Anti-IDH2 Monoclonal Antibody

In this issue of Blood, Stein et al(1) report the outcomes for all isocitrate dehydrogenase-2 (IDH2) mutant relapsed or refractory acute myeloid leukemia (R/R AML) patients treated with enasidenib in the first phase 1/2 study including data on molecular clearance and molecular relationships to response or resistance.

Studies comparing the prognostic role of RUNX1 mutations (RUNX1(mut)) in acute myeloid leukemia (AML) and acute myeloid leukemia-with myelodysplasia-related changes (AML-MRC) are limited. Our study examines the genetic profile of 118 RUNX1(mut) AML patients including 57 AML with RUNX1(mut) and 61 AML-MRC with RUNX1(mut) and 100 AML, NOS patients with wild type RUNX1 (RUNX1(wt)). Results revealed that AML-MRC patients with RUNX1(mut) had shorter median overall survival (OS) (11 +/- 3.3 months) when compared to AML with RUNX1(mut) (19 +/- 7.1 months) and AML, NOS with RUNX1(wt) (not reached) (p = .001). The most common concurrent mutations observed in AML-MRC with RUNX1(mut) patients were DNMT3A, SRSF2, ASXL1, and IDH2 while in AML with RUNX1(mut) patients were ASXL1, SRSF2, TET2, IDH2, and DNMT3A. ASXL1 and TET2 mutations appeared to adversely affect OS in AML-MRC, but not in AML with RUNX1(mut). Concurrent RUNX1/DNMT3A mutations, in contrast had negative impact on OS in AML with RUNX1(mut), but not in AML-MRC with RUNX1(mut).