Inclusion Criteria:

- Have a histologic diagnosis of DLBCL, including transformed histology and follicular
grade 3 disease.

- Must have at least one site of biopsy-proven disease demonstrating both of the
following: bidimensional measurable disease with the longest axis >= 1.5cm by
radiographic imaging or positive FDG-PET scan at baseline.

- Patients with DLBCL and who have either relapsed, refractory, or progressive disease
following salvage therapy, OR relapsed, refractory, or progressive disease following
initial therapy and be medically unfit to receive aggressive therapy.

- Either fresh or archived tumor specimen must be available.

Exclusion Criteria:

- Documented history within 6 months of registration of a cerebral vascular event,
unstable angina, myocardial infarction, or cardiac symptoms.

- Patients who have received allogeneic stem cell transplant.

- Patients with evidence of another invasive primary malignancy within the past three
years other than non-melanoma skin cancer, cervical carcinoma in situ, in situ
carcinoma of the breast, or fully resected prostate cancer with normal PSA within 8
weeks of registration.

- Patients with any active systemic viral, bacterial, or fungal infection requiring
intravenous anti-infectives within 4 weeks prior to first dose of study drug.

- Patients with a history or clinical evidence of leptomeningeal or central nervous
system (CNS) lymphoma.