Phase 2, Open-label, Single-arm Study on the Use of Metformin as Adjunctive Therapy in High-grade Glioma

This study tests whether metformin (a common diabetes drug) can be safely combined with standard radiation and chemotherapy (the Stupp protocol) to improve outcomes in people with newly diagnosed glioblastoma — the most aggressive type of brain tumor. **You may be eligible if...** - You are 18 or older with newly diagnosed glioblastoma (WHO grade IV) confirmed by surgery - You are starting the standard radiation and chemotherapy (Stupp protocol) - Your performance status (Karnofsky score) is above 60 after surgery - Your estimated survival is at least 6 months - You do not have diabetes **You may NOT be eligible if...** - You have diabetes or are taking insulin, metformin, or any biguanide drugs - Your cancer involves multiple parts of the brain (multicentric GBM) - You have poor kidney or liver function that would make metformin unsafe - You are pregnant or breastfeeding - You are allergic to metformin - You have another active cancer Talk to your doctor to see if this trial is right for you.