Given the established role of high dose cytarabine (HiDAC) combined with rituximab, along with recent data showing the encouraging efficacy of bendamustine, the investigators seek to integrate the synergistic effects of these medicines in alternating cycles as induction therapy prior to autologous stem cell transplant (ASCT). Based on prior experience with bendamustine and rituximab (BR) based induction therapy, the investigators seek to evaluate the efficacy and safety of stem cell mobilization in this pilot study

Inclusion Criteria:

• Histologically confirmed mantle cell lymphoma with documented expression of CD20 (or CD 19) and cyclin D1 (BCL1) by immunohistochemical stains and/or t (11; 14) by cytogenetics or FISH

• Eighteen to 65 years of age, inclusive.

• Presence of evaluable disease by PET imaging per the Lugano classification (Cheson 201418)

• Eligible for autologous stem cell transplantation.

• ECOG performance status ≤ 2

• Normal bone marrow and organ function as defined below:

  • Absolute neutrophil count ≥ 1,000/mcl unless in the opinion of the treating physician, neutropenia is due to splenomegaly or bone marrow involvement
  • Platelets ≥ 100,000/mcl unless in the opinion of the treating physician, thrombocytopenia is due to splenomegaly or bone marrow involvement
  • Total bilirubin ≤ 2 x IULN and AST(SGOT)/ALT(SGPT) ≤ 3.0 x IULN except when, in the opinion of the treating physician, is due to direct involvement of lymphoma (e.g., hepatic infiltration or biliary obstruction due to lymphoma) or Gilbert's disease
  • Creatinine ≤ IULN OR creatinine clearance ≥ 40 mL/min/1.73 m2 for patients with creatinine levels above institutional normal

• Women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control, abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she must inform her treating physician immediately.

• Ability to understand and willingness to sign an IRB approved written informed consent document (or that of legally authorized representative, if applicable).

• Negative HIV serology.

Exclusion Criteria:

• Any previous chemotherapy or radiation for mantle cell lymphoma. Short course of steroids for symptom relief prior to presentation is permissible.
• Symptomatic meningeal or parenchymal brain lymphoma.
• A history of allergic reactions attributed to compounds of similar chemical or biologic composition to rituximab, cytarabine, bendamustine or other agents used in the study.
• Severe concurrent illness, which would limit compliance with study requirements.
• Subjects with serologic status reflecting active viral hepatitis B or C infection are not eligible. Subjects whoare hepatitis B core antibody positive but antigen negative will need negative polymerase chain reaction (PCR) prior to enrollment. Hepatitis B surface antigen positive or PCR positive patients will be excluded. Subjects who are hepatitis C antibody positive will need negative PCR prior to enrollment. Patients with positive hepatitis C will be excluded.
• Pregnant and/or breastfeeding. Women of childbearing potential must have a negative serum or urine pregnancy test within 14 days of study entry.