This phase II trial studies how well clofarabine, idarubicin, cytarabine, vincristine sulfate, and dexamethasone work in treating patients with mixed phenotype acute leukemia that is newly diagnosed or has returned after a period of improvement (relapsed). Drugs used in chemotherapy, such as clofarabine, idarubicin, cytarabine, vincristine sulfate, and dexamethasone, work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading.

PRIMARY OBJECTIVE:

I. To evaluate the response rate of the chemotherapy regimen in patients with mixed phenotype acute leukemia.

SECONDARY OBJECTIVE:

I. To evaluate the durability of response, the overall and event-free survival rates, and the safety profile of the regimen.

OUTLINE:

INDUCTION THERAPY: Patients receive clofarabine intravenously (IV) over 60 minutes on days 1-4 or 1-3; idarubicin IV over 30-60 minutes on days 1-3 or 1-2; cytarabine IV over 2 hours on days 1-4; vincristine sulfate IV over 15-30 minutes on days 1, 8, and 15; and dexamethasone IV over 10-30 minutes on days 1-4 and 15-18. Patients with a certain type of leukemia may receive rituximab IV over 4-6 hours on days 1 and 8 or sorafenib tosylate orally (PO) twice daily (BID) on days 1-14. Treatment repeats every 28 days for up to 2 cycles in the absence of disease progression or unacceptable toxicity.

CONSOLIDATION THERAPY: Patients receive clofarabine IV over 60 minutes on days 1-3 or 1-2; idarubicin IV over 30-60 minutes on days 1-2; cytarabine IV over 2 hours on days 1-3 or 1-2; vincristine sulfate IV over 15-30 minutes on days 1, 8, and 15; and dexamethasone IV over 10-30 minutes on days 1-4 and 15-18. Patients with a certain type of leukemia may receive rituximab IV over 4-6 hours on days 1 and 8 of cycles 1-3 or sorafenib tosylate PO BID on days 1-28 of cycle 1-6 and beyond. Treatment repeats every 28 days for up to 6 cycles in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up at 30 days and then every 6 months thereafter.

Inclusion Criteria:

• Sign an informed consent document
• Newly diagnosed or relapsed mixed phenotype acute leukemia (MPAL), which for this protocol, will be defined as follows: bone marrow result interpreted by the reading pathologist (or tissue biopsy for cases of extramedullary disease) as: biphenotypic leukemia, bilineal leukemia, undifferentiated leukemia, mixed lineage leukemia, leukemia of ambiguous lineage, T/myeloid leukemia, B/myeloid leukemia, or other diagnosis indicating the presence of multiple lineages within the cell population
• Eastern Cooperative Oncology Group (ECOG) performance status of =< 3 at study entry
• Adequate organ function as outlined below (unless due to leukemia)
• Serum creatinine =< 3 mg/dL
• Total bilirubin =< 2.5 mg/dL
• Alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT]) and/or aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT]) =< 3 x upper limit of normal (ULN) or =< 5 x ULN if related to disease
• Women of childbearing potential must have a negative serum or urine pregnancy test within 7 days; women of childbearing potential and men must agree to use contraception at study entry and for the duration of active study treatment
• Cardiac ejection fraction >= 40% (by either cardiac echocardiogram [echo] or multi gated acquisition [MUGA] scan); documentation of recent (=< 6 months from screening) outside reports is acceptable
• If newly diagnosed, prior therapy with hydrea and/or steroid and the use of a single or a two day dose of cytarabine (up to 3 g/m^2), for emergency use up to 24 hours prior to start of study therapy is allowed

Exclusion Criteria:

• Breast feeding females
• Patients with active, uncontrolled infections
• Patients with active secondary malignancy will not be eligible unless approved by the principal investigator