Prior rituximab correlates with less acute graft‐versus‐host disease and better survival in B‐cell lymphoma patients who received allogeneic peripheral blood stem cell transplantation

Summary Prior therapy with rituximab might attenuate disparate histocompatibility antigen presentation by B cells, thus decreased the risk of acute graft‐versus‐host disease (GVHD) and improved survival. We tested this hypothesis by comparing the outcomes of 435 B‐cell lymphoma patients who received allogeneic transplantation from 1999 to 2004 in the Center for International Blood and Marrow Transplant Research database: 179 subjects who received rituximab within 6 months prior to transplantation (RTX cohort) and 256 subjects who did not receive RTX within 6 months prior to transplantation (No‐RTX cohort). The RTX cohort had a significantly lower incidence of treatment‐related mortality (TRM) [relative risk (RR) = 0·68; 95% confidence interval (CI), 0·47–1·0; P = 0·05], lower acute grade II–IV (RR = 0·72; 95% CI, 0·53–0·97; P = 0·03) and III–IV GVHD (RR = 0·55; 95% CI, 0·34–0·91; P = 0·02). There was no difference in the risk of chronic GVHD, disease progression or relapse. Progression‐free survival (PFS) (RR = 0·68; 95% CI 0·50–0·92; P = 0·01) and overall survival (OS) (RR = 0·63; 95% CI, 0·46–0·86; P = 0·004) were significantly better in the RTX cohort. Prior RTX therapy correlated with less acute GVHD, similar chronic GVHD, less TRM, better PFS and OS.