SUO 2022: Early Experience with UGN-101 for the Treatment of Upper Tract Urothelial Cancer – A Multi-Center Evaluation of Practice Patterns and Outcomes

( A poster session focusing on Bladder and Kidney cancer took place at the Annual Meeting of the Society of Urologic Oncology and in this session, Dr. Jacob Taylor presented the results of a multi-center study examining the early clinical experience with the use of UGN-101.

UGN-101 is a mitomycin-containing reverse thermal gel. This novel delivery system allows for the topical treatment of upper tract urothelial cancer (UTUC), addressing issues associated with dwell time for standard topical treatments in liquid formulation. UGN-101 provides a kidney-sparing alternative for patients with low grade, non-invasive tumors or in patients whose renal function would be severely compromised after nephroureterectomy. Following a pivotal, single arm trial, UGN-101 was approved for small volume residual low-grade UTUC. However, post-approval data are sparse. Therefore, these authors sought to report a multi-center experience with UGN-101 in a more heterogenous and real-world setting.

To do so, they performed a retrospective review of all patients treated with UGN-101 from 15 institutions with a focus on practice patterns, efficacy, and adverse effects. They considered patients who received UGN-101 in both the chemoablative and adjuvant setting. When considering characteristics and outcomes, they looked at demographic data, progression, and survival outcomes on per patient basis while tumor characteristics, treatment, and recurrence outcomes were examined on a per renal unit basis. In addition to these features, the authors collected data on adverse events were collected.

As of a database lock of February 20th, 2022, the authors identified 132 patients who received UGN-101 treatment in 136 renal units. The majority of cases (88%) were biopsy proven low-grade UTUC.

The authors identified significant variation in practice patterns, though more than half (57.4%) of patients had treatment administered via retrograde instillation. When utilized in the adjuvant setting, 69% of patients were disease free at the time of their first endoscopic evaluation, while in the chemoablative setting, 37% were endoscopically clear on the first evaluation, a difference that was statistically significant (p<0.001).

Not surprisingly, complete response was higher in patients with smaller tumor size prior to UGN-101 induction. In patients who had low volume (<1cm) residual disease prior to treatment, complete response rates were 70% while this fell to less than 25% in those with more than 3cm of tumor prior to treatment (Figure 1).UGN-101.jpg
When restricting their cohort to a subset similar to the OLYMPUS trial (in which the maximum tumor size was 1.5%), these results compare quite favourably as the complete response rate in the registration trial was 59%.

Among the 94 patients with biopsy proven LGTa disease who underwent at least one endoscopic evaluation following UGN-101 induction, 16 patients (17%) were reported to have progression of disease, with median progression free survival not reached. In terms of adverse events, the authors noted that 23% of patients had new onset, clinically significant ureteral stenosis.

Thus, the authors conclude that this report represents the largest cohort of patients treated with UGN-101. In real world practice, this approach was used in clinical contexts that differed from the registration trial including tumors below the UPJ, after complete endoscopic ablation, in tumors >1.5cm, and in rare cases for high-grade histology. This report is limited by a lack of centralized pathology review, inevitable under-staging, and short follow-up.

Presented by: Jacob Taylor MD, MPH, Chief Urology Resident at NYU Langone Health, Manhattan, NY