Oral Forodesine Hydrochloride (BCX-1777) in Patients With Recurrent or Refractory T/NK-cell Malignancies

Inclusion Criteria: * Histologically documented with histopathological diagnosis from biopsy, T/NK-cell malignancies (WHO classification). Precursor T-cell lymphoblastic leukemia/lymphoma (T-ALL/T-LBL) should be excluded in this study * A patient with recurrent, relapse or refractory T/NK-cell malignancies who has received at lease one chemotherapeutic regimen * Age 20 or greater * Eastern Cooperative Oncology Group(ECOG) performance status:0,1. * Able to be hospitalized at least for 15 days from the first dose * In the case of subject with tumor cell rate of ≤25% in bone marrow, a patient who satisfies both of the following criteria. * Neutrophil count: ≥1,200/mm3 * Platelet count: ≥75,000/mm3 * In the case of CTCL, the tumor cell rate is handled as ≤25%. * Adequate Liver function: AST, ALT ≤ 5.0 x upper limit of normal (ULN) * Adequate Renal function: Creatinine Clearance (using cockcroft-Gault formula) ≥ 50mL/min * Life expectancy of at least 3 months * A patient who has given a written informed consent prior to the start of procedures proper to this study. Exclusion Criteria: \-