Mitomycin Exhibits Sustained 24-Month Survival in NMIBC Population

Treatment with mitomycin (Zusduri) exhibited sustained event-free survival (EFS) among responders with low-grade intermediate-risk non-muscle invasive bladder cancer (NMIBC), according to findings from the phase 3 ENVISION trial (NCT05243550) published in The Journal of Urology.¹

Specifically, among 191 complete responders after 3 months of treatment in a population consisting of 240 patients (80%; 95% CI, 74%-85%), the 12- and 24-month EFS rates were 82% (95% CI, 76%-87%) and 72.2% (95% CI, 64%-79%), respectively. Additionally, the median duration of response (DOR) per Kaplan-Meier estimate was not estimable (NE; 95% CI, 29.6-NE). Moreover, complete responses (CRs) were sustained after an initial 3-month response at a rate of 76% (95% CI, 69%-82%) at 12 months and 59% (95% CI, 51%-66%) at 24 months.

An exploratory analysis examining outcomes among patients who underwent 1 or fewer (n = 123) or 2 or more transurethral resection of bladder tumor (TURBT) procedures (n = 68) showed respective 12- and 24-month EFS rates of 86% (95% CI, 79%-91%) and 75% (95% CI, 63%-84%) and 78% (95% CI, 68%-85%) vs 61% (95% CI, 47%-73%) in the respective arms. Moreover, among patients with single (n = 33) or multiple tumors at baseline (n = 158), the 12- and 24-month EFS rates were 87% (95% CI, 68%-95%) vs 81% (95% CI, 74%-87%) and 72% (95% CI, 52%-85%) vs 72% (95% CI, 63%-79%).

“The publication of these long-term data in The Journal of Urology provides important peer-reviewed validation of the durability of [mitomycin] treatment observed in the ENVISION trial,” said Sandip Prasad, MD, MPhil, director of Genitourinary Surgical Oncology and vice chair of Urology at Morristown Medical Center/Atlantic Health System in New Jersey, and principal investigator of the ENVISION trial, said in a news release on the findings.² “For patients who achieved a [CR], the likelihood of remaining event-free through 2 years was substantial, underscoring the potential of [mitomycin] to change the long-term management of this highly recurrent disease with a 6-week induction treatment alone without maintenance. For the first time, adult patients with recurrent [low-grade intermediate-risk] NMIBC have an FDA-approved therapy.”

Patients with a history of low-grade NMIBC requiring TURBT underwent 6 weekly intravesical instillations of mitomycin. Those who experienced a CR returned for follow-up every 3 months for a maximum of 24 months, and those who remained disease-free returned every 6 months for an additional 36 months thereafter. Patients did not receive maintenance treatment following the 6-week course of mitomycin.

The prespecified primary end point of the trial was the 3-month CR rate. A key prespecified secondary end point was DOR, with additional secondary end points including durable CR rate and safety. An exploratory analysis was DOR based on receipt of prior TURBT and number of tumors at baseline.

In the safety analysis, 143 patients (60%) experienced any-grade treatment-emergent adverse effects (TEAEs), including 82 (34%) experiencing treatment-related events. The most common AEs occurring in at least 10% of patients included dysuria, hematuria, urinary tract infection, increased creatinine, increased potassium, decreased hemoglobin, decreased lymphocytes, decreased neutrophils, increased eosinophils, and increased liver enzymes. AEs were largely mild to moderate in severity, according to investigators.

Serious TEAEs occurred in 38 (16%) patients. TEAEs leading to study discontinuation, treatment discontinuation, or death occurred in 4.6%, 2.9%, and 2.9% of patients. All deaths on study due to TEAEs were deemed unrelated to treatment study. Events included septic shock, acute myocardial infarction, pneumonia, cardiac failure, sepsis, cardiopulmonary failure, and an unknown cause.

“Now that the 24-month [DOR] data from ENVISION are published in a leading urology journal, we’re seeing even stronger validation of [mitomycin’s] clinical impact,” Mark Schoenberg, MD, chief medical officer at UroGen, stated in the release.² “As the first and only approved treatment for recurrent [low-grade, intermediate-risk] NMIBC, [mitomycin] gives patients a real chance at meaningful, recurrence-free periods. These results suggest we may finally be able to break the long-standing cycle of repeated recurrences and surgeries that has defined care for patients with recurrent [low-grade, intermediate-risk] NMIBC.”

References

1. Prasad SM, Shishkov D, Mihaylov NH, et al. UGN-102 for recurrent low-grade intermediate-risk non-muscle invasive bladder cancer: 24-month duration of response results from the phase 3 ENVISION trial. J Urol. PublishedMarch 25, 2026. doi:10.1097/JU.0000000000005041
2. Journal of Urology publishes ENVISION trial results showing 72.2% 24-month duration of response with Zusduri. News release. UroGen Pharma. March 30, 2026. Accessed March 30, 2026. https://tinyurl.com/4hakdsan