Intravesical mitomycin (UGN-102) has shown a significant duration of response (DOR) in patients with low-grade intermediate-risk non-muscle-invasive bladder cancer (LG-IR-NMIBC) who achieved a complete response (CR), according to data from the phase 3 ENVISION trial (NCT05243550). The study results indicate a robust and durable response, potentially offering a new non-surgical treatment option for this patient population.
Durable Response Rates
The 12-month DOR in patients who received intravesical mitomycin and achieved a CR at 3 months (n = 108) was 82.3% (95% CI, 75.9%-87.1%). The DOR estimates at 15 months (n = 43) and 18 months (n = 9) following the 3-month CR were both 80.9% (95% CI, 73.9%-86.2%). These findings suggest a sustained benefit from the treatment over time.
The ENVISION trial previously met its primary endpoint, demonstrating a CR rate of 79.6% (95% CI, 73.9%-84.5%) at 3 months following the first instillation.
Expert Commentary
"These data demonstrate that treatment with [intravesical mitomycin] results in a clinically meaningful CR rate and that the durability of the response in patients with LG-IR-NMIBC is robust," said Sandip Prasad, MD, MPhil, director of genitourinary surgical oncology, Morristown Medical Center/Atlantic Health System, New Jersey, and principal investigator of the ENVISION trial. "This study adds to the mounting evidence supporting [intravesical mitomycin] as a potentially valuable treatment option for patients with recurrent LG-IR-NMIBC."
Regulatory Milestone
In October 2024, the FDA accepted the new drug application of intravesical mitomycin for this patient population, setting a Prescription Drug User Fee Act target action date of June 13, 2025.
About the ENVISION Study
The phase 3 ENVISION study enrolled approximately 220 patients with LG-IR-NMIBC across 65 global sites. Participants received six once-weekly intravesical instillations of mitomycin. Intermediate-risk disease was defined as the presence of multiple tumors, a solitary tumor greater than 3 cm, and/or early or frequent recurrence within 1 year of the current diagnosis. Key exclusion criteria included prior Bacillus Calmette-Guérin treatment within 1 year, a history of high-grade bladder cancer in the past 2 years, or a history of muscle-invasive disease.
Intravesical mitomycin utilizes a sustained-release hydrogel-based formulation, designed to prolong drug exposure to bladder tissue without requiring surgery. The agent is administered via catheter in an outpatient setting. The study's primary endpoint was CR rate, with secondary endpoints including DOR, durable CR rate, disease-free survival, and the incidence of treatment-emergent adverse events.
