This study is for people with newly diagnosed grade 3 astrocytoma, a type of brain cancer. After radiation treatment, participants will take a usual medicine called temozolomide, which damages tumor cells, along with either vorasidenib or a placebo. Vorasidenib is a targeted therapy that stops the growth of certain tumor cells. The study aims to see if adding vorasidenib helps more than temozolomide alone.
- Participants will take medicine and have MRI scans and blood tests over a 12-month period.
- Patients must be 12 years or older and have certain health conditions to join.
- Participants will have follow-up visits for up to 10 years after treatment ends.
The study will check how well the treatment works, how safe it is, and its side effects. Participants can't have had certain treatments before and must be able to take an MRI. They should also agree to use birth control during and after the study, if applicable. The study excludes those with certain medical conditions or other medications that may interfere with the treatment.