Pharmacokinetic Study of Forodesine in Children With Relapsed or Refractory T-cell or B-cell Precursor Acute Lymphoblastic Leukaemia or T-cell Non- Hodgkin's Lymphoma.

Inclusion Criteria

• •Males and females aged ≥ 2 years to ≤18 years. ≥ 13 kg
• •Female subjects of childbearing potential (i.e. have reached the age of menarche) must have a negative serum or urine pregnancy test recorded prior to the first dose of study medication, be non-lactating, and be willing to use adequate and highly effective method of contraception throughout the study and for one month after the last dose of study medication, if sexually active.
• •Sexually active male subjects must be willing and able to use a barrier form of contraception (i.e. condoms) or sexual abstinence throughout the study and for one month after the last dose of study medication
• •Unequivocal histological diagnosis of T-ALL, BCP-ALL or T-NHL (World Health Organisation \[WHO\] classification) at initial diagnosis
• •Relapse (³25% marrow blasts) or failure to respond after at least one standard regimen for their disease for subjects with a T-cell malignancy who are ineligible for other therapy of greater curative potential, or failure to respond after at least two standard regimens for subjects with a B-cell precursor malignancy
• •KPS or LPS (as appropriate for subject's age) scores ³60
• •Anticipated life expectancy of at least 6 weeks
• •Adequate kidney (creatinine levels ≤ 2.0 times upper limit of normal) and liver function tests (aspartate aminotransferase \[AST\] and/or alanine aminotransferase \[ALT\] ≤3 times upper limit of normal and total bilirubin ≤5 times upper limit of normal)
• •Signed ICF and assent if appropriate according to local laws and regulations prior to start of any study specific procedures.