Dr Sfakianos on Outcomes With Intravesical Mitomycin for Recurrent, Low-Grade, Intermediate-Risk NMIBC

"Of those patients who responded, the duration of response at 12 months was 80.6%. That was a very positive finding for this agent."

John Sfakianos, MD, associate professor of Urology and Urologic Oncology at the Icahn School of Medicine at Mount Sinai, discussed the affect of tumor burden and focality on outcomes with mitomycin intravesical solution (Zusduri; UGN-102) in patients with recurrent low-grade, intermediate-risk non–muscle-invasive bladder cancer (nMIBC), based on findings from a substudy of the phase 3 ENVISION trial (NCT05243550).

Findings presented during the 2025 ASCO Annual Meeting showed that intravesical mitomycin produced high complete response (CR) rates. At the data cutoff of October 2, 2024, 240 patients had been enrolled. At 3 months, the CR rate was 79.6% (95% CI, 73.9%-84.5%). Among patients achieving a CR, the estimated 18-month duration of response (DOR) rate was 80.6% (95% CI, 74.0%-85.7%). Non-CRs occurred in 20% of patients and included residual disease (15%), disease progression (2.9%), indeterminate response (0.83%), and missing data (2.1%). With a median follow-up of 18.7 months, the median DOR was not reached, reflecting sustained responses and limited recurrence.

Safety findings demonstrated that adverse effects (AEs) were generally mild to moderate and self-limiting. Treatment-emergent AEs occurred in 57% of patients, most frequently dysuria (23%), hematuria (8.3%), urinary tract infection (7.1%), pollakiuria (6.7%), fatigue (5.4%), and urinary retention (5.0%). Serious AEs were observed in 12% of patients; 2 cases—urinary retention and urethral stenosis—were considered treatment related. The substudy results support the potential of intravesical mitomycin as an effective, organ-sparing alternative to surgery, with consistent benefit observed across varying levels of tumor burden and focality.

On May 21, 2025 the FDA’s Oncologic Drugs Advisory Committee (ODAC) voted 5 to 4 against the risk/benefit profile of the mitomycin intravesical solution for this patient population, citing concerns surrounding the studies limited long-term follow-up data.

Following this vote, the FDA approved intravesical mitomycin for the treatment of this patient population on June 12, 2025.