BGB-290 and Temozolomide in Treating Isocitrate Dehydrogenase (IDH)1/2-Mutant Grade I-IV Gliomas

Inclusion Criteria: * Arm A Only: Participants must have histologically confirmed World Health Organization (WHO) grade III-IV newly diagnosed IDH1/2-mutant glioma. * Arm B Only: WHO grades I-IV recurrent IDH1/2 mutant glioma. Participants in Arm B must have magnetic resonance imaging (MRI) confirming progressive disease; re-biopsy is encouraged, but not required at the time of recurrence for confirmation. * Participants with a primary spinal tumor, secondary glioma, or multifocal disease in the brain, but without evidence of diffuse leptomeningeal spread, are eligible. In cases where there are questions about multifocality versus diffuse leptomeningeal spread, the study chair or co-chair must be contacted to make a final decision on eligibility. * Participants must have IDH1 or IDH2 mutation associated with neomorphic activity of the encoded proteins. * Participants must be willing to provide archival formalin-fixed embedded (FFPE) and frozen tissue specimens for biomarker studies if available. * Participants in Arm A must have been treated with maximal safe resection of primary tumor followed by adjuvant radiation therapy (RT). Treatment with TMZ during radiation is allowed but not required. * Participants in Arm B must have been treated with maximal safe resection of tumor. * Lower grade glioma (LGG) participants who progressed after initial surgery alone are eligible. Any number of prior therapies are allowed. * High grade glioma (HGG) participants enrolled on Arm B…