Belimumab in systemic lupus erythematosus: an update for clinicians.

Systemic lupus erythematosus (SLE) is a chronic inflammatory disorder that is driven by autoantibodies that target multiple organ systems. B-lymphocyte stimulator (BLyS) and its receptors on B-cell subsets play an important role in autoimmune B-cell development and SLE pathogenesis. Targeted therapy with belimumab, the monoclonal antibody against BLyS, has shown clinical benefit in two large-scale, multicenter phase III trials leading to US Food and Drug Administration approval for patients with serologically positive SLE who have active disease despite standard therapy. This review will discuss the challenges in lupus drug development and clinical trials, the basics of B-cell pathogenesis in SLE, the recent lupus clinical trials of B-cell targeted treatments, and other potential targeted therapies under investigation for patients with lupus.