CBFB-MYH11 Fusion Transcripts Distinguish Acute Myeloid Leukemias with Distinct Molecular Landscapes and Outcomes.

Patients with inv(16)/CBFB-MYH11 AML are considered favorable risk, however, nearly one-third relapse despite intensive therapy. Despite efforts to define risk groups within this favorable risk cohort, CBFB-MYH11 AML patients continue to be treated as a uniform cohort. Through transcriptome sequencing of 186 patients with inv(16) AML, we demonstrate that fusion junction breakpoints (exon 5-exon 33 versus other) are highly associated with outcome. The presence of exon 17 KIT mutations provides additional prognostic significance. Additionally, we provide insights into the transcriptional landscapes that differentiate these distinct CBFB-MYH11 AML subtypes. Children's Oncology Group trials include CCG-2961 (registered at www.clinicaltrials.gov as NCT00002798), AAML03P1 (NCT00070174), AAML0531 (NCT00372593), and AAML1031 (NCT01371981).