A Phase 1 Study of MEDI7734 in Type I Interferon-Mediated Autoimmune Diseases

Key Inclusion Criteria: 1. Age 18-65 years old 2. Diagnoses of dematomyositis, polymyositis, Sjogren's syndrome, systemic lupus erythematosus and/or systemic sclerosis based on standard criteria. 3. Weight 40-120kg 4. Stable disease such that in the opinion of the investigator it is unlikely that a change in subject's therapeutic regimen would be required during the subsequent 3 months. Key Exclusion Criteria: 1. History of a hypersensitivity reaction or anaphylaxis to a previous mAb or human immunoglobulin therapy. 2. Chronic hepatitis B, chronic hepatitis C, or HIV infection. 3. History of latent or active tuberculosis (TB), or a positive QuantiFERON®-TB Gold test at screening. 4. Herpes zoster infection within 3 months before randomization 5. Any of the following medications within 6 months of Day 1: cyclophosphamide, leflunomide \> 20 mg/day, abatacept. 6. Receipt of a mAb within 5 published half-lives prior to Day 1. 7. Receipt of rituximab or an experimental B-cell depleting mAb within 6 months of Day 1. 8. Receipt of rituximab or an experimental B-cell depleting mAb without return of CD19 or CD20 count to above the lower limit of normal. 9. Receipt of alemtuzumab, bone marrow transplantation, stem cell transplantation, total lymphoid irradiation, or T-cell vaccination therapy -