A rational approach to nivolumab dosing using cost analysis.

Abstract

e15101 Background: Immune checkpoint inhibitors have changed the landscape in oncology, offering durable responses and improved survival across several tumor types. A significant problem in many countries is access to these drugs, as the yearly treatment cost can exceed $100,000. One of the alternatives to reduce the total cost of therapy is to optimize the dosing strategy. Nivolumab was initially approved with a 3mg/kg Q2W dosage, later fixed dose nivolumab 240mg Q2W was also approved. Fixed dose regimens can lead to unnecessarily high doses for patients under 80 kg. Methods: We performed a cost analysis using weight data from 53 patients diagnosed with melanoma or metastatic renal cell carcinoma who were treated with nivolumab at our institution. With that information we generated a model which calculated the total cost if they were to receive the 240mg fixed dose regimen, versus a a cost-saving strategy as follows: all patients weighing up to 79.9Kg were to be dosed at 3mg/kg, while patients 80kg or more were to use the fixed 240mg dose. Since nivolumab is available in 100mg, 40mg and 240mg vials, there is dose wastage when using the 3mg/kg calculation, this was considered for the cost analysis. Results: The median weight of our patients was 73.6kg (range 56,0kg - 103,1kg). Analyzing individual patient data, 75% of them would receive a higher dose if treated with the fixed dose regimen, versus 3mg/kg dosing. Among them, the median comparative overdosage is 50,9mg (range 3.0mg - 87.0mg). Considering drug wastage, and a USD 12.96 per mg local price for nivolumab, treating our 53 patients with the proposed model for one year would result in USD 366.886 in cost savings, versus using the 240mg fixed dose regimen, equivalent to a 9.3% of the total treatment costs. Conclusions: Expanding access to immunotherapy is a challenge for health systems. We have shown a potential 9.3% cost savings using a rational dosing regimen for nivolumab, which could be very important in cost-constrained scenarios which many countries are facing. Considering the world average weight is 62.0kg, it is plausible than even greater cost savings could be realized in many other locations around the globe.