Budget impact analysis of enasidenib treatment in patients with relapsed or refractory acute myeloid leukemia with an isocitrate dehydrogenase-2 mutation

Abstract

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.