Phase II study of everolimus in metastatic urothelial cancer

Objective To assess the efficacy and tolerability of everolimus in advanced urothelial carcimoma (UC). Patients and Methods The present study comprised a single-arm, non-randomized study in which all patients received everolimus 10mg orally once daily continuously (one cycle = 4 weeks). In total, 45 patients with metastatic UC progressing after one to four cytotoxic agents were enrolled between February 2009 and November 2010 at the Memorial Sloan-Kettering Cancer Center. The primary endpoints were 2-month progression-free survival (PFS) and the safety of everolimus, with the secondary endpoint being the response rate. A Simon minimax two-stage design tested the null hypothesis that the true two month PFS rate was 50%, as opposed to the alternative hypothesis of 70%. Results The most common grade 3/4 toxicities were fatigue, infection, anaemia, lymphopaenia, hyperglycaemia and hypophosphataemia. There were two partial responses in nodal metastases, with one patient achieving a 94% decrease in target lesions and remaining on drug at 26 months. An additional 12 patients exhibited minor tumour regression. There were 23 of 45 (51%) patients who were progression-free at 2 months with a median (95% CI) PFS of 2.6 (1.8-3.5) months and a median (95% CI) overall survival of 8.3 (5.5-12.1) months. No clear association was observed between mammalian target of rapamycin pathway marker expression and 2-month PFS. Conclusions Although everolimus did not meet its primary endpoint, one partial response, one near-complete response and twelve minor regressions were observed. Everolimus possesses meaningful anti-tumour activity in a subset of patients with advanced UC. Studies aiming to define the genetic basis of everolimus activity in individual responders are ongoing.