The purpose of this study is to evaluate the clinical efficacy of blisibimod as measured by a composite responder index in subjects who, despite corticosteroid use, continue to have autoantibody positive, clinically-active Systemic Lupus Erythematosus (SLE) as defined by SELENA SLEDAI score ≥10.

Inclusion Criteria:

• Fulfill at least 4 diagnostic criteria for SLE defined by American College of Rheumatology
• Positive antinuclear antibodies (ANA) and/or anti-double stranded DNA (anti-dsDNA)
• Active SLE disease as defined by SELENA-SLEDAI score ≥10 despite on-going stable corticosteroid therapy
• Subjects with stable nephritis may be enrolled
• 18 years of age or older

Exclusion Criteria:

• Severe active vasculitis, active central nervous system lupus, uncontrolled hypertension or poorly controlled diabetes
• Malignancy within past 5 years
• Known to be positive for HIV and/or positive at the screening visit for hepatitis B, or hepatitis C
• Liver disease
• Anemia, neutropenia, or thrombocytopenia
• Active infection requiring hospitalization or treatment with parenteral antibiotics within the past 60 days or history of repeated herpetic viral infections
• History of active tuberculosis or a history of tuberculosis infection
• Pregnant or nursing