Repeat-Dose of Forodesine Hydrochloride (BCX-1777) Infusion in Patients With Advanced T-Cell Leukemia

Inclusion Criteria: Documented T-cell leukemia (precursor T-lymphoblastic leukemia/lymphomia or T-PLL) Failure to have responded to one or more standard regimens for their disease. Performance status of <=2 by Eastern Cooperative Oncology Group (ECOG) criteria All ages are eligible Life expectancy of at least 3 months Adequate liver function (aspartate transaminase [AST] and/or alanine transaminase [ALT] not >3 times upper limits or normal [ULN]) Adequate kidney function (calculated creatinine clearance >50 mL/min) Negative urine pregnancy test within 2 to 7 days prior to the start of study treamtment in females of childbearing potential Females of childbearing potential and males must be willing and able to use an adequate method of contraception to avoid pregnancy for the duration of the study Signed informed consent/assent form (ICF) prior to start of any study specific procedures Exclusion Criteria: Patients with known HIV infection or human T-cell leukemia virus type (HTLV-1) Patients with known Hepatitis B and/or Hepatitis C active infection Patients with active CMV infection Tumor-related central nervous system (CNS) leukemia requiring active treatment Active serious infection not controlled by oral or IV antibiotics Treatment with any investigational anti-leukemic agent or chemotherapy agent within 7 days prior to study entry, unless full recovery from side effects has occurred. Rapidly progressive disease with compromised organ function judged to be life-threatening by the investigator Concurrent treatment with other anticancer agents (corticosteroid use will not be excluded, but patient must remain on the stable dose) Cutaneous T-cell lymphoma (CTCL) diagnosis (including Sezary Syndrome) Pregnant and/or lactating women