Study on Mogamulizumab to Prevent Adult T-cell Leukemia/Lymphoma in People with HTLV-1

Inclusion Criteria

Screening Cohort (US patients only):

• Must be 18 years or older.
• Must provide written consent to participate.

Treatment Cohorts (Cohorts 1 and 2):

• Must test positive for the HTLV-1 virus using approved tests.
• Must have a high-risk immune cell profile.
• Must be 18 years or older.
• Must have stable primary organ functions, including:
  • Neutrophil count of at least 1000/mm3, unless diagnosed with ethnic neutropenia.
  • Platelet count of at least 100,000/mm3.
  • Hemoglobin level of at least 9.0 g/dL.
  • Liver enzymes and bilirubin within specified limits.
  • Kidney function within specified limits.
  • Blood oxygen levels of at least 90%.
• Must have a normal ECG without issues needing treatment.
• Must provide written consent to participate.
• Women of childbearing potential must use effective contraception during treatment and for 3 months after. Men must use effective contraception during treatment and for 3 months after.

Exclusion Criteria

• History of low neutrophil count, unless due to ethnic neutropenia.
• History of liver disease, except certain cases with negative PCR tests.
• History of tuberculosis or active tuberculosis.
• Recent heart attack within the past year.
• Allergic reactions to antibody drugs.
• History of other cancers, unless treated and disease-free for 5 years, or certain localized cancers that are completely cured.
• Recent treatment with immunosuppressants or interferon alpha products.
• Serious health issues like heart, lung, kidney, or liver failure, or uncontrolled diabetes.
• Active autoimmune disease requiring treatment in the past 2 years, except for certain replacement therapies.
• Any condition that could worsen with the study drug, as judged by the study doctor.
• Diagnosis of ATL.
• Women who are pregnant, breastfeeding, or planning to become pregnant during or shortly after treatment.
• Recent use of certain vitamins or supplements.
• Recent participation in other drug studies.
• Spinal cord issues like disc herniation.
• Uncontrolled mental health disorders.
• Positive tests for Hepatitis B or C, unless certain conditions are met.
• Positive HIV test, unless under control with treatment.
• Any other reason deemed unfit for the study by the study doctor.