Original Research Article Zevalin and BEAM (Z-BEAM) versus rituximab and BEAM (R-BEAM) conditioning chemotherapy prior to autologous stem cell transplantation in patients with mantle cell lymphoma Martin D. Berger 1 , Giacomo Branger 1 , Bernd Klaeser 2 , Behrouz Mansouri Taleghani 3 , Urban Novak 1 , Yara Banz 4 , Beatrice U. Mueller 5 and Thomas Pabst 1 * 1 Department of Medical Oncology, University Hospital, Berne, Switzerland 2 Department of Nuclear Medicine, University Hospital, Berne, Switzerland 3 Department of Hematology, University Hospital, Berne, Switzerland 4 Institute of Pathology, University of Berne, Berne, Switzerland 5 Department of Clinical Research, University of Berne, Berne, Switzerland *Correspondence to: Associate Professor, Thomas Pabst M.D., Department of Medical Oncology University Hospital 3010 Bern, Switzerland. E-mail: thomas.pabst@insel.ch Received 9 October 2014 Revised 17 January 2015 Accepted 21 January 2015 Abstract Early relapse is common in patients with mantle cell lymphoma (MCL) highlighting the unmet need for further improvement of therapeutic options for these patients. CD20 inhibition combined with induction chemotherapy as well as consolidation with high-dose chemotherapy (HDCT) is increasingly considered cornerstones within current therapy algorithms of MCL whereas the role of radioimmunotherapy is unclear. This retrospective single center study compared 46 consecutive MCL patients receiving HDCT in first or second remission. Thirty-five patients had rituximab and BEAM (R-BEAM), and 11 patients received ibritumomab tiuxetan (Zevalin®), an Yttrium-90 labeled CD20 targeting antibody, prior to BEAM (Z-BEAM) followed by autologous stem cell transplantation (ASCT). We observed that the 5-year overall survival (OS) in the R-BEAM and Z-BEAM groups was 55% and 71% (p = 0.288), and the 4-year progression free survival (PFS) was 32% and 41%, respectively (p = 0.300). There were no treatment related deaths in both groups, and we observed no differences in toxicities, infection rates or engraftment. Our data suggest that the Z-BEAM conditioning regimen followed by ASCT is well tolerated, but was not associated with significantly improved survival compared to R-BEAM. Copyright © 2015 John Wiley & Sons, Ltd. Keywords: autologous transplantation; BEAM; Yttrium-90 ibritumomab tiuxetan; zevalin; mantle cell lymphoma; radioimmunotherapy; rituximab Introduction Mantle cell lymphomas (MCL) account for 7% of Non-Hodgkin Lymphomas (NHL). The hallmark of the disease is the oncogenic translocation t(11;14)(q13;q32) mediating deregulated expression of the cell cycle regulat- ing protein cyclin D1. The median age of MCL patients at diagnosis is 68 years, and the majority of patients present with advanced stages. The clinical course of classical MCL is characterized by early relapses, with a median sur- vival of three to five years [1–4]. Current first-line treatment algorithms in young MCL patients without relevant comor- bidities suggest dose-intensified immuno-chemotherapy such as three cycles of R-CHOP and three cycles of a cytarabine containing regimen such as R-ESAP or R-DHAP followed by HDCT and ASCT [5]. However, even such dose-intensified strategies are usually not cura- tive in the majority of MCL patients [6]. Lymphoma cells are generally sensitive to radiation, and local radiotherapy can be curative in limited stage NHL. These facts led to the introduction of radio-immunotherapy (RIT) in lymphoma treatment [7]. Ibritumomab tiuxetan (Zevalin®) is an Yttrium-90 labeled antibody directed against the B-cell surface antigen CD20 and acts as a beta-emitting radiation source with a half-life of 64 h. Zevalin® specifically delivers radiation directly to target cells and to neighboring cells within 5-mm distance (crossfire effect), thereby enhancing cytotoxicity to tumor cells with relative sparing of normal tissues [7–10]. Zevalin® is approved for the treatment of relapsed or Hematological Oncology Hematol Oncol 2015 Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/hon.2197 Copyright © 2015 John Wiley & Sons, Ltd.