OBJECTIVES

Acute Myeloid Leukemia (AML) patients with fms-related tyrosine kinase 3 gene (FLT3) mutation of the internal tandem duplication (ITD) subtype are known to have a poor prognosis. This study assessed and compared the disease burden of AML patients with and without FLT3 mutation.

METHODS

A retrospective observational study was conducted using electronic medical record (EMR) database of the Samsung Medical Center (SMC) in Korea. Newly diagnosed adult (≥18years) AML patients, confirmed by a bone marrow examination, who received induction therapy between Jan 2010 and May 2017 were identified and followed until May 2018. The Analysis of variance (ANOVA) method was used to assess the differences among the subgroups.

RESULTS

The study included 442 newly diagnosed adult AML patients (mean age 53.1y; 60.9% male; 17.4% FLT3-mutant). Among patients who received FLT3 mutation test (n=394, 89.1%), outcomes were compared amongst the four subgroups; Younger (18-59 years) FLT3-mutated AML (n=51), older (≥60 years) FLT3-mutated AML (n=26), younger FLT3-wildtype AML (n=196), and older FLT3-wildtype AML (n=119), respectively. The average direct medical cost was overall significantly higher in younger AML patients, with highest cost occurring in younger FLT3-wildtype AML patients (KRW 108,611,618) with the longest mean follow-up time (35.6 months). With FLT3 mutation, cost in younger AML was insignificantly lower (KRW 106,058,454) with a shorter mean follow-up time (31.8 months). A similar trend was observed among older AML patients. The FLT3-wildtype group had a higher average medical cost and a longer mean follow-up time (KRW 75,055,397, 19.5 months) when compared to the FLT3-mutant group (KRW 54,165,423, 12.1 months).

CONCLUSIONS

There still exists high medical unmet needs and disease burden with current standard of care in AML management. Early introduction of new treatment options for AML, especially among FLT3-mutated patients with poor prognosis is critical to lessen the burden of disease.