UroGen's mitomycin shows durable response in Phase III ENVISION bladder cancer trial

Urogen reported three-year durability data from the ZUSDURI ENVISION trial reinforcing the clinical profile of mitomycin (Zusduri) as a non-surgical option for recurrent low-grade intermediate-risk non-muscle invasive bladder cancer. As per [a press release from the firm](https://www.globenewswire.com/news-release/2026/05/13/3293931/0/en/ZUSDURI-Median-Duration-of-Response-Still-Not-Reached-with-64-5-36-month-Duration-of-Response-in-the-Pivotal-ENVISION-Trial.html), the median duration of response was still unreached at a median follow-up of 35.5 months. The [Phase III ENVISION trial](https://app.allsci.com/clinical-trial/ASC-CT-0000000000585-1.0-1745615182) is a single-arm, multinational, multicenter pivotal study that enrolled 240 adults with recurrent LG-IR-NMIBC across 56 sites. Participants received six once-weekly intravesical instillations of Zusduri, administered in an outpatient setting via urinary catheter using UroGen Pharma's (Nasdaq: URGN) proprietary RTGel sustained-release hydrogel technology. A total 79.6% of patients achieved a complete response at three months, the trial's primary endpoint. Among those complete responders, the Kaplan-Meier estimated probability of remaining event-free at 36 months was 64.5% (95% CI, 54.6%–72.8%), and the median duration of response had not been reached. Notably, this durability was observed without maintenance therapy following the initial six-week treatment course. Serious adverse reactions occurred in 12% of patients, including urinary retention in 0.8% and urethral stenosis in 0.4%. The most common adverse reactions — occurring in 10% or more of patients — included dysuria, electrolyte and laboratory abnormalities, urinary tract infection, and hematuria, with the majority characterized as mild to moderate in severity. ## The demand for alternatives to surgery LG-IR-NMIBC affects approximately 82,000 people in the US each year, with an estimated 59,000 of those cases representing recurrent disease. The median age at diagnosis is 73 years, a demographic that carries elevated surgical risk from comorbidities and cumulative anesthetic exposure. The current standard of care is transurethral resection of bladder tumor, or TURBT. Because up to 70% of NMIBC patients experience at least one recurrence, many undergo multiple TURBT procedures over their lifetime. The procedural cycle imposes a compounding burden: repeat surgeries, recovery periods, and the attendant risks that accumulate with each intervention, particularly in older patients. Zusduri's mechanism addresses this directly. Mitomycin is a bioreductive alkylating agent that crosslinks DNA strands, inhibiting replication and inducing apoptosis in tumor cells. Delivered intravesically via RTGel — a hydrogel that remains liquid at room temperature and transitions to a gel at body temperature — the formulation is designed to maximize bladder contact time and sustained drug exposure, a pharmacokinetic advantage over conventional aqueous mitomycin C solutions that are cleared more rapidly. Zusduri received US FDA approval in June 2025, becoming the first and only approved therapy with a label specifically written for recurrent LG-IR-NMIBC. That regulatory precision matters commercially: BCG and conventional intravesical mitomycin C, both guideline-supported in this population, carry broader NMIBC labels rather than the defined LG-IR-NMIBC subgroup classification. Neither is positioned as a chemoablative replacement for TURBT in the way Zusduri is. Conventional intravesical mitomycin C is typically administered as a single perioperative instillation within 24 hours of TURBT to reduce early recurrence — it is a post-surgical adjunct, not a primary treatment. BCG functions as adjuvant immunotherapy following resection, activating a T-cell-mediated granulomatous response to reduce recurrence and progression risk. Zusduri, by contrast, is designed to ablate existing tumors without surgery. UroGen has not announced a specific next data readout or regulatory milestone in this update. The 36-month ZUSDURI clinical trial results represent a durability follow-up from an already-approved product rather than a preapproval filing package, positioning the data primarily as a commercial and medical affairs asset. Continued follow-up from the ENVISION trial, with the median duration of response still not reached, will determine whether the 64.5% event-free rate at three years holds or improves as the dataset matures. *** This article was generated with AI assistance and reviewed and edited by the AllSci editorial team Explore more at AllSci News: [https://allsci.com/news/](https://allsci.com/news/) --- Spot something wrong? [Report an issue with this article](https://newsgen-prod.reframedata.com/feedback/mitomycin-bladder-cancer-phase-iii-urogens-shows)