Lenalidomide Plus Rituximab Followed by Lenalidomide Versus Rituximab Maintenance for Relapsed/Refractory Follicular, Marginal Zone or Mantle Cell Lymphoma.

Inclusion Criteria:

-- Age ≥18 years

Histologically confirmed Follicular Lymphoma (FL, Grade 1, 2, 3a, or 3b), Transformed FL, Marginal Zone Lymphoma, or Mantle Cell Lymphoma
Must have documented relapsed, refractory or Progressive Disease after last treatment with systemic therapy
Bi-dimensionally measurable disease
Eastern Cooperative Oncology Group (ECOG) Performance status < 2
Adequate bone marrow function
Willingness to follow pregnancy precautions

Exclusion Criteria:

Histology other than follicular or marginal zone lymphoma or clinical evidence of transformation or Grade 3b follicular lymphoma
Any medical condition (other than the underlying lymphoma) that requires chronic steroid use
Subjects taking corticosteroids during the last 1 week prior treatment, unless administered at a dose equivalent to < 20 mg/day of prednisone
Systemic anti-lymphoma therapy within 28 days or use of antibody agents within 4 weeks use of radioimmunotherapy within 3 months
Known seropositive for or active viral infection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV)
Known sensitivity or allergy to murine products
Presence or history of central nervous system involvement by lymphoma. Subjects who are at a risk for a thromboembolic event and are not willing to take prophylaxis for it
Any condition that places the subject at unacceptable risk if he/she were to participate in the study or that confounds the ability to interpret data from the study

Other protocol-defined inclusion/exclusion criteria apply