Larotaxel with Cisplatin in the First-Line Treatment of Locally Advanced/Metastatic Urothelial Tract or Bladder Cancer: A Randomized, Active-Controlled, Phase III Trial (CILAB)

Abstract

Background: This open-label, randomized phase III trial evaluated larotaxel/cisplatin versus gemcitabine/cisplatin as first-line treatment for locally advanced (T4b) or metastatic urothelial tract or bladder cancer. Methods: Patients were randomized to larotaxel 50 mg/m² with cisplatin 75 mg/m² every 3 weeks (larotaxel/cisplatin) or gemcitabine 1,000 mg/m² on days 1, 8, and 15 with cisplatin 70 mg/m² on day 1 every 4 weeks (gemcitabine/cisplatin). The primary endpoint was overall survival (OS). Results: The trial was prematurely closed following the sponsor's decision to stop clinical development of larotaxel (n = 337 randomized). The larotaxel dose was reduced to 40 mg/m² and cisplatin to 60 mg/m² following a data monitoring committee safety review of the first 97 patients. At the time of analysis, the median OS was 13.7 months [95% confidence interval (CI) 11.2-17.1] with larotaxel/cisplatin and 14.3 months (95% CI 10.5 to not reached) with gemcitabine/cisplatin [hazard ratio (HR) 1.21; 95% CI 0.83-1.76; p = 0.33]. The median progression-free survival (PFS) was 5.6 months (95% CI 4.1-6.2) with larotaxel/cisplatin and 7.6 months (95% CI 6.6-9.1) with gemcitabine/cisplatin (HR 1.67; 95% CI 1.24-2.25). More myelosuppression was observed with gemcitabine/cisplatin. Conclusion: There was no difference in OS. Although the trial was closed prematurely, PFS appeared worse with larotaxel/cisplatin, suggesting that larotaxel/cisplatin does not improve outcomes versus cisplatin/gemcitabine.