A Study of Galiximab + Rituximab Versus Rituximab + Placebo in Follicular Non-Hodgkin's Lymphoma (NHL)

Key Inclusion Criteria: Key Inclusion Criteria: * Aged \>= 18 years old at the time of informed consent. * Histologically confirmed follicular Grade 1-3a NHL. * Relapsed or progressive disease after at least 1 prior chemotherapy requiring treatment. * Bidimensionally measurable disease with at least 1 lesion \>= 2.0 cm in a single dimension. * Acceptable hematologic, hepatic, and renal function parameters. * Recovered fully from any significant toxicity associated with prior surgery, radiation treatments, chemotherapy, biological therapy, autologous bone marrow or stem cell transplant, or investigational drugs. Key Exclusion Criteria: * Follicular lymphoma Grade 3b. * Rituximab refractory or refractory to anti-CD20 radioimmunotherapy (no response to prior rituximab or prior rituximab-containing regimen, or a response with a TTP of less than 6 months). * Cancer radiotherapy, biological therapy, or chemotherapy within 3 weeks prior to Study Day 1 (6 weeks if nitrosourea or mitomycin C). * Prior lymphoma vaccine therapy within 12 months prior to Study Day 1. * Prior antibody therapy for lymphoma (including radioimmunotherapy) within 6 months prior to Study Day 1. * Autologous bone marrow or stem cell transplant within 6 months prior to Study Day 1. * Prior allogeneic transplant. * Transfusion-dependent subjects. * Another primary malignancy requiring active treatment (except hormonal therapy). * Serious nonmalignant disease (e.g., congestive heart failure, hydronephrosis); active uncontrolled bacterial, viral, or fungal infections; or other conditions, which would compromise protocol objectives in the opinion of the Investigator and/or the Sponsor. * New York Heart Association Class III or IV cardiac disease or myocardial infarction within 6 months prior to Study Day 1.