Inclusion Criteria:

- Patient must have documentation of histologically confirmed and measurable Chronic
Lymphocytic Leukemia (CLL) or Prolymphocytic Leukemia (PLL) arising from CLL;

- Patient must have symptomatic and progressive disease;

- Patient must have received prior alkylating agent(s) and be fludarabine refractory;

- Patient must have the adequate organ functions;

- Patient's Eastern Cooperative Oncology Group performance (ECOG) status must be 0-2;

Exclusion Criteria:

- Patient with de novo PLL;

- Patient with secondary malignancy that will limit survival ≤5 years;

- Patient with prior allogenic or autologous bone marrow transplant or peripheral blood
stem cell transplant ≤12 months;

- Patient receiving an investigational agent or an approved agent for an
investigational purpose within last 4 weeks prior to study entry;

- Patient with known history of glucose-6-phosphate dehydrogenase deficiency;

- Patient with autoimmune hemolytic anemia;

- Patient with known Central Nervous System involvement;

- Patient with active, uncontrolled serious bacterial, viral or fungal infections

The above information is not intended to contain all considerations relevant to a
patient's potential participation in a clinical trial.