Real-World Outcomes of Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation in Japan: Retrospective Analysis of the Transplant Registry Unified Management Program Registry

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an important therapeutic option for patients with hematologic malignancies. However, the development of graft-versus-host disease (GVHD) after allo-HSCT remains a challenge. Although systemic steroid therapy is the established first-line therapy for acute GVHD (aGVHD) and chronic GVHD (cGVHD), many patients are unresponsive or resistant to corticosteroid therapy, and the response is insufficient. This study aimed to evaluate the clinical characteristics of patients who developed aGVHD and cGVHD after allo-HSCT. This noninterventional, retrospective study used large national registry data from the Transplant Registry Unified Management Program. The study included 29,690 patients with a hematologic disease who underwent their first allo-HSCT between January 2010 and December 2019. The primary study endpoints were the cumulative incidence of aGVHD and cGVHD. The secondary endpoints were overall survival (OS) and nonrelapse mortality (NRM) of patients with aGVHD and cGVHD and OS and NRM of patients who received second-line therapy for aGVHD. Of 29,690 patients who underwent allo-HSCT, the graft source was related bone marrow (RBM) in 2807, related peripheral blood (RPB) in 6167, unrelated bone marrow in 10,556, unrelated peripheral blood (UPB) in 774, and unrelated cord blood in 9339. The cumulative incidence of grade II-IV aGVHD at 100 days was high after the related and unrelated mismatched transplantation. The response rates for first- and second-line therapy for aGVHD were low in the RBM/RPB-mismatched (59.6%/61.6%) and UPB-mismatched subgroups (45.5%), respectively. The 3-year NRM in patients with aGVHD was high in the RPB and UPB mismatched subgroups (37.9% and 31.2%, respectively). Developing a novel treatment for steroid-refractory aGVHD is necessary to improve transplantation outcomes, particularly for patients undergoing HLA-mismatched allo-HSCT.