The purpose of this study is to determine the proportion of confirmed responses (complete response, partial response, and hematologic improvement as defined by revised IWG criteria during the 12 months of treatment.

Inclusion Criteria:

• Patient must be able to understand and voluntarily sign an informed consent form.

• Patient must be ≥ 18 years old.

• Patient must be able to adhere to the study visit schedule and other protocol requirements.

• Patient must have histologically confirmed Myelodysplastic Syndrome as defined by FAB Classification including CMML and secondary MDS which has either:

  • progressed at any time during treatment with hypomethylating agents
  • failed to achieve a response after 6 cycles
  • progressed after treatment with hypomethylating agents had been discontinued Criteria for response and for progression as defined by revised IWG criteria

• Patient must have discontinued all previous cancer therapy, including radiation, hormonal therapy and surgery at least 4 weeks prior to treatment in this study.

• Patient must have an ECOG performance status of ≤ 2 at study entry

• Patient must have laboratory test results within these ranges:

  • calculated creatinine clearance ≥ 30ml/min by Cockcroft-Gault formula
  • total bilirubin ≤ 1.5 x ULN
  • AST (SGOT) and ALT (SGPT) ≤ 3 x ULN

• Patient must be disease free of prior malignancies for at least 5 years with exception of currently treated basal cell, squamous cell carcinoma of the skin, or carcinoma "in situ" of the cervix or breast.

• Patient must be registered into the mandatory Revlimid REMS® program and be willing and able to comply with the requirements of Revlimid REMS®.

• If a female of childbearing potential (FCBP), patient must have a negative serum or urine pregnancy test with a sensitivity of at least 50 mIU/mL within 10 to 14 days prior to initiation of therapy and again within 24 hours prior to prescribing lenalidomide for Cycle 1 (prescriptions must be filled within 7 days).

Females of reproductive potential must adhere to the scheduled pregnancy testing as required in the Revlimid REMS® program. A FCBP is defined as a sexually mature woman who: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 24 consecutive months (i.e., has had menses at any time in the preceding 24 consecutive months).

-If a FCBP, patient must agree to use two reliable forms of contraception simultaneously or to practice complete abstinence from heterosexual intercourse during the following time periods related to this study: 1) for at least 28 days before starting study drug; 2) while participating in the study; and 3) for at least 28 days after discontinuation from the study. The two methods of reliable contraception must include one highly effective method (i.e. intrauterine device (IUD), hormonal [birth control pills, injections, or implants], tubal ligation, partner's vasectomy) and one additional effective (barrier) method (i.e. latex condom, diaphragm, cervical cap). FCBP must be referred to a qualified provider of contraceptive methods if needed

Exclusion Criteria:

• Patient must not have any serious medical condition, laboratory abnormality, or psychiatric illness that would prevent the subject from signing the informed consent form.
• Patient must not be pregnant or breastfeeding.
• Patient must not have 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.
• Patient must not use any other experimental drug or therapy within 28 days of baseline.
• Patient must not have a known hypersensitivity to thalidomide.
• Patient must not have developed of erythema nodosum if characterized by a desquamating rash while taking thalidomide or similar drugs.
• Patient must not have any prior use of lenalidomide.
• Patient must not be concurrently using other anti-cancer agents or treatments.
• Patient must not have known seropositivity for or active viral infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV). Patients who are seropositive because of hepatitis B virus vaccine are eligible.