Study of Bendamustine and Ofatumumab in Elderly Patients With Newly Diagnosed Diffuse Large B-Cell Lymphoma Who Are Poor Candidates for R-CHOP Chemotherapy

Inclusion Criteria: 1. Histologically confirmed CD20-positive DLBCL. 2. Newly diagnosed, stage III-IV DLBCL considered poor candidates for R-CHOP. 3. Age \>=70 years 4. At least one of the following criteria: * ECOG PS 2 * Cardiac compromise precluding anthracycline therapy * Previous anthracycline therapy for other malignancy precluding further anthracycline therapy. * Severe coexisting medical problems * General frailty 5. ECOG 0-2 6. Measurable disease with at least one bidimensional lymph node or tumor mass \>1.5 cm in the longest diameter that can be followed for response as a target lesion as measured by CT 7. Patients must be HBV sAg and HBV cAb negative within 6 weeks of screening. 8. Patient must understand and voluntarily sign the IRB-approved informed consent. 9. Life expectancy \>= 3 months 10. Laboratory parameters: * Absolute neutrophil count \>=1,000 cells/mm3 * Platelet count \>=75,000 cells/mm3 * Hemoglobin \>=8 g/dL * Creatinine \<=2.0 mg/dL or Creatinine Clearance \>= 40 mL/min (calculated or 24 hour urine sample) * AST/SGOT \<=2.0 x ULN (\<=5.0 x ULN if secondary to lymphoma) * ALT/SGPT \<=2.0 x ULN (\<=5.0 x ULN if secondary to lymphoma) * Bilirubin level of \<2.0 mg/dL unless secondary to Gilbert's disease (or pattern consistent with Gilbert's) Exclusion Criteria: 1. Patients with active/symptomatic central nervous system (CNS) involvement based on clinical evaluation by lumbar puncture, PET, CT or MRI. 2. Known sensitivity to bendamustine or any component of bendamustine. 3. Known anaphylaxis or sensitivity to ofatumumab. 4. Major surgery within 28 days of Cycle 1, Day 1. Patients undergoing minor surgery within 7 days of Cycle 1, Day 1. (no wait needed for port placement) 5. Prior chemotherapy, immunotherapy, or irradiation for lymphoma. 6. Prior use of investigational anti-cancer agents for lymphoma. 7. HIV-related lymphoma. 8. Known active HIV or HCV infection, or known seropositivity for HIV, or current or chronic HBV or HCV infection. HBV test required at screening or a negative result within 6 weeks of screening. 9. Concurrent active or history of other malignancies, except non-melanoma skin cancer or carcinoma in situ of cervix or breast. Patients with previous malignancies are eligible provided they have been treated with curative intent and disease free for \>= 1 year. 10. Serious (grade 3-4), active, intercurrent infection requiring therapy, or deep seated or systemic mycotic infections. 11. Myocardial infarction within 6 months prior to registration or New York Hospital Association (NYHA) Class III or IV heart failure, uncontrolled angina, severe uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute ischemia or significant conduction system abnormalities, in the judgment of the Investigator. 12. Concurrent uncontrolled serious medical or psychiatric conditions likely to interfere with participation in this clinical study, in the judgment of the Investigator 13. Patients who have current active hepatic or biliary disease (with exception of patients with Gilbert's syndrome, asymptomatic gallstones, liver metastases or stable chronic liver disease per investigator assessment). 14. Treatment with any known non-marketed drug substance or experimental therapy within 5 terminal half lives or 4 weeks prior to enrollment, whichever is longer, or currently participating in any other interventional clinical study. 15. Significant concurrent, uncontrolled medical condition including, but not limited to, renal, hepatic, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which in the opinion of the investigator may represent a risk for the patient. 16. Male patients unable or unwilling to use adequate contraception methods from study start to one year after the last dose of protocol therapy.