A Phase II, Open-Label Study of Clofarabine in Paediatric Patients With Refractory/Relapsed Acute Lymphoblastic Leukaemia

Inclusion Criteria: * Have a diagnosis of ALL and confirmed by pathologic assessment. * Be ≤ 21 years old at time of initial diagnosis. * Eligible patients must have: Primary refractory disease; OR relapsed or refractory disease after a minimum of 2 prior blocks of treatment. * Must not be eligible for therapy of higher curative potential. * Have a Karnofsky Performance Status of ≥ 50 or Lansky Performance Scale of ≥ 30. * Provide a signed, written informed consent from parent or guardian or young adult patients. * Be able to comply with study procedures and follow-up examinations. * Have adequate cardiac function without treatment. * Have adequate organ function as indicated by the laboratory values for serum creatinine, serum bilirubin, AST and ALT, obtained within 7 days prior to registration. Exclusion Criteria: * Received previous treatment with clofarabine. * Patients with isolated extramedullary disease. * Have received prior BMT or PBSCT within the last 6 months. * Have received prior BMT or PBSCT more than 6 months ago, but now has compromised organ function. * Have an active, uncontrolled systemic infection. * Are pregnant or lactating. Male and female patients who are fertile must agree to use an effective means of birth control to avoid pregnancy. * Have a psychiatric disorder that would interfere with consent, study participation, or follow-up. * Have received any other chemotherapy within the previous 2 weeks and must have recovered from acute toxicity oa all previous therapy prior to enrollment. * Have any other severe concurrent disease. * Have recent history of significant renal, hepatic or pulmonary dysfunction, or cardiac dysfunction or on treatment to support cardiac function. * Have CNS disease.