Key Inclusion Criteria:

• • Documented acute lymphoblastic leukemia (ALL) or lymphoblastic lymphoma (LL) as defined by the criteria below:
    1.B-cell cohort: Stage 1; ALL in second or greater relapse or refractory to 2 prior induction regimens with greater than or equal to (>=) 5 percent (%) blasts in the bone marrow and aged 1 to less than (<) 18 years. Stage 2; ALL in second or greater relapse or refractory to 2 prior induction regimens with (>=) 5% blasts in the bone marrow and aged 1 to 30 years. LL in second or greater relapse or refractory to 2 prior induction regimens and biopsy proven and with evidence of measurable disease by radiologic criteria and aged 1 to 30 years.
    2.T-cell cohort: Stage 1; ALL in first relapse or refractory to 1 prior induction/consolidation regimen with (>=) 5% blasts in the bone marrow and aged 1 to <18 years. Stage 2; ALL in first relapse or refractory to 1 prior induction/consolidation regimen with (>=) 5% blasts in the bone marrow and aged 1 to 30 years. LL in first relapse or refractory to 1 prior induction/consolidation regimen biopsy proven and with evidence of measurable disease by radiologic criteria and aged 1 to 30 years
  • Performance status greater than or equal to (>=) 70 by Lansky scale (for participants less than [<] 16 years of age) or Karnofsky scale (for participants [>=] 16 years of age)
    •Adequate hematology laboratory values at Cycle 1 Day 1 pre-dosing defined as follows:
    1.Hemoglobin (>=) 7.5 gram per deciliter (g/dL) ([>=] 5 millimole per liter [mmol/L]; prior red blood cell [RBC] transfusion is permitted)
    2.Platelet count (>=) 10*10^9 per liter (L) (prior platelet transfusion is permitted)
  • Adequate renal function
  • Adequate liver function

Key Exclusion Criteria:

• Received an allogeneic hematopoietic transplant within 3 months of screening
• Active acute graft-versus-host disease of any grade or chronic graft-versus-host disease of Grade 2 or higher
• Received immunosuppression post hematopoietic transplant within 1 month of study entry
• Philadelphia chromosome positive (Ph+) B-cell ALL eligible for tyrosine kinase inhibitor therapy
• Has either of the following:
  1.Evidence of dyspnea at rest or oxygen saturation (<=) 94 percent (%).
  2.Known moderate or severe persistent asthma within the past 2 years, or uncontrolled asthma of any classification
• Received an investigational drug, was vaccinated with live attenuated vaccines, or used an invasive investigational medical device within 4 weeks before the planned first dose of study drug, or is currently being treated in an investigational study