Definition

A humanized monoclonal antibody directed against the immune checkpoint molecule sialic acid-binding immunoglobulin (Ig)-like lectin 10 (Siglec-10; SIGLEC10), with potential immune checkpoint inhibitory and antineoplastic activities. Upon administration, anti-Siglec-10 monoclonal antibody ONC-841 targets and binds to Siglec-10 expressed on various immune cells, including tumor-associated macrophages (TAMs) and natural killer (NK) cells, in the tumor microenvironment (TME). This prevents Siglec-10-mediated signaling, and activates NK cells, macrophages, and T cells. This abrogates Siglec-10-mediated inhibition of phagocytosis of tumor cells and induces antibody-dependent cell-mediated cytotoxicity (ADCC), thereby killing tumor cells and inhibiting tumor cell growth. Siglec-10, an inhibitory receptor expressed on a variety of immune cells, plays an important role in tumor immune invasion through its interaction with the tumor-expressed co-stimulatory molecule CD24.