TuHURA Biosciences Presents IFx-Hu2.0 Trial-in-Progress Poster at the 2025 American Society of Clinical Oncology Annual Meeting

Rhea-AI Summary

TuHURA Biosciences (NASDAQ:HURA) presented a Phase 3 trial-in-progress poster at ASCO 2025 for IFx-Hu2.0, a novel innate immune agonist being developed as adjunctive therapy with Keytruda in checkpoint inhibitor-naïve patients with advanced Merkel cell carcinoma (MCC). The Phase 3 trial, operating under FDA's Accelerated Approval Pathway and Special Protocol Assessment agreement, will enroll 118 patients across 22-25 U.S. sites. Previous Phase 1b results showed promising efficacy with a 63% overall response rate in MCC patients who progressed on prior therapy. The randomized, double-blinded trial will evaluate IFx-Hu2.0 (0.1mg) administered weekly for three weeks with pembrolizumab versus pembrolizumab plus placebo, with overall response rate as the primary endpoint.

Positive

• Phase 1b trial demonstrated strong 63% overall response rate with 2 complete responses and 5 partial responses
• Duration of responses ranging from 6 to 33 months with 5 ongoing responses
• FDA granted Special Protocol Assessment (SPA) agreement and Accelerated Approval Pathway
• Trial design can potentially satisfy both accelerated and regular approval without requiring post-approval confirmatory trial

Negative

• Current survival rate for MCC patients not responding to first-line checkpoint inhibitor therapy is poor at less than 30 months
• Trial is limited to only U.S. sites, potentially limiting global market access
• Relatively small trial size of 118 patients

Insights

Oncology Clinical Trials Expert

TuHURA's Phase 3 trial for IFx-Hu2.0 with FDA accelerated pathway shows promise for Merkel cell carcinoma with 63% response rate in Phase 1b.

TuHURA Biosciences has presented details of their Phase 3 trial for IFx-Hu2.0, an innate immune agonist designed to overcome resistance to cancer immunotherapy. The trial will evaluate IFx-Hu2.0 as an adjunctive therapy with pembrolizumab (Keytruda) in patients with advanced or metastatic Merkel cell carcinoma (MCC) who are checkpoint inhibitor-naïve.

The Phase 3 trial has secured both Accelerated Approval Pathway designation and a Special Protocol Assessment (SPA) agreement with the FDA, which significantly de-risks the regulatory pathway. These designations indicate the FDA has agreed with the trial design and endpoints, potentially enabling faster approval if successful.

The efficacy data from their Phase 1b trial is particularly noteworthy, showing a 63% overall response rate (2 complete responses, 5 partial responses) in MCC patients who had previously progressed on anti-PD-(L)1 therapy. The durability of responses ranged from 6 to 33 months, with 5 ongoing responses as of June 2024. This represents substantial activity in a challenging patient population with limited options.

The upcoming Phase 3 trial will enroll 118 checkpoint inhibitor-naïve patients across 22-25 U.S. sites, randomized 1:1 to receive either IFx-Hu2.0 (0.1 mg weekly for three weeks) plus pembrolizumab or placebo plus pembrolizumab. The primary endpoint is overall response rate, with progression-free survival as a key secondary endpoint.

The mechanism of IFx-Hu2.0 - activating the innate immune response to overcome primary resistance to checkpoint inhibitors - addresses a critical unmet need in MCC treatment, where patients who don't respond to first-line checkpoint inhibitors have poor survival (<30 months). This approach of enhancing response to pembrolizumab could potentially improve outcomes in this aggressive cancer.

Phase 3 IFx-Hu2.0 trial as an adjunctive therapy with Keytruda^® (pembrolizumab) in checkpoint inhibitor (CPI)-naïve patients with advanced or metastatic Merkel cell carcinoma (MCC) detailed in Trial in Progress Poster at ASCO

Phase 3 trial of IFx-Hu2.0 to be conducted under Accelerated Approval Pathway and Special Protocol Assessment (SPA) agreement with U.S. Food and Drug Administration (FDA)

TAMPA, Fla., June 2, 2025 /PRNewswire/ -- TuHURA Biosciences, Inc. (NASDAQ:HURA) ("TuHURA"), a Phase 3 immune-oncology company developing novel technologies to overcome resistance to cancer immunotherapy, today announced that Moffitt Cancer Center presented a Trial in Progress poster of the Company's planned Phase 3 accelerated approval trial at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting on June 1, 2025, in Chicago, Illinois.

The Company's poster, titled "Multicenter, randomized, double-blinded, placebo-controlled trial of IFx-Hu2.0 (IFx) as adjunctive therapy with pembrolizumab (pembro) in checkpoint inhibitor (CPI)-naïve patients with advanced or metastatic Merkel cell carcinoma (MCC)" details the Company's Phase 3 accelerated approval trial design of IFx-Hu2.0, its novel innate immune agonist. The Trial in Progress poster was presented by Andrew Brohl, M.D., Medical Oncologist at Moffitt Cancer Center, and highlighted the importance of innate immune system activation in Merkel cell carcinoma patients with primary resistance to checkpoint inhibitors (CPIs).

"Merkel cell carcinoma is a rare and aggressive tumor type. While checkpoint inhibitor therapy has markedly improved the outcome for patients with advanced or metastatic MCC, unfortunately for patients who don't respond to first line checkpoint inhibitor therapy the survival is poor at less than 30 months.¹ Based on the results from our Phase 1 clinical trials, IFx-Hu2.0 intralesional administration has demonstrated it can activate an innate immune response, resulting in the production and activation of tumor specific B cells and T cells, to overcome the primary CPI resistance in both advanced or metastatic MCC or melanoma," stated James Bianco, M.D., President and Chief Executive Officer of TuHURA Biosciences. "We believe we have provided data requested by the FDA that addresses the requirements listed in the partial clinical hold letter to allow us to initiate our Phase 3 accelerated approval trial this month. The FDA was constructive in the trial design, which can potentially satisfy both the requirements for accelerated and regular approval without the requirements for a post approval confirmatory trial. They continue to work with us under the SPA Agreement in preparing the trial's initiation."

In the Phase 1b trial of IFx-Hu2.0, MCC among patients who progressed on pembrolizumab (anti-PD-1) or avelumab (anti-PDL-1) therapy, weekly administration of IFx-Hu2.0 for up to 3 doses followed by rechallenge with anti-PD(L)-1 therapy, demonstrated an overall response rate of 63% (2CR, 5 PR) with duration of responses ranging from 6 to 33 months with 5 ongoing responses as of last follow-up in June 2024.  

The Company's Phase 3 accelerated approval trial of adjunctive IFx-Hu2.0, to be conducted under a SPA agreement with the U.S. FDA, will evaluate IFx-Hu2.0 (0.1 mg) as an adjunctive therapy administered weekly for three weeks concurrent to pembrolizumab (200 mg) Q3W, compared to the same pembrolizumab regimen plus placebo. The pivotal trial is expected to enroll 118 CPI-naïve patients with advanced or metastatic MCC across approximately 22 to 25 U.S. sites. Trial participants will be randomized on a 1:1 basis and receive CPI therapy for up to two years, or until disease progression or CPI related toxicities. The primary endpoint for the trial is overall response rate (ORR) with a key secondary endpoint of progression free survival (PFS). Other secondary endpoints are safety, duration of response, and overall survival. 

The Trial in Progress poster is available on the Scientific Publications page of TuHURA's website.

¹ Kacew et al. (2020). Predictors of immunotherapy benefit in Merkel cell carcinoma. Oncotarget, 11(47), 4401–4410. https://doi.org/10.18632/oncotarget.27823

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 is preparing to initiate 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 leveraging its Delta Opioid Receptor technology to develop first-in-class, bi-specific antibody drug conjugates and antibody peptide conjugates 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, Section 21E of the 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. Examples of such forward-looking statements include but are not limited to express or implied statements regarding TuHURA's expectations, hopes, beliefs, intentions or strategies regarding the future and include, without limitation, statements regarding TuHURA's IFx-Hu2.0 product candidate and anticipated Phase 3 trial and any developments or results in connection therewith and the anticipated regulatory pathway and timing thereof. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are 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 are described in detail in our registration statements, reports and other filings with the SEC, which are available on the combined company'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. Nothing herein shall constitute an offer to sell or the solicitation of an offer to buy any securities.

Investor Contact:

Monique Kosse
Gilmartin Group
Monique@GilmartinIR.com 

 

View original content to download multimedia:https://www.prnewswire.com/news-releases/tuhura-biosciences-presents-ifx-hu2-0-trial-in-progress-poster-at-the-2025-american-society-of-clinical-oncology-annual-meeting-302470640.html

SOURCE TuHURA Biosciences, Inc.

FAQ

What is the primary endpoint of HURA's Phase 3 IFx-Hu2.0 trial in Merkel cell carcinoma?

The primary endpoint is overall response rate (ORR), with progression-free survival (PFS) as a key secondary endpoint. Other secondary endpoints include safety, duration of response, and overall survival.

How many patients showed response in HURA's Phase 1b trial of IFx-Hu2.0?

In the Phase 1b trial, the overall response rate was 63%, with 2 complete responses (CR) and 5 partial responses (PR), with response duration ranging from 6 to 33 months.

How is IFx-Hu2.0 administered in HURA's Phase 3 trial?

IFx-Hu2.0 (0.1 mg) is administered weekly for three weeks concurrently with pembrolizumab (200 mg) given every three weeks.

How many sites and patients will be involved in HURA's Phase 3 trial?

The trial will enroll 118 checkpoint inhibitor-naïve patients across approximately 22 to 25 U.S. sites.

What regulatory designations has HURA received for the IFx-Hu2.0 trial?

The trial will be conducted under FDA's Accelerated Approval Pathway and has received a Special Protocol Assessment (SPA) agreement from the FDA.