Real-World Nivolumab Wastage and Leftover Drug Stability Assessment to Facilitate Drug Vial Optimization for Cost Savings.

Abstract

Nivolumab dosage was initially selected on the basis of body weight, often resulting in leftover drug after sterile compounding. This study sought to investigate the real-world wastage of nivolumab and assess the long-term stability of leftover nivolumab within vials to facilitate drug vial optimization (DVO). We collected all discarded vials after preparation from 17 regional hospitals in Japan over a 6-month period preceding the adoption of a fixed dose of 240 mg per administration. The actual amount of waste was measured for each preparation. Stability assessment was performed under different storage conditions. A total of 2,789 100-mg vials and 4,069 20-mg vials were collected. Overall, the drug cost associated with the expenditure of nivolumab alone was $12.1 million, whereas the total cost due to drug wastage was $0.735 million (rate of wastage, 6.1%). Furthermore, the immunoglobulin G concentrations of nivolumab remaining within vials, as well as binding activity to programmed death-1 protein, did not change significantly over 4 weeks of storage at either 4°C or room temperature. Significant drug wastage occurs during sterile preparation of nivolumab according to body weight-based dosing. Although nivolumab dosing has been changed to a fixed dose in Japan, body weight-based dosing is still applied in some other countries, as well as in combination therapy with ipilimumab. Our findings regarding the long-term stability of leftover nivolumab within the vials should motivate hospitals to implement DVO for cost savings.