The purpose of this study is to test the safety of rhIL-18 combined with ofatumumab to see what effects (good and bad) it has on subjects and their non-Hodgkin's lymphoma.

Inclusion Criteria:

• Patients who have undergone high-dose therapy and autologous PBSCT for treatment of CD20+ lymphoma.
• Patients must be between 2-6 months post-transplantation at the time of study registration.
• Patients must have at least stable disease (no overt progressive disease) at the time of study registration.
• Laboratory values must be within protocol specified ranges.
• Females of childbearing potential must have a negative pregnancy test.
• Females of childbearing potential and males must use an effective method of contraception from the time of consent until at least 365 days following discontinuation of protocol therapy.

Exclusion Criteria:

• Patient must not have obvious clinical progression of lymphoma after PBSCT as determined by the treating physician.
• Cannot be positive for hepatitis B surface antigen, hepatitis B core antibody or HIV antibody.
• No major or uncontrolled comorbid conditions as determined by the treating physician: history of ventricular arrhythmias requiring drug or device therapy; uncontrolled angina or symptomatic congestive heart failure; • severe or uncontrolled infection requiring systemic antibiotic or antifungal therapy or active hepatitis C infection; severe or uncontrolled psychiatric illness.
• No known leptomeningeal involvement by lymphoma or current metastatic brain disease.
• No Corrected QTc interval > 480 msec.
• No known or suspected hypersensitivity to ofatumumab or SB-485232 that in the opinion of the investigator is a contraindication to their participation in the study.
• No systemic (oral or parenteral) corticosteroids within 14 days of study entry.
• Not receiving concurrent chemotherapy, biologic therapy, radiotherapy, or other investigational therapy.
• No previous treatment with SB-485232 or ofatumumab.
• No history of other malignancy except for adequately treated non-invasive cancers of the skin (basal or squamous cell) or carcinoma in situ of the uterine cervix.
• No diabetes mellitus with poor glycemic control (documented hemoglobin A1c >7% within 4 weeks prior to study entry).