BI 655064

BI 655064 is a humanized antagonistic anti-CD40 monoclonal antibody developed by Boehringer Ingelheim. It is designed to inhibit the CD40 antigen, thereby blocking the CD40–CD40L pathway, which plays a key role in immune activation and inflammation. The drug has been investigated primarily for autoimmune diseases such as lupus nephritis and rheumatoid arthritis. Mechanistically, it reduces inflammatory markers, autoantibody production, and activated B-cell subsets. Despite showing biological activity in clinical trials (notably reductions in inflammatory and bone resorption markers), it did not demonstrate significant clinical efficacy over placebo in phase II studies for lupus nephritis or rheumatoid arthritis[1][4][5][6].