Successful treatment strategy in corporating mogamulizumab and cord blood transplantation in aggressive adult T-cell leukemia-lymphoma: a case report.

Adult T-cell leukemia-lymphoma (ATL) is a rare type of mature T cell lymphoma caused by human T-lymphotropic virus type 1 (HTLV-1) with dismal outcome with conventional chemotherapy. A humanized anti-CC chemokine receptor 4 (CCR4) monoclonal antibody, mogamulizumab (MOG), has been shown to be effective for CCR4-positive ATL. However, MOG administration before allogeneic hematopoietic stem cell transplantation (allo-HSCT) was reported to be associated with an increased risk of severe acute graft-versus-host disease (aGVHD) after allo-HSCT due to reduction of donor-derived regulatory T cells (Tregs). We herein present a patient with ATL who underwent allo-HSCT after MOG administration without developing severe GVHD while referring to serum MOG concentration. The clinical course of our case suggests that it might be possible to determine the appropriate timing of allo-HSCT with monitoring of residual MOG level while avoiding the detrimental effect of MOG on post-transplant clinical outcome without increasing the risk of relapse/progression.