Inclusion Criteria:

          1. Confirmed diagnosis of acute lymphoblastic leukemia. Diagnosis should be made by bone
             marrow aspirate or biopsy demonstrating ≥ 25% involvement by lymphoblasts, with flow
             cytometry or immunohistochemistry confirming B-precursor or T-ALL phenotype.

             -- For patients with circulating blasts in the peripheral blood, flow cytometry
             confirmation of B-ALL or T-ALL phenotype is sufficient for registration onto the
             study. Bone marrow aspirate and/or biopsy should be performed as soon as feasible,
             preferably prior to the initiation of any therapy.

          2. Prior Therapy: No prior therapy is allowed except for the following:

               -  Corticosteroids: Short courses of corticosteroid (defined as ≤ 7 days of
                  corticosteroids within the 4-weeks preceding registration) are allowed prior to
                  registration.

                  --- Participants who have been on corticosteroids chronically (defined as more
                  than 7 days of corticosteroids within the 4-weeks preceding registration or more
                  than 28 days of corticosteroids over the preceding 6 months) are not eligible.

               -  IT cytarabine: A single dose of intrathecal cytarabine (at the time of the
                  diagnostic lumbar puncture) is allowed prior to registration. If patient has
                  received IT cytarabine prior to registration, Day 1 IT cytarabine should not be
                  administered.

               -  Emergent Radiation Therapy: Emergent radiation to the mediastinum or other
                  life-threatening masses is allowed prior to registration.

          3. Age: 365 days to < 22 years

          4. Direct bilirubin < 1.4 mg/dL (23.9 micromoles/L).

          5. Ability of parent or guardian to understand and the willingness to sign a written
             informed consent document.

        Exclusion Criteria:

          1. Mature B-cell (Burkitt's) ALL (defined by the presence of surface immunoglobulin
             and/or the t(8;14)(q24;q32), t(8;22), or t(2;8) translocation and/or c-myc-gene
             rearrangement).

          2. World Health Organization diagnostic criteria of mixed phenotype acute leukemia (MPAL)
             or leukemia of ambiguous lineage

          3. Any chemotherapy or radiotherapy for previous malignancy are not eligible.

          4. Treatment in past with any anti-neoplastic agent, including methotrexate,
             6-mercaptopurine, 6-thioguanine, vincristine cyclophosphamide, cytarabine (except for
             IT cytarabine), or any anthracycline, for any reason (eg, rheumatologic or autoimmune
             condition).

          5. Currently receiving any investigational agents.

          6. Known HIV-positivity

          7. Uncontrolled intercurrent illness including, but not limited to ongoing infection with
             vital sign instability (hypotension, respiratory insufficiency), life-threatening
             acute tumor lysis syndrome (eg, with renal failure), symptomatic congestive heart
             failure, cardiac arrhythmia, intracranial or other uncontrolled bleeding, or
             psychiatric illness/social situations that would limit compliance with study
             requirements.

          8. Pregnant women are excluded from this study because many of the agents used on this
             protocol have potential for teratogenic and/or abortifacient effects. Because there is
             an unknown but potential risk of adverse events in nursing infants secondary to
             treatment of the mother with these chemotherapy agents, breastfeeding should be
             discontinued if the mother is enrolled.

          9. History of a previous malignancy. Exception: Individuals with a previous malignancy
             treated with surgery only (no chemotherapy or radiotherapy) more than 5 years prior to
             registration may be enrolled.