Inclusion Criteria:

- MSKCC or Weill Cornell biopsy confirmation of relapsed/refractory diffuse large
B-cell lymphoma.Patients with large cell transformation of a low-grade B-cell
lymphoma will be eligible.

- One or two prior chemotherapy regimens not including autologous stem cell
transplantation.

- Age ≥ 60 years.

- Not a candidate for autologous stem cell transplantation.

- Patient must have performance status of ≤2 on the ECOG Performance Scale.

- Measurable disease

- Adequate organ and bone marrow function: ANC ≥ 1000/mm3, platelet count ≥ 50,000/mm3,
total bilirubin ≤ 1.5 ULN (with exception of Gilbert's disease), AST/ALT ≤ 2.5 ULN,
creatinine ≤ 1.5 mg/dL or creatinine clearance ≥ 50 ml/min, potassium and magnesium
within normal limits.

- Male patients agree to use an adequate method of contraception for the duration of
the study.

- Patient is available for periodic blood sampling, study related assessments, and
management at the treating institution for the duration of the study.

Exclusion Criteria:

- Patient who has had chemotherapy, radiotherapy, or biological therapy [including
growth factors], within 30 days (42 days for nitrosoureas or mitomycin C) prior to
initial dosing with study drug(s) or who has not recovered from adverse events due to
agents administered more than 30 days earlier. Patients on a stable dose of steroids
for at least 4 weeks prior to onset of study therapy may be included.

- Patient is currently participating or has participated in a study with an
investigational compound or device within 30 days of initial dosing with study
drug(s).

- Patient had prior treatment with an HDAC inhibitor (e.g., romidespin
(Depsipeptide),NSC-630176, MS 275, LAQ-824, belinostat (PXD-101), LBH589,
MGCD0103,CRA024781, etc). Patients who have received compounds with HDAC
inhibitor-like activity, such as valproic acid, as anti-tumor therapy should not
enroll in this study. Patients who have received such compounds for other
indications, e.g. valproic acid for epilepsy, may enroll after a 30-day washout
period.

- Patients with active CNS lymphoma and/or lymphomatous meningitis are excluded.
However, patients with a history of CNS lymphoma and/or lymphomatous meningitis who
have been stable without evidence of CNS and/or leptomeningeal recurrence would be
eligible. They must be off steroids or on a stable dose of steroids.

- Patient with a primary central nervous system lymphoma.

- Patient has known hypersensitivity to the components of study drug or its analogs.

- Patient has known psychiatric or substance abuse disorders that would interfere with
cooperation with the requirements of the trial.

- Patient is, at the time of signing informed consent, a regular user (including
"recreational use") of any illicit drugs, substance abuse or had a recent history
(within the last year) of drug or alcohol abuse.

- Patient is expecting to father children within the projected duration of the study.

- Patient has uncontrolled intercurrent illness or circumstances that could limit
compliance with the study, including, but not limited to the following: active
infection, acute or chronic graft versus host disease, symptomatic congestive heart
failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric conditions.

- Patient has a history or current evidence of any condition, therapy, or lab
abnormality that might confound the results of the study, interfere with the
patient's participation for the full duration of the study or is not in the best
interest of the patient to participate.

- Patient has a history of a gastrointestinal surgery or other procedures that might,
in the opinion of the investigator, interfere with the absorption or swallowing of
the study drugs.

- Patient with a "currently active" second malignancy, other than non-melanoma skin
cancer and carcinoma in situ of the cervix, should not be enrolled. Patients are not
considered to have a "currently active" malignancy if they have completed therapy for
a prior malignancy, are disease free from prior malignancies for >5 years or are
considered by their physician to be at less than 30% risk of relapse.

- Patient is HIV +.

- Patient has active hepatitis B or C.