A Study of the Drugs Selumetinib Versus Carboplatin/Vincristine in Patients With Neurofibromatosis and Low-Grade Glioma

PRIMARY OBJECTIVES: I. To determine whether the efficacy of treatment with selumetinib sulfate (selumetinib) as measured by event-free survival (EFS) is non-inferior to treatment with carboplatin/vincristine sulfate (vincristine) (CV) in previously untreated neurofibromatosis type 1 (NF1)-associated low-grade glioma (LGG). II. To determine whether visual acuity (VA) using Teller acuity cards (TAC), in patients with NF1-associated LGG within the optic pathway, is better in those treated with selumetinib compared to CV. SECONDARY OBJECTIVES: I. To estimate tumor response rates and overall survival (OS) in each treatment regimen in previously untreated NF1-associated LGG. II. To evaluate VA outcomes utilizing HOTV letter acuity testing in previously untreated NF1-associated LGG within the optic pathway in patients who are old enough to perform visual acuity testing utilizing HOTV (a recognition acuity measure). III. To describe the improvement in motor function as measured by the Vineland scale in patients with previously untreated NF1-associated LGG that have documented motor deficits at enrollment. IV. To prospectively evaluate and compare the quality of life among patients treated with selumetinib or CV. V. To prospectively evaluate and compare the cognitive, social, emotional, and behavioral functioning of patients with NF1-associated LGG treated with either selumetinib or CV. EXPLORATORY OBJECTIVES: I. To evaluate optical coherence tomography (OCT) measures of retinal axon and ganglion cell thickness as a marker of treatment response in previously untreated NF1-associated LGG within the optic pathway. II. To compare novel, semi-automated volumetric magnetic resonance imaging (MRI) measures to traditional measurements of treatment response (bi-dimensional MRI measurements) in NF1-associated optic pathway tumors. III. To obtain paired blood and tumor tissue to be banked for future NF1-LGG biology studies involving comprehensive molecular analysis, including but not limited to whole exome and ribonucleic acid (RNA) sequencing. OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: INDUCTION: Patients receive carboplatin intravenously (IV) over 60 minutes on days 1, 8, 15, 22, 43, 50, 57, and 64 and vincristine IV on days 1, 8, 15, 22, 29, 36, 43, 50, 57, and 64 in the absence of disease progression or unacceptable toxicity. Patients also undergo MRI throughout the trial. MAINTENANCE: Patients receive carboplatin IV over 60 minutes on days 1, 8, 15, and 22 of each cycle and vincristine IV on days 1, 8, and 15 of each cycle. Cycles repeat every 6 weeks for 8 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo MRI throughout the trial. ARM II: Patients receive selumetinib sulfate orally (PO) twice daily (BID) on days 1-28 of each cycle. Treatment is continuous and cycles repeat every 28 days for 27 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 with MRIs and physical exams every 3 months for 1 year, every 6 months for 2 years, and then once yearly for up to 10 years.