Study of Orally Administered Enasidenib (AG-221) in Adults With Advanced Solid Tumors, Including Glioma, or Angioimmunoblastic T-cell Lymphoma, With an IDH2 Mutation

Inclusion Criteria: * Subject must be ≥ 18 years of age * Histologically or cytologically confirmed advanced solid tumor, including glioma, or angioimmunoblastic T-cell lymphoma (AITL) that has recurred or progressed following standard therapy, or that has not responded to standard therapy * Subjects must be amenable to peripheral blood sampling, urine sampling, and biopsies during the study. Subjects with AITL must also be amenable to serial bone marrow biopsies * Documented IDH2 gene-mutated disease based on local site testing * Measurable disease by RECIST v1.1 for subjects with solid tumors without glioma, by modified RANO criteria for subjects with glioma, or by the revised IWG criteria for subjects with AITL * Subjects must have Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 * Adequate bone marrow function (subjects other than those with AITL) as evidenced by: absolute neutrophil count ≥ 1.0 ×10\^9/L; hemoglobin \> 9 g/dL (subjects may be transfused red blood cells to this level.); platelets ≥ 50 × 10\^9/L * Adequate hepatic function as evidenced by: serum total bilirubin ≤ 1.5 × upper limit of normal (ULN), unless considered due to Gilbert's disease, a gene mutation in UGT1A1, or disease involvement, following approval by the Medical Monitor; aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) ≤ 2.5 × ULN, with the exception of subjects with bone metastases and/or suspected disease-related liver or bilia…