Long-Term Outcomes of Primary Chemoablation of Low-Grade Upper Tract Urothelial Carcinoma With UGN-101, a Mitomycin Reverse Thermal Gel

Purpose:We evaluate long-term outcomes of primary chemoablation using a mitomycin reverse thermal gel (UGN-101) in patients with low-grade upper tract urothelial carcinoma.Materials and Methods:Patients who participated in the OLYMPUS trial (IRB No. TC-UT-03, NCT02793128) and achieved a complete response (CR) after 6 weekly doses of UGN-101 were followed up to 12 months after initial CR. Those with CR at study completion were eligible for long-term follow-up for up to 5 years or until disease recurrence, progression, or death.Results:Of the 71 patients enrolled in the OLYMPUS trial, 42 patients achieved CR 4 to 6 weeks after completing ≥ 1 instillation of UGN-101. Among the 41 patients followed after initial CR, median follow-up was 28.1 months (95% CI, 13.1-57.5), and median duration of response was 47.8 months (95% CI, 13.0-not estimable [NE]). Twenty patients (49%) had long-term follow-up (median 53.3 months [95% CI, 27.9-65.3]). Seventy-five percent of patients had no evidence of recurrence at the last follow-up, with median duration of response NE (95% CI, 43.5-NE) because of a low event rate.Conclusions:Primary intracavitary chemoablation with UGN-101 for low-grade upper tract urothelial carcinoma is associated with favorable long-term durability.