BACKGROUND: In 2017, an estimated 21,380 new cases of acute myeloid leukemia (AML) and 10,590 deaths from AML occurred in the US. Gemtuzumab ozogamicin (GO) is an anti-CD33 antibody-drug conjugate approved for treatment of newly-diagnosed (ND) CD33- positive (CD33+) AML in adults as monotherapy or in combination with standard induction chemotherapy, and for relapsed/refractory (R/R) CD33+ AML in adults and pediatric patients ≥2 years of age. We developed budget-impact models (BIMs) for the treatment of (1) adult ND AML and (2) adult and pediatric R/R AML.
METHODS: Models estimating the budget impact of introducing GO were built with data on drug costs and treatmentrelated outcomes over 5 years with and without GO. Efficacy and safety data were taken from published clinical trials. Public data were used for resource use and cost. The model assumed all included newly diagnosed adult patients are eligible for treatment and 90% with first relapse are CD33+ and eligible for R/R treatment with GO. Scenario analyses reflected low and high estimated use for GO and assumed the lowest price for each formulation across all treatments. Results were analyzed by indication (ND, R/R) and reported on a per member per month (PMPM) basis to examine the relative impact on a US health plan budget.
RESULTS: Base-case results of the ND BIM indicated that use of GO minimally impacted a 1 million-member health plan budget, with PMPM costs not exceeding $0.0024 over the 5-year period. Cost savings were observed in years 4 and 5, resulting from a GO-associated reduction in relapses and transplants over the first 3 years following treatment in the combination therapy setting. For R/R AML, base-case results of the BIM indicated use of GO increased costs, although PMPM cost was low ($0.0018 in year 1 up to $0.0047 in year 5). The scenario analyses indicated the price per vial of GO had the largest budget impact.
CONCLUSION: The introduction and estimated use of GO for ND and R/R AML patients resulted in minimal budget impact to a US health plan. Increased costs were largely offset by reduction in medical costs related to a decrease in transplants and relapses for ND AML. Furthermore, the low incremental drug costs and small patient population suggest GO may provide an alternative option for R/R AML patients at minimal incremental cost for health plans. As such, GO may provide substantial value for money spent on treatment of CD33+ AML in the US.
