Intrathecal Rituximab for EBV-Associated Post-Transplant Lymphoproliferative Disorder with Central Nervous System Involvement Unresponsive to Intravenous Rituximab-Based Treatments: A Prospective Study

Backgroud:

   Although the introduction of rituximab as a first-line treatment has improved outcome of post-transplant lymphoproliferative disorder (PTLD), PTLD with central nervous system involvement (CNS-PTLD) still has a dismal prognosis because of low penetrance across the blood-brain barrier. In this prospective study, we reported intrathecal rituximab was efficacy and safety in the patients with CNS-PTLD who had failed to respond to the intravenous rituximab-based treatments. 

Methods:

   From June 2009 to November 2013, 32 cases of EBV-associated PTLD were recorded in the Southern Medical University Institute of Hematology. Fourteen patients diagnosed with CNS-PTLD were enrolled in this prospective study. For the patients who failed to response to the initial intravenous rituximab-based treatments, sequential dose-escalation schedule of intrathecal rituximab (initial dose of 20mg, increased by 10mg each week and maximum dose of 50 mg) was administrated weekly.

Results:

   Three patients were responsive and 11 were unresponsive to the initial treatments within one week after the treatments. For the 11 patients who failed to respond to the initial treatments, 9 patients received intrathecal rituximab within 7-11 days and 2 patients refused the treatment. After two cycles of rituximab-based treatments, 10 patients achieved complete response (CR), 2 patients were partial response and 2 patients were non-response. With a median follow up of 664 (range 18 to 1545) days after the diagnosis of CNS-PTLD, 7 patients survived and 7 died. The causes of death included PTLD progressing (n=3), PTLD relapse (n=1), GVHD (n=1), CMV pneumonia (n=1) and pseudomonas aeruginosa sepsis (n=1). The 3-year probability of OS was 45.7% ±14.7% in CNS-PTLD，which was no significant difference as compared to PTLD without CNS involvement(55.6% ±11.7%, P=0.706).

Conclusion:

 Intrathecal rituximab might be an effective and safe method for CNS-PTLD in the allo-HSCT recipients who were unresponsive to the intravenous rituximab-based treatments.