1. Patients must have a histologically confirmed diagnosis of a recurrent/progressive WHO Gr.4 malignant glioma (glioblastoma multiforme or gliosarcoma) or WHO Gr.3 malignant glioma (anaplastic astrocytoma, anaplastic oligodendroglioma or anaplastic mixed glioma). Recurrence will be defined based on the modified MacDonald criteria or based on histopathologic confirmation of tissue obtained via surgical intervention. Patients with prior low-grade glioma are eligible if histologic assessment demonstrates transformation to WHO Gr.III or IV malignant glioma;