Phase II study of sunitinib in patients with metastatic urothelial cancer

No standard therapy exists for metastatic urothelial cancer (UC) that has progressed after initial chemotherapy. This trial was designed to assess the efficacy and tolerability of sunitinib in patients with advanced, previously treated UC.

In this phase II trial, 77 patients received sunitinib between September 2006 and January 2009 on one of two schedules (50 mg per day for 4 weeks on and 2 weeks off [cohort A], 37.5 mg per day continuously [cohort B]), using a Simon 2 stage design in each cohort separately.

A partial response was seen in three of 45 patients (95% CI, 1% to 18%) in cohort A, and in one of 32 patients (95% CI, 0% to 16%) in cohort B. Clinical regression or stable disease was achieved in 33 of 77 patients (43%). Tumor regression lasted between 0.6 and 23.4 months with 29% of patients achieving response lasting longer than 3 months. The progression-free survival (2.4 v 2.3 months; P = .4) and overall survival (7.1 v 6.0 months; P = .4) were similar in both cohorts. There was one treatment-related death, and 47 patients (33 cohort A, 24 cohort B) experienced grade 3 or 4 toxicity.

Sunitinib did not achieve the predetermined threshold of >or= 20% activity defined by Response Evaluation Criteria in Solid Tumors. However, antitumor responses were observed, identifying the vascular endothelial growth factor axis as a viable pathway for UC treatment. The reported clinical benefit in previously treated patients warrants further investigation in a disease for which there is no US Food and Drug Administration-approved treatment.