A Multicenter Retrospective Study of Mogamulizumab Efficacy in Adult T-Cell Leukemia/Lymphoma.

BACKGROUND: Mogamulizumab, a defucosylated humanized monoclonal antibody targeting C-C chemokine receptor 4, recently became available for the treatment of adult T-cell leukemia/lymphoma (ATL). We conducted a multicenter retrospective study of the efficacy of mogamulizumab in ATL treatment in patients on Hokkaido Island, Japan. MATERIALS AND METHODS: A total of 125 patients with ATL treated from January 2010 to December 2014 in 20 hospitals affiliated with the Hokkaido Hematology Study Group were enrolled in the present retrospective study. RESULTS: Of the 125 ATL patients, 62 (46.6%) presented with the acute type, 51 (38.3%) with the lymphoma type, and 12 (9.0%) with the chronic type; the latter group included 7 unfavorable chronic cases. The median age at diagnosis was 68 years (range, 35-86 years). The median survival for those with acute, lymphoma, and unfavorable chronic types was 302, 279, and 921 days, respectively. Advanced age, high lactate dehydrogenase level, poor performance status (3-4), and the existence of B symptoms were unfavorable prognostic factors for overall survival (OS). Survival rate calculated from the day of diagnosis was significantly higher in patients treated with mogamulizumab. The OS of individuals receiving hematopoietic stem cell transplantation (HSCT) was superior to that of the non-HSCT group. The median interval between the last mogamulizumab dose and allogeneic HSCT was 38 days (range, 21-53 days). Of the 22 HSCT recipients who were not treated with mogamulizumab, overall acute graft-versus-host disease (aGVHD) and grade III-IV aGVHD occurred in 12 (54.5%) and 3 (13.6%) patients, respectively. However, overall aGVHD and grade III-IV aGVHD developed in 8 (88.9%) and 3 (33.3%) of the 9 HSCT recipients treated with mogamulizumab, respectively. CONCLUSION: Mogamulizumab improves OS in patients with ATL, although its use in HSCT patients might trigger severe GVHD. Determining the optimal pre-HSCT mogamulizumab treatment regimen is thus a priority.