A Phase 3 Trial Investigating Blinatumomab (NSC# 765986) in Combination With Chemotherapy in Patients With Newly Diagnosed Standard Risk or Down Syndrome B-Lymphoblastic Leukemia (B-ALL) and the Treatment of Patients With Localized B-Lymphoblastic Lymphoma (B-LLy)

• All B-ALL patients must be enrolled on APEC14B1 and consented to Eligibility Screening (Part A) prior to treatment and enrollment on AALL1731. APEC 14B1 is not a requirement for B-LLy patients. B-LLy patients may directly enroll on AALL1731.

• Age at diagnosis:

• Patients must be >= 365 days and < 10 years of age (B-ALL patients without DS).

• Patients must be >= 365 days and =< 31 years of age (B-ALL patients with DS).

• Patients must be >= 365 days and =< 31 years of age (B-LLy patients with or without DS).

• B-ALL patients without DS must have an initial white blood cell count < 50,000/uL (performed within 7 days prior to enrollment).

• B-ALL patients with DS are eligible regardless of the presenting white blood cell count (WBC) (performed within 7 days prior to enrollment).

• Patient has newly diagnosed B-cell ALL, with or without Down syndrome: > 25% blasts on a bone marrow (BM) aspirate;

• OR if a BM aspirate is not obtained or is not diagnostic of B-ALL, the diagnosis can be established by a pathologic diagnosis of B-ALL on a BM biopsy;

• OR a complete blood count (CBC) documenting the presence of at least 1,000/uL circulating leukemic cells;

• OR patient has newly diagnosed B-cell LLy Murphy stages I or II, with or without Down syndrome.

• Note: For B-LLy patients with tissue available for flow cytometry, the criterion for diagnosis should be analogous to B-ALL. For tissue processed by other means (i.e., paraffin blocks), the methodology and criteria for immunophenotypic analysis to establish the diagnosis of B-LLy defined by the submitting institution will be accepted (diagnostic biopsy for B-LLy must be performed within 14 days prior to enrollment).

• All patients and/or their parents or legal guardians must sign a written informed consent.

• All institutional, Food and Drug Administration (FDA), and National Cancer Institute (NCI) requirements for human studies must be met.