A Phase II Trial of Cytarabine and Clofarabine in Patients with Relapsed or Refractory Acute Lymphoblastic Leukemia (ALL)

Pts must have a prior morphologic diagnosis of ALL and be either refractory to a standard induction regimen or have relapsed following successful prior induction therapy. Pts with M0 or mixed lineage AML are not eligible for this study. Pts with L3 (Burkitts) are also not eligible. Pts must have evidence of ALL in their marrow or peripheral blood. Pts may have received prior allogeneic or autologous bone marrow transplant. Pts known to have Ph+ ALL or bcr/abl+ ALL who were eligible for treatment with imatinib mesylate, must have received imatinib either alone or in combination with chemotherapy for ALL and must have either failed treatment or been unable to tolerate the treatment. Pts must not have psychiatric disorders that would interfere with consent, study participation, or follow-up. Pts must not have a systemic fungal, bacterial, viral, or other infection that is not controlled. Pts must not have any other severe concurrent disease, or have a history of serious organ dysfunction or disease involving the heart, kidney, liver, or other organ system that may place the pt at undue risk to undergo induction therapy with either or both of these agents. Pts with history of CNS involvement must have a lumbar puncture that is negative for CNS involvement of ALL within 14 days prior to registration. Testicular involvement at diagnosis must be evaluated. Biopsy is required if clinical findings (or ultrasound) are equivocal or suggestive of a hydrocele or non-leukemic mass. Pts must have passed their 16th birthday. Pts must not have received previous treatment with clofarabine. Zubrod PS 0-2. Pts must have a serum creatinine less than or equal to 1.5 x IULN obtained within 14 days prior to registration. Pts must have SGOT(AST) or SGPT(ALT) less than or equal to 1.5 x IULN obtained within 14 days prior to registration. Pts must have a pretreatment bilirubin less than or equal to 1.5 x IULN obtained within 14 days prior to registration. Pts must not have greater than or equal to Grade 2 neuropathy-motor or sensory toxicities of any prior treatment within 14 days prior to registration. Pts must not have received chemotherapy, any other investigational agents, or have undergone any major surgery within 14 days prior to registration, with the following exceptions: hydroxyurea, which may be administered concurrently with study drug until the white blood count has come down to a reasonable level (as deemed by the treating physician) and/or monoclonal antibodies, which must not have been received for 6 weeks before registration and maintenance therapy with steroids, vincristine and/or anti-metabolite agents, such as but not limited to, mercaptopurine, thioguanine and methotrexate. All drug-related toxicities must have resolved to less than or equal to Grade 2. Pts must not have any serious or poorly controlled medical condition that could be exacerbated by the treatment or would seriously complicate compliance with the protocol. Pts must be negative for HIV within 14 days prior to registration. Pts must be regsitered on S9910 and SWOG-9007. Women of reproductive potential must have a negative pregnancy test performed within 14 days prior to registration. Pts must not be pregnant or nursing because of the teratogenic potential of the drug used in this study. Pts of reproductive potential must have agreed to use an effective contraceptive method. No other prior malignancy is allowed except for the following: adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, adequately treated Stage I or II cancer from which the pt is currently in complete remission, or any other cancer from which the pt has been disease-free for 5 years.