Inclusion Criteria:

1. Subjects must understand and voluntarily sign an informed consent document.
2. Age >or = to 18 years at the time of signing informed consent form.
3. Subjects must be able to adhere to the study visit schedule and other protocol requirements.
4. Histological or cytological documentation of advanced ovarian or primary peritoneal carcinoma.
5. Radiographic or clinical evidence of measurable metastatic advanced ovarian or primary peritoneal carcinoma. Subjects must have measurable disease at least 2 cm in diameter.
6. Subjects must have been treated and progressed following chemotherapy which includes platinum and paclitaxel.
7. ECOG performance status of 0 or 1 (Appendix I: ECOG Performance Status Scale).

Exclusion Criteria:

1. Any of the following laboratory abnormalities:

   1. Absolute neutrophil count (ANC) <1,500 cells/mm3 (1.5 x 109/L)
   2. Platelet count <100,000 cells/mm3 (100 x 109/L)
   3. Serum creatinine >1.5 mg/dL (133 mmol/L)
   4. Serum SGOT/AST or SGPT/ALT >3.0 x upper limit of normal (ULN)
   5. Serum total bilirubin >2.0 mg/dL (34 mmol/L)
2. 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.
3. Prior history of malignancy (except basal cell or squamous cell carcinoma or carcinoma in situ of the breast) unless the subject has been free of disease for > 1 year.
4. Known brain or leptomeningeal disease (CT scan or MRI of the brain required only in case of clinical suspicion of central nervous system involvement).
5. More than 1 prior chemotherapy regimen. However, subjects with platinum sensitive disease (i.e., subjects who fail a platinum containing regimen at least six months after completing the regimen) who are retreated with a platinum containing regimen are eligible.
6. Concurrent use of any other anti-cancer agents.
7. Any prior use of lenalidomide.
8. Prior > or = to grade 3 (see Appendix III) rash or any desquamating (blistering) rash while taking thalidomide.
9. Prior . Or = to grade 3 (see Appendix III) allergic reaction/hypersensitivity to thalidomide.
10. Use of any standard or experimental anti-cancer drug therapy within 28 days of the initiation of study drug therapy.
11. Known active Hepatitis C.