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 ELIGIBILITY CRITERIA - PHASE I (ARMS A, B, C): No evidence of isolated extramedullary relapse (i.e., testicular or central nervous system [CNS]) ELIGIBILITY CRITERIA - PHASE II (ARM D): No evidence of isolated extramedullary relapse (i.e., testicular or CNS) Subjects may not have presence of active CNS disease or extramedullary disease. Solitary bone or solitary extramedullary plasmacytoma as the only evidence of plasma cell dyscrasia. PHASE I: If relapse/refractory status with no prior history of allogeneic HCT (one of the following)\r\n* 2nd or greater marrow relapse, with or without extramedullary disease\r\n* 1st marrow relapse at end of 1st month of re-induction with marrow having\r\n* >= 0.01% blast by morphology and/or MPF, with or without extramedullary disease\r\n* Primary refractory as defined as having M2 or M3 marrow after 2 or more separate induction regimens\r\n* Subject has indication for HCT but has been deemed ineligible PHASE II: Confirmed CD19+ leukemia recurrence defined as >= 0.01% disease in the marrow or isolated extramedullary disease following allogeneic HCT OR PHASE II: No prior history of allogeneic HCT (one of the following)\r\n* 2nd or greater relapse, with or without extramedullary disease (isolated extramedullary disease is eligible)\r\n* 1st marrow relapse at end of 1st month of re-induction with marrow having >= 0.01% blast disease, with or without extramedullary disease\r\n* Primary refractory as defined as having M2 or M3 marrow after induction\r\n* Subject has indication for HCT but has been deemed ineligible OR Extramedullary disease status: patients with isolated CNS disease or isolated testicular disease are not eligible Patients with extramedullary disease only are eligible Isolated extramedullary disease Subjects who have received prior radiation therapy for extramedullary disease within 2 weeks of first dose Patients with active extramedullary disease. Patients with extramedullary disease as their sole site of relapsed AML. Patients with isolated extramedullary disease or with known parenchymal central nervous system (CNS) disease No evidence of disease-related symptoms and extramedullary disease, including the liver and spleen Isolated extramedullary leukemia without also meeting bone marrow criteria for leukemia A histologically or pathologically confirmed diagnosis of AML based on WHO classification with or without extramedullary disease except for central nervous system disease. Participants with extramedullary AML with no evidence of systemic involvement Isolated extramedullary relapse (i.e. testicular, central nervous system) PHASE II ONLY: Isolated extramedullary relapse Solitary bone or extramedullary plasmacytoma disease only No active extramedullary leukemia or known active CNS involvement by malignancy; such disease treated into remission is permitted Extramedullary leukemia allowed except CNS disease Extramedullary (CNS) disease; Patients with known extramedullary leukemia are not eligible Patients with isolated extramedullary disease or with parenchymal central nervous system (CNS) disease Patients with isolated central nervous system (CNS), testicular, or other extramedullary site of relapse Patient must have one of the following:\r\n* Recurrent disease with >= 5% blasts in the bone marrow (M2/M3 bone marrow), with or without extramedullary disease.\r\n* Recurrent disease with an absolute blast count greater than 1,000 per microliter in the peripheral blood with or without extramedullary disease Disease status: \r\n* Phase 1 (Part A):\r\n** Patients must have either measurable or evaluable disease \r\n* Phase 2 (Part B):\r\n** Ewing sarcoma or peripheral PNET: patients must have measurable disease\r\n* Phase 2 (Part C):\r\n** Acute lymphoblastic leukemias (ALL): patients with ALL must have an M3 marrow with or without extramedullary site of relapse OR an M2 bone marrow with an extramedullary site of relapse; patients with CNS 3 status are not eligible for enrollment Isolated extramedullary relapse (i.e., testicular, CNS). Patients must be in morphologic leukemia-free state (marrow blasts < 5%) without evidence of extramedullary disease within 21 days of HCT Subjects with solitary bone or extramedullary plasmacytoma as the only evidence of plasma cells dyscrasia Extramedullary disease only. Isolated extramedullary disease Patients may have CNS or other sites of extramedullary disease; no cranial irradiation is allowed during the protocol therapy Isolated extramedullary disease relapse Isolated extramedullary relapse (leukemia) or isolated CNS lymphoma Active extramedullary disease at any site. (Note: Definitive therapy of known previous sites of extramedullary disease is allowed) Isolated extramedullary relapse (i.e., testicular or CNS) Isolated extramedullary disease (leukemia) Multiple myeloma: solitary bone or solitary extramedullary plasmacytoma as the only evidence of plasma cell dyscrasia Patient must have relapsed/refractory acute lymphoblastic leukemia (ALL) with ? 5 blasts in the bone marrow or biopsy confirmed extramedullary disease. Patient may have CNS 1, 2 or 3 disease. Isolated CNS relapse is not eligible. Isolated extramedullary disease Isolated extramedullary disease Solitary bone or solitary extramedullary plasmacytoma as the only evidence of plasma cell dyscrasia. Active extramedullary disease Extramedullary disease in the absence of bone marrow or blood involvement Extramedullary disease in the absence of any measurable medullary involvement Patients with known extramedullary leukemia Extramedullary disease only Active leukemia in the testes or isolated extramedullary relapse; patients with a history of treated leukemia in testes but no active disease at the time of enrollment are eligible Isolated extramedullary relapse.