Maintenance therapy in acute myeloid leukemia (AML) after induction and consolidation chemotherapy has been studied for more than 2 decades. 1 No randomized trial had shown an overall survival (OS) benefit compared with observation until the recent QUAZAR AML-001 trial of oral azacitidine. 2 The QUAZAR AML-001 trial randomized 472 patients with transplant-ineligible AML $ 55 years of age, who were in complete remission (CR) or CR with incomplete count recovery after induction and/or consolidation therapy, to maintenance therapy with oral azacitidine or placebo. 2 Oral azacitidine demonstrated improvements in both OS and relapse-free survival (RFS) compared with placebo, leading to its approval in the United States. 2 Quality of life was similar in the oral azacitidine and placebo arms. 2 With a current average wholesale price (AWP) of $25 390 for a 1-month supply using the standard 14-day schedule or $1813.55 per tablet, oral azacitidine could add a substantial financial burden on the US health care system. 3 We therefore conducted a cost-effectiveness analysis of maintenance therapy with oral azacitidine compared with observation in patients with AML from a US health care system perspective.We used a partitioned survival analysis similar to previous publications from our group, which was based on the QUAZAR AML-001 study. 2,4 Additional information on the model development is provided in the supplemental Materials. Briefly, patients entered the model as patients with AML in remission and received oral azacitidine using dosing schedules outlined in the QUAZAR AML-001 study or no treatment (ie, observation). 2 Patients who experienced disease progression entered a postprogression disease state and received salvage therapies that included intensive chemotherapy, allogeneic hematopoietic cell transplant (allo-HCT), lowerintensity therapies, or best supportive care using the distributions outlined in the QUAZAR AML-001 study. 2 Among patients treated with lower-intensity therapies, we assumed that patients with targetable mutations in FLT3, IDH1, or IDH2 would be treated with gilteritinib, ivosidenib, or enasidenib, respectively.Costs and utilities were modeled over a lifetime horizon. Utilities were measured in quality-adjusted life years (QALYs). Model outputs were used to calculate the incremental cost-effectiveness ratio (ICER) for oral azacitidine, which represents the cost in 2020 US dollars (USD) of each additional QALY gained compared with observation. Costs and utilities were discounted by 3% annually as recommended by the second panel on cost-effectiveness in health and medicine. 5 We used Kaplan-Meier curves and at-risk tables for RFS and OS for both study arms of the QUAZAR AML-001 trial to recreate individual patient-level data, which was then fit to various parametric survival distributions. 4,6 Log-logistic regression distributions were chosen based on Akaike information criterion and visual inspection (supplemental Figure 1).Clinical parameters used in this model were derived from the QUAZAR AML-001 s...