Pediatric Trial of Indoximod With Chemotherapy and Radiation for Relapsed Brain Tumors or Newly Diagnosed DIPG

Disease-specific Cohorts : Cohort 1A, 1B (closed to enrollment): relapsed or refractory glioblastoma Cohort 2A, 2B: relapsed or refractory medulloblastoma Cohort 3A, 3B, 3C: relapsed or refractory ependymoma Cohort 4C (closed to enrollment): newly-diagnosed DIPG (must have no prior radiation or other therapy) . Radiation (or proton) plan sub-cohorts: Sub-cohort A: for patients not eligible for re-irradiation Sub-cohort B: for patients who are eligible for partial re-irradiation Sub-cohort C: for patients who are eligible for full-dose radiation (All newly diagnosed DIPG patients and some relapsed ependymoma patients)