Study of Talabostat and Rituximab in Advanced Chronic Lymphocytic Leukemia (CLL)

INCLUSION CRITERIA: Men or women ≥18 years of age Histopathologically confirmed diagnosis of B-CLL expressing surface CD20 of any detectable intensity Rai Stage III or IV. Rai Stages I and II with massive or progressive lymphadenopathy or hepatosplenomegaly. Primary resistance to a fludarabine regimen (no PR or CR) or progressive disease within 1 year of a prior response ECOG performance status 0, 1, or 2 Written informed consent EXCLUSION CRITERIA: Therapy for CLL within 4 weeks of Study Day 1 (including chemotherapy, radiation, immunotherapy, cytokine or biologic [with the exception of hematopoietic growth factors]). Patients must have recovered from the adverse effects of prior therapy. Known primary or secondary malignancy of the central nervous system Any malignancy within the 5 years immediately prior to the first dose of study medication with the exception of basal cell or non-metastatic squamous cell carcinoma of the skin, and carcinoma in-situ of the cervix Serum creatinine >2.0mg/dL (>176 micromol/L) AST or ALT ≥3 x the upper limit of normal (ULN) Total bilirubin ≥1.5 x ULN (unless secondary to Gilbert's) Positive serology for hepatitis B (HBsAg) or hepatitis C (anti-HCV antibody) Known positivity for HIV Prior organ allograft Concurrent comorbid medical conditions that, in the opinion of the investigator, preclude the safe delivery of the experimental treatment Pregnant or nursing women