Inclusion Criteria:

- Histologically proven mantle cell lymphoma

- Adequate organ function as defined by the following criteria:

- Serum aspartate transaminase (AST; serum glutamic oxaloacetic transaminase
(SGOT)) and serum alanine transaminase (ALT; serum glutamic pyruvic transaminase
(SGPT)) ≤2.5 x local laboratory upper limit of normal (ULN), or AST and ALT less
than or equal to 5 x ULN if liver function abnormalities are due to underlying
malignancy

- Total serum bilirubin ≤1.5 x ULN

- Absolute neutrophil count (ANC) ≥1500/µL

- Platelets ≥100,000/µL

- Hemoglobin ≥9.0 g/dL (may be transfused or erythropoietin treated)

- Serum calcium ≤12.0 mg/dL

- Serum creatinine ≤1.5 x ULN

- Normal potassium and magnesium at baseline

- All patients should be relapsed patients after previous treatments including
chemotherapy

- At least one measurable lesion (lymph node or tumor mass)

- The size of lesion must be > 1.0cm in the greatest transverse diameter

- ECOG PS 0-2

- Serum HCG test: negative if a patient is female eligible for pregnancy

Exclusion Criteria:

- Major surgery or radiation therapy within 4 weeks of starting the study treatment.

- History of or known carcinomatous meningitis, or evidence of symptomatic
leptomeningeal disease or secondary CNS involvement on CT or MRI scan.

- Ongoing cardiac dysrhythmias of NCI CTCAE grade ≥2.

- Pregnancy or breastfeeding.

- Patients with HIV positive

- Patients with HBs antigen positive

- Patients with anti-HCV positive

- History of the use of another HDAC inhibitor: e.g. valproic acid