Transfusion independence in patients who were transfusion dependent at baseline. Non-CR/CRh responders include patients with CR with incomplete hematologic recovery/incomplete platelet recovery and morphologic leukemia-free state not meeting the criteria for CRh, and patients with PR. Nonresponders include patients with stable disease and progressive disease. *One patient enrolled in dose-escalation phase was positive for the IDH1-D54N mutation by local testing and was not positive for the IDH1-R132 mutation by the companion diagnostic test; this patient was therefore excluded from the efficacy analyses.