A Study of the Drugs Selumetinib vs. Carboplatin and Vincristine in Patients With Low-Grade Glioma

PRIMARY OBJECTIVE: I. To demonstrate that the efficacy of treatment with selumetinib as measured by event-free survival (EFS) is non-inferior compared to treatment with carboplatin/vincristine (CV) in previously-untreated low-grade glioma (LGG) not associated with BRAFV600E mutations or systemic neurofibromatosis type 1 (NF1). SECONDARY OBJECTIVES: I. To estimate tumor response rates to each regimen of chemotherapy. II. To evaluate visual acuity (VA) outcomes utilizing Teller Acuity Cards (TAC) and HOTV letter acuity testing in previously-untreated optic pathway gliomas (OPGs). III. To describe the improvement in motor function as measured by the Vineland Scale in children with previously-untreated LGG that have motor deficits at enrollment. IV. To estimate the difference in EFS and tumor response rate between BRAF rearranged and non-BRAF rearranged patients treated on each chemotherapy regimen. V. To prospectively evaluate the quality of life of children with LGG not associated with BRAFV600E or systemic NF1 treated with either CV or selumetinib. VI. To prospectively evaluate the cognitive, social, emotional, and behavioral functioning of children with LGG not associated with BRAFV600E or systemic NF1 treated with either CV or selumetinib. EXPLORATORY OBJECTIVE: I. To obtain paired blood and tumor specimens for future biology studies as well as data from Molecular Characterization Initiative (MCI) testing, to correlate genomic drivers to efficacy outcomes. OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: INDUCTION: Patients receive vincristine sulfate intravenously (IV) on days 1, 8, 15, 22, 29, 36, 43, 50, 57, and 64, and carboplatin IV over 60 minutes on days 1, 8, 15, 22, 43, 50, 57, and 64 in the absence of disease progression or unacceptable toxicity. Patients also undergo collection of blood and magnetic resonance imaging (MRI) throughout the trial. MAINTENANCE: Patients receive vincristine sulfate IV on days 1, 8, and 15, and carboplatin IV over 60 minutes on days 1, 8, 15, and 22 of each cycle. Cycles repeat every 42 days for up to 8 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo collection of blood and MRI throughout the trial. ARM II: Patients receive selumetinib sulfate orally (PO) twice daily (BID) on days 1-28 of each cycle. Cycles repeat every 28 days for up to 27 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo echocardiography (ECHO) at baseline and undergo collection of blood and MRI throughout the trial. After completion of study treatment, patients are followed up every 3 months for year 1, every 6 months for years 2-3, and then annually for years 4-10.