Yttrium 90 Plus High Dose BEAM Conditioning with Autologous Stem Cell Transplantation (ASCT); Effects of Prior Rituximab and Outcome of Poor Risk Non Hodgkin Lymphoma (NHL).

Abstract

Abstract 2323Poster Board II-300 Introduction:High dose chemotherapy with ASCT can increase overall survival (OS) in patients with poor risk or relapsed Non- Hodgkin lymphoma (NHL). Novel conditioning regimens combining radioimmunotherapy (RIT) with high dose chemotherapy have demonstrated favorable toxicity profiles and potentially improved response rates. Herein we report on 84 patients who underwent conditioning with Y90 Ibritumomab plus high dose BEAM (BCNU VP16 AraC Melphalan) and the effects of pretreatment rituximab levels on relapse. On day-23 and day-16 of conditioning pts had a blood draw for rituximab levels. If levels were &10ug/ml, pts received rituximab 250mg/m2. This was followed by pretherapy imaging with Indium 111 on day -21 and Y90 treatment on day -14. High dose BEAM chemotherapy started on day-7and all pts received rituximab 250mg/m2 at day+8. Results:The median age at ASCT was 58.5 years (range 19-78). Histologies included DLC n=36, Mantle Cell n=27, Follicular n=11, Transformed NHL n=10. Disease status at ASCT was 1st or 2nd CR n=35, 1stPR n=13, 1st or 2nd rel n=18, induction failure (IF) n=18. Median length of f/u for living pts was 34 months. All patients engrafted at a median of 11 days (anc>500) Transplant related mortality was 2.3 %. Two year OS/PFS for the entire cohort was 85.62% (77-91) and 66% (58-73). There was no significant difference in either DFS or OS based on histology (figure 1)Rituximab levels were available in a subset of 18 pts. and of note there was a trend towards higher relapse rates in patients with higher day-23 rituximab levels (35% vs. 0) (see figure 2). Conclusions.Y90 BEAM conditioning is well tolerated. Short term outcome is similar among different histologic types of NHL. The true effects of rituximab levels may not yet be fully appreciated due to small patient numbers. However, the trend towards higher relapse rates in the cohort with high circulating pre RIT rituximab levels suggests that titration of rituximab dosing pre RIT may be another strategy in which to improve transplant outcomes by optimizing targeting of the RIT. [Display omitted] [Display omitted] Disclosures:Off Label Use: yttrium 90 in combination with high dose BEAM chemotherapy.