Inclusion Criteria:  Confirmed MCL tissue diagnosis with CD20- and cyclin D1-positive cells, or cyclin D1 negative but t (11;14) positive and diagnosis confirmed by pathologist from the tissue biopsy Patients with confirmed relapsed/refractory (R/R) MCL Understand and voluntarily sign an Institutional Review Board (IRB)-approved informed consent form Patients must have a biopsy-accessible lesion and be willing to undergo biopsy Patients must have bi-dimensional measurable disease as per Cheson criteria (bone marrow and or gastrointestinal [GI] only involvement is acceptable) Age >= 18 years at the time of signing the informed consent Absolute neutrophil count >= 1.0 x 10^9/L Absolute lymphocyte count >= 0.6 x 10^9/L Platelet count >= 50 x 10^9/L Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) =< 3 x upper limit of normal (ULN) Total bilirubin =< 1.5 x ULN unless bilirubin rise is due to Gilbert's syndrome or of non-hepatic origin Creatinine clearance (CLcr) > 50 mL/min Cardiac ejection fraction has to be >= 50% by echocardiogram (ECHO) or multigated acquisition (MUGA) No anticoagulation is allowed. No anti-platelet agents such as aspirin or clopidogrel are allowed Women of childbearing potential (WCBP) must have a negative serum or urine pregnancy test. Men must agree not to father a child and agree to use a condom if his partner is of child-bearing potential  Exclusion Criteria:  Any serious medical condition that places the patient at unacceptable risk and/or would prevent the subject from signing the informed consent form. Examples include but are not limited to uncontrolled hypertension, uncontrolled diabetes mellitus, active /symptomatic coronary artery disease, active infection, active hemorrhage, and psychiatric illness Patient with rapid progressive disease, which means If the patient has significant pain from tumor, very significant disease related symptoms or if the tumor is more than 5 cm in the longest diameter with symptoms, or if the tumor in obstructing any internal organs, if the tumor is threatening the spinal cord Pregnant or breastfeeding females Known human immunodeficiency virus (HIV) infection or active hepatitis B infection (not including patients with prior hepatitis B vaccination; or positive serum Hepatitis B antibody). Known hepatitis C infection is allowed as long as there is no active disease and is cleared by GI consultation The patient has a prior or concurrent malignancy that, in the opinion of the investigator, presents a greater risk to the patient's health and survival than the MCL, with a life expectancy =< 2 years Clinically significant cardiovascular disease such as uncontrolled or symptomatic arrhythmias, congestive heart failure or myocardial infarction within 6 months at the time of consent, or any class 3 (moderate) or 4 (severe) cardiac disease defined by the New York Heart Association classification Prior chemotherapy within 3 weeks, nitrosoureas within 6 weeks, therapeutic anticancer antibodies within 4 weeks, radio- or toxin-immunoconjugates within 10 weeks, radiation therapy or other investigational agents within 3 weeks, major surgery within 4 weeks, or vaccination with live attenuated vaccines within 4 weeks of the first dose of study drug The patient receives corticosteroids for non-malignant conditions (e.g., asthma, inflammatory bowel disease) equivalent to a dexamethasone dose >= 4 mg/day or prednisone >= 20 mg/day