Telaglenastat With Radiation Therapy and Temozolomide in Treating Patients With IDH-Mutated Diffuse Astrocytoma or Anaplastic Astrocytoma

PRIMARY OBJECTIVE: I. Determine the maximum tolerated dose (MTD) and/or the recommended phase 2 dose (RP2D) of telaglenastat (CB-839) hydrochloride (HCl) when combined with radiation therapy (RT) and temozolomide (TMZ) in patients with newly diagnosed IDH-mutated diffuse astrocytoma (DA) and anaplastic astrocytoma (AA). SECONDARY OBJECTIVES: I. To observe and record anti-tumor activity. II. Determine the safety and tolerability of RT/TMZ/telaglenastat (CB-839) HCl in patients based on physician reported adverse event (AE) data. III. Estimate the 2-year progression-free survival (PFS2) of RT/TMZ/telaglenastat (CB-839) HCl in patients with IDH-mutated glioma based on the Response Assessment in Neuro-Oncology (RANO) criteria. IV. Estimate the 2-year overall survival (OS2) of RT/TMZ/telaglenastat (CB-839) HCl in patients with IDH-mutated glioma based on RANO criteria. CORRELATIVE OBJECTIVES: I. Determine the minor response rate (MRR) and clinical benefit rate (CBR) for the combination of telaglenastat (CB-839) HCl and RT/TMZ in IDH-mutated glioma based on RANO criteria. II. Determine the patient-reported tolerability of RT/TMZ/telaglenastat (CB-839) HCl using the MD Anderson Symptom Inventory-Brain Tumor (MDASI-BT) instrument to measure self-reported symptom severity and interference with daily activities. II. Determine the neurocognitive impact of telaglenastat (CB-839) HCl when used in combination with RT/TMZ. III. Determine the effect of telaglenastat (CB-839) HCl/RT/TMZ on plasma oncometabolite levels of glutamine, glutamate, aspartate, asparagine, and 2-hydroxyglutarate (2-HG) in patients with IDH-mutated glioma and associate the changes with disease response. IV. Determine the effect of telaglenastat (CB-839) HCl/RT/TMZ on tumor glutamine and glutamate MRS signals in patients with IDH-mutated glioma and associate the signal with disease response. V. Determine the pharmacokinetics (PK) of telaglenastat (CB-839) HCl when used alone and in combination with TMZ. VI. To perform molecular profiling assays on archived tumor tissue and peripheral blood, including, but not limited to, low-pass whole genome sequencing (WGS), whole exome sequencing (WES), and messenger ribonucleic acid (RNA) sequencing (RNA-Seq) in order to VIa. Identify potential predictive and prognostic biomarkers beyond any genomic alteration by which treatment may be assigned. VIb. Identify resistance mechanisms using genomic deoxyribonucleic acid (DNA)- and RNA-based assessment platforms. VII. To contribute genetic analysis data from de-identified biospecimens to Genomic Data Commons (GDC), a well annotated cancer molecular and clinical data repository, for current and future research; specimens will be annotated with key clinical data, including presentation, diagnosis, staging, summary treatment, and if possible, outcome. VIII. To bank formalin-fixed, paraffin-embedded (FFPE) tissue, blood (for cell-free DNA analysis), and nucleic acids obtained from patients at the Experimental Therapeutics Clinical Trials Network (ETCTN) Biorepository at Nationwide Children's Hospital. OUTLINE: This is a dose escalation study of telaglenastat. Patients receive telaglenastat orally (PO) twice daily (BID) 7 days a week, temozolomide PO once daily (QD) 7 days a week, and undergo RT 5 days a week for up to 5.5 weeks (diffuse astrocytoma) or 6.5 weeks (anaplastic astrocytoma) in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months for up to 2 years.