A Phase I/II Study of Zotiraciclib for Recurrent Malignant Gliomas With Isocitrate Dehydrogenase 1 or 2 (IDH1 or IDH2) Mutations

Background: Diffuse gliomas are tumors that affect the brain and spinal cord. Gliomas that develop in people with certain gene mutations (IDH1 or IDH2) are especially aggressive. Better treatments are needed. Objective: To see if a study drug (zotiraciclib) is effective in people with recurrent diffuse gliomas who have IDH1 or IDH2 mutations. Eligibility: People aged 15 years and older with diffuse gliomas that returned after treatment. They must also have mutations in the IDH1 or IDH2 genes. Design: Participants will be screened. They will have a physical exam with blood and urine tests. They will have tests of their heart function. They will have an MRI of their brain. A new biopsy may be needed if previous results are not available. Zotiraciclib is a capsule taken by mouth with a glass of water. Participants will take the drug at home on days 1, 4, 8, 11, 15, and 18 of a 28-day cycle. They may also be given medications to prevent side effects of the study drug. The schedule for taking the study drug may vary for participants who will undergo surgery. Participants will be given a medication diary for each cycle. They will write down the date and time of each dose of the study drug. Participants will visit the clinic about once a month. They will have a physical exam, blood tests, and tests to evaluate their heart function. An MRI of the brain will be repeated every 8 weeks. Participants may remain in the study for up to 18 cycles (1.5 years).