Budget impact analysis of enasidenib treatment in patients with relapsed or refractory acute myeloid leukemia with an isocitrate dehydrogenase-2 mutation
Graham, C., McGuire, M., Knox, H., & Ung, B. (2018). Budget impact analysis of enasidenib treatment in patients with relapsed or refractory acute myeloid leukemia with an isocitrate dehydrogenase-2 mutation. Journal of Managed Care and Specialty Pharmacy, 24(4-a Suppl), S31. Article C30. https://doi.org/10.18553/jmcp.2018.24.4-a.s1
BACKGROUND: Enasidenib was recently approved in the USA for patients with relapsed or refractory (R/R) acute myeloid leukemia (AML) with an isocitrate dehydrogenase-2 (IDH2) mutation. OBJECTIVE: To estimate the budgetary impact of adding enasidenib to the formulary of a hypothetical third-party payer with 5,000,000 covered lives in the USA over a 5-year period. METHODS: A decision-analytic model was developed in Microsoft Excel to estimate drug acquisition, drug administration, red blood cell transfusion, diagnostic testing, and adverse event (AE) costs associated with enasidenib and standard high- and low-intensity chemotherapies for patients with R/R AML. Eligible patients, market share, and treatment duration were estimated from published epidemiologic studies and market research. Regimen dosing information and AE incidence data were taken from published clinical studies and product labels. Transfusion-related data were extracted from enasidenib clinical data and a published Medicare study for comparators. Drug costs were set to wholesale acquisition costs, whereas other medical costs were estimated from standard U.S. sources. Per member per month (PMPM) and total costs were calculated for 2 market scenarios; without enasidenib, and with enasidenib. The difference between the scenarios results in the budget impact of adding enasidenib to formulary. Sensitivity analyses were performed for enasidenib drug-acquisition costs, market share uptake, and treatment duration. RESULTS: In the modeled health plan, approximately 15 patients were estimated to have an IDH2 mutation and be eligible for R/R AML treatment during a calendar year. Overall, with the introduction of enasidenib to formulary, costs for administration, transfusions, and AEs were calculated to decrease slightly, whereas costs for drug acquisition and diagnostic testing would increase. Additional PMPM costs were estimated at USD 0.002 in the first year post-introduction of enasidenib, USD 0.006 in the second year, and plateaued at USD 0.011 in the third year. Total cost differences post-introduction ranged from approximately USD 103,000 in the first year to USD 686,000 in the fifth year. Sensitivity analyses (±10% of base case) showed PMPM to increase from a minimum of USD 0.001 to a maximum of USD 0.013 across the 5 years analyzed. CONCLUSIONS: Adding enasidenib to the formulary for patients with IDH2-mutated R/R AML has minimal impact on the PMPM costs of a U.S. health plan, while providing another treatment for patients with a disease that has limited modern therapy options.