Phase I-II Study of Intravenous BCX-1777 in Relapsed or Refractory Aggressive (High Grade) T-Cell Malignancies

Inclusion Criteria:

- Previously treated, relapsed or refractory aggressive T-cell malignancies (leukemias
and lymphomas) histologically proven with measurable disease.

- Capable of only limited self-care, confined to bed or chair more than 50% of waking
hours.

- All ages are eligible. Pediatric patients (<15 years of age) are eligible to be
treated at a dose level previously tested in adults.

- Adequate liver and renal function.

- Patients with prior history of stem cell transplant if they meet all other
eligibility requirements.

- Negative pregnancy test within 72 hours of study treatment in females of childbearing
potential.

- Life expectancy of at least 2 months.

Exclusion:

- Active serious infection not controlled by oral or intravenous antibiotics.

- Treatment with any investigational antileukemic agents or chemotherapy agents in the
last 7 days before study entry, unless full recovery from side-effects has occurred
or patient has rapidly progressive disease judged to be life-threatening by the
investigator.

- Concurrent treatment with other anti-cancer agents.

- Known CNS leukemia or lymphoma requiring intrathecal or craniospinal radiation
therapy. Lumbar puncture not required in asymptomatic patients.

- Pregnant and/or lactating women; or fertile men or women not willing to use
contraception.