Mitomycin intravesical solution (Zusduri) demonstrates significant efficacy in recurrent low-grade intermediate-risk NMIBC, achieving a 78% complete response rate at 3 months with durable responses lasting ≥12 months in 79% of responders. This FDA-approved treatment offers a new therapeutic option for patients who have failed prior TURBT, though monitoring for genitourinary toxicities is essential.
Study Design & Population
- Single-arm, multicenter trial (ENVISION, NCT05243550)
- 240 enrolled patients, 223 evaluable for response
- Adult patients with low-grade NMIBC recurrent after prior TURBT
- Intermediate-risk criteria: multiple tumors, solitary tumor >3 cm, and/or recurrence within 1 year
- Treatment: 75 mg mitomycin instilled weekly × 6 weeks
Key Findings
- Complete response rate: 78% (95% CI: 72-83%) at 3 months
- Duration of response: 0 to 25+ months
- 79% of responders maintained response for ≥12 months
- Assessment via cystoscopy, urine cytology, and for-cause biopsy every 3 months
Clinical Implications
- Provides new treatment option for recurrent LG-IR-NMIBC after failed TURBT
- High response rate with durable responses supports use in intermediate-risk disease
- Weekly 6-week regimen offers standardized treatment protocol
Limitations
- Single-arm design without comparator group limits interpretation
- 12% serious adverse reaction rate including urinary retention and urethral stenosis
- One fatal cardiac event raises concern for systemic absorption effects
- Long-term durability data beyond 25 months not yet available
