Pharmacokinetic (PK) and Pharmacodynamic (PD) Study of Nelarabine in Patients With Relapsed/Refractory Lymphoid Malignancies

Inclusion Criteria:

1. Patients must have one of the following relapsed/ refractory lymphoid malignancies: Chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL) or B-prolymphocytic leukemia which has been previously treated with a purine analog, and are not candidates for higher priority clinical studies. Follicular lymphoma, mantle cell lymphoma, lymphoplasmacytoid lymphoma or marginal zone lymphoma which has been previously treated with autologous or allogeneic stem cell transplantation.
2. Continued from #1:T-cell prolymphocytic leukemia, large granular lymphocyte leukemia, mycosis fungoides / Sezary syndrome or peripheral T-cell lymphoma which has been previously treated with at least one line of chemotherapy or monoclonal antibody therapy. T-cell or B-cell acute lymphoblastic leukemia (ALL) which has been previously treated with at least one line of chemotherapy.
3. Patients (both pediatrics and adults) must have adequate renal function (calculated creatinine clearance \>/= 50ml/min). For adults this will be calculated per the Cockcroft -Gault formula and in pediatric cases this will be calculated per the Schwartz formula.
4. Patients must have adequate hepatic function (bilirubin \</= 2 mg/dL; SGOT or SGPT \</= 3X the ULN for the reference lab unless due to leukemia).
5. Patients must have adequate marrow function (neutrophils \>/= 0.5x10\^9/L and platelets \>/= 50x10\^9/L) unless cytopenias are deemed due to disease.
6. Patients must have adequate performance status (Zubrod 0-2).
7. Female patients must not be pregnant or lactating. Female patients of childbearing potential (including those \<1 year postmenopausal) and male patients must agree to use contraception.
8. Patients must sign an informed consent form indicating that they are aware of the investigational nature of this study, in keeping with the policies of the hospital.

Exclusion Criteria:

1. Patients must not have untreated or uncontrolled life-threatening infection.
2. Patients known to be HIV positive or known to have Hepatitis B and/or C are excluded.
3. Patients must not have received systemic chemotherapy or monoclonal antibody therapy within 2 weeks of study enrollment. Patients who have previously received bolus nelarabine are still eligible. Hydroxyurea or corticosteroids for control of blood counts is allowed, but must be discontinued 24 hours prior to initiating nelarabine.
4. Patients must not have a history of grade \>/=2 neurological toxicity with previous treatment, or persistent grade \>/=2 peripheral neuropathy. Drowsiness and lethargy were exempted from this criteria unless previously persistent for more than one week.
5. Patients must not have uncontrolled central nervous system disease. Patients with a history of seizure disorders must be seizure-free for one year prior to enrolment.
6. Patients must not have any other medical condition, including mental illness or substance abuse, deemed by the Investigator to be likely to interfere with a patient's ability to give informed consent or cooperate and participate in the study or interfere with the interpretation of the results.