A Phase 3 Open Label Randomized Study to Compare the Efficacy and Safety of Rituximab Plus Lenalidomide (CC-5013) Versus Rituximab Plus Chemotherapy Followed by Rituximab in Subjects With Previously Untreated Follicular Lymphoma

Inclusion Criteria: * Histologically confirmed CD20+ follicular lymphoma grade 1, 2 or 3a * Have no prior systemic treatment for lymphoma. * Must be in need of treatment * Bi-dimensionally measurable disease with at least one mass lesion \> 2 cm that was not previously irradiated. * Stage II, III or IV disease. * Must be ≥ 18 years and sign an informed consent. * Performance status ≤ 2 on the ECOG scale. * Adequate hematological function (unless abnormalities are related to lymphoma infiltration of the bone marrow) * Willing to follow pregnancy precautions Exclusion Criteria: * Clinical evidence of transformed lymphoma by investigator assessment or Grade 3b follicular lymphoma. * Patients taking corticosteroids during the last 4 weeks, unless administered at a dose equivalent to \< 10 mg/day prednisone (over these 4 weeks). * Major surgery (excluding lymph node biopsy) within 28 days prior to signing informed consent. * Known Seropositive for or active viral infection with hepatitis B virus (HBV), hepatitis C virus (HCV)or human immunodeficiency virus (HIV). * Life expectancy \< 6 months. * Known sensitivity or allergy to murine products. * Prior history of malignancies, other than follicular lymphoma, unless the patient has been free of the disease for ≥ 10 years. * Prior use of lenalidomide. * Neuropathy \> Grade 1. * Presence or history of CNS involvement by lymphoma. * Patients who are at a high risk for a thromboembolic event and are not willing to take venous thromboembolic (VTE) prophylaxis. * serum aspartate transaminase (AST/SGOT) or alanine transaminase (ALT/SGPT) \> 3x upper limit of normal (ULN), except in patients with documented liver or pancreatic involvement by lymphoma * total bilirubin \> 2.0 mg/dl (34 µmol/L) except in cases of Gilberts Syndrome and documented liver involvement by lymphoma * creatinine clearance of \< 30 mL/min * Pregnant or lactating females. * Any condition, including the presence of laboratory abnormalities, which places the patient at unacceptable risk if he/she were to participate in the study, or which confounds the ability to interpret data from the study.