Background Nivolumab is a highly selective anti-programmed death1 (PD-1) human monoclonal antibody that potentiates T-cell responses by blocking the binding of PD-1 to its ligands. Nivolumab, on June 2015 was authorised to treat melanoma, renal cell cancer (RCC) and non-small-cell lung cancer (NSCLC) administered in weight-based dosing (BW) schedules at 3 mg/kg every 2 weeks. In May 2018 the European Commission approved 240 mg flat dose (FD) every 2 weeks based on pharmacokinetics parameters.

Purpose Compare the financial impact of FD methodology versus BW in our population.

Material and methods Patients treated with nivolumab for melanoma, RCC and NSCLC in 2017 in our hospital were included in the analysis. Patients with the treatment started before the drug was commercialised were excluded. We analysed prescriptions on our informatic application to obtain the personal data of patients (age, sex, weight). We calculated the number of drug vials needed to fill a single prescription and the hypothetical drug waste. We used tender price (€11.8/mg) to calculate the hypothetical cost of BW and FD.

Results Ninety-one patients were treated in 2017 (636 doses), median age 68 years (SD ±8.7) and weight of 71 kg (SD ±15.8). The percentage of men was 63%. Seventy-two (79%) patients weighed less than 80 kg (75% doses). The diagnoses were: melanoma 19 (21%), RCC 12 (13%) and NSCLC 60 (66%). In our centralised unit we used a processing residue drug during compounding to minimise waste. The hypothetical cost of BW would be €1,748,932 with a hypothetical waste of 7.970 mg (€94,620) which is 5% of the total drug cost. The real cost of nivolumab was €1,661,154. This policy allowed us to save €87 778 (5%). If the same patients received the FD, no waste would have been produced but the cost would be greater €1,777,950 (+7%).

Conclusion FD simplifies prescribing, preparation, inventory and billing but the costs would be greater. In our cohort the median patient’s weight was less than 80 kg so we would have used fewer vials using BW versus FD protocol.

Reference and/or acknowledgements

1. Zhao X, et al. Assessment of nivolumab benefit-risk profile of a 240-mg flat dose relative to a 3-mg/kg dosing regimen in patients with advanced tumors. Ann Oncol 2017.

Reference and/or acknowledgementsNo conflict of interest.