IDH1 and acute myeloid leukemia: IDH1 mutations are less frequent in AML compared to IDH2; however, the more durable responses to oral inhibitor AG-120, now called ivosidenib, led to its FDA approval initially for R/R AML with IDH1 mutations in July 2018, soon followed by approval for newly diagnosed AML patients who were unable to obtain intensive chemotherapy by May 2019.