CLINICAL TRIALS AND OBSERVATIONS Distinct clinical and biologic characteristics in adult acute myeloid leukemia bearing the isocitrate dehydrogenase 1 mutation

Mutations of nicotinamide adenine dinucleotide phosphate-dependent isocitrate dehydrogenase gene (IDH1) have been identified in patients with gliomas. Recent genomewide screening also revealed IDH1 mutation as a recurrent event in acute myeloid leukemia (AML), but its clinical implications in AML are largely unknown. We analyzed 493 adult Chinese AML patients in Taiwan and found 27 patients (5.5%) harboring this mutation. IDH1 mutation was strongly associated with normal karyotype (8.4%, P .002), isolated monosomy 8 (P .043), NPM1 mutation (P < .001), and FrenchAmerican-British M1 subtype (P < .001), but inversely associated with French-AmericanBritish M4 subtype (P .030) and expression of HLA-DR, CD13, and CD14 (P .002, .003, and .038, respectively). There was no impact of this mutation on patient survival. Sequential analysis of IDH1 mutation was performed in 130 patients during followups. None of the 112 patients without IDH1 mutation at diagnosis acquired this mutation at relapse. In all 18 IDH1-mutated patients studied, the mutation disappeared in complete remission; the same mutation reappeared in all 11 samples obtained at relapse. We conclude that IDH1 is associated with distinct clinical and biologic characteristics and seems to be very stable during disease evolution. (Blood. 2010;115(14): 2749-2754)