Definition

A monoclonal antibody directed against B- and T-lymphocyte attenuator (BTLA), with potential immune checkpoint inhibitory, immunomodulating and antineoplastic activities. Upon administration, anti-BTLA monoclonal antibody HFB200603 targets and binds to BTLA. This prevents BTLA-mediated inhibition of T-cell activation and induces the production of inflammatory cytokines in the tumor microenvironment (TME), leading to antigen specific T-cell proliferation and activation of a cytotoxic T-lymphocyte (CTL)-mediated immune response against tumor cells. BTLA, an immunoglobulin (Ig) receptor family member expressed on activated T and B lymphocytes, subsets of dendritic cells (DCs), macrophages, and nature killer (NK) cells, is an immune checkpoint involved in suppressing immune responses. It mediates inhibition of human tumor-specific CTLs upon engagement by tumor expressed herpesvirus-entry mediator (HVEM).