Clinical utility of genomic profiling of AML using paraffin‐embedded bone marrow clots: HM‐SCREEN‐Japan 01

Next‐generation sequencing of AML has identified specific genetic mutations in AML patients. Hematologic Malignancies (HM)‐SCREEN‐Japan 01 is a multicenter study to detect actionable mutations using paraffin‐embedded bone marrow (BM) clot specimens rather than BM fluid in AML patients for whom standard treatment has not been established. The purpose of this study is to evaluate the presence of potentially therapeutic target gene mutations in patients with newly diagnosed unfit AML and relapsed/refractory AML (R/R‐AML) using BM clot specimens. In this study, 188 patients were enrolled and targeted sequencing was undertaken on DNA from 437 genes and RNA from 265 genes. High‐quality DNA and RNA were obtained using BM clot specimens, with genetic alterations successfully detected in 177 patients (97.3%), and fusion transcripts in 41 patients (23.2%). The median turnaround time was 13 days. In the detection of fusion genes, not only common fusion products such as RUNX1‐RUX1T1 and KMT2A rearrangements, but also NUP98 rearrangements and rare fusion genes were observed. Among 177 patients (72 with unfit AML, 105 with R/R‐AML), mutations in KIT and WT1 were independent factors for overall survival (hazard ratio = 12.6 and 8.88, respectively), and patients with high variant allele frequency (≥40%) of TP53 mutations had a poor prognosis. As for the detection of actionable mutations, 38% (n = 69) of patients had useful genetic mutation (FLT3‐ITD/TKD, IDH1/2, and DNMT3A (R822)) for treatment selection. Comprehensive genomic profiling using paraffin‐embedded BM clot specimens successfully identified leukemic‐associated genes that can be used as therapeutic targets.