Multicenter, Randomized, Open-label, Parallel-group Study to Compare mLSG15 + KW-0761 to mLSG15

Inclusion Criteria: * Subjects who have been positive for serum anti-human T-cell lymphotropic virus type I antibody * Subjects with hematologically or pathohistologically confirmed as peripheral lymphoid tumor which surface antigen analysis has identified to be of T-cell origin * Subjects who have been classified into acute subtype, the lymphoma subtype or chronic subtype with poor prognostic factors * Subjects who have been positive for CCR4 by CCR4 expression analysis * Subjects who have never been treated for adult T-cell leukemia-lymphoma * Subjects who have presented enlarged lymph nodes, tumor nodules in extranodal organs, abnormal lymphocytes in peripheral blood or cutaneous lesions * Subjects with a performance status of 0 to 2 * Subjects who have been negative for HBs antigen and anti-HCV antibody * Subjects who have given written voluntary informed consent to participate in the study Exclusion Criteria: * Subjects who are scheduled for transplant therapy such as hematopoietic stem-cell transplantation * Subjects who had myocardial infarction within 12 months before study enrollment or who have cardiac disease that may worsen during treatment with doxorubicin * Subjects who have been positive for anti-HIV antibody * Subjects with active multiple cancer * Subjects with a history of allergic reactions to therapeutic antibodies * Subjects who require emergency radiotherapy for treating the symptoms caused by bulky masses or who may require such radiotherapy after the start of the study * Subjects who are pregnant, lactating or of childbearing potential, or who are planning to have children