Despite the great strides that have been made in improving the outcome with frontline programs of intensive chemotherapy in patients with aggressive T-cell malignancies, the prognosis with relapsed or refractory T-cell leukemias or lymphomas is poor. BCX-1777 is a purine nucleoside phosphorylase (PNP) inhibitor and a potential T-cell target therapy.

The purpose of the phase I portion of the study is to determine the maximum tolerated dose (MTD) of BCX-1777 and the dose to be studied in the phase II portion of the study.

The purpose of the phase II portion of the study is to determine the safety and efficacy of BCX-1777 in patients with relapsed or refractory aggressive T-cell malignancies.

Patients who respond to BCX-1777 or have stable disease may be eligible to receive an additional course of treatment.

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.