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

Overall Response Rate was determined based on the response in all compartments (lymph nodes, extranodal masses, spleen/liver, skin, peripheral blood, and bone marrow), referencing Tsukasaki, 2009 as follows: Complete Response (CR) = All compartments involved with disease must be CR; Uncertified Complete Response (CRu) = \> 75% decrease in lymph nodes and/or extranodal disease with all other compartments involved with disease CR; Partial Response (PR) = If any compartment is CR/PR and all other compartments involved with disease are at least SD; Stable Disease (SD) = All compartments involved with disease are SD; Progressive Disease (PD) = PD in any compartment. Lymph node and extranodal masses response ≥50% decrease by CT, skin response ≥50% decrease in mSWAT score; blood response ≥50% decrease in malignant cells by flow cytometry; normal bone marrow if abnormal at baseline. PD equals New or ≥50% increase in any compartment.

Time frame: every 8 weeks from date of randomization until the date of first documented progression or date of death from any cause, whichever came first

The FACT-Lym consists of a 27-item general core questionnaire (i.e., Functional Assessment of Cancer Therapy - General \[FACT-G\]) and a 15-item disease-specific questionnaire (Lymphoma Subscale). The FACT-G includes 4 domains: physical well-being, social/family well-being, emotional well-being, and functional well-being. The total FACT-Lym score (0-168) was obtained by summing individual subscale scores. Higher scores for the scales indicate better quality of life. Change was calculated as the value at the last observation minus the value at baseline.

Time frame: From date of randomization until the date of first documented progression, up to 36 months

Population: All participants in Intention-to-Treat who had both the values at baseline and last observation

The estimates and summary statistics for OS were calculated based on Kaplan-Meier method, and the median OS was 4.9 months for subjects randomized to the mogamulizumab group versus 6.87 months for subjects randomized to the Investigator's Choice group.

Time frame: up to 36 months

Progression-free survival was defined as the time from the first date of treatment until the date that PD or death was first reported. Disease progression included PD in any compartment per ATL response criteria, clinical progression at the end of the randomized treatment, or disease progression reported during the follow-up period. The date of PD was the earliest date at which disease progression could be declared.

Time frame: From date of randomization until the date of first documented progression, start of alternative therapy, or date of death from any cause, whichever came first, up to 36 months