Posaconazole versus fluconazole or itraconazole for prevention of invasive fungal infections in patients undergoing intensive cytotoxic therapy for acute myeloid leukemia or myelodysplasia: a cost effectiveness analysis

Invasive fungal infections (IFI) remain a clinical concern in hematological patients with prolonged neutropenia because they are a major cause of morbidity and mortality. In a recent randomized trial, prophylaxis with posaconazole was associated with fewer IFI and related deaths relative to a fluconazole or itraconazole (Flu/Itra) control group (p < 0.001). In the current study, a cost effectiveness analysis was conducted to estimate the economic value of posaconazole as an alternative to Flu/Itra when used to prevent IFI in this patient population. A decision analysis model was developed using clinical and economic data from randomized comparative trials, the economic literature, and from expert opinion. The data were then used to estimate the incremental cost per life year saved with oral posaconazole prophylaxis relative to Flu/Itra from the Canadian provincial health care system perspective. The base case results were then tested with a sensitivity analysis which evaluated extremes in the incidence of IFI as well as variations in their cost of management. Prophylaxis with posaconazole provides increased efficacy and an overall cost savings of approximately $Can4,259 per patient. Despite variations in the base case parameters, the sensitivity analysis suggested stability in the primary findings. Posaconazole was associated with an overall cost savings (range = $Can1,765 to $Can4,505) in all of the scenarios evaluated. Optimal cost effectiveness was obtained because the drug was able to avoid the more resource intensive Aspergillus infections. Prophylaxis with posaconazole in cancer patients with prolonged neutropenia is not only cost effective but also cost saving. The economic benefits were due to the drug's ability to reduce the incidence of high cost fungal infections, particularly Aspergillus species.