Liposomal Vincristine Plus Dexamethasone in Patients With Relapsed or Refractory Acute Lymphoblastic Leukemia

Inclusion Criteria: * Previously treated, relapsed or refractory ALL (including lymphoblastic lymphoma and Burkitt's subtypes) with measurable disease. * Performance status ≤3 (ECOG). * All ages are eligible. Those aged 12 years or older may be counted towards the MTD in the Phase I portion of the trial. Pediatric patients are eligible, but must be treated at a dose level previously tested in an adult (one full course). * Adequate liver function (bilirubin ≤2 x upper limit normal), and renal function (creatinine ≤2 x upper limit normal). * Negative pregnancy test in females of childbearing potential. * Patients with prior history of stem cell transplant are eligible if they meet all other eligibility requirements. Exclusion Criteria: * Active serious infection not controlled by oral or intravenous antibiotics. * Treatment with any investigational agents or chemotherapy agents in the last 21 days before study entry, unless full recovery from side effects has occurred or the patient has rapidly progressive disease judged to be life threatening by the Investigator. * Concurrent treatment with other anti-cancer agents other than dexamethasone. * Known CNS leukemia or lymphoma requiring intrathecal or craniospinal radiation therapy or with CNS neuropathy limiting evaluation of study drug. Patients with controlled CNS disease (no progression signs or symptoms at the time of study entry) may be eligible after approval by the Principal Investigator. Lumbar puncture not required in asymptomatic patients. * Prior history of Grade 3 or 4 sensory or motor neuropathy related to chemotherapeutic treatment, or persistent Grade 2 or greater active neuropathy. * History of active neurologic disorders unrelated to chemotherapy (including familial neurologic diseases and acquired demyelinating disorders). * Prior history of hypersensitivity reactions to vincristine or any of the other components of VSLI. * Pregnant and/or lactating women; or fertile men or women not willing to use contraception.