Radioimmunotherapy (90Y-Ibritumomab Tiuxetan) for Posttransplant Lymphoproliferative Disorders After Prior Exposure to Rituximab

Abstract

Posttransplantation lymphoproliferative disorders (PTLDs) are life‐threatening complications after solid organ and hematopoietic stem cell transplantation. Only half of CD20‐positive PTLDs respond to rituximab monotherapy, and outcomes remain poor for patients with relapsed/refractory disease, especially those who do not qualify for an anthracycline containing regimen due to frailty or comorbidities. Radioimmunotherapy (RIT) might be an option in this particular setting. We report a panel of eight patients with rituximab refractory/relapsed CD20‐positive PTLDs including three ineligible for subsequent CHOP‐like chemotherapy who received 90Y‐Ibritumomab tiuxetan as a single agent (n = 7) or combined to chemotherapy (n = 1). Five out of eight patients were kidney transplant recipients, while 2/8 had a liver transplant and 1/8 had a heart transplant. Patients received a median of two previous therapies. Overall response rate was 62.5%. Importantly, all responders achieved complete response. At a median follow‐up of 37 months [5; 84], complete response was ongoing in four patients. Toxicity was predominantly hematological and easily manageable. No graft rejection was noticed concomitantly or following RIT administration despite immunosuppression reduction after diagnosis of PTLDs. This report emphasizes the potential efficiency of salvage RIT for early rituximab refractory PTLDs without any unexpected toxicity.

Post‐transplant lymphoproliferative disorder in pediatric intestinal transplant recipients: A literature review

“…Novel treatment strategies under investigation also include brentuximab vedotin, an antibody‐drug conjugate with CD30‐directed antibody conjugated to MMAE, immune checkpoint inhibitors, and radioimmunotherapy with 90Y‐ibritumomab tiuxetan and the proteasome inhibitor bortezomib …”

Screening and Management of PTLD

“…147,169,170 Moreover, radiotherapy with (90Y-ibritumomab tiuxetan) has been used as salvage therapy with a 62.5% response rate for rituximab-refractory or relapsing CD20 positive PTLD. 171 This is a promising option for patients who are unable to tolerate cytotoxic chemotherapy, but its cost and accessibility may limit widespread clinical implementation.…”

Recent Advances in Adult Post-Transplant Lymphoproliferative Disorder

“…Ibritumomab tiuxetan, an anti-CD20 mAb conjugated with a radioactive isotope, was assessed in a series of eight patients post-SOT with relapsed-refractory PTLD (median of two prior lines of therapy), as a single agent ( n = 7) or with chemotherapy ( n = 1) and yielded an OS rate of 62.5% (all CR) after a median follow-up of 37 months [ 107 ].…”