Background: High-grade gliomas (WHO grade III-IV) patients experience marked morbidity and mortality. While the standard of care for newly diagnosed high-grade glioma patients is surgery followed by concurrent chemotherapy and radiation therapy (RT), the outcomes remain poor. BMX-001 (MnTnBuOE-2-PyP⁵⁺) is a metalloporphyrin with differential action in response to radiation therapy and chemotherapy-induced oxidative stress. As shown in preclinical evaluations, BMX-001, when used with radiation, can protect normal, healthy tissues and augment cell kill in malignant cancer cells, notably, human glioblastoma xenografts. We evaluated the safety of BMX-001 in combination with concurrent RT and temozolomide (TMZ) in a phase 1 study of newly diagnosed high-grade glioma patients and we found that BMX-001 is safe and well-tolerated in this population. The maximum tolerated dose of BMX-001 during concurrent RT and TMZ was determined to be 28 mg delivered subcutaneously (SC) followed by 16 biweekly SC doses at 14 mg (Peters et al., Neuro-Oncology 2018). Methods: For this multi-site, open-label, phase 2 study (NCT02655601), we will randomize approximately 160 patients 1:1 to concurrent RT and TMZ with BMX-001 versus concurrent RT and TMZ alone. Key eligibility criteria include newly diagnosed histologically confirmed high-grade glioma (WHO III-IV), 18 ≥ years, and Karnofsky performance status ≥ 70%. The primary endpoint is overall survival. Secondary endpoints are objective cognitive performance, bone marrow protection, safety and tolerability, progression-free survival, overall tumor response rate, and plasma pharmacokinetics. Exploratory endpoints are patient-reported outcomes of health-related quality of life (as assessed by Functional Assessment of Cancer Therapy–Brain, Functional Assessment of Cancer Therapy-Cognition, and Functional Assessment of Chronic Illness Therapy-Fatigue), qualitative hair loss, and white matter integrity (as measured by MRI diffusion tensor/susceptibility imaging). Since November 2018, this phase 2 study has enrolled 147 of 160 high-grade glioma patients at nine sites in US. Clinical trial information: NCT02655601