Inclusion Criteria:

To be eligible to participate in this study, a patient must meet the following criteria:

- WHO-confirmed Acute lymphoblastic leukemia with > 10% bone marrow or peripheral blood
blasts; failed to achieve CR or relapse after prior therapy.

- Untreated patients > 60, if not candidates for standard induction, will also be
eligible to participate.

- Age >= 18 and not a candidate for alternative, curative treatment regimens

- Unwilling or unable to receive conventional chemotherapy (any age)

- ECOG performance status <= 2 (See Appendix B for definitions)

- Life expectancy > 2 months

- All study participants must be registered into the mandatory RevAssist program, and
be willing and able to comply with the requirements of RevAssist

- 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 study
enrollment and again within 24 hours prior to prescribing lenalidomide cycle 1
(prescriptions must be filled within 7 days) and must either commit to continued
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. (See Appendix A:
Risks of Fetal Exposure, Pregnancy Testing Guidelines and Acceptable Birth Control
Methods).

- Willing and able to understand and voluntarily sign a written informed consent

- Able to adhere to the study visit schedule and other protocol requirements

Exclusion Criteria:

Patients meeting any of the following criteria will be excluded from this study:

- Prior therapy with lenalidomide

- History of intolerance to thalidomide or development of erythema nodosum while taking
thalidomide or similar drugs

- Patients with advanced malignant hepatic tumors.

- Concomitant treatment with other anti-neoplastic agents, with the exception of
hydroxyurea

- Anti-neoplastic treatment less than four weeks prior to enrollment, with the
exception of hydroxyurea

- Use of any other experimental drug or therapy within 14 days of baseline

- Inability to swallow or absorb drug

- Active opportunistic infection or treatment for opportunistic infection within four
weeks of first day of study drug dosing

- New York Heart Association Class III or IV heart failure

- Unstable angina pectoris

- Cardiac arrhythmias with rapid ventricular response (defined as heart rate greater
than 100 beats/minute)

- Uncontrolled psychiatric illness that would limit compliance with requirementsKnown
HIV infection, active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection.
Patients who are seropositive because of hepatitis B virus vaccine are eligible

- Pregnant or breast feeding females; lactating females must agree not to breast feed
while taking lenalidomide

- Other medical or psychiatric illness or organ dysfunction or laboratory abnormality
which in the opinion of the investigator would compromise the patient's safety or
interfere with data interpretation

- Laboratory abnormalities:

- Either creatinine >=1.5 mg/dL or creatinine clearance <=60 mL/min.

- Total bilirubin > 1.5 x institutional ULN (unless documented Gilbert's syndrome)

- AST and ALT > 3 x institutional ULN