Significantly Minimizing Drug Wastage and the Cost of Cabazitaxel Used to Treat Metastatic Castration-Resistant Prostate Cancer

Cabazitaxel is used to treat patients with metastatic castration-resistant prostate cancer progressing after docetaxel. It is prepackaged in 60 mg single-dose vials, a quantity much higher than the average prescribed dose, which leads to, substantial drug wastage (DW) and associated costs. To minimize DW we implemented a cost-saving, cohorting strategy where multiple patients scheduled to receive cabazitaxel (at a dose of 20mg/m2 every 3 wks) were cohorted and treated on a single weekday whenever possible. Excess drug from each vial was then saved and used for subsequent patients treated on the same day. The drug cost with cohorting was calculated from the actual number of vials used, and the drug cost without cohorting was estimated by assumingthat one vial was used per treatment. The cost of DW was determined based on the amount of drug that was discarded. All cost calculations also accounted for the discount incentives offered by Sanofi-Aventis. Over a 3-yr period, 74 patients received 402 treatments of cabazitaxel. Multiple patients were treated on 67.4% of the treatment days, and grouping of three patients on one day saved one vial. The estimated total drug cost saved was $394 536 CAD (21.1%). Pending further studies on safety and efficacy, this strategy could potentially be adopted to mitigate DW for cabazitaxel and similarly for other oncology drugs. This would significantly decrease the overall financial burden on patients, institutions, and stakeholders.