UroGen’s Five-Year Data Support Durable JELMYTO Responses

UroGen Pharma has reported final results from the five-year follow-up of the OLYMPUS study, showing sustained responses to JELMYTO (mitomycin) for pyelocalyceal solution in adults with low-grade upper tract urothelial carcinoma (LG-UTUC). Published in Therapeutic Advances in Urology, the findings provide additional evidence of long-term disease control among patients who achieved a complete response following treatment.

The results are relevant to patients with LG-UTUC for whom preserving the kidney is an important treatment consideration. However, the findings apply to patients who initially responded to treatment and should not be interpreted as outcomes for the entire population treated in OLYMPUS.

Long-Term Response Outcomes in OLYMPUS

Among the 41 patients who achieved a complete response following primary treatment in OLYMPUS, the median duration of response was 47.8 months. The median follow-up for this group was 28.1 months, with a 95% confidence interval (CI) of 13.1 to 60.1 months.

A subset of 20 patients entered the long-term follow-up study, with a median follow-up of 53.3 months (95% CI: 27.9 to 72.8). In this cohort, the median duration of response was not estimable, with a 95% CI ranging from 43.5 months to a non-estimable upper limit, because relatively few events had occurred.

As of March 2025, 15 of the 20 patients (75%) remained event-free. No progression to high-grade disease was observed in this long-term follow-up cohort.

These findings indicate that disease control can persist for several years in some patients who achieve a complete response to JELMYTO. However, the 75% event-free proportion reflects the 20 patients who entered extended follow-up, not all patients who received treatment. The small cohort and low event rate also limit the precision of the long-term estimates.

A median duration of response that is not estimable does not mean that responses will continue indefinitely. It indicates that the available events were insufficient to calculate the median reliably at the time of analysis.

Clinical Significance of Sustained Response

JELMYTO is a mitomycin-containing reverse thermal gel approved in the United States for adults with LG-UTUC. Its formulation is liquid when cooled and forms a semisolid gel at body temperature. Following administration into the upper urinary tract, the formulation enables local chemotherapy to remain in the collecting system for approximately four to six hours before dissolving and being cleared through normal urine flow.

The formulation is designed to deliver chemotherapy directly to the affected urinary tract, offering a kidney-sparing alternative for appropriately selected patients. JELMYTO can be administered retrogradely through a ureteral catheter or antegradely through a nephrostomy tube.

The long-term OLYMPUS findings are clinically relevant because treatment decisions in LG-UTUC must balance disease control with preservation of kidney function. Endoscopic treatment and nephroureterectomy, which involves removal of the kidney and ureter, are established management approaches, although their suitability depends on disease characteristics and individual patient factors.

Sustained responses following JELMYTO treatment may help inform decisions about kidney-sparing management. Nevertheless, the follow-up results do not establish superiority over surgical approaches, demonstrate that all patients can avoid surgery, or quantify a reduction in subsequent procedures.

Study Limitations and Further Evidence

The long-term findings should be interpreted in the context of the study population. Patients entering extended follow-up had already achieved a complete response, creating a selected group that may not represent the broader population with LG-UTUC. The analysis also involved only 20 patients, and the low number of events prevented estimation of the median response duration in that cohort.

The absence of observed progression to high-grade disease is encouraging, but it does not establish that such progression cannot occur with longer follow-up. Similarly, the reported efficacy outcomes alone do not establish long-term safety or provide a comparative assessment against other treatments.

UroGen has indicated that additional real-world evidence from the uTRACT Registry is expected. These data may provide further information on JELMYTO use beyond the clinical trial setting.

Clinical Interpretation

The five-year OLYMPUS follow-up supports the durability of response to JELMYTO among patients who initially achieved a complete response. The median response duration of 47.8 months in the 41-patient complete-response population and the 75% event-free proportion in the 20-patient long-term cohort provide complementary evidence of sustained disease control.

The findings strengthen the evidence base for considering JELMYTO as a kidney-sparing treatment option in appropriately selected adults with LG-UTUC. However, the small long-term cohort, selection of complete responders and low event rate mean that the results should be interpreted as evidence of durable response in a subset of patients rather than proof of long-term disease control for all treated patients.

Reference

UroGen’s Final Results from Olympus Five-Year Follow-Up Study Reinforces Durable Response with JELMYTO in Patients with Low-Grade Upper Tract Urothelial Cancer, Urogen Pharma, 28 October 2026

The OLYMPUS Study – Optimized DeLivery of Mitomycin for Primary UTUC Study (Olympus), ClinicalTrials.gov ID NCT02793128