Inclusion Criteria

• Age ≥18 years
• Histological diagnosis of MCL and presence of either nuclear Cyclin D1 positivity by immunohistochemistry or t by fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), or conventional karyotyping
• Documented progression or relapse after at least 1 line of prior chemotherapy
• Presence of measurable disease
• ECOG performance status 0, 1, or 2
• Life expectancy of at least 3 months
• Ability to understand and the willingness to sign a written informed consent document (ICD)
• Full recovery from all prior treatment toxicities of Common Terminology Criteria for Adverse Events (CTCAE) grade ≤ 1

Exclusion Criteria

• Prior radiation therapy, chemotherapy or biologic/targeted anticancer agents within 4 weeks of study drug administration
• Prior treatment with monoclonal antibodies or any radio- or toxin- immunoconjugates within 3 months of study drug administration
  • However rituximab treatment within 3 months and PD after such treatment is allowed in the study
• Prior allogeneic stem cell transplantation within 1 year of study drug administration
• Current or prior CNS lymphoma
• QTc > 450 msec
• Unstable angina, myocardial infarction, CHF or stroke within previous 6 months of study drug administration
• Presence of active and serious comorbidity and uncontrolled illness other than MCL
• History of other prior malignancies except for properly treated basal cell or squamous cell carcinoma of skin, in situ cervical cancer, in situ breast cancer or early stage prostate cancer
• Hemoglobin <8.0 gm/dL
• Absolute neutrophil count <1000/mm3
• Platelet count <50,000/mm3
• Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) >3 × institutional upper limit of normal (ULN) (> 5 × institutional ULN if liver is involved with lymphoma or if patient has Gilbert's Disease)
• Total bilirubin, >1.5 × institutional ULN (> 3 × institutional ULN if liver is involved with lymphoma or if patient has Gilbert's Disease)
• Serum creatinine >1.5 × institutional ULN
• Known to be suffering from infection with human immunodeficiency virus (HIV), tuberculosis, Hepatitis C or Hepatitis B
• Pregnant or lactating women
• Women of childbearing potential or men not willing to use at least 2 approved methods of contraception after signing the ICD, during the entire study, and for at least 4 weeks following withdrawal from the study
  • One must be a barrier method