Radioimmunotherapy (RIT) with ⁹⁰yttrium Zevalin Followed by BEAM Conditioning Regimen (Z-BEAM) and Autologous Stem Cell Transplantation (ASCT) for the Treatment of High Risk Relapsed/Resistant Non Hodgkin's Lymphoma (NHL)

Abstract 3107

High dose chemotherapy (HDC) and ASCT is actually considered an effective treatment for relapsed NHL. Standard dose Zevalin (0.4 mCi/kg) combined with conventional BEAM (Z-BEAM) is a promising conditioning regimen for the treatment of high risk relapsed/resistant NHL. We evaluated the feasibility and the efficacy of Z-BEAM in a group of relapsed/refractory patients treated in a single institution. Between October 2006 and December 2010 twenty nine pts were treated with Zevalin (day –14) followed by standard dose BEAM (day –7 to –1) and ASCT. Patients were included into the study and considered at high risk of failure if showed: progression or early relapse (<1 year) from previous therapy or multiple relapses. Rituximab followed by standard dose DHAP or ICE were used as debulking and mobilizing schedule. Clinical characteristics were as follows: 14 refractory and 15 early or multiple relapse; 8 grade I-II follicular, 16 PML/DLBCL, 3 MCL, 2 indolent non follicular; 6 stage II and 23 stage III-IV; 10 patients had bulky disease and 15 bone marrow involvement; 9 LDH level above normal. 13 patients received only one previous line of treatment and 16 were treated with 2 or more lines before Z-BEAM, all containing Rituximab. Only 5/29 patinets received a reducted dose of 0.3 mCi/kg Zevalin because of low platelets counts. Response status before RIT was: 14 CR (49%), 9 PR (33%), 3 SD (9%) and 3 PD (9%). At the end of treatment response status is actually available in 26/29 pts: CR 18(69%), PR 5(19%) and PD 3 (12%). Overall response rate was converted from 81% before Z-BEAM and ASCT to 88% at the end of the entire program. Median CD34+ cells infused was 7.26 10⁶/kilograms (range 4.43–8.9). All pts engrafted with median time to platelet and neuthrophils count higher than 20×10⁹/l and 0.5×10⁹/L of 11 and 10 days respectively. Febrile neutropenia occurred in 12/29 pts. One pulmonary Aspergillosis and 8 bacteriemia were documented. One patient experienced an intestinal perforation during aplasia and one cardiac failure was documented in a woman previously treated with cumulative antraciclines doses and mediastinal radiotherapy. With a median follow up of 15 months progression free survival (PFS) is 79% and overall survival is 83%. 4/14 pts before Z-BEAM showed a subsequent progression and 2/15 relapsed: five pts died of lymphoma. No toxic deaths were recorded. In this group of pts with high risk relapsed/resistant NHL Z-BEAM+ASCT is able to achieve a good response with engraftment and toxicity not different from standard BEAM. This approach needs to be tested in a larger multicenter study. A matched pair analysis to compare this group with a similar group treated with standard BEAM without Zevalin is actually planned in our institution