KW-0761 or Investigator's Choice in Subjects With Previously Treated Adult T-cell Leukemia-Lymphoma (ATL)

CCR4 expression in ATL patients has been demonstrated to be very high and has been associated with shorter survival compared with CCR4-negative patients. KW-0761, a monoclonal antibody targeted to CCR4, has been shown to be safe and tolerable in several clinical trials in subjects with a variety of T-cell malignancies, including ATL, mycosis fungoides and Sézary syndrome. The objective of this study is to estimate the overall response rate of KW-0761 for subjects with relapsed or refractory ATL.