A Study to Evaluate the Safety of Rituximab Retreatment in Subjects With Systemic Lupus Erythematosus

Inclusion Criteria:

   - Diagnosis of systemic lupus erythematosus (SLE).

   - Active disease at screening.

   - Stable use of one immunosuppressive drug.

   - Use of an antimalarial drug.

   - For subjects of reproductive potential (males and females), use of a reliable means of
   contraception throughout their study participation.

Exclusion Criteria:

   - Unstable patients with thrombocytopenia experiencing or at high risk for developing
   clinically significant bleeding or organ dysfunction requiring therapies such as
   plasmapheresis or acute blood or platelet transfusions.

   - Active moderate to severe glomerulonephritis.

   - Retinitis, poorly controlled seizure disorder, acute confusional state, myelitis,
   stroke or stroke syndrome, cerebellar ataxia, or dementia that is currently active and
   resulting from SLE.

   - Lack of peripheral venous access.

   - Pregnant women or nursing (breast feeding) mothers.

   - History of severe, allergic, or anaphylactic reactions to humanized or murine
   monoclonal antibodies.

   - Significant, uncontrolled medical disease in any organ system not related to SLE that
   in the investigator's opinion would preclude subject participation.

   - Concomitant conditions that require oral or systemic corticosteroid use.

   - Known human immunodeficiency virus (HIV) infection.

   - Known active infection of any kind (excluding fungal infection of nail beds) or any
   major episode of infection requiring hospitalization or treatment with intravenous
   (IV) antibiotics.

   - History of deep space infection.

   - History of serious recurrent or chronic infection.

   - History of cancer, including solid tumors, hematological malignancies, and carcinoma
   in situ.

   - Active alcohol or drug abuse, or history of alcohol or drug abuse.

   - Major surgery.

   - Previous treatment with CAMPATH-1H antibody.

   - Previous treatment with any B cell-targeted therapy.

   - Treatment with any investigational agent within 28 days of screening (Day -7) or 5
   half-lives of the investigational drug (whichever is longer).

   - Receipt of a live vaccine within 28 days prior to screening.

   - Intolerance or contraindication to oral or IV corticosteroids.

   - Use of a new immunosuppressive drug prior to screening or change in dose of ongoing
   immunosuppressive drug prior to screening.

   - Prednisone dose of ≥ 1 mg/kg/day prior to screening.

   - Treatment with cyclophosphamide or a calcineurin inhibitor.

   - Treatment with a second immunosuppressive or immunomodulatory drug.

   - Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 2.5 x the upper
   limit of normal.