A Phase II Study of Carfilzomib in the Treatment of Relapsed/Refractory Mantle Cell Lymphoma

Inclusion Criteria: 1. Confirmed diagnosis of mantle cell lymphoma. 2. Patients must have relapsed or refractory MCL. 3. Understand and voluntarily sign an IRB-approved informed consent form. 4. Age \>/= 18 years at the time of signing the informed consent. 5. Patients must have bi-dimensional measurable disease (bone marrow only involvement is acceptable). 6. Eastern Cooperative Oncology Group (ECOG) performance status of 2 or less 7. Serum bilirubin \<1.5 mg/dl and Creatinine Clearance \>/= 30 mL/min, platelet count \>50,000/mm\^3 and absolute neutrophil count (ANC) \> 1,000/mm\^3. \[Patients who have bone marrow infiltration by MCL are eligible if their ANC is ≥ 500/mm\^3 (growth factor allowed) or their platelet level is equal to or \> than 30,000/mm\^3.\]. AST (SGOT) and ALT (SGPT) \< 2 x upper limit of normal or \< 5 x upper limit of normal if hepatic metastases are present. Uric acid within normal limits. 8. Females of childbearing potential (FCBP)\* must have a negative serum or urine pregnancy test within 30 days of initiation of therapy. \* A female of childbearing potential is a sexually mature woman who: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 24 consecutive months (i.e., has had menses at any time in the preceding 24 consecutive months). 9. FCBP must agree to use a highly-effective form of birth control while taking the study drug and for 1 month after the last dose of study drug. Highly-effective forms of birth control include implants, injectables, birth control pills with 2 hormones, some intrauterine devices (IUDs), or having a sterilized partner. The type of birth control used must be discussed with and approved by the attending physician prior to initiation of study drug. 10. Males must agree to use a condom with spermicide every time they have sex during the study and for 3 months after the last dose of study drug. They also must agree to not donate sperm during the study and for 3 months after the last dose of study drug. 11. Patients must be willing to receive transfusions of blood products. Exclusion Criteria: 1. Any serious medical condition including but not limited to, uncontrolled hypertension, uncontrolled diabetes mellitus, active/symptomatic coronary artery disease, chronic obstructive pulmonary disease (COPD), renal failure, active hemorrhage, or psychiatric illness that, in the investigators opinion places the patient at unacceptable risk and would prevent the subject from signing the informed consent form. 2. Pregnant or breast feeding females. 3. Known HIV infection. Patients with 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 4. All patients with active central nervous system lymphoma. 5. Significant neuropathy (Grades 3 - 4, or Grade 2 with pain) within 14 days prior to enrollment. 6. Known history of allergy to Captisol® (a cyclodextrin derivative used to solubilize carfilzomib). 7. Contraindication to any of the required concomitant drugs or supportive treatments or intolerance to hydration due to preexisting pulmonary or cardiac impairment including pleural effusion requiring thoracentesis to ascites requiring paracentesis. 8. Patients with active pulmonary embolism or deep vein thrombosis (diagnosed within 30 days of study enrollment). 9. Patients with symptomatic bradycardia (heart rate \< 50 bpm, hypotension, light-headedness, syncope). 10. Use of any standard/experimental anti-lymphoma drug therapy, including steroids, within 3 weeks of initiation of the study or use of any experimental non-drug therapy (e.g. donor leukocyte/mononuclear cell infusions) within 56 days of initiation of the study drug treatment. Prior allogeneic SCT within 16 weeks or autologous SCT within 8 weeks of initiation of therapy. 11. Patients with New York Health Association (NYHA) Class III and IV heart failure, myocardial infarction in the preceding 6 months, and conduction abnormalities, including but not limited to atrial fibrillation, atrioventricular (AV) block block, QT prolongation, sick sinus syndrome, ventricular tachycardia, as these patients may be at greater risk for cardiac complication, per carfilzomib labeling. 12. 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 of the MCL, within the subsequent 6 months at the time of consent. Investigator discretion is allowed. 13. Acute active infection requiring treatment (systemic antibiotics, antivirals, or antifungals) within 14 days prior to enrollment. 14. Patients who have received any previous Carfilzomib treatment.