Belimumab patient profile in Spain: evolution during the last decade and future directions.

Introduction: Belimumab (BEL), an anti B-lymphocyte stimulator monoclonal antibody, is the only approved biological therapy for systemic lupus erythematosus (SLE) and lupus nephritis (LN).

Areas Covered: This review discusses BEL's real-world use and its positioning in clinical practice guidelines, focusing on the evolution of its application and patient profile over the last decade in Spain.

Expert Opinion: Initially used for refractory, non-major SLE manifestations, BEL's application has expanded. International guidelines now recommend earlier use of BEL in treatment algorithms. With its 2021 approval for LN, BEL is increasingly used for renal manifestations and as a first-line therapy. Safety data confirm its tolerability without a significant increase in severe infections. However, real-world evidence in Spain reveals discrepancies with these recommendations for both SLE and LN. The optimal patient for BEL treatment is one with mild, moderate, or severe SLE that cannot be controlled with hydroxychloroquine (HCQ), with or without glucocorticoids (GC) and immunosupressants (IS), in patients with a disease duration of ≤2 years, no initial organ damage, GC doses ≥5 mg/day, and a high risk of severe flares. Further studies are needed to determine optimal timing for BEL initiation to improve patient outcomes and modify the disease course.