anti-CD24/anti-4-1BB bispecific monoclonal antibody IBD0333

A bispecific monoclonal antibody targeting the cell surface antigen cluster of differentiation 24 (CD24) and the costimulatory receptor 4-1BB (CD137; tumor necrosis factor receptor superfamily member 9; TNFRSF9), with potential immunostimulating and antineoplastic activities. Upon administration, anti-CD24/anti-4-1BB bispecific monoclonal antibody IBD0333 simultaneously targets and binds to CD24 expressed on the surface of tumor cells and 4-1BB expressed on a variety of leukocyte subsets including activated T lymphocytes. This crosslinks CD24-expressing tumor cells and 4-1BB-expressing T-cells, and activates 4-1BB signaling locally in the tumor microenvironment (TME). This results in cytotoxic T-cell co-stimulation, enhances T-lymphocyte-mediated anti-tumor activity and leads to cytotoxic T-cell-mediated lysis of CD24-expressing tumor cells. CD24, a glycophosphatidylinositol (GPI)-anchored, highly glycosylated cell adhesion protein, is overexpressed on the surface of a variety of cancer cells. Expression of CD24, and its interaction with Siglec-10, protects cancer cells from phagocytosis, thereby allowing cancer cells to proliferate. Its expression is correlated with poor prognosis. 4-1BB, a surface glycoprotein of the tumor necrosis factor receptor superfamily, is an inducible costimulatory receptor that plays a key role in T-cell proliferation, survival and cytolytic activity.