Clofarabine and Cytarabine in Treating Young Patients With Refractory or Relapsed Acute Myeloid Leukemia or Acute Lymphoblastic Leukemia

DISEASE CHARACTERISTICS:

• Histologically confirmed diagnosis of 1 of the following:
• Acute myeloid leukemia (AML) with ≥ 5% blasts in the bone marrow (M2/M3 bone marrow) with or without extramedullary disease
• Acute lymphoblastic leukemia (ALL) with > 25% blasts in the bone marrow (M3 bone marrow) with or without extramedullary disease
• Acute leukemia of ambiguous lineage with ≥ 5% blasts in the bone marrow (M2/M3 bone marrow) with or without extramedullary disease
• Disease must have relapsed after or be refractory to prior induction therapy
• Patients with AML or acute leukemia of ambiguous lineage must be in first relapse OR refractory to first induction therapy with ≤ 1 attempt at remission induction
• Patients with AML who enroll on the phase I portion of the study must have received prior mitoxantrone hydrochloride and cytarabine for newly diagnosed AML (phase I closed to accrual as of 09/16/09)
• Patients with ALL must be in second or third relapse (≤ 3 prior induction regimens) OR refractory to reinduction in first relapse
• Patients with ALL refractory to first induction therapy are not eligible
• No acute promyelocytic leukemia
• No CNS 3 involvement (i.e., WBC ≥ 5/μL in the cerebrospinal fluid with blasts present on cytospin)

PATIENT CHARACTERISTICS:

• Karnofsky performance status (PS) 50-100% (> 16 years of age) OR Lansky PS 50-100% (≤ 16 years of age) OR ECOG PS 0-2
• Life expectancy ≥ 8 weeks
• Creatinine clearance or radioisotope glomerular filtration rate ≥ 70 mL/min
• Direct bilirubin ≤ 1.5 times upper limit of normal (ULN)
• ALT 94% at room air
• Amylase ≤ 1.5 times ULN
• Lipase < 1.5 times ULN
• No active, uncontrolled grade 3 or 4 infection
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for ≥ 3 months after completion of study treatment
• No known hepatitis B or C infection or history of cirrhosis

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Recovered from all prior therapy*
• At least 14 days since prior cytotoxic therapy (except hydroxyurea and intrathecal chemotherapy)*
• At least 7 days since prior biologic agent*
• At least 14 days since prior monoclonal antibody therapy*
• No more than 1 prior autologous or allogeneic hematopoietic stem cell transplantation
• No evidence of active graft-vs-host disease
• At least 4 months since transplantation
• No other concurrent chemotherapy or immunomodulating agents
• No other concurrent investigational therapy NOTE: *Patients who relapse during ALL maintenance therapy do not require a waiting period.