This study included patients ages 18–65 years with SLE. Patients had to weigh ≥40 kg and fulfill ≥4 of the 11 American College of Rheumatology 1997 classification criteria for SLE 20, 21. At screening, all patients were required to have antinuclear antibodies and/or anti–double‐stranded DNA (anti‐dsDNA) antibodies, and/or anti‐Sm antibodies, and to be receiving treatment with at least one of the following: oral prednisone (≤40 mg/day or equivalent), azathioprine (≤200 mg/day), an antimalarial, mycophenolate mofetil/mycophenolic acid (≤2.0 gm/day), or methotrexate (≤25 mg/week).
Treatments for SLE had to be administered for at least 24 weeks prior to study entry and at stable dosages for ≥2 weeks (for prednisone and nonsteroidal antiinflammatory drugs) or ≥8 weeks (for other therapies) before screening. Biologic agents and protocol‐prohibited immunosuppressants had to be discontinued before the study.
Patients had to meet all of the following disease activity criteria at screening: a score of ≥6 on the SLE Disease Activity Index 2000 (SLEDAI‐2K) 22, excluding points attributable to lupus headache or organic brain syndrome; a British Isles Lupus Assessment Group (BILAG) 2004 23 organ domain score of ≥1A or ≥2B 24; and a physician's global assessment of disease activity of ≥1 on a visual analog scale from 0 (none) to 3 (severe disease). In addition, patients were required to have a score of ≥4 in clinical components of the SLEDAI‐2K (clinical SLEDAI‐2K; points attributed to laboratory components were excluded) at week 1 (prior to receiving the study drug). Patients with active and severe lupus nephritis or neuropsychiatric SLE were excluded from the study. Additional study exclusion criteria are provided in the Supplementary Methods, available on the Arthritis & Rheumatology web site at http://onlinelibrary.wiley.com/doi/10.1002/art.39962/abstract.