA, Fla., Oct. 5, 2026 /PRNewswire/ -- TuHURA Biosciences, Inc. (NASDAQ:HURA) ("TuHURA" or the "Company"), a Phase 3 immuno-oncology company developing novel therapeutics to overcome resistance to cancer immunotherapy, today announced that the United States Patent and Trademark Office has issued U.S. Patent No. 12,734,168 entitled, "Delta Opioid Receptor Antagonists Reprogram Immunosuppresive Microenvironment to Boost Immunotherapy." The patent is directed to, among other things, administration of DOR antagonists to subjects having cancer associated with DOR expressing Myeloid Derived Suppressor Cells (MDSCs).  It is further directed to uses of a variety of DOR antagonist combination therapies in treating, inhibiting, reducing, ameliorating, and/or preventing cancer and/or metastasis.

"We are the first company to identify both the presence of and central role the DOR plays in modulating the ability of MDSCs to allow cancers to survive in an immunologic sanctuary. Inhibiting the DOR on MDSCs may allow cancer immunotherapies to work better and allow them to keep on working by removing their immunosuppressive shield thereby preventing cancer fighting T cells becoming exhausted. T cell exhaustion remains a major obstacle for cancer immunotherapies," said Dr. James Bianco, President and Chief Executive Officer of TuHURA Biosciences. "Further, we are pleased the patent covers uses of our DOR technology beyond ADCs and its potential application to other important classes of cancer immunotherapies, such as adoptive cellular immunotherapies like CAR-T, T  Tregs , or TIL cell therapies. Utilizing our patented DOR technology, we are excited about our progress in advancing our novel class of bi-functional, bi-specific immune modulating ADCs targeting the DOR on MDSCs toward proof-of-concept in preclinical models of blood-related cancers like AML and MDS."  

The patent, issued on September 15, 2026, covers administering a DOR antagonist to cancer subjects and  mediating immunosuppressive myelopoiesis.  Additionally, the patent discloses applications of DOR antagonists not only with bi-specific or bi-functional ADC technology,  but also  in the context of autologous or allogeneic adoptive cellular immunotherapies such as CAR-T, Treg or TIL cellular therapies. The patent term runs through 2043 before any patent term extension.  

About TuHURA Biosciences, Inc. 
TuHURA Biosciences, Inc. (Nasdaq: HURA) is a Phase 3 immuno-oncology company developing novel technologies to overcome primary and acquired resistance to cancer immunotherapy, two of the most common reasons cancer immunotherapies fail to work or stop working in the majority of patients with cancer.

TuHURA's lead innate immune agonist, IFx-2.0, is designed to overcome primary resistance to checkpoint inhibitors. TuHURA has initiated a single randomized placebo-controlled Phase 3 registration trial of IFx-2.0 administered as an adjunctive therapy to Keytruda^® (pembrolizumab) compared to Keytruda^® plus placebo in first-line treatment for advanced or metastatic Merkel Cell Carcinoma.

In addition to its innate immune agonist product candidates, TuHURA is developing TBS2025, a VISTA-inhibiting mAb moving into Phase 1b clinical trial in patients with mutNPM1 r/r AML, a molecularly defined subgroup of  AML. In addition, TuHURA is leveraging its Delta Opioid Receptor technology to develop first-in-class, bi-specific, bi-functional antibody drug conjugates (ADCs) targeting Myeloid-Derived Suppressor Cells to inhibit their immune-suppressing effects on the tumor microenvironment to prevent T cell exhaustion and acquired resistance to checkpoint inhibitors and cellular therapies. For more information, please visit www.tuhurabio.com and connect with TuHURA on Facebook, X, and LinkedIn.

Cautionary Statement Regarding Forward-Looking Statements
This press release contains certain "forward-looking statements" within the meaning of, and subject to the safe harbor created by, Section 27A of the Securities Act of 1933, as amended, Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995. These forward-looking statements are based only on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, projections, anticipated events and other future conditions. In some cases, you can identify these statements by forward-looking words such as "believe," "may," "will," "estimate," "continue," "anticipate," "intend," "could," "should," "would," "project," "plan," "expect," "goal," "seek," "future," "likely," or the negative or plural of these words or similar expressions. Our statements in this press release regarding our planned Phase1b study of TBS-2025 is an example of such forward-looking statements. You are cautioned that such statements are not guarantees of future performance and that actual results or developments may differ materially from those set forth in these forward-looking statements. Factors that could cause actual results to differ materially from these forward-looking statements include, among others, the risks associated conducting the planned Phase 1 study of TBS-2025 and the general risks associated with continuing the development of TBS-2025; risks related to patient enrollment, trial design, data outcomes and regulatory interactions; uncertainty regarding the timing and likelihood of regulatory approvals; and the other risks described from time to time in detail in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2025, as filed on March 31, 2026, and TuHURA's other reports and filings with the SEC from time to time, which are available on TuHURA's website and at www.sec.gov. 

The forward-looking statements and other information contained in this press release are made as of the date hereof, and TuHURA does not undertake any obligation to update publicly or revise any forward-looking statements or information, whether as a result of new information, future events or otherwise, unless so required by applicable securities laws.

Investor Contact:
Monique Kosse
Gilmartin Group
Monique@GilmartinIR.com