Inclusion Criteria:

1. Patients with chronic lymphocytic leukemia (CLL), prolymphocytic leukemia, Richter's
transformation or T-PLL who have previously been treated with fludarabine or another
regime are eligible.

2. Patients with histologically or cytologically confirmed Richter's transformation.

3. Serum glutamic-oxaloacetic transaminase (SGOT) or serum glutamic-pyruvic transaminase
(SGPT) less than x 2 normal levels.

4. Women of childbearing potential who have a negative pregnancy test prior to
azacytidine treatment.

5. Women of childbearing potential who agreed not to become pregnant and men agreed not
to father a child while on azacytidine treatment.

6. Performance 0-2 (ECOG). Adequate liver function (bilirubin of less than2mg/dl) and
renal function (creatinine less than 2mg/dl). Adequate cardiac functions (NYHA
cardiac III-IV excluded).

7. Signed informed consent.

Exclusion Criteria:

1. Breast feeding or pregnant females. Patients of (male and female) childbearing
potential should practice effective methods of contraception; otherwise, they will be
excluded. Should a woman become pregnant or suspect she is pregnant while
participating in this study, she should inform her treating physician immediately.

2. Known or suspected hypersensitivity to azacytidine or Mannitol.

3. Active and uncontrolled infections.

4. Patients with advanced malignant hepatic tumors.

5. Uncontrolled intercurrent illness including, but not limited to, symptomatic
congestive heart failure, unstable angina pectoris, or psychiatric illness/social
situations that would limit compliance with study requirements.