Study of Lenalidomide and Docetaxel in Subjects With Androgen Independent Prostate Cancer

Inclusion Criteria: * Subjects must understand and voluntarily sign an informed consent document. * Age \> 18 years at the time of signing informed consent form. * Histological documentation of prostate cancer. * Subjects must be able to adhere to the study visit schedule and other protocol requirements. * Radiographic or clinical evidence of measurable or evaluable androgen independent prostate cancer stages D1 or D2. * Patients must be surgically or medically castrated. If the method is medical castration, the patient must have a serum testosterone level of \<50 ng/dl/. The patient should maintain treatment with LH RH antagonists or agonists. * Patients must have metastatic prostate cancer unresponsive or refractory to androgen blockade by one or more of the following criteria: * Progression of unidimensionally measurable disease. * Progression of non measurable disease * Rising PSA (absolute value of PSA \> 5 mg/ml). * Rising PSA is defined as at least 2 consecutive rises in PSA to be documented over the reference value (measure 1). The first rising PSA (measure 2) must be taken at least 7 days after the reference value. A third confirmatory PSA is required, and it must be obtained at least seven days after the second measure. If the third measure does not confirm the rise in PSA, a fourth PSA measure is required to be taken to confirm the rise over the second measure. * Patients who were treated with antiandrogens such as flutamide, or other hormonal agents such as estrogens, or ketoconazole must have been stopped for at least 28 days prior to enrollment. In the case of nilandron and bicalutamide, treatment with these agents must have stopped at least 42 days prior to treatment. If the patient is being treated with corticosteroids, the dose should be stable for 14 days prior to study entry * ECOG performance status of ≤2 (Appendix I: ECOG Performance Status Scale). * Regarding Lenalidomide: 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. See Appendix V: Risks of Fetal Exposure, Pregnancy Testing Guidelines and Acceptable Birth Control Methods, AND also Appendix VI: Education and Counseling Guidance Document. * Laboratory values as indicated below: * Serum Creatinine \<2.0 mg/dL * Absolute Neutrophil Count ≥1,500/mm3 (or 1.5 X109/L) * Platelet Count \>100,000/mm3 (or 100 x 109/L) * Aspartate Aminotransferase (AST/SGOT) ≤ 1.5 x upper limit of normal (ULN) * Alkaline Phosphatase \< 2.5 x ULN (In the absence of liver metastasis, elevated alk phos due to bone mets is permitted) * Conjugated Bilirubin \< ULN Exclusion Criteria: * Any serious medical condition or psychiatric illness that places the subject at an unacceptable risk for study participation or would prevent the subject from signing the informed consent. * More than 2 prior regimens of chemotherapy. * Use of thalidomide or biologic response modifier therapy within 28 days of initiation of therapy * Prior desquamating rash while taking thalidomide therapy. * Prior \> grade-2 allergic reaction to thalidomide. * Any prior use of lenalidomide. Subjects may have received prior thalidomide therapy. * Concurrent use of any other anti-cancer agents, excluding bisphosphonates. * Known brain or leptomeningeal disease (CT scan or MRI of the brain required only in case of clinical suspicion of central nervous system involvement). * Active infection, known positive for HIV or hepatitis B or C. * Known hypersensitivity or intolerance to taxanes or polysorbate 80. * Known hypersensitivity reaction to thalidomide * Use of any other experimental drug or therapy within 28 days. * Subjects with \> grade-2 neuropathy. * Prior history of malignancy (except basal cell or squamous cell carcinoma or carcinoma in situ of the breast, or superficial bladder cancer) unless the subject has been free of disease for \> 3 years. * Prior whole pelvic radiation, or prior treatment with strontium. Prior treatment with samarium is permitted.