[Relapsed primary central nervous system lymphoma treated with CD19 chimeric antigen receptor T-cell therapy and allogeneic hematopoietic stem cell transplantation].

Relapsed and/or refractory (R/R) primary central nervous system lymphoma (PCNSL) has a poor prognosis. A 57-year-old man diagnosed with PCNSL achieved a complete response by high-dose methotrexate-based chemotherapy followed by autologous hematopoietic stem cell transplantation (ASCT). The disease was not cured, so he was treated with the anti-CD19 chimeric antigen receptor (CAR) T-cell therapy tisagenlecleucel after the third relapse. However, the disease relapsed again 28 days after CAR T-cell therapy. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) was attempted as curative therapy after bridging with second ASCT and tirabrutinib monotherapy. Although a temporary response was achieved, the disease relapsed 98 days after allo-HSCT. While receiving tirabrutinib for relapse after allo-HSCT, the patient developed acute respiratory failure due to transplant-related toxicity and post-transplant thrombotic microangiopathy. He died 175 days after allo-HSCT. Although various treatments for PCNSL have been investigated in recent years, the treatment strategy for R/R PCNSL has not been established. Further studies are warranted to improve the outcomes of patients with R/R PCNSL.