A Study of the Efficacy and Safety of MEDI-546 in Systemic Lupus Erythematosus

Inclusion Criteria:

- Fulfills at least 4 of the 11 American College of Rheumatology (ACR) criteria for
systemic lupus erythematosus (SLE) including a positive antinuclear antibody (ANA)
greater than or equal to 1:80 or elevated anti-double-stranded DNA or anti-Smith
antibody at screening

- Pediatric or adult SLE with chronic disease activity for greater than or equal to 24
weeks

- Weight greater than or equal to 40 kg

- Currently receiving stable dose of oral prednisone (or equivalent) less than or equal
to 40 mg/day and/or antimalarials/immunosuppressives

- Active moderate to severe SLE disease based on SLE disease activity score (SLEDAI)
and British Isles Lupus Assessment Group Index (BILAG) and Physicians Global
Assessment

- No evidence of cervical malignancy on Pap smear within 2 years of randomization

- Female subjects must be willing to avoid pregnancy

- Negative tuberculosis (TB) test or newly positive TB test due to latent TB for which
treatment must be initiated at or before randomization

Exclusion Criteria:

- Active severe SLE-driven renal disease or unstable renal disease prior to screening

- Active severe or unstable neuropsychiatric SLE

- Clinically significant active infection including ongoing and chronic infections

- History of human immunodeficiency virus (HIV)

- Confirmed Positive tests for hepatitis B or positive test for hepatitis C

- History of severe herpes infection such as herpes encephalitis, ophthalmic herpes,
disseminated herpes

- Live or attenuated vaccine within 4 weeks prior to screening

- Subjects with significant hematologic abnormalities