Adult T-cell leukemia-lymphoma (ATL) is a peripheral T-cell lymphoma caused by human T-cell lymphotropic virus type I. Patients with aggressive ATL exhibit poor outcomes, even with dose-dense intensive chemotherapy. Thus, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered in all patients eligible for transplant. However, patients with aggressive ATL often have chemo-refractoriness or experience early relapse during chemotherapy. Allo-HSCT is often ineffective in patients with active disease status. Mogamulizumab (Moga) was approved in 2012 in Japan as a potent treatment option for patients with relapsed or refractory ATL. However, there is a major concern that the use of Moga before allo-HSCT could increase the risk of post-transplant complications, such as graft-versus-host disease (GVHD), because Moga depletes regulatory T cells. Here, we would like to describe the possible effects of pre-transplant Moga on post-transplant complications, such as acute GVHD, and to discuss how Moga could be efficiently incorporated in the treatment regimen of patients with aggressive ATL to maximize the expected clinical benefit.
Keywords: Adult T-cell leukemia-lymphoma; Allogeneic hematopoietic stem cell transplantation; Mogamulizumab; Regulatory T cell.