Lusvertikimab is a humanized IgG4-kappa monoclonal antibody that specifically targets the interleukin-7 receptor (IL-7R). The IgG4 isotype is selected to minimize effector functions such as antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC), focusing the mechanism on receptor blockade. By binding to IL-7R, it inhibits the interaction between the receptor and its cytokine, IL-7, thereby blocking downstream JAK/STAT signaling. This pathway is critical for the development, survival, and homeostasis of T cells and B cells. It is being developed as a potential therapeutic for autoimmune and inflammatory diseases where dysregulated IL-7/IL-7R signaling contributes to pathogenesis, such as rheumatoid arthritis, multiple sclerosis, or inflammatory bowel disease (IBD).