UGN-501 enters phase 1 testing for recurrent non–muscle invasive bladder cancer

The first patient has been dosed in a phase 1 clinical trial evaluating UGN-501, an investigational oncolytic virus administered intravesically for the treatment of patients with recurrent non-muscle invasive bladder cancer (NMIBC).¹

UGN-501 is designed to selectively replicate within bladder tumor cells, inducing direct tumor cell destruction while also stimulating an antitumor immune response. The open-label, dose-escalation study will assess the agent's safety, tolerability, and pharmacokinetics and establish a recommended phase 2 dose.

“The first patient dosed with UGN-501 marks an important step in advancing this investigational therapy from nonclinical research into clinical evaluation,” said Mark Schoenberg, MD, Chief Medical Officer of UroGen, in the news release from the company.¹ “We can now begin to understand its safety and tolerability in patients with NMIBC and generate insights to guide its continued development. This progress brings us closer to our goal of expanding treatment options for patients with bladder cancer.”

Trial design and patient population

The phase 1 study (NCT07725796) is an open-label, dose-escalation trial enrolling approximately 30 adults with recurrent NMIBC through clinical trials sites across the US.² Eligible disease categories include high-grade Ta/T1 tumors and/or carcinoma in situ (CIS), as well as low-grade Ta/T1 disease.

Before receiving UGN-501, participants must undergo resection of all visible papillary tumors, with fulguration of obvious areas of CIS. Treatment consists of 6 once-weekly intravesical instillations of an aqueous formulation of UGN-501 during a 12-week induction period.

Patients without evidence of disease at week 12 may proceed to maintenance treatment. The maintenance regimen consists of 3 once-weekly instillations administered quarterly from month 3 through month 12. Treatment will continue until disease recurrence, disease progression, or death, whichever occurs first. A safety follow-up visit is planned at month 15.

The primary objectives are to characterize safety and tolerability, assess pharmacokinetics, and determine a recommended phase 2 dose. The study will also provide initial information about the feasibility of administering an oncolytic virus directly into the bladder.

An important distinction in the current development program is the formulation being evaluated. Although UroGen is conducting parallel nonclinical investigations of UGN-501 formulated with its proprietary reverse-thermal hydrogel technology, RTGel, the phase 1 trial is evaluating an aqueous formulation that does not contain RTGel.

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REFERENCES

1. UroGen announces first patient dosed in phase 1 trial of UGN-501, an investigational next-generation oncolytic virus for non-muscle invasive bladder cancer. News release. UroGen Pharma. November 2, 2026. Accessed November 4, 2026. https://investors.urogen.com/news-releases/news-release-details/urogen-announces-first-patient-dosed-phase-1-trial-ugn-501

2. A Phase 1 Dose-escalation Study of UGN-501 Administered Intravesically in Adult Participants With Recurrent NMIBC. ClinicalTrials.gov. Last updated October 13, 2026. Accessed November 4, 2026. https://clinicaltrials.gov/study/NCT07725796