Eligibility Criteria:
Inclusion Criteria:
* Participants must have newly diagnosed T-cell acute lymphoblastic leukemia (T-ALL) or T-lineage lymphoblastic lymphoma (T-LBL) based on 2022 World Health Organization (WHO) criteria. Participants with acute leukemia of ambiguous lineage (ALAL), including mixed phenotype acute leukemia (MPAL), are not eligible for this trial
* For T-ALL, immunophenotyping of the blood or marrow lymphoblasts must be performed by flow cytometry to confirm T-cell lineage and exclude ALAL or MPAL. Appropriate lineage-specific antigens include cytoplasmic or surface CD3 for T lineage, myeloperoxidase (MPO) or monocytic antigens (CD11c, CD14, CD64, lysozyme) for myeloid lineage, and CD19, CD20, CD22, CD79a, CD10 and PAX5 for B lineage. For T-LBL, immunohistochemistry on paraffin embedded tissue alone can be used to establish the diagnosis, although flow cytometry is preferred
* NOTE: Systemic chemotherapy must begin within 72 hours of first dose of intrathecal therapy
* Collection of pretreatment blood and bone marrow specimens must be completed within 14 days prior to registration for all participants. If bone marrow is unable to be aspirated and blood blast percentage is at least 5%, additional blood should be collected as instructed in the study calendar
* Participants must not have received prior induction chemotherapy for T-ALL/LBL. Prior treatments with hydroxyurea, all-trans retinoic acid (ATRA), corticosteroids, leukapheresis to reduce peripheral blast count and prevent complications from leukocytosis, and a single dose of intrathecal cytarabine and/or methotrexate with or without steroids are permitted
* Participants must discontinue strong CYP3A4 inducers within 7 days prior to registration. Dose adjustments for CYP3A4 inhibitors/inducers during protocol therapy are defined in the protocol
* Participants must be 18-60 years old
* Participants must have Zubrod/Eastern Cooperative Oncology Group (ECOG performance status of 0-2
* Participants must have a complete medical history and physical exam within 28 days prior to registration
* Participants with extramedullary disease at diagnosis must have a CT scan with contrast of chest, neck, abdomen, pelvis, or whole body to obtain baseline values within 28 days prior to registration
* Total bilirubin ≤ 1.5 institutional upper limit of normal (ULN). Participants with history of Gilbert's disease or leukemia involving the liver must have total bilirubin ≤ 5 x institutional ULN within 7 days prior to registration
* Aspartate aminotransferase (AST)/ Alanine aminotransferase (ALT) Both must be ≤ 3 × institutional ULN unless related to leukemia involving the liver
* Participants must have a serum creatinine 1.5 ≤ the ULN OR measured OR calculated creatinine clearance ≥ 50 mL/min using the Cockcroft-Gault Formula. This specimen must have been drawn and processed within 7 days prior to registration
* Participants must have a lumbar puncture to determine CNS involvement of ALL within 14 days prior to registration. Intrathecal cytarabine and/or methotrexate administered prior to study registration may count as the first dose of intrathecal therapy required as part of protocol therapy
* Participants must have cardiac ejection fraction \>= 50% by MUGA or 2-D echocardiogram within 28 days before registration. Participants with known history or current symptoms of cardiac disease, or history of treatment with cardiotoxic agents, must have a clinical risk assessment of cardiac function using the New York Heart Association Functional Classification. To be eligible for this trial, participants must be class 2B or better
* Participants with evidence of chronic hepatitis B virus (HBV) infection must have undetectable HBV viral load while on suppressive therapy on the most recent test results obtained within 6 months prior to registration, if indicated
* Participants with known human immunodeficiency virus (HIV)-infection must be on effective anti-retroviral therapy at registration and have undetectable viral load test on the most recent test results obtained within 6 months prior to registration
* Participants with a history of hepatitis C virus (HCV) infection must have been treated and cured. Participants currently being treated for HCV infection must have undetectable HCV viral load test on the most recent test results obtained within 6 months prior to registration, if indicated
* Participants with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial (in the opinion of the treating physician)
* Participants must not be pregnant or nursing. Individuals who are of reproductive potential must have agreed to use an effective contraceptive method with details provided as a part of the consent process. A person who has had menses at any time in the preceding 24 consecutive months or who has semen likely to contain sperm is considered to be of "reproductive potential." In addition to routine contraceptive methods, "effective contraception" also includes refraining from sexual activity that might result in pregnancy and surgery intended to prevent pregnancy (or with a side-effect of pregnancy prevention) including hysterectomy, bilateral oophorectomy, bilateral tubal ligation/occlusion, and vasectomy with testing showing no sperm in the semen
* Participants with T-ALL must not have a history of seizure disorder due to nelarabine administration
* Participants must be offered the opportunity to participate in specimen banking. With participant consent, specimens must be collected and submitted via the Southwest Oncology Group (SWOG) Specimen Tracking System
* Participants must agree to have blood and bone marrow specimens submitted for MRD