Safety Study of CPX-351 in Children With Relapsed Leukemia or Lymphoma

Inclusion Criteria: * Age 1. 12 months to 21 years at time of enrollment into dose exploration phase 2. 12 months to 30 years at time of enrollment into expanded phase * Diagnosis: Patients must have a diagnosis of a hematologic malignancy (acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), or aggressive lymphoma. * Disease Status 1. Acute myeloid leukemia - patients with non-therapy related AML must be in first or greater relapse or have refractory disease to at least two courses of induction therapy. 2. Acute lymphoid leukemia - patients with ALL must be in second or greater relapse or have relapsed disease refractory to re-induction therapy. 3. Aggressive Lymphoma - patients must have relapsed or refractory disease for which there is no known curative therapy available. Patients must have measurable disease by CT scan. * Performance status: Karnofsky \> or = to 50% or Lansky \> or = to 50. * Prior therapy: Patients must have fully recovered from acute toxicities of prior therapy. 1. Hematopoetic Stem cell transplant (HSCT): Patients who relapsed after HSCT, are eligible provided they have no evidence of active graft versus host disease (GVHD) and are at least 2 months post-transplant. 2. Anthracycline exposure: Patients who have not previously had TBI (total body irradiation) must have a total previous cumulative anthracycline exposure ≤ 450 mg/m2 daunorubicin equivalents. Patients who have had prior TBI or radiation to the mediastinum must have a previous cumulative anthracycline exposure e ≤ 300 mg/m2 daunorubicin equivalents. 3. Cytotoxic therapy: 1. AML and Lymphoma: at least 14 days must have elapsed since the completion of systemic cytotoxic therapy, with the exception of hydroxyurea. 2. ALL: patients who relapsed while receiving standard maintenance therapy do not have a waiting period. At least 14 days must have elapsed since receiving systemic cytarabine or an anthracycline/anthracenedione. 3. Intrathecal cytotoxic therapy: no waiting period is required for patients receiving intrathecal cytarabine, methotrexate and/or hydrocortisone. At least 14 days must have elapsed since receiving liposomal cytarabine in intrathecal injection. * Organ function requirements 1. Adequate bone marrow function - platelet count \>/= 20,000/uL (may receive platelet transfusions; Hemoglobin \>/= 8 g/dL (may receive red blood cell transfusions) 2. Adequate Renal function - a maximum serum creatinine is based on age/gender. Subjects that do not meet eligibility criteria based upon serum creatinine may meet eligibility criteria based upon a 24 hour creatinine clearance or radioisotope determined GFR \>/= 70 mL/min/1.73 m2. 3. Adequate liver function - Direct bilirubin \</= 1.5 x upper limit of normal (ULN) for age and SGPT (ALT) \< 5.0 x upper limit of normal (ULN) for age and institution (unless elevation is related to leukemia involvement). 4. Adequate cardiac function - Shortening fraction of \>/= 27% by echocardiogram, or Ejection fraction of \>/= 50% by gated radionuclide study or echocardiogram. 5. Central Nervous system function - patients with seizure disorder may be enrolled if on anticonvulsants and well controlled and CNS toxicity \</= Grade 2. Exclusion Criteria: * Patients with the following diagnosis are not eligible: acute promyelocytic leukemia (APML), Down Syndrome, Fanconi Anemia, acute lymphoblastic leukemia with central nervous system leukemia (CNS status 3), Wilson's disease * Pregnant or breast-feeding women. Males and females of reproductive potential may not participate unless they have agreed to use an effective method of contraception. * Concomitant medications 1. Growth factors- growth factors that support platelet or white cell number or function must not be administered within 7 days prior to enrollment. 2. Investigational drugs - patients currently receiving another investigational drug are not eligible. 3. Anti-cancer agents- patients who are currently receiving other anti-cancer agents are not eligible with the exception of intrathecal cytarabine and oral hydroxyurea. Hydroxyurea must be discontinued 24 hours prior to initiation of protocol therapy. * Infection: Patients who have an uncontrolled infection are not eligible. * Patients who in the opinion of the investigator may not be able to comply with the safety monitoring requirements of the study are not eligible. * History of Wilson's disease or other copper-metabolism disorder * Major surgery within 4 weeks of enrollment. * Greater than 13.6 Gy prior radiation to the mediastinum