Outcomes of rituximab-BEAM versus BEAM conditioning regimen in patients with diffuse large B cell lymphoma undergoing autologous transplantation

Abstract

Background: Although rituximab-based high-dose therapy is frequently used in diffuse large B cell lymphoma (DLBCL) patients undergoing autologous hematopoietic cell transplantation (auto-HCT), data supporting the benefits are not available. Herein, we report the impact of rituximab-based conditioning on auto-HCT outcomes in patients who have DLBCL. Methods: Using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry, 862 adult DLBCL patients undergoing auto-HCT between 2003 and 2017 using BEAM (BCNU, etoposide, cytarabine, melphalan) conditioning regimen were included. All patients received frontline rituximab-containing chemoimmunotherapy and had chemosensitive disease pre-HCT. Early chemoimmunotherapy failure was defined as not achieving complete remission (CR) after frontline chemoimmunotherapy or relapse within 1 year of initial diagnosis. The primary outcome was overall survival (OS). Results: The study cohort was divided into 2 groups: BEAM (n = 667) and R-BEAM (n = 195). On multivariate analysis, no significant difference was seen in OS (P =.83) or progression-free survival (PFS) (P =.61) across the 2 cohorts. No significant association between the use of rituximab and risk of relapse (P =.15) or nonrelapse mortality (P =.12) was observed. Variables independently associated with lower OS included older age at auto-HCT (P '.001), absence of CR at auto-HCT (P '.001) and early chemoimmunotherapy failure (P '.001). Older age (P '.0002) and non-CR pre-HCT (P '.0001) were also associated with inferior PFS. There was no significant difference in early infectious complications between the 2 cohorts. Conclusion: In this large registry analysis of DLBCL patients undergoing auto-HCT, the addition of rituximab to the BEAM conditioning regimen had no impact on transplantation outcomes. Older age, absence of CR pre auto-HCT, and early chemoimmunotherapy failure were associated with inferior survival.