A Phase I/II, Multi-Center, Open-Label, Repeat-Dose Study of Forodesine Hydrochloride Infusion in Patients With B-Cell Acute Lymphoblastic Leukemia With an Option of Extended Use of Forodesine Hydrochloride

Inclusion Criteria:

- Documented B-cell acute lymphoblastic leukemia (B-ALL), which under WHO Guidelines is
now referred to as precursor B-lymphoblastic leukemia/lymphoma

- Must have failed at least 1 treatment regimen for B-ALL, which under WHO Guidelines
is now referred to as precursor B-lymphoblastic leukemia/lymphoma

- Performance status of ≤2 by Eastern Cooperative Oncology Group (ECOG) criteria

- Any age is allowed

- Life expectancy of at least 3 months

- Adequate liver function (aspartate transaminase [AST] and/or alanine transaminase
[ALT] not >3 times upper limits of normal [ULN])

- Adequate kidney function (calculated creatinine clearance >40 mL/min)

- Negative serum or urine pregnancy test within 2 to 7 days prior to the start of study
treatment 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 in
such a manner that the risk of pregnancy is minimized. Acceptable contraceptives
include intra-uterine devices (IUDs), hormonal contraceptives (oral, depot, patch, or
injectable) and double barrier methods such as condoms or diaphragms with spermicidal
gel or foam.

- Signed informed consent form (ICF), minor assent form (if applicable), prior to start
of any study-specific procedures

Exclusion Criteria:

- Active serious infection not controlled by oral or intravenous antibiotics

- Treatment with any investigational antileukemic agent or chemotherapy agent in the
last 7 days prior to study entry and lack of full recovery from side effects due to
prior therapy independent of when that therapy was given

- Rapidly progressive disease with compromised organ function judged to be
life-threatening by the Investigator

- Patients with clinical evidence of active central nervous system (CNS) disease

- Concurrent treatment with other anticancer agents

- Pregnant and/or lactating female

- Patients with known human immunodeficiency virus (HIV) infection HIV testing will be
performed at the Screening visit for patients who have not been tested within 6
months of receiving study drug, as well as those patients who have had exposure or
have been transfused with blood products that were not appropriately screened.

- Patients with known active hepatitis B and/or hepatitis C infection Hepatitis testing
will be performed at the Screening visit for patients who have not been tested within
6 months of receiving study drug, as well as those patients who have had exposure or
have been transfused with blood products that were not appropriately screened.

- Hypersensitive or intolerant to any component of the study drug formulation