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KEY CONCEPTS
Newer techniques and wider applicability of genomic sequencing have identified numerous recurrent somatic mutations and patterns of mutation that reveal the extensive heterogeneity of acute myeloid leukemia (AML). Better understanding of the biology behind the genomic aberrations has led to more accurate disease prognostication as well as development of specific therapies for genomically defined subgroups. The most recent European LeukemiaNet (ELN) 2017 classification system incorporates several of these mutations for risk classification. Therefore, pretreatment assessment of these mutations (FLT3, NPM1, CEBPA, TP53, RUNX1, ASXL1) along with conventional karyotyping is becoming a part of standard practice.
Since 2017 and as of 2020, several new therapies have been approved or reintroduced for the treatment of patients with AML. These include the FLT3 (fms-like tyrosine kinase 3) inhibitors midostaurin and gilteritinib, the IDH1 inhibitor ivosidenib, the IDH2 inhibitor enasidenib, the BCL2 inhibitor venetoclax, the hedgehog inhibitor glasdegib, the CD33 antibody–drug conjugate gemtuzumab ozogamicin (GO), the liposomal formulation CPX-351, and oral azacytidine.
The CD33 antibody–drug conjugate GO has been shown to provide significant survival benefit in patients with favorable or intermediate-risk disease and should be incorporated into the frontline treatment of core-binding factor AML when appropriate. GO also has an important role in the treatment of patients with acute promyelocytic leukemia.
Chemotherapy combined with an FLT3 inhibitor such as midostaurin or others on clinical trial are now part of the standard of care for patients with newly diagnosed FLT3-mutated AML.
The BCL2 inhibitor venetoclax has significantly improved outcomes for older and unfit patients with newly diagnosed AML, having demonstrated a significant survival benefit in combination with hypomethylating agents (HMAs) compared with HMAs alone.
Monitoring of minimal residual disease (MRD) by multiparameter flow cytometry or molecular methods at the time of remission after induction and after consolidation is a powerful tool to help predict the risk of relapse and guide risk stratification, including postremission strategies such as stem cell transplant (SCT). Complete remission with or without MRD positivity is being incorporated into response criteria.
Maintenance therapy with oral azacytidine (CC486) has become the standard of care for patients not eligible for postremission SCT after demonstrating improvement in survival compared with placebo. Maintenance strategies with targeted therapies after achieving remission and even after SCT are being investigated.
Repeat molecular testing for mutations at the time of relapse should be strongly considered to allow incorporation of specific targeted therapies that are indicated in genomically defined subgroups (eg, enasidenib, ivosidenib, gilteritinib).
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Acute myeloid leukemia (AML) consists of a heterogeneous group of hematologic neoplasms characterized by clonal proliferation of myeloid blasts involving peripheral blood and bone marrow, with occasional tumor formation in extramedullary tissues. Despite advances in our understanding of the molecular biology of AML, its treatment remains challenging, and outcomes vary greatly depending on a constellation of cytogenetic and molecular features as well as age and comorbidities.
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AML is thought to be the culmination of genetic mutations and ...