The safety of belimumab for the treatment of systemic lupus erythematosus

Introduction: Systemic lupus erythematosus (SLE) is a systemic autoimmune inflammatory disease with extensive clinical variability. In 2011, the anti-BAFF monoclonal antibody, belimumab, became the first FDA-approved drug for SLE in 50+ years. As with all immunomodulating medications, the benefits must be weighed against the adverse side effects. This is especially pertinent for SLE patients, given the chronic nature of their disease and their need for long-term treatment. The focus of the present review is the safety of belimumab, including data gleaned from clinical trials, their open-label extensions, and 'real-world' clinical settings.Areas covered: Safety data from phase I, phase II, phase III, extension open-label trials, and 'real-world' observational studies of belimumab are reviewed and discussed.Expert opinion: As the only FDA-approved treatment for SLE in the past 60+ years, belimumab has demonstrated significant, albeit modest, efficacy and a reassuring safety profile. Long-term data to date show that it is well-tolerated with a low risk of side effects, even when administered for up to 13 years. Given that belimumab allows providers to decrease daily corticosteroid doses over time (and, thereby, decrease the serious risks associated with chronic corticosteroid use), it should be seen as a valuable tool in the rheumatologist's arsenal.