(UroToday.com) The 2025 GU ASCO annual meeting featured a urothelial carcinoma session and a presentation by Dr. Sandip Prasad discussing a substudy of the phase 3 ENVISION trial assessing the impact of tumor burden or focality in recurrent low-grade intermediate-risk non-muscle-invasive bladder cancer on response to treatment with UGN-102.
The ENVISION phase 3 study treated patients with low-grade intermediate-risk non-muscle-invasive bladder cancer with UGN-102, a reverse thermal hydrogel containing mitomycin. Primary efficacy and safety results were previously reported, including a complete response rate at 3 months of 79.6%, with an 82.3% probability of remaining in response 12 months later by Kaplan-Meier estimate.1 Dr. Prasad and colleagues subsequently conducted a post-hoc analysis to evaluate if certain tumor characteristics influenced response rate and durability.
In the single-arm ENVISION study, 240 patients with low-grade intermediate-risk non-muscle-invasive bladder cancer received 6 weekly intravesical instillations of UGN-102. Three months after the first dose, patients were examined for the presence of bladder cancer using cystoscopy, urine cytology testing, and for-cause biopsy. Patients achieving complete response (no detectable disease) entered the follow-up period and were surveilled regularly for recurrence:
Between group comparisons were performed for complete response rate at 3 months and duration of response 12 months after achieving complete response in patients with tumor burden ≤ or >3 cm (calculated as total length of all tumors), and for single versus multiple tumors.
In patients with multiple versus single tumors, the 3 month complete response rate was 79.3% versus 82.9% respectively, with recurrence rates of 18.5% versus 11.8%, respectively:
Complete response rate at 3 months was 82.8% versus 73.2% for patients with tumor burden ≤3 cm and >3 cm, respectively. Of the patients with complete response at 3 months, 15.4% versus 20% experienced recurrence of low grade disease, progression (either in stage or grade), or death by 15 months. Duration of response hazard ratios were not statistically significant for any comparison made:
Study limitations were the small sample size of the comparator groups, single arm design, and post-hoc nature of the analysis.
Dr. Prasad concluded his presentation discussing a substudy of the phase 3 ENVISION trial assessing the impact of tumor burden or focality in recurrent low-grade intermediate-risk non-muscle-invasive bladder cancer on response to treatment with UGN-102 with the following take-home points:
- Treatment with UGN-102 resulted in a high, clinically meaningful complete response rate in patients with low-grade intermediate-risk non-muscle-invasive bladder cancer, and there was no significant difference in complete response rate or duration of response at 12 months based on tumor burden or focality
- These results should be interpreted with caution, given the small sample sizes of the comparator groups
- UGN-102 may represent a valuable treatment option for many patients with low-grade, intermediate-risk non-muscle-invasive bladder cancer
Presented by: Sandip M. Prasad, MD, Atlantic Medical Center, Morristown, NJ
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Wellstar MCG Health, @zklaassen_md on Twitter during the 2025 Genitourinary (GU) American Society of Clinical Oncology (ASCO) Annual Meeting, San Francisco, CA, Thurs, Feb 13 – Sat, Feb 15, 2025.
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