UroGen Pharma (URGN) stock was up 18% in premarket activity Monday, a day after it reported long-term data from a follow-up analysis of its phase 3 trial of urothelial cancer therapy Jelmyto showing treatment response duration of nearly four years.

The company said the study showed that 41 patients treated had a median duration of response of 47.8 months, with no significant difference in outcomes between those with new-onset disease and those with recurrent cancer.

The drugmaker said that while the overall trial demonstrated the potential of Jelmyto, the sub-analysis was post-hoc and may involve selection bias, as only some patients entered long-term follow-up.

UroGen has so far enrolled 251 patients at 22 sites as of April 2025 in the uTRACT Registry to understand Jelmyto's real-world impact.

Jelmyto, a reverse thermal gel formulation of mitomycin, was approved by the US Food and Drug Administration for low-grade upper tract urothelial cancer in 2020.