Testing the Addition of the Chemotherapy Drug Lomustine (Gleostine) to the Usual Treatment (Temozolomide and Radiation Therapy) for Newly Diagnosed MGMT Methylated Glioblastoma

PRIMARY OBJECTIVE: I. To determine if the regimen with the two alkylating agents temozolomide and lomustine with radiotherapy (RT) significantly prolongs overall survival (OS) versus (vs.) standard chemoradiotherapy with temozolomide in patients with newly diagnosed glioblastoma (GBM) with MGMT promoter methylation. SECONDARY OBJECTIVES: I. To determine if the regimen with the two alkylating agents temozolomide and lomustine with radiotherapy (RT) significantly prolongs progression-free survival (PFS) vs. standard chemoradiotherapy with temozolomide in patients with newly diagnosed GBM with MGMT promoter methylation. II. To compare the two different chemotherapy regimens on patient-reported outcomes (PROs), as measured by the MD Anderson Symptom Inventory - Brain Tumor (MDASI-BT) in patients with newly diagnosed GBM with MGMT promoter methylation. III. To determine if the regimen with the two alkylating agents temozolomide and lomustine with radiotherapy (RT) is associated with inferior short-term change in PROs as measured by MDASI-BT vs. standard chemoradiotherapy with temozolomide in patients with newly diagnosed GBM with MGMT promoter methylation. IV. To assess toxicity in the two different chemotherapy regimens. EXPLORATORY OBJECTIVES: I. To assess the association between absolute lymphocyte counts and outcomes. II. To assess the association between CD4+ lymphocyte counts and outcomes. III. To compare the two different chemotherapy regimens in terms of long-term PROs as measured by MDASI-BT at years 1 and 2. OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: Patients undergo radiation therapy 5 days per week and receive temozolomide orally (PO) once daily (QD) for 6 weeks in the absence of disease progression or unacceptable toxicity. Patients then receive temozolomide PO QD on days 1-5 of each cycle. Treatment repeats every 28 days for 6 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo magnetic resonance imaging (MRI) throughout the trial. ARM II: Patients undergo radiation therapy 5 days per week for 6 weeks in the absence of disease progression or unacceptable toxicity. Patients also receive lomustine PO on day 1 of each cycle and temozolomide PO QD on days 2-6 of each cycle. Treatment repeats every 42 days for 6 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo MRI throughout the trial. After completion of study treatment, patients are followed up every 3 months for year 1, every 4 months for year 2, and then every 6 months thereafter.