The evolution of drug discovery in systemic lupus erythematosus.

Drug discovery in systemic lupus erythematosus (SLE) has lagged behind other rheumatic diseases, in large part because of difficulty in measuring change or improvement in a disorder that involves multiple organ systems to varying degrees at different times. The metrics currently used as primary endpoints are composite indices that rely mainly on disease assessment measures derived before the era of clinical trials of targeted therapies. Only one agent has been approved for the treatment of SLE since 1957. This monograph reviews the evolution of drug development for SLE, problems and pitfalls that have been encountered, and outlines the domains used to evaluate SLE in the clinic. Finally, several initiatives underway to improve clinical trial design are outlined.