Cabazitaxel is a semi-synthetic novel tubulin-binding taxane drug with antitumour activity in docetaxel-resistant cancers. In the phase III open label randomised TROPIC trial, men with mCRPC who had received previous hormone therapy, but whose disease had progressed during or after treatment with a docetaxel-containing regimen were enrolled.20Patients were treated with 10 mg of oral prednisone daily, and were randomly assigned to receive either 12 mg of mitoxantrone per square metre of body surface area intravenously over 15 to 30 min or 25 mg per square metre of cabazitaxel intravenously over 1 h every 3 weeks. Men treated with cabazitaxel plus prednisone had a better overall survival compared with those treated with mitoxantrone plus prednisone (HR = 0.70; 95% CI, 0.59 to 0.83; median survival 15.1 vs 12.7 months). PFS was also significantly prolonged (2.8 vs 1.4 months, HR = 0.74; 95% CI, 0.64 to 0.86). With additional follow-up, the 2-year estimated survival was greater than 2 years in 27% of patients treated with cabazitaxel versus 16% in those treated with mitoxantrone.21The most common clinically significant grade III or higher adverse events were neutropenia (cabazitaxel, 303 [82%] patients vs mitoxantrone, 215 [58%]) and diarrhoea (23 [6%] vs 1 [<1%]). Twenty-eight (8%) patients in the cabazitaxel group and 5 (1%) in the mitoxantrone group had febrile neutropenia. About 5% of patients treated with cabazitaxel died within 30 days of the last infusion and the most frequent cause of death in the cabazitaxel group was neutropenia and its clinical consequences. In this heavily pretreated, high risk population, current guidelines for prophylactic white blood cell growth factor use should be adhered to.
There have been no cost-effectiveness analyses on cabazitaxel performed using local cost data and Singaporean societal norms. The NICE Committee considered that the most plausible ICER would be above USD $134,183 per QALY gained.22The Committee further noted that there remains considerable uncertainty in the robustness of this ICER because the utility values that were used in the model were based on unpublished data from an interim analysis of a small number of patients from the TROPIC study, and the costs associated with managing febrile neutropenia were underestimated.