Cabazitaxel in Platinum Pre-treated Patients with Locally Advanced or Metastatic Transitional Cell Carcinoma Who Developed Disease Progression after Platinum based Chemotherapy: Results of the Phase II CAB-B1 Trial

There is a paucity of chemotherapy options for patients with urothelial cancers who have relapsed following platinum based chemotherapy (CT). CAB-B1 was a single centre phase II randomised controlled trial of Cabazitaxel (CAB; 25mg/m2 q3 week for 6 cycles) versus best supportive care (BSC) in patients with histologically proven transitional cell carcinoma (TCC), locally advanced or metastatic, who had recurred after receiving platinum based treatment. Primary outcome was overall response rate (ORR) using RESIST. Secondary outcomes included Progression Free Survival (PFS) and Overall Survival (OS). Between January 2013 and October 2016, 20 patients were randomised (10 on each arm). BSC included paclitaxel CT for 9 patients and radiotherapy for 1 patient. 8 patients completed 6 cycles of CT (3 on CAB; 5 on BSC). 2 patients had an ORR on CAB and 1 patient on BSC. Median OS was 5.8 months (95% confidence interval (CI) 0.7-14.6) for CAB patients and 7.5 months (95% CI 1.0-10.8) for BSC patients. Median PFS was 4.8 months (95% CI 0.7-8.3) for CAB patients and 3.7 months (95% CI 1.0-7.0) for BSC patients. CAB-B1 successfully reached the efficacy target for 1st stage, showing that there could be a role for CAB in these patients.