San Diego, California, U.S., September 14, 2026
TuHURA Biosciences has announced that the U.S. Food and Drug Administration (FDA) has issued a “Study May Proceed” notice and cleared the Investigational New Drug (IND) application for TBS-2025, an investigational VISTA-inhibiting antibody being developed for molecularly defined subsets of acute myeloid leukemia (AML) and other hematologic malignancies. The regulatory milestone allows TuHURA to advance TBS-2025 into clinical development and initiate a first-in-human Phase 1/2 clinical trial. The investigational antibody is designed to target V-domain Ig suppressor of T-cell activation (VISTA), an immune checkpoint protein that can contribute to an immunosuppressive tumor microenvironment. The program is focused initially on patients with specific molecular characteristics, including NPM1-mutated AML, where TuHURA believes VISTA-directed treatment may offer a new therapeutic approach.
FDA Clearance Enables Clinical Evaluation
The FDA’s IND clearance represents a key regulatory milestone because it authorizes TuHURA to proceed with clinical investigation of TBS-2025 in human participants. The company’s planned Phase 1/2 study will evaluate the investigational antibody in patients with selected hematologic cancers and is expected to assess its safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary antitumor activity. The initial clinical development strategy will concentrate on molecularly defined patient populations, including NPM1-mutated AML. NPM1 mutations are among the most common genetic alterations identified in AML and can define biologically distinct patient populations. By selecting patients according to molecular characteristics, TuHURA aims to investigate whether VISTA inhibition can produce meaningful therapeutic activity in cancers with particular immune and biological features. The “Study May Proceed” notification indicates that the FDA has reviewed the IND submission sufficiently for the clinical study to move forward. However, IND clearance does not constitute FDA approval of TBS-2025, nor does it establish the therapy’s safety or efficacy. Those questions will be evaluated through the clinical development program.
TBS-2025 Targets the VISTA Immune Checkpoint
TBS-2025 is an investigational monoclonal antibody designed to inhibit VISTA, an immune checkpoint that has emerged as a potential target for cancer immunotherapy. VISTA is expressed on various immune cells and has been associated with suppression of T-cell activity within the tumor microenvironment. Blocking this pathway could potentially enhance immune-cell function and improve the ability of the immune system to recognize and attack malignant cells. TuHURA is developing TBS-2025 as part of its broader strategy to address cancers that may not respond adequately to currently available immunotherapies. The company believes that VISTA inhibition could be particularly relevant in hematologic malignancies characterized by an immunosuppressive microenvironment. The molecularly targeted development strategy is intended to identify patients most likely to benefit from treatment. In addition to NPM1-mutated AML, the planned clinical evaluation is expected to investigate other molecularly defined subsets of AML and blood cancers. This approach reflects the growing role of precision medicine in oncology, where genomic and molecular characteristics are increasingly used to guide clinical-trial enrollment and therapeutic development.
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Phase 1/2 Study to Establish Safety and Activity
With the FDA’s IND clearance now in place, TuHURA can move TBS-2025 toward its first clinical evaluation. Early-stage development will primarily focus on establishing an appropriate dose and characterizing the candidate’s safety and tolerability profile. Investigators will also assess pharmacological activity and look for preliminary signals of antitumor response. The Phase 1/2 design is expected to provide an opportunity to evaluate TBS-2025 across selected patient populations while informing subsequent dose-expansion and efficacy studies. Data generated during these early clinical stages will be important for determining whether VISTA-targeted immunotherapy can provide meaningful clinical benefit in AML and other hematologic malignancies. AML remains a serious and potentially life-threatening blood cancer, with outcomes varying substantially according to disease biology, genetic alterations, age and previous treatment. Patients with relapsed or refractory disease in particular continue to face significant therapeutic challenges, creating a need for new targeted and immune-based treatment strategies. The FDA clearance therefore marks an important transition for TuHURA’s TBS-2025 program, moving the candidate from preclinical development into human clinical testing. Future clinical data will determine whether inhibition of VISTA can translate into improved outcomes for molecularly selected AML patients and support progression into later-stage studies.
Source: TuHURA Biosciences press release
