FDA greenlights phase 1 study of UGN-501 for NMIBC

The FDA has cleared an investigational new drug (IND) application for UGN-501, an investigational intravesical oncolytic virus for non–muscle invasive bladder cancer (NMIBC), allowing a first-in-human phase 1 clinical trial to proceed in the US.¹

According to UroGen Pharma, enrollment is expected to begin in the fourth quarter of 2026, with the study designed to evaluate the safety, tolerability, and feasibility of local intravesical administration in patients with NMIBC.

UGN-501 is an investigational next-generation oncolytic virus engineered to selectively replicate within tumor cells. According to the company, viral replication results in tumor cell destruction while simultaneously promoting an antitumor immune response. UroGen reported that non-clinical studies demonstrated cytotoxic activity across multiple bladder cancer cell lines representing a range of disease grades and stages.

"Patients with non-muscle invasive bladder cancer continue to face a significant risk of disease recurrence despite available treatment options," said Mark Schoenberg, MD, Chief Medical Officer of UroGen, in the news release.¹ "UGN-501 is an investigational next-generation oncolytic virus designed to selectively destroy tumor cells while generating an anti-tumor immune response. FDA clearance of the IND allows us to begin evaluating whether the encouraging non-clinical profile of UGN-501 can translate into a safe and meaningful therapeutic approach for patients with NMIBC. We look forward to initiating the phase 1 study and advancing our efforts to develop innovative treatment options for patients with bladder cancer."

Development pipeline

UGN-501 adds to UroGen's existing bladder cancer portfolio, which includes approved and investigational intravesical therapies for NMIBC.

In June 2025, the FDA approved mitomycin for intravesical solution (Zusduri; formerly UGN-102) for adults with recurrent low-grade, intermediate-risk NMIBC. The approval was based primarily on results from the phase 3 ENVISION trial (NCT05243550), in which 78% (95% CI, 72 to 83) of patients achieved a complete response (CR) at 3 months after the first instillation. Response durations ranged from 0 months to more than 25 months, and 79% of responders remained in CR at 12 months.²

UroGen is also developing UGN-103, a next-generation intravesical formulation of mitomycin, for recurrent low-grade, intermediate-risk NMIBC. According to the company, UGN-103 is intended to simplify preparation and administration compared with Zusduri while maintaining similar therapeutic activity. The agent is currently being evaluated in the phase 3 UTOPIA trial (NCT06331299), which reported interim data in November 2025. At 3 months, UGN-103 achieved a CR rate of 77.8% (95% CI, 68.3 to 85.5) in this patient population.³

REFERENCES

1. UroGen announces FDA clearance of the IND for UGN-501, an investigational next-generation oncolytic virus for non-muscle invasive bladder cancer. News release. UroGen Pharma. July 8, 2026. Accessed July 9, 2026. https://investors.urogen.com/news-releases/news-release-details/urogen-announces-fda-clearance-ind-ugn-501-investigational-next

2. FDA approves mitomycin intravesical solution for recurrent low-grade intermediate-risk non-muscle invasive bladder cancer. News release. US Food & Drug Administration. Published online and accessed June 12, 2025. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-mitomycin-intravesical-solution-recurrent-low-grade-intermediate-risk-non-muscle

3. UroGen reports 77.8% three-month complete response rate from phase 3 UTOPIA trial of UGN-103 and receives FDA agreement on NDA submission strategy in recurrent LG-IR-NMIBC based on UTOPIA trial. News release. UroGen Pharma Ltd. November 6, 2025. Accessed December 15, 2025. https://investors.urogen.com/news-releases/news-release-details/urogen-reports-778-three-month-complete-response-rate-phase-3