FDA Clears TuHURA Biosciences for Phase 1b Leukemia Drug Trial

TuHURA Biosciences has received FDA clearance to initiate a Phase 1b clinical trial for TBS-2025, a VISTA-inhibiting antibody designed to treat patients with relapsed or refractory mutNPM1 Acute Myeloid Leukemia (AML). The "Study May Proceed" notice confirms that the company's Investigational New Drug application has passed initial regulatory review, allowing the firm to begin testing in a patient population that has exhausted standard treatment options.

"As the only known company to advance a VISTA-inhibiting mAb through the FDA's IND process into a Phase 1b study in mut NPM1 AML, this is a major milestone for the Company and a testament to our commitment to advancing novel therapies to address the unmet needs of patients with AML," said Dr. James Bianco, President and Chief Executive Officer of TuHURA Biosciences.

Targeting Unmet Needs in AML

The trial focuses specifically on patients with mutNPM1 AML who have failed or relapsed following treatment with menin inhibitors. This subset represents a gap in current oncology care, as these patients lack approved or effective therapies after progressing through existing standards of care.

By targeting the VISTA (V-domain Ig suppressor of T cell activation) pathway, TBS-2025 aims to overcome immune suppression in the tumor microenvironment. While other checkpoint inhibitors have seen success in solid tumors, VISTA-targeting therapies are in early stages of clinical validation. This Phase 1b study serves as an evaluation of the antibody's potential efficacy in blood-related cancers.

The 'Study May Proceed' Mechanism

In the U.S. regulatory framework, the "Study May Proceed" notification follows a 30-day review period after a company submits an IND application. During this window, the FDA assesses the preclinical data, manufacturing quality, and the proposed study protocol to ensure that human subjects will not be exposed to unreasonable risks.

Receiving this notice indicates that the agency found the preclinical evidence sufficient to support initial human testing. The Phase 1b trial will be the first time TBS-2025 is evaluated in this specific molecularly defined subset of AML patients.

Market Context

TuHURA Biosciences (HURA) shares were trading at $2.06, up 1.48% as of September 16, 2026. The company is prioritizing the development of its pipeline as it seeks to address high-mortality blood cancers through its proprietary antibody platform.

The initiation of this trial marks a shift for the company from preclinical development into active clinical engagement. For patients with relapsed mutNPM1 AML, the trial provides a new avenue for intervention where current standard-of-care options have proven insufficient.