Clinical potential of introducing next‐generation sequencing in patients at relapse of acute myeloid leukemia

Abstract

Relapse of acute myeloid leukemia (AML) remains a major determinant of outcome. A number of molecularly directed treatment options have recently emerged making comprehensive diagnostics an important pillar of clinical decision making at relapse. Acknowledging the high degree of individual genetic variability at AML relapse, nextgeneration sequencing (NGS) has opened the opportunity for assessing the unique clonal hierarchy of individual AML patients. Knowledge on the genetic makeup of AML is reflected in patient customized treatment strategies thereby providing improved outcomes. For example, the emergence of druggable mutations at relapse enable the use of novel targeted therapies, including FLT3 inhibitors or the recently approved IDH1/2 inhibitors ivosidenib and enasidenib, respectively. Consequently, some patients may undergo novel bridging approaches for reinduction before allogeneic stem cell transplantation, or the identification of an adverse prognostic marker may initiate early donor search. In this review, we summarize the current knowledge of NGS in identifying clonal stability, clonal evolution, and clonal devolution in the context of AML relapse. In light of recent improvements in AML treatment options, NGS-based molecular diagnostics emerges as the basis for molecularly directed treatment decisions in patients at relapse.

Clonal Hematopoiesis after Autologous Stem Cell Transplantation Does Not Confer Adverse Prognosis in Patients with AML

“…While recurrent mutations in genes such as FLT3 or NPM1 have been incorporated in risk assessment for a long time [1,3], the introduction of next-generation sequencing (NGS) into the hematologic routine has enabled the discovery of a multitude of additional and often novel mutations [5]. The detection of druggable mutations has also opened the door for customized treatment strategies, some of which were integrated in the European LeukemiaNet (ELN) risk assessment and treatment for patients with AML [1,6,7].…”

Monitoring of Measurable Residual Disease Using Circulating DNA after Allogeneic Hematopoietic Cell Transplantation

“…Peripheral blood and bone marrow processing, isolation of PBMCs and BMMCs, plasma isolation and storage were performed as previously described [ 9 ]. Genomic DNA was extracted from PBMCs and cfDNA from plasma using the Qiasymphony miniDNA and the QIAmp circulating nucleic acid kit according to the manufacturer’s instructions (Qiagen GmbH, Hilden, Germany).…”

“…Long-standing evidence suggests that early detection of measurable residual disease (MRD) by identifying leukemia-associated immunophenotypes (LAIP) by flow cytometry, and fusion transcripts as well as gene expression (e.g., WT1) by quantitative RT-PCR, are able to predict relapse in patients with acute myeloid leukemia (AML) [ 4 , 5 , 6 ]. Recent technological advances to detect MRD after allo-HSCT such as multicolor flow cytometry, the introduction of droplet digital PCR (ddPCR) and next-generation sequencing (NGS), have resulted in improved MRD detection [ 7 , 8 , 9 , 10 ]. As recently reported by an expert panel, MRD detection in AML is based either on PCR amplification of leukemia-associated targets or on flow cytometric detection of LAIPs.…”

Donor cell leukemia/myelodysplastic syndrome after allogeneic stem cell transplantation: a rare phenomenon with more challenges for hematologists

“…However, new technologies, such as NGS and single cell sequence, could identify some newer diallelic polymorphic markers for more sensitive detection of mixed chimerism. NGS can help identify molecular markers suitable for the early detection of gene mutation, monitoring of molecular minimal residue disease, as well as for tracking of distinct mutational patterns [4,5], and may decipher the mechanisms of leukemogenesis in the near future.…”