Blinatumomab in Treating Younger Patients With Relapsed B-cell Acute Lymphoblastic Leukemia

Inclusion Criteria: * Patients \>= 1 year and \< 31 years of age at the time of relapse will be eligible * First relapse of B-ALL, allowable sites of disease include isolated bone marrow, combined bone marrow and CNS and/or testicular, and isolated CNS and/or testicular; extramedullary sites are limited to the CNS and testicles * No waiting period for patients who relapse while receiving standard maintenance therapy * Patients who relapse on frontline therapy in phases other than maintenance must have fully recovered from the acute toxic effects of all prior chemotherapy, immunotherapy, or radiotherapy prior to entering this study * Cytotoxic therapy: at least 14 days since the completion of cytotoxic therapy with the exception of hydroxyurea, which is permitted up to 24 hours prior to the start of protocol therapy, or maintenance chemotherapy, or intrathecal chemotherapy (methotrexate strongly preferred) administered at the time of the required diagnostic lumbar puncture to establish baseline CNS status * Biologic (anti-neoplastic) agent: at least 7 days since the completion of therapy with a biologic agent; for agents that have known adverse events occurring beyond 7 days after administration, this period must be extended beyond the time during which adverse events are known to occur * Stem cell transplant or rescue: patient has not had a prior stem cell transplant or rescue * Patient has not had prior treatment with blinatumomab * With the exception of intrathecal chemoth…