This study investigates the effectiveness of combination chemotherapy with or without an investigational medication in patients with newly diagnosed T-cell acute lymphoblastic leukemia (T-ALL) or stage II-IV T-cell lymphoblastic lymphoma (T-LLy). T-cell acute lymphoblastic leukemia is a type of cancer that affects the blood and bone marrow, while T-cell lymphoblastic lymphoma is a similar type of cancer that affects the lymph nodes.
Participants in the study will receive either chemotherapy alone or chemotherapy combined with an investigational medication. Chemotherapy is a treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing.
- Who can participate: Eligible individuals must be newly diagnosed with T-ALL or T-LLy stages II-IV, enrolled in Project: Every Child, and meet age criteria. Exclusions include prior cytotoxic chemotherapy, uncontrolled seizure disorder, and Down syndrome.
- Study details: Participants will be randomly assigned to receive either chemotherapy alone or with an investigational medication. No placebo will be used in this study.

