IDH1 and acute myeloid leukemia: Similarly, in patients with IDH1-mutated AML treated with ivosidenib, bulk NGS at time of progression identified multiple patients with new FLT3-ITD or -TKD mutations not present at therapy initiation (154), and in patients with IDH2-mutated AML treated with enasidenib, analysis of paired pre- and post-treatment samples described several cases with increased FLT3 variant allele frequency at relapse (155).