New drugs in systemic lupus erythematosus: when to start and when to stop.

Survival of patients with systemic lupus erythematosus (SLE) has greatly improved compared to earlier decades. However, this improvement appears to have reached a plateau. In addition, damage accrual appears to have an important impact on patient prognosis. In this scenario a number of new drugs targeting different pathways of the immune response are being developed, and some are already available in clinical practice. In clinical practice and in clinical trials, the indications for treating SLE patients with new drugs are active or refractory disease despite standard-of-care treatment. While RCTs are able to document the capacity of new drugs to control the disease in selected patients, many important questions arise from clinical practice and at present are largely unanswered. When should we start a new drug? Should this drug be introduced early, as are anti-TNF drugs in rheumatoid arthritis? Perhaps some drugs should be initiated only after a patient's incomplete response? How many traditional drugs should be used and for how long, before considering a new therapy? Should we stop an effective drug and if yes, when and how? Additional studies and data derived from registries and observational studies will give valuable evidence to answer these questions. In this article, we review indications for the use of new drugs in SLE, and examine existing data on patient outcome after withdrawal, focusing our attention on rituximab and belimumab.