Mogamulizumab Every 4 Week dosing in Participants with R/R CTCL

You likely can't join if

• 1) Current evidence of large cell transformation (LCT). Participants with clinical features suggestive of LCT must have a biopsy performed within 4 months prior to Cycle 1 Day 1 to rule out transformed disease. Participants with a history of LCT but without current aggressive disease and no current evidence of LCT on pathology in skin or lymph nodes would be eligible. 2) Diagnosed with another malignancy in the past 2 years. However, participants with non-melanoma skin cancers, melanoma in situ, localized cancer of the prostate with current prostate-specific antigen of < 0.1 ng/mL, treated thyroid cancer, or cervical carcinoma in situ or ductal/lobular carcinoma in situ of the breast within the past 2 years may enroll as long as there is no current evidence of disease. 3) Clinical evidence of CNS metastasis. 4) Psychiatric illness, disability, or social situation that would compromise the participant's safety or ability to provide consent, or limit compliance with study requirements.
• 5) Significant uncontrolled intercurrent illness including, but not limited to: a) uncontrolled infection requiring antibiotics; b) clinically significant cardiac disease (class III or IV of the NYHA classification); c) unstable angina pectoris; d) angioplasty, stenting, or myocardial infarction within 6 months; e) uncontrolled hypertension (systolic BP > 160 mmHg or diastolic BP > 100 mmHg, found on two consecutive measurements separated by a one week period) despite the use of two anti-hypertensive medications; f) clinically significant cardiac arrhythmia; or g) uncontrolled diabetes.
• 6) Active HIV, HTLV-1, hepatitis B, or hepatitis C disease. 7) Active herpes simplex or herpes zoster. Participants on prophylaxis for herpes may enter the study and should continue to take the prescribed medication for the duration of the study if they started taking medication at least 30 days prior to the Pre-treatment Visit, have no signs of active infection, and their last active infection was more than six months ago. 8) Experienced allergic reactions to monoclonal antibodies or other therapeutic proteins. 9) Hypersensitivity to the active substance or to any of the excipients. 10) Known active autoimmune disease (i.e., Graves' disease; systemic lupus erythematosus; rheumatoid arthritis; Crohn's disease; psoriasis). 11) Is pregnant (confirmed by beta human chorionic gonadotropin) or lactating. 12) Prior treatment with mogamulizumab. 13) Have had any therapy directed against the participant's underlying cancer or any investigational medications within 4 weeks of enrollment (skin directed treatments, including topicals and radiation within 2 weeks of enrollment). However, participants with rapidly progressive malignant disease may be enrolled prior to this period after discussion with and approval from the Medical Monitor.
• 14) Participants on a stable dose of a low dose systemic corticosteroid (≤ 20 mg prednisone equivalent) for at least 4 weeks prior to the Cycle 1 Day 1 may continue use, although the Investigator should attempt to taper the use to the lowest dosage tolerable while on study. Initiation of treatment with systemic corticosteroids or increase in dose while on study is not permitted except to treat an infusion reaction. Participants may receive intra-articular corticosteroid injections, intraocular corticosteroid drops, inhalation or nasal corticosteroids, and replacement doses of systemic corticosteroids as needed. 15) Participants on a stable dose of medium or low potency topical corticosteroids for at least 4 weeks prior to the Cycle 1 Day 1 may continue use at the same dose, although the Investigator should attempt to taper the use to the lowest dosage tolerable while on study. Initiation of treatment with topical corticosteroids while on study is not permitted except to treat an acute rash. 16) History of allogeneic transplant. 17) Autologous hematopoietic stem cell transplant within 90 days of the Pre-treatment Visit. 18) Participants will be excluded if on any immunomodulatory drug for concomitant or intercurrent conditions other than T-cell lymphoma or who have received any of these agents within four weeks of treatment.