The purpose of this study is to evaluate the efficacy and safety of subcutaneous blisibimod administered in addition to standard therapy in subjects with active Systemic Lupus Erythematosus (SLE) disease as defined by SELENA-SLEDAI score ≥10 despite on-going stable corticosteroid therapy.

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
• 18 years of age or older

Exclusion Criteria:

• Severe active vasculitis, active central nervous system lupus, active lupus nephritis, 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