Failure of rituximab is associated with a poor outcome in diffuse large B cell lymphoma‐type post‐transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD) may arise after solid organ transplantation, and the most common subtype resembles diffuse large B cell lymphoma (DLBCL). In DLBCL-type PTLD, the anti-CD20 antibody rituximab (R) may be combined with chemotherapy (R-CHOP) or use a strategy (R-primary; similar to the PTLD-1 clinical trial) consisting of induction with four weekly doses of R-alone, without any chemotherapy or sequential R-CHOP follow-up. Here we report on a multicentre retrospective cohort of solid organ transplant patients with DLBCL-type PTLD that were treated with R. In 168 adults, two-year overall survival (OS) was 63.7% [95% CI (confidence interval) 56.6-71.7%]. No difference in OS was observed, whether patients were treated with R-CHOP versus the R-primary strategy. In the 109 patients treated with R-primary, multivariate analysis found that baseline IPI score and the response to R-induction predicted OS. Patients who responded to R-induction had durable remissions without the addition of chemotherapy. Conversely, of the 46 patients who had stable or progressive disease after R-induction (R-failure), those who received R-CHOP had an only marginally improved outcome, with a two-year OS of 45% (23.1-65.3%) vs. no R-CHOP at 32% (14.7-49.8%). In real-world patients, R-failure and high IPI scores predict a poor outcome in DLBCL-type PTLD.