Molecular Classification and Overcoming Therapy Resistance for Acute Myeloid Leukemia with Adverse Genetic Factors

The European LeukemiaNet (ELN) criteria define the adverse genetic factors of acute myeloid leukemia (AML). AML with adverse genetic factors uniformly shows resistance to standard chemotherapy and is associated with poor prognosis. Here, we focus on the biological background and real-world etiology of these adverse genetic factors and then describe a strategy to overcome the clinical disadvantages in terms of targeting pivotal molecular mechanisms. Different adverse genetic factors often rely on common pathways. KMT2A rearrangement, DEK-NUP214 fusion, and NPM1 mutation are associated with the upregulation of HOX genes. The dominant tyrosine kinase activity of the mutant FLT3 or BCR-ABL1 fusion proteins is transduced by the AKT-mTOR, MAPK-ERK, and STAT5 pathways. Concurrent mutations of ASXL1 and RUNX1 are associated with activated AKT. Both TP53 mutation and mis-expressed MECOM are related to impaired apoptosis. Clinical data suggest that adverse genetic factors can be found in at least one in eight AML patients and appear to accumulate in relapsed/refractory cases. TP53 mutation is associated with particularly poor prognosis. Molecular-targeted therapies focusing on specific genomic abnormalities, such as FLT3, KMT2A, and TP53, have been developed and have demonstrated promising results.

Risk adapted therapeutic strategy in newly diagnosed acute myeloid leukemia: Refining the outcomes of ELN 2017 intermediate-risk patients

INTRODUCTION

Despite advances in the treatment of acute myeloid leukemia (AML), cytotoxic chemotherapy remains the standard induction regimen.

PATIENTS AND METHODS

In this single center retrospective study, we assessed outcomes of 99 consecutive adult AML patients treated with a risk-adapted strategy with a median follow-up of 35.5 months.

RESULTS

We identified 24 (24 %), 55 (56 %) and 20 (20 %) patients classified as favorable-, intermediate-, and adverse- risk group respectively, according to the European LeukemiaNet (ELN) 2017 classification. Patients either received idarubicin and cytarabine induction chemotherapy with or without FLT3 inhibitors or hypomethylating agents based on age and comorbidity. The complete response (CR) rate was 76 % (82 % and 61 % in patients aged < 60 and ≥ 60, respectively). For the whole cohort, the 3-year overall survival (OS) was 53 %, being 62 % and 30 % in patients aged < 60 and ≥ 60, respectively. The 3-year leukemia-free survival (LFS) was 54 %, with 56 % and 45 % in patients aged < 60 and ≥ 60, respectively. The 3-year LFS were 58 %, 62 % and 25 % for patients within ELN favorable-, intermediate-, and adverse-risk groups respectively. Twenty-seven (36 %) out of 75 patients with intermediate- and adverse-risk disease underwent allogeneic hematopoietic cell transplantation (allo-HCT) in first CR with 92 % of them receiving post-transplant maintenance consisting of azacitidine in 19 (76 %) patients or sorafenib in 6 (24 %) patients. Of these patients younger than 60 years, the 3-year OS and LFS were 85 % and 69 %, respectively.

CONCLUSION

These results indicate an improved OS for AML patients especially in intermediate-risk category who were treated with a total therapy consisting of induction chemotherapy followed by allo-HCT and post-transplant maintenance.