Abstract
Epratuzumab (anti-CD22) is a humanized monoclonal antibody that recognizes a pan-B-cell marker. It potentially downregulates B cell activity through negative signaling, as well as depleting B cells moderately. The uncontrolled series discussed by Dörner and colleagues in this issue of Arthritis Research & Therapy suggests that epratuzumab may be safe and efficacious for systemic lupus erythematosus. A randomized controlled trial is currently active to test this possibility.