Effectiveness and safety of belimumab in patients with systemic lupus erythematosus in a real-world setting

Objective: To investigate the effectiveness and safety of belimumab in patients with active systemic lupus erythematosus (SLE) in a real-life setting.Methods: All SLE patients treated with belimumab in the Department of Autoimmune Diseases of the Hospital Clinic of Barcelona were retrospectively analysed. The Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score, clinical SLEDAI-2K, levels of anti-double-stranded DNA (anti-dsDNA) antibody, complement components C3 and C4, and 50% haemolytic complement activity (CH50) were recorded at baseline and at 6, 12, and 24 months. Adverse events were also collected.Results: Twenty-three patients (100% women) were enrolled in the study. The most frequent manifestations that led to belimumab use were arthritis (91%) and skin involvement (39%). Both SLEDAI-2K and clinical SLEDAI-2K improved over time at all time-points (p < 0.005). Complement levels increased and the values of anti-dsDNA antibody decreased during treatment. The mean dose of prednisone could be tapered at all time-points and achieved maximum and significant reduction at 24 months (10.4 ± 4.8 mg/day to 4.8 ± 2.1 mg/day; p < 0.0005). Belimumab was well tolerated and only six patients (26%) experienced adverse events, all of which were classified as infections (one urinary tract infection without bacterial detection in urine culture and five viral infections). No deaths, severe infusion reactions, or hypersensitivity reactions were noted.Conclusion: In our patients with SLE, belimumab decreased disease activity and allowed tapering of the daily glucocorticoid dose with a good safety profile.