(UroToday.com) The 2025 GU ASCO annual meeting featured a urothelial carcinoma session and a presentation by Dr. Sandip Prasad discussing results of the phase 3 ATLAS and ENVISION studies assessing treatment of low-grade intermediate-risk non-muscle-invasive bladder cancer with UGN-102. Low grade intermediate risk non-muscle invasive bladder cancer is a persistent, recurrent cancer inadequately controlled by TURBT, which is the current standard of care. Patients often require multiple TURBTs under general anesthesia, which can be associated with complications, particularly in an elderly population. The ATLAS1 and ENVISION2 phase 3 studies treated patients with low-grade intermediate-risk non-muscle-invasive bladder cancer with UGN-102, a reverse thermal hydrogel containing mitomycin. The primary efficacy and safety results were previously reported for the individual studies, and at GU ASCO 2025 Dr. Prasad and colleagues reported additional data.
In the randomized controlled ATLAS study, patients with newly diagnosed or recurrent low-grade intermediate-risk non-muscle-invasive bladder cancer were randomized to 6 weekly intravesical instillations of UGN-102 (n = 142) or TURBT (n = 140). In the single-arm ENVISION study, patients with recurrent low-grade intermediate-risk non-muscle-invasive bladder cancer received 6 weekly intravesical instillations of UGN-102 (n = 240). In both trials, patients were examined for recurrence of bladder cancer using cystoscopy, urine cytology testing, and for-cause biopsy at 3 months, and in those with a complete response, at regular intervals thereafter. Duration of response was calculated using the Kaplan–Meier method:
In both studies (ATLAS, ENVISION) patients were mostly ≥65 years of age (60%, 68%), white (99%, 98%), and male (70%, 61%). In ENVISION, 79.6% had a complete response at 3 months, and 82.3% remained event free 12 months later, again with the majority of recurrences being low-grade disease. In the ATLAS study, 92 patients (64.8%) in the TURBT arm and 89 patients (63.6%) in the UGN-102 arm had a complete response at 3 months. Among patients achieving a complete response at 3 months in ATLAS, 79.7% in the UGN-102 arm versus 67.7% in the TURBT arm remained event free 12 months later, of which the majority had recurrence had low-grade disease:
The median duration of response was not estimable in any arm due to low recurrence rates, with a between arms hazard ratio in ATLAS of 0.46 (95% CI 0.24–0.86) favoring the UGN-102 arm. The most common adverse event with UGN-102 in both studies was dysuria, occurring in 30.4% in ATLAS and 22.5% in ENVISION.
Dr. Prasad concluded his presentation discussing results of the phase 3 ATLAS and ENVISION studies assessing treatment of low-grade intermediate-risk non-muscle-invasive bladder cancer with UGN-102 with the following take-home points:
- In both studies, complete response rate in patients initially treated with UGN-102 was robust, with the majority of patients remaining event-free at 12 months follow-up
- The 3 month complete response rate and probability of remaining in response by KM estimate later achieved with UGN-102 was consistent between both studies
- In ATLAS, UGN-102 was associated with a 54% reduction in risk of recurrence, progression, or death compared to TURBT
- These results demonstrate that treatment with UGN-102 results in a high and clinically meaningful durable complete response rate in patients with newly diagnosed or recurrent low-grade intermediate-risk non-muscle-invasive bladder cancer
- UGN-102 may represent a valuable non-surgical treatment option for these patients
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.
References:
- Prasad SM, Huang WC, Shore ND, et al. Treatment of low-grade intermediate-risk nonmuscle-invasive bladder cancer with UGN-102 +/- transurethral resection of bladder tumor compared to transurethral resection of bladder tumor monotherapy: A randomized, controlled, phase 3 trial (ATLAS). J Urol. 2023 Oct;210(4):619-629.
- Prasad SM, Shishkov D, Vladimirov Mihaylov N, et al. Primary Chemoablation of Recurrent Low-Grade Intermediate-Risk Nonmuscle-Invasive Bladder Cancer with UGN-102: A Single-Arm, Open-Label, Phase 3 Trial (ENVISION). J Urol. 2025 Feb;213(2):205-216.