Inclusion Criteria:

Patients must have a definitive diagnosis of B-CLL as defined by the International
Workshop on CLL (IWCll) criteria Patient must have early stage B-CLL defined as Rai stage
0, 1 or 2 Patients must not have received any prior treatment for management of B-CLL

Patients must be assessed to have high risk B-CLL as defined by either one of the
following criterion:

- High-risk cytogenetics (either 17p deletion or 11q deletion);

- Unmutated immunoglobulin heavy chain gene rearrangement Patents must understand and
voluntarily sign an informed consent form Able to adhere to the study visit schedule
and other protocol requirements Patients must have measurable disease either an
absolute lymphocyte counts (ALC) of more than 5,000/ul or measurable lymphadenopathy
or organomegaly Eastern Cooperative Oncology Group (ECOG) performance status of =< 2
at study entry Females of childbearing potential (FCBP) must have a negative serum or
urine pregnancy test with a sensitivity of at least 50 mIU/mL 10-14 days prior to and
again within 24 hours before starting lenalidomide and must either commit to continue
abstinence from heterosexual intercourse or begin TWO acceptable methods of birth
control, one highly effective method and one additional effective method AT THE SAME
TIME, at least 28 days before she starts taking lenalidomide; FCBP must also agree to
ongoing pregnancy testing; men must agree to use a latex condom during sexual contact
with a FCBP even if they have had a successful vasectomy; all patients must be
counseled at a minimum of every 28 days about pregnancy precautions and risks of
fetal exposure Able to take aspirin (81 or 325mg) or warfarin sodium daily as
prophylactic anticoagulation Absolute neutrophil count >= 1.0 x 10^9/L Platelet count
>= 30 x 10^9/L Serum creatinine =< 1.5 x upper limit of normal (ULN) Total bilirubin
=< 1.5 mg/dL Aspartate aminotransferase (AST/SGOT) and alanine aminotransferase
(ALT/SGPT) < 2 x ULN or =< 5 x ULN if hepatic metastases are present

Exclusion Criteria:

Any serious medical condition, laboratory abnormality, or psychiatric illness that would
prevent the subject from signing the informed consent form Pregnant or lactating females
(lactating females must agree not to breast feed while taking lenalidomide) Any condition,
including the presence of laboratory abnormalities, which places the subject at
unacceptable risk if he/she were to participate in the study or confounds the ability to
interpret data from the study Use of any other experimental drug or therapy within 28 days
of baseline Known hypersensitivity to thalidomide or lenalidomide Prior history of
development of erythema nodosum if characterized by a desquamating rash while taking
thalidomide or similar drugs Patients who have been treated with any prior therapy for
B-CLL Patients with history of any other cancer (except non-melanoma skin cancer or
carcinoma in-situ of the cervix, unless in complete remission and off therapy for that
disease for > 3 years) Patient with history of cardiac arrest within the past 6 months Any
prior use of lenalidomide Concurrent use of other anti-cancer agents or treatments Known
history of hepatitis B or C Known human immunodeficiency virus (HIV) positive status