INCLUSION CRITERIA

• Diagnosis of myelofibrosis or Philadelphia negative myeloproliferative disorder with myelofibrosis requiring therapy.
• Disease-free of prior malignancies for greater than or equal to 2 years with exception of basal cell, squamous cell carcinoma of the skin, or carcinoma "in situ" of the cervix or breast.
• ECOG performance status 0 to 3.
• Total bilirubin less than or equal to 3.0 mg/dL (unless due to tumor) and serum creatinine less than or equal to 3.0 mg/dL (unless due to tumor).
• Females of childbearing potential (FCBP)† must have a negative serum or urine pregnancy test with a sensitivity of at least 50 mIU/mL within 10 - 14 days prior to and again within 24 hours of starting lenalidomide 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 4 weeks before she starts taking lenalidomide. FCBP must also agree to ongoing pregnancy testing.
• continued from above.....Men must agree to use a condom during sexual contact with a female of child bearing potential 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. See Appendix K: Risks of Fetal Exposure, Pregnancy Testing Guidelines and Acceptable Birth Control Methods, AND also Appendix I: Education and Counseling Guidance Document.
• continued from above.....† A female of childbearing potential is 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).
• Signed informed consent.

EXCLUSION CRITERIA

• Use of any other experimental drug or therapy within 28 days of therapy, except in cases with rapidly progressive disease and/or recovery from all toxicity from previous therapy (does not apply to growth factors).
• Platelet count less than 30,000.
• Known prior clinically relevant hypersensitivity reaction or desquamating rash with thalidomide.
• Prior therapy with CC-5013.
• Pregnancy, suspected pregnancy or breast feeding females.