Patients with B-cell Chronic Lymphocytic Leukemia, Rai Stage 0-II with indication for treatment by NCI Working Group Criteria or Rai Stage III or IV.

Patients must have received at least one prior purine analogue-based chemotherapy regimen.

ECOG Performance Status of 0, 1, or 2.

Female patients cannot be pregnant and must use birth control during the course of the study and for three weeks after the study ends.

Study of ONTAK in Patients With B-Cell Chronic Lymphocytic Leukemia (CLL)