RecruitingPhase 2Drug trialStudy of Ribociclib and Everolimus in HGG and DIPG or Ribociclib and Temozolomide in DHG, H3G34-mutantThe goal of this study is to determine the efficacy of the 1) ribociclib and everolimus to treat pediatric and young adult patients newly diagnosed with a high-grade glioma (HGG), including DIPG, that have genetic changes in pathways (cell cycle, PI3K/mTOR) that these drugs target or 2) ribociclib and temozolomide to treat pediatric and young adult patients newly diagnosed with diffuse hemispheric glioma (DHG), H3G34-mutant. The main question the study aims to answer is whether the combinations of ribociclib and everolimus or ribociclib and temozolomide can prolong the life of patients diagnosed with HGG/DIPG or DHG H3G34-mutant.