Definition

A humanized monoclonal antibody targeting triggering receptor expressed on myeloid cells 2 (TREM2; TREM-2), with potential immunomodulating and antineoplastic activities. Upon administration, anti-TREM2 monoclonal antibody PY314 targets and binds to TREM2 located on immunosuppressive tumor-associated myeloid cells within the tumor microenvironment (TME), including tumor associated macrophages (TAMs). This induces antibody dependent cell mediated cytotoxicity (ADCC) and/or antibody dependent cell mediated phagocytosis (ADCP), thereby killing TREM2-positive cells, including TAMs. The depletion of TAMs alters the TME, activates cytotoxic T lymphocytes (CTLs), natural killer (NK) cells and M1-like macrophages, which stimulate anti-tumor immune responses, and leads to tumor cell destruction. TREM2, an immunoglobulin (Ig) superfamily transmembrane protein, is expressed within the TME and is associated with poorer patient outcomes.