Belimumab, an anti-BLyS human monoclonal antibody for potential treatment of inflammatory autoimmune diseases

Background: B lymphocyte stimulator (BLyS) is a factor determining the survival of B cells, and elevated levels in serum or locally have been observed in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) patients. Belimumab (LymphoStat-B), a human monoclonal antibody that inhibits BlyS, was developed for the treatment of these diseases. Objective: To summarize preclinical development, efficacy and safety of belimumab in treatment of RA and SLE. Methods: Articles found in a PubMed search and data presented in abstract form at international conferences up to August 2008 are described. Results/conclusions: Belimumab was well tolerated in treatment of RA over 24 weeks and SLE over 3 years. It significantly decreased rheumatoid factor (RF) levels, and modestly reduced symptoms of RA, especially in some subgroups such as patients with high disease activity, positive RF and no anti-TNF treatment experience. It also significantly reduced symptoms of SLE, and decreased anti-double-stranded DNA autoantibodies among patients with positive baseline anti-double-stranded DNA or antinuclear antibodies during a long-period treatment. These results suggest that careful patient selection is necessary to achieve optimal outcomes.