Economic Evaluation of Posaconazole Versus Standard Azole Prophylaxis in High Risk Neutropenic Patients in The Netherlands.

Abstract

Background: Acute leukemia and high risk myelodysplastic syndrome patients experience prolonged neutropenia after treatment with intensive chemotherapy, leading to a high risk of acquiring potentially fatal invasive fungal infections (IFI). Pharmacoeconomic analysis is considered a valuable tool to justify the significant costs involved in managing these fungal infections. The present study evaluates the cost-effectiveness of posaconazole versus standard azoles for the prevention of IFIs in neutropenic patients in the Netherlands.Methods: A decision-tree model was developed that starts with the choice of antifungal prophylaxis: posaconazole or standard azole treatment (fluconazole or itraconazole). The decision tree was estimated using data from a recently published prospective, randomized, double blind, multi-center trial that compared both treatments in neutropenic patients receiving remission-induction chemotherapy for AML/MDS (Cornely et al., 2007). Following initiation of prophylaxis, clinical events are modeled with chance nodes reflecting probabilities of IFIs, IFI related death, and death from other causes. It is assumed that patients surviving the prophylactic period will have a life expectancy that reflects that of the underlying condition. This allows translation of the trial outcomes to a lifetime horizon. Data on life expectancy, quality of life, medical resource consumption and costs were obtained from the literature. Model outcomes include incremental cost per IFI avoided, incremental cost per life years saved and incremental cost per QALYs gained.Results: The total cost (treatment of breakthrough IFI + prophylaxis) for posaconazole amounted to €4,566 (95% uncertainty interval €3,574 –€5,769), which is €63 (−€1,552 - €1,903) less than costs with standard azoles. Posaconazole prophylaxis resulted in 0.1 (0.03 – 0.15) QALYs gained in comparison to prophylaxis with standard azoles. Results from a probabilistic sensitivity analysis indicate that there is a 87% probability that the cost per QALY gained with posaconazole is below €20,000, a commonly accepted threshold for cost-effectiveness. Additional scenario analyses with different assumptions confirmed these findings.Conclusion: Given the underlying data and assumptions, our economic evaluation demonstrated that posaconazole prophylaxis is cost and QALY saving compared to fluconazole / itraconazole in neutropenic AML/MDS patients after intensive chemotherapy.