LTA Pilot Study of Glucarpidase in Patients With Central Nervous System Lymphoma

Inclusion Criteria: Arm A: * Histologically documented B-cell non-Hodgkin"s lymphoma involving the brain, spinal cord, and/or leptomeningeal space. °Patients in whom the type of lymphoma could not be determined or is unknown (e.g., not enough tissue for further analysis) are assumed to have a B cell lymphoma and are eligible * Patients with parenchymal lesions must have received no more than two cycles of treatment for treatment of CNS lymphoma or have unequivocal evidence of disease progression on imaging (MRI of the brain/spine or CT head) 28 days prior to study registration. For patients with leptomeningeal disease only, CSF cytology must document lymphoma cells and/or imaging findings must be consistent with CSF disease 28 days prior to study registration (at the discretion of the investigator). * Patients who have already received two doses of treatment of CNS lymphoma are eligible for enrollment. * (Arm A only) as long as they are planned for at least 6 additional doses of methotrexate. Patients must not have evidence of systemic non-Hodgkin lymphoma requiring active treatment. * Men and woman must be at least 18 years of age on the day of consenting to the study. * Patients must have a Karnofsky Performance Status (KPS) ≥ 50 (See Appendix 2). * Patients must be willing and able to comply with scheduled visits, treatment plan, and laboratory tests. * Patients must have adequate bone marrow and organ function shown by: * Absolute neutrophil count (ANC) ≥ 1.0 x 10…