Imatinib with intensive chemotherapy in AML with t(9;22)(q34.1;q11.2)/BCR::ABL1. A DATAML registry study.

Abstract

Acute myeloid leukemia (AML) with t(9;22) (q34.1; q11.2)/BCR::ABL1, a distinct entity within the group of AML with defining genetic abnormalities, belong to the adverse-risk group of the 2022 ELN classification. However, there is little data on outcome since the era of tyrosine kinase inhibitors. Among 5819 AML cases included in the DATAML registry, 20 patients with de novo BCR::ABL1⁺AML (0.3%) were identified. Eighteen patients treated with standard 3+7 induction chemotherapy were analyzed in this study. Imatinib was added to chemotherapy in 16 patients. The female to male ratio was 1.25 and median age was 54 years. The t(9;22) translocation was the sole chromosomal abnormality in 12 patients. Main gene mutations detected by NGS were ASXL1, RUNX1 and NPM1. No patients had detectable ABL1 mutations. Compared with patients with myeloid blast phase of chronic myeloid leukemia (CML-BP), de novo BCR::ABL1⁺AML had higher WBC, mutational burden, fewer additional chromosomal abnormalities, lower CD36 or CD7 expression and no ABL1 mutations. Seventeen patients (94.4%) achieved complete remission (CR) or CR with incomplete hematologic recovery. Twelve patients were allografted in first remission. With a median follow-up of 6.3 years, the median OS was not reached and 2-year OS was 77% (95% CI: 50–91). Four out of five patients who were not transplanted did not relapse. Comparison of BCR::ABL1⁺AML, CML-BP, 2017 ELN intermediate and adverse-risk patients showed that patients with BCR::ABL1⁺AML had a significant better outcome than intermediate and adverse-risk patients. This entity should not be included in the adverse-risk group of current AML classifications.