PF719 CLINICAL OUTCOMES OF SOLID ORGAN TRANSPLANT PATIENTS WITH EBV+PTLD WHO FAIL FIRST-LINE RITUXIMAB OR RITUXIMAB PLUS CHEMOTHERAPY: AN ANALYSIS OF GERMAN PTLD REGISTRY
Authors: H. Zimmermann, H. Xu, A. Barlev, A. Feng, X. Li, W. Navarro, R. Ulrich Trappe
Journal: HemaSphere (2019)

Background: The optimal management of post-transplant lymphoproliferative disorder (PTLD) for solid organ transplant (SOT) patients (pts) failing initial therapy is not established. The PTLD-1 trials showed that risk-stratified sequential treatment with 4 doses of rituximab induction followed by rituximab consolidation or 4 cycles of CHOP or R-CHOP chemotherapy (CT) yields favorable treatment outcomes and tolerable treatment-related mortality.1 However, outcomes for those pts failing the PTLD-1 treatment scheme remain unclear. Aims: To characterize outcomes for patients (pts) diagnosed with EBV+PTLD post-SOT refractory to or relapsed after 1st-line rituximab or rituximab plus CT in a real-world setting in Germany. Methods: The German PTLD registry database was screened for pts with EBV+PTLD post-SOT who received rituximab or rituximab plus CT during 2000–2015 and who were refractory (failed to achieve complete-CR or partial remission-PR) to rituximab or rituximab plus CT or relapsed at any point after such therapy. Pts with CNS PTLD were excluded. Medical charts were reviewed by an experienced physician and response to therapy was determined by computed tomography staging. Kaplan-Meier (KM) method was used to estimate the distribution of overall survival (OS) in this cohort and for the subgroup of patients who fail to respond to the first CT. Results: A total of 36 EBV+PTLD pts were identified with a median follow up time of 23.4 months (mos) from the date of PTLD diagnosis. Median age at PTLD diagnosis was 47.5 years (yrs) (range 18–75); median time to PTLD onset from transplant was 2.4 yrs (range 0.2–28). Of these, 6 (16.7%) were polymorphic, 22 were diffuse large B cell lymphoma (61.1%), 3 were Burkitt lymphoma (8.3%), and other types 5 (13.9%). Among the 36 pts, 24 (66.7%) died (12 from PTLD, 6 treatment-related, 2 organ failure, and 4 other causes), and with a median overall survival (mOS) of 24.8 mos (95%CI: 10.3–67.6) from PTLD diagnosis. Of 36 pts, 31 received 1st CT regimen following rituximab (29 CHOP/R-CHOP, 2 other). Of those 31, 19 responded to CT with a mOS of 63 mos; for the other 12 who failed to respond to 1st CT, mOS was 3.3 mos. For the 5 pts who did not receive 1st CT, mOS was less than 2 mos from the date of disease progression. Summary/Conclusion: Pts who failed to respond or did not receive 1st CT had a mOS of <3 mos. Two-thirds of rituximab failure patients ultimately died; half of the deaths were from PTLD and 25% were from treatment-related causes. There remains significant unmet medical need for EBV+ PTLD pts who fail to respond to initial treatment with rituximab. 1. Trappe et al. Response to Rituximab Induction Is a Predictive Marker in B-Cell Post-Transplant Lymphoproliferative Disorder and Allows Successful Stratification Into Rituximab or R-CHOP Consolidation in an International, Prospective, Multicenter Phase II Trial. J Clin Oncol 35:536-543.