Inclusion Criteria:

1. Must sign an informed consent form.

2. Age ≥ 65 years

3. Must be able to adhere to the study visit schedule and other protocol requirements.

4. Must have a documented diagnosis of B-cell CLL.

5. Must have an Eastern Cooperative Oncology Group (ECOG) performance status score of
≤2.

6. Must agree to follow pregnancy precautions as required by the protocol.

7. Must agree to receive counseling related to teratogenic and other risks of
lenalidomide.

8. Must agree not to donate blood or semen as defined by the protocol

Exclusion Criteria:

1. Prior treatment for B-cell CLL.

2. Any medical condition, that would prevent the subject from signing the informed
consent form.

3. Active infections requiring systemic antibiotics.

4. Systemic infection that has not resolved > 2 months prior to initiating lenalidomide

5. Pregnant or lactating females.

6. Participation in any clinical study or having taken any investigational therapy
within 28 days.

7. Known presence of alcohol and/or drug abuse.

8. Central nervous system (CNS) involvement.

9. Prior history of malignancies, other than CLL, unless the subject has been free of
the disease for ≥3 years. Exceptions include the following:

- Basal cell carcinoma of the skin

- Squamous cell carcinoma of the skin

- Carcinoma in situ of the cervix

- Carcinoma in situ of the breast

- Incidental histologic finding of prostate cancer (TNM stage of T1a or T1b)

10. History of renal failure requiring dialysis.

11. Known Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV) and/or Hepatitis C
Virus (HCV) infection.

12. Prior therapy with lenalidomide.

13. Evidence of TLS at screening

14. Presence of specific hematology and/or chemistry abnormalities

15. Uncontrolled hyperthyroidism or hypothyroidism

16. Venous thromboembolism within one year

17. ≥ Grade-2 neuropathy

18. Uncontrolled autoimmune hemolytic anemia or thrombocytopenia

19. Disease transformation [i.e. Richter's Syndrome (lymphomas) or prolymphocytic
leukemia]