FDA Grants Orphan Drug Status to IFx-2.0 for Advanced Melanoma Care

The U.S. Food and Drug Administration (FDA) has granted orphan drug designation to the investigational therapy IFx-2.0 for the treatment of patients with stage 2B to stage 4 cutaneous melanoma.

The designation, awarded by the FDA Office of Orphan Products Development and announced in a news release issued by TuHURA Biosciences Inc., identifies the therapy as a potential treatment for a rare condition affecting fewer than 200,000 individuals in the United States. This regulatory milestone follows previous clinical data suggesting that the immune-priming agent may help patients with advanced skin cancer who have not responded to standard immunotherapy options.

Main data that support the findings

The FDA decision was based on data from a completed phase 1 study of IFx-2.0, with results published in the journal Molecular Therapeutics. The study, authored by Dr. Joseph Markowitz of the Moffitt Cancer Center and Research Institute, evaluated the therapy in patients with stage 2 to 4 melanoma.

Findings from this first-in-human trial demonstrated that patients who were refractory to checkpoint inhibitor therapy — specifically anti-PD1 treatments — experienced clinical benefit when they received subsequent anti-PD1 based treatment following IFx-2.0. This indicates that the therapy, an innate immune agonist, is designed to overcome primary resistance to immunotherapies. Primary and acquired resistance are the two most common reasons cancer treatments stop working or fail to work in the majority of patients with cancer.

By receiving orphan drug designation, TuHURA Biosciences is eligible for several benefits, including: seven years of market exclusivity, tax credits for certain research, research grants, increased engagement and assistance from the FDA and a waiver of the new drug application user fee.

Dr. James Bianco, president and chief executive officer of TuHURA Biosciences, stated in the news release that receiving orphan drug designation highlights IFx-2.0 as a potential new therapeutic approach in this patient population and underscores the significant need for new treatments in skin cancer.

IFx-2.0 is the lead innate immune agonist for TuHURA Biosciences, a phase 3 immuno-oncology company. While the new designation focuses on cutaneous melanoma, the company is currently prioritizing a single randomized placebo-controlled phase 3 registration trial of IFx-2.0 for a different skin cancer. This trial evaluates the therapy as an adjunctive treatment to Keytruda (pembrolizumab) compared to Keytruda plus a placebo for the first-line treatment of advanced or metastatic Merkel cell carcinoma.

The company is also developing other technologies to address immunotherapy resistance. Following a merger with Kineta Inc. on June 30, 2025, the company acquired TBS-2025, a VISTA-inhibiting monoclonal antibody moving into phase 2 development for certain types of leukemia. Additionally, TuHURA is leveraging delta opioid receptor technology to develop bi-specific antibody drug conjugates. These target myeloid derived suppressor cells to inhibit their immune-suppressing effects, which can prevent T cell exhaustion and acquired resistance to checkpoint inhibitors and cellular therapies.

Safety

The Phase 1 clinical trial of IFx-2.0 demonstrated that the treatment was safe for patients with stage 2 to 4 melanoma. According to the published results, there were no serious dose-limiting toxicities observed during the study.

Establishing a safety profile is a core requirement for the FDA's Office of Orphan Products Development, which grants status to drugs intended for the safe and effective treatment of rare diseases. The company continues to study the therapy to overcome primary resistance to checkpoint inhibitors, aiming to provide new options for patients who otherwise have limited success with current standard-of-care immunotherapies.

Reference:

1. “TuHURA Biosciences received FDA Orphan Drug Designation for IFx-2.0 for the Treatment of Stage IIB to Stage IV Cutaneous Melanoma,” news release.

Editor's note: This article is for informational purposes only and is not a substitute for professional medical advice, as your own experience will be unique. Use this article to guide discussions with your oncologist. Content was generated with AI and reviewed by a human editor.

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