Impact of Pre-transplant Rituximab on Survival after Autologous Hematopoietic Stem Cell Transplantation for Diffuse Large B Cell Lymphoma

Incorporation of the anti-CD20 monoclonal antibody rituximab into front-line regimens to treat diffuse large B cell lymphoma (DLBCL) has resulted in improved survival. Despite this progress, however, many patients develop refractory or recurrent DLBCL and then undergo autologous hematopoietic stem cell transplantation (AuHCT). It is unclear to what extent pre-transplant exposure to rituximab affects outcomes after AuHCT. Outcomes of 994 patients receiving AuHCT for DLBCL between 1996 and 2003 were analyzed according to whether rituximab was (n = 176; +R cohort) or was not (n = 818; -R cohort) administered with front-line or salvage therapy before AuHCT. The +R cohort had superior progression-free survival (PFS; 50% vs 38%; P = .008) and overall survival (OS; 57% vs 45%; P = .006) at 3 years. Platelet and neutrophil engraftment were not affected by exposure to rituximab. Nonrelapse mortality (NRM) did not differ significantly between the 2 cohorts. In multivariate analysis, the +R cohort had improved PFS (relative risk of relapse/progression or death, 0.64; P < .001) and improved OS (relative risk of death, 0.74; P = .039). We conclude that pre-transplant rituximab is associated with a lower rate of progression and improved survival after AuHCT for DLBCL, with no evidence of impaired engraftment or increased NRM.