Imatinib Mesylate With or Without Radiation Therapy in Treating Young Patients With Newly Diagnosed or Recurrent Glioma

PRIMARY OBJECTIVES: I. Determine the maximum tolerated dose (MTD) of imatinib mesylate after completion of radiation in children with newly diagnosed poor prognosis brainstem gliomas. (Phase I, strata I closed to accrual as of 5/28/04.) II. Determine the maximum tolerated dose (MTD) of imatinib mesylate in children with recurrent high-grade intracranial glioma stratified according to the use of enzyme-inducing anticonvulsant drugs (EIACDs). (Phase I, strata IIA and IIB closed to accrual as of 8/15/03 and 8/15/04, respectively) III. Determine the safety and efficacy of this drug in patients with newly diagnosed diffuse intrinsic brainstem gliomas. (Phase II) SECONDARY OBJECTIVES: I. Explore neuroimaging and biological correlatives of therapeutic activity of this regimen in these patients. (Phase I, all strata closed to accrual as of 8/15/04) II. Determine the pharmacokinetics of these regimens in these patients overall and by enzyme-inducing anticonvulsant drugs (EIACDs) (Phase I, all strata closed to accrual as of 8/15/04.) III. Estimate the progression-free survival (PFS) and overall survival (OS) of newly diagnosed diffuse intrinsic brainstem gliomas treated with this drug. (Phase I and II) OUTLINE: This is a phase I dose-escalation, multicenter study followed by a phase II. Patients are stratified according to tumor type (newly diagnosed intrinsic brainstem glioma vs recurrent/refractory intracranial high-grade glioma). Patients in stratum II (phase I only) are further stratified according to concurrent use of enzyme-inducing anticonvulsant drugs (EIACDs) (yes vs no). Patients are assigned to one of three strata in the phase I study. * Phase I * Stratum I (newly diagnosed brainstem glioma): Patients undergo radiotherapy once daily five days a week for 6 weeks. Beginning 1-3 weeks after completion of radiotherapy, patients without evidence of intratumoral bleed receive oral imatinib mesylate twice daily. Imatinib mesylate treatment repeats every 4 weeks for up to 13 courses in the absence of disease progression or unacceptable toxicity. (Closed to accrual as of 5/28/04.) * Stratum II A (recurrent or refractory high-grade intracranial gliomas/no concurrent EIACDs): Patients receive imatinib mesylate as in stratum I. (Closed to accrual as of 8/15/03.) * Stratum II B (recurrent or refractory high-grade intracranial gliomas and concurrent EIACDs): Patients receive imatinib mesylate as in stratum I. (Closed to accrual as of 8/15/04.) Cohorts of 2-3 patients receive escalating doses of imatinib mesylate until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose at which it is estimated that 20% of patients will experience dose-limiting toxicity. MTDs are independently estimated in each strata. For stratum I, newly diagnosed brain stem gliomas, the dose level which at least 5 of 6 patients experience no dose-limiting toxicity will be the dose used in the efficacy and safety phase (phase II). * Phase II: (Open to accrual as of 5/28/04.) * Stratum I only: Patients undergo radiotherapy as in phase I. Patients receive imatinib mesylate at the MTD established in phase I. Patients enrolled in the phase I portion and not treated at the MTD are to be followed for the shortest of 1) three months after the last protocol based treatment or 2) the date other therapy is initiated. Stratum I patients treated at the MTD in the phase I portion and all patients in the phase II portion of the study are to be followed until death or withdrawal from the study PROJECTED ACCRUAL: Approximately 140 patients will be accrued for this study within 2 years.