Successful treatment of a patient with adult T cell leukemia/lymphoma using anti-CC chemokine receptor 4 monoclonal antibody mogamulizumab followed by allogeneic hematopoietic stem cell transplantation.

Adult T cell leukemia/lymphoma (ATLL) is an aggressive peripheral T cell neoplasm caused by human T cell lymphotropic/leukemia virus type-1 and has a poor prognosis. A new anti-CC chemokine receptor 4 monoclonal antibody (mogamulizumab) has been shown to be effective for ATLL. Although mogamulizumab is now available in Japan for patients with ATLL, the influence on allogeneic hematopoietic stem cell transplantation (HSCT) remains unclear. Here we report a woman with ATLL resistant to combination chemotherapy, who achieved complete remission following treatment with mogamulizumab and subsequently received allogeneic HSCT. The patient has remained in complete remission with controlled graft-versus-host disease. To our knowledge, this is the first report of an ATLL patient who received mogamulizumab treatment followed by allogeneic HSCT. We suggest that administration of mogamulizumab to chemotherapy-resistant patients with ATLL may improve their disease status before allogeneic HSCT and result in better survival.