A Multicenter Phase II Study of Modified FOLFIRINOX for First-line Treatment for Advanced Urachal Cancer (ULTMA; KCSG GU20-03)

Purpose To assess the efficacy and safety of the first-line modified FOLFIRINOX in patients with advanced urachal cancer. Materials and Methods The ULTIMA trial (NCT04611724) is a single-arm, open-label, multicenter phase II study evaluating modified FOLFIRINOX (Oxaliplatin 85 mg/m2 over 2 hours, Irinotecan 150 mg/m2 over 1.5 hours, Leucovorin 400 mg/m2 over 2 hours, and 5-FU 2400 mg/m2 over 46 hours) plus prophylactic pegteograstim in patients with recurrent or metastatic urachal cancer every 2 weeks for up to 12 cycles, or until disease progression or unacceptable toxicity. The primary endpoint was the objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and the incidence of febrile neutropenia. Results Between April 2021 and November 2023, 21 patients with advanced urachal cancer were enrolled across five cancer centers. The median age was 50 (28–68), with 15 male patients. The most common metastatic site was the lung (47.6%), followed by lymph nodes (38.1%) and peritoneal seeding (33.3%). Two patients and 11 patients achieved a complete and partial response, respectively, yielding an ORR of 61.9%. The study met its primary endpoint in the first stage. With a median follow-up of 23.3 months, the median PFS was 9.3 months (95% CI, 6.7–11.9), and the median OS was 19.7 months (95% CI, 14.3–25.1). The treatment regimen was well tolerated, with no unexpected adverse events, and no instances of febrile neutropenia or grade 4 adverse events. Conclusion In this preliminary analysis of ULTIMA trial, Modified FOLFIRINOX demonstrated a promising ORR and PFS in patients with advanced urachal cancer. Completing the full study is essential to confirm the potential role of this regimen in the management of advanced urachal cancer.