Astrocytoma, IDH-Mutant, Grade 3

This phase III trial compares the effect of vorasidenib to placebo in combination with usual treatment, temozolomide, in treating patients with newly diagnosed grade 3 astrocytoma after radiation. Temozolomide is in a class of medications called alkylating agents. It works by damaging the cell's deoxyribonucleic acid and may kill tumor cells and slow down or stop tumor growth. Vorasidenib citrate blocks the proteins made by the mutated IDH1 and IDH2 genes, which may help keep tumor cells from growing. It is a type of enzyme inhibitor and a type of targeted therapy. Adding vorasidenib to the usual treatment, temozolomide, may be more effective than temozolomide alone in treating patients with newly diagnosed grade 3 astrocytoma after radiation therapy.

This is a 3-part study. The purpose of Part 1 of the study is to evaluate the efficacy, safety, and pharmacokinetic (PK) characteristics of safusidenib in participants with recurrent/progressive IDH1-mutant World Health Organization (WHO) Grade 2 or Grade 3 glioma. The purpose of Part 2 will be to evaluate the efficacy of maintenance safusidenib treatment versus placebo in IDH1-mutant Grade 2 or Grade 3 astrocytoma with high-risk features or IDH1-mutant Grade 4 astrocytoma, following standard-of-care radiation or chemoradiation and adjuvant temozolomide. Part 2 will be randomized, double-blind, and placebo-controlled. The purpose of Part 3 will be to evaluate the efficacy of safusidenib in participants with residual or recurrent IDH1-mutant Grade 3 oligodendroglioma who have received surgery as their only treatment. Part 3 will be an open-label single-arm cohort and will enroll participants concurrently with Part 2.

This phase I/II trial tests the safety, side effects best dose and effect of retifanlimab with or without difluoromethylornithine (DFMO) for the treatment of high grade gliomas that are growing, spreading, or getting worse (progressive). Immunotherapy with monoclonal antibodies, such as retifanlimab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. DFMO is in a class of medications called ornithine decarboxylase (ODC) inhibitors. It works by blocking the action of a substance that signals tumor cells to multiply. This helps stop or slow the spread of tumor cells. Giving retifanlimab with or without DFMO mat be safe, tolerable and/or effective in treating patients with progressive high grade glioma.