Gefitinib and Radiation Therapy in Treating Children With Newly Diagnosed Gliomas

PRIMARY OBJECTIVES: I. To define the safety of gefitinib administered in conjunction with irradiation in children with newly diagnosed non-disseminated diffuse intrinsic brainstem gliomas and newly diagnosed incompletely resected supratentorial malignant gliomas (STMG) not receiving enzyme inducing anticonvulsant drugs (EIACDs). II. To define the safety of gefitinib in children with newly diagnosed, incompletely resected STMG receiving EIACDs. III. To assess the safety and efficacy of gefitinib given with radiation therapy in children newly diagnosed with a brainstem glioma as measured by progression-free survival and to estimate the survival distribution. SECONDARY OBJECTIVES: I. To compare hemodynamic magnetic resonance (MR) parameters to metabolic fludeoxyglucose F 18 (FDG)-positron emission tomography (PET) scanning and correlate both with clinical response or progression in this population. II. To characterize the expression of ErbB1 receptors in tissue from STMG patients using immunohistochemistry and western blot assays. III. To characterize the pharmacokinetics of gefitinib in the above patient groups and determine the effects of EIACD on the pharmacokinetics. IV. To explore the pharmacogenetic polymorphisms for gefitinib (e.g., CYP3A4/5 and BCRP) and relate them to gefitinib pharmacokinetics and pharmacodynamics (phenotype-genotype). OUTLINE: This is a multicenter, dose-escalation study of gefitinib (Phase I closed to accrual effective 10/27/2003). Patients are stratified according to the following: Stratum 1A: Intrinsic brain stem glioma; not receiving concurrent enzyme-inducing anticonvulsant drugs (EIACDs) Stratum 1B: Incompletely resected supratentorial malignant gliomas (STMG); not receiving concurrent EIACDs Stratum 2: Incompletely resected STMG; receiving concurrent EIACDs. Phase I portion (patients in strata 1A, 1B, and 2) (phase I closed to accrual effective 10/27/2003): Patients receive oral gefitinib once daily. Treatment repeats every 4 weeks for 13 courses (1 year). Patients also receive standard brain irradiation once daily, 5 days a week, for 6 weeks beginning concurrently with initiation of the first course of gefitinib. Treatment continues in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of gefitinib until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients experience dose-limiting toxicity. Phase II portion (patients in stratum 1A): Once the MTD or the recommended Phase-II dose is determined, additional patients who have newly diagnosed brain stem gliomas (BSG) are treated at the MTD or the recommended Phase-II dose. Patients are followed for three months after the last protocol treatment for those enrolled strictly on the phase I component. Patients contributing to the phase II portion are followed until the earliest of date of death or three years after initiation of protocol therapy. PROJECTED ACCRUAL: Considering the seven dose levels to be investigated in three strata, where each dose level can accrue up to six patients, a total of 126 patients (42 for each strata) may be accrued for this study within 2 years. (Phase I closed to accrual effective 10/27/2003). A total of 40 patients including the patients treated at the maximum tolerated dose or the recommended Phase-II dose during Phase I will be accrued for phase II of this study within 10 months.