MINIMUN COST-ANALYSIS OF METASTATIC MELANOMA TREATMENT BASED ON PATIENTS’S WEIGHT

OBJECTIVES: Incorporation of new therapies for the treatment of metastasic melanoma(mM) in our hospitals has resulted in the requirement of measures to optimize available resources.The aim of this study is to perform a cost-minimization analysis for the treatment of mM based on current therapies, immunotherapy and antiBRAF-antiMEK targeted drugs. METHODS: Treatments were: nivolumab, pembrolizumab and vemurafenib-cobimetinib and dabrafenib-trametinib. Only direct costs of acquisition of drugs were assessed. Linear-modeling was made, which allowed us to represent the anual-costs of each treatment against the patient's weight with a timeframe of one year. A deterministic model for the sensitivity analysis was performed incorporating the costs of staying in oncology-day-hospital and the outpatient-units and vial use optimization. RESULTS: Base-case: nivolumab is shown as the least expensive treatment regardless of the patient's weight, but with an equal cost to pembrolizumab in patients weighing between 74-76kg. Moreover in patients over 76kg weight is less expensive to use vemurafenib-cobimetinib than pembrolizumab. Sensitivity-analysisl(with cost of staying in ODH): nivolumab is the less expensive therapy again, except for patients weighing 50kg; in which pembrolizumab is the most cheap treatment. The base-case results for patients over 76kg weight are repeated in this scenario. Sensitivity-analysis2(with vial-use optimization): nivolumab reappears as less expensive treatment for all weights studied. Again for patients over 76kg, the base case results are repeated in this analysis. CONCLUSIONS: Our results shows that nivolumab is the less expensive treatment for most patients, so with this study we wanted to show a tool to optimize resources indicating lower-cost therapy for the treatment of mM base of patient's weight. Of course, will be the characteristics of the pathological process of each patients that will determine the ideal treatment. However, in those situations where it's considered that two therapies are equivalent for a patient, this model can help to choose the suitable therapy.