UGN-101 has been approved for the chemoablation of low-grade upper tract urothelial cancer (UTUC) involving the renal pelvis and calyces. Herein is the first reported cohort of patients with ureteral tumors treated with UGN-101.
We performed a retrospective review of patients treated with UGN-101 for UTUC at 15 high-volume academic and community centers focusing on outcomes of patients treated for ureteral disease. Patients received UGN-101 with either adjuvant or chemo-ablative intent. Response rates are reported for patients receiving chemo-ablative intent. Adverse outcomes were characterized with a focus on the rate of ureteral stenosis.
In a cohort of 132 patients and 136 renal units, 47 cases had tumor involvement of the ureter, with 12 cases of ureteral tumor only (8.8%) and 35 cases of ureteral plus renal pelvic tumors (25.7%). Of the 23 patients with ureteral involvement who received UGN-101 induction with chemo-ablative intent, the complete response was 47.8%, which did not differ significantly from outcomes in patients without ureteral involvement. Fourteen patients (37.8%) with ureteral tumors had significant ureteral stenosis at first post-treatment evaluation, however, when excluding those with pre-existing hydronephrosis or ureteral stenosis, only 5.4% of patients developed new clinically significant stenosis.
UGN-101 appears to be safe and may have similar efficacy in treating low-grade urothelial carcinoma of the ureter as compared to renal pelvic tumors.

UGN-101 is a novel delivery system for intracavitary treatment of upper tract urothelial cancer (UTUC). UGN-101 was approved based on a pivotal trial for small volume residual low-grade UTUC. Our aim was to report our experience with UGN-101 in a more heterogenous and real-world setting.
We performed a retrospective review of all UGN-101 cases from 15 institutions with a focus on practice patterns, efficacy, and adverse effects. We include UGN-101 utilization in both the chemoablative and adjuvant setting.
There were a total 136 renal units treated from 132 patients. The majority of cases were biopsy proven low-grade UTUC. Practice patterns varied considerably - the most common administration technique was antegrade instillation via a percutaneous nephrostomy. 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 (P < 0.001). Complete response was higher in patients with smaller tumor size prior to UGN-101 induction; low volume (<1 cm) residual disease was associated with a 70% complete response, similar to disease free rate at first endoscopic evaluation when UGN-101 was used in the adjuvant setting. The use of maintenance doses of UGN-101 was reported in 27% of cases. The overall incidence of new onset, clinically significant ureteral stenosis was 23%.
This study represents the largest review of patients treated with UGN-101 and can serve as a basis of ongoing hypotheses regarding treatment with UGN-101 for UTUC.