Examination of Useful Formulation Standards in Japan: Stimulating Reduced Medical Costs with a Low-Dose Standard for Cabazitaxel in Prostate Cancer Treatment

Discarding expensive anticancer drugs during preparation can lead to substantial economic losses. This study aimed to identify a practical formulation standard for preparing the prostate cancer drug cabazitaxel (CBZ) by comparing healthcare cost savings with the current standard and assuming the existence of a low-dose standard formulation. We retrospectively reviewed the electronic medical records of body surface area, total number of treatments, and volume discarded. With five different low-dose standard vials (50, 40, 30, 20, and 10 mg), we calculated and compared the total number of treatments assigned to the existing 60-mg vials, amount discarded, cost of drugs, and closed drug transfer systems for each standard as medical costs. The median disposal was lower for the 10 (4.1 mg), 50 (9.3 mg), and 20 (14.3 mg) mg vials than that for the 60-mg vials (28.2 mg; all P < 0.01). The median disposal was the lowest for the 10-mg vial (4.1 mg), followed by the 20- and 40-mg vials (both 8.2 mg), compared with the 60-mg vial (28.2 mg; all P < 0.01). The median medical cost was lowest for the 40-mg vial (¥ 354,899) compared with the 60-mg vial (¥ 511,456; P < 0.01), indicating that the practical formulation standard for CBZ preparation should be 40-mg vial. Using the same technique and preparation time as the marketed formulation can reduce medical costs.