Belimumab for the Treatment of Refractory Systemic lupus Erythematosus: Real-life Experience in the First Year of use in 18 Italian Patients

T o date, it has been estimated that more than 50% of patients affected by systemic lupus erythematosus (SLE) have suboptimal disease control: while 40% of them have chronic active disease (CAD), the remaining 10% suffer from relapsingremitting disease (RRD) with frequent exacerbations [1,2]. This situation requires frequent changes of therapy and, in particular, increased steroid dosage, along with the obvious risk of one or more of the well-known related side effects [3,4]. In this scenario the need for new treatment options is even more evident than in other rheumatic diseases. After 50 years with no new drug licensed for SLE, belimumab was recently approved for the treatment of active and refractory SLE. Belimumab is a human immunoglobulin G (IgG)1λ monoclonal antibody specific for soluble human B lymphocyte stimulator protein (BLyS) able to inhibit the survival of B cells, including autoreactive B cells, and it reduces the differentiation of B cells into Ig-producing plasma cells. It is indicated in active SLE in the presence of hypocomplementemia and anti-ds-DNA antibody positivity, in addition to the standard treatment regimen. The recommended dose is 10 mg/ kg belimumab in intravenous administration on day 0, 14 and 28, and once a month thereafter. The development of belimumab represents the largest trial ever conducted in SLE patients, with 2200 patients enrolled in clinical studies with long-term treatment, in some cases for more than 7 years [5]. The aim of the study was to evaluate the efficacy and safety of belimumab in the real-life experience of a single tertiary referral center of rheumatology after the first year of licensed use in Italy. METHodS