A Clinical Pharmacological Study of MT-3921 in Subjects With HTLV-1 Associated Myelopathy (HAM)

Exclusion Criteria

• •Additional screening criteria check may apply for qualification:
• •Subjects who have a history of anaphylaxis or clinically significant allergic reactions due to administration of antibody products
• •Subjects exhibiting or with a history of malignant tumor.
• •Subjects with adult T-cell leukemia/lymphoma (ATL) or those with positive HTLV-1 clonality test (Southern blot) at screening and suspected of having ATL
• •Subjects with spinal cord compression lesions, such as cervical spine disease, disc herniation, and ossification of the yellow ligament
• •Subjects with psychiatric disorders, epileptic seizures, or dementia.
• •Subjects with suicide attempts or suicidal ideation corresponding to item 4 or 5 on the Columbia Suicide Rating Scale (C-SSRS) at screening and/or on the first day of the Treatment period (predose)
• •Subjects exhibiting or with a history of hepatitis B virus (HBV), hepatitis C virus (HCV), or human immunodeficiency virus (HIV) infection.
• •Subjects with the novel Coronavirus disease 2019 (COVID-19)
• •Subjects with severe illness
• •Male or female subjects of childbearing potential who do not agree to use a contraceptive measure from the day of consent to 16 weeks after the last dose of the investigational medical product
• •Female subjects who are pregnant, lactating, or may be pregnant
• •Subjects who have received anti-repulsive guidance molecule (RGM) a antibody containing this investigational medical product
• •Subjects who participated in other clinical studies (including clinical trials) and received drugs (including investigational medical products) or therapy within 12 weeks before the day of consent