Successful treatment with mogamulizumab followed by allogeneic hematopoietic stem-cell transplantation in adult T-cell leukemia/lymphoma: a report of two cases.

A humanized anti-CC chemokine receptor 4 (CCR4) monoclonal antibody, mogamulizumab (MOG), has been shown to be safe and effective in the treatment of relapsed/refractory adult T-cell leukemia/lymphoma (ATLL). MOG depletes ATLL cells as well as regulatory T cells (Tregs), as CCR4 is expressed on these cells as well. In this context, pretransplant treatment with MOG may induce severe graft-versus-host disease (GVHD) in allogeneic hematopoietic stem-cell transplantation (HSCT). However, the influence of MOG on allogeneic HSCT, including its induction of GVHD, is unclear. In this report, we describe two patients treated with MOG who subsequently underwent allogeneic HSCT. They did not develop severe GVHD or treatment-related complications. In addition, we examined the kinetics of Tregs in the second case. Finally, we suggest that the detrimental effects of MOG can be avoided, which should be prospectively evaluated in future studies.