IO-202 + pembrolizumab

IO-202 + pembrolizumab is a combination therapy under clinical investigation for the treatment of advanced solid tumors and hematologic malignancies. IO-202 is a first-in-class humanized IgG1 monoclonal antibody that targets Leukocyte immunoglobulin-like receptor subfamily B member 4 (LILRB4), a cell surface receptor overexpressed in certain myeloid malignancies such as chronic myelomonocytic leukemia (CMML) and acute myeloid leukemia (AML). By binding to LILRB4, IO-202 induces antibody-dependent cellular cytotoxicity and phagocytosis, potentially reversing immune suppression in the tumor microenvironment and enhancing dendritic cell function and T cell activation[1][5][8]. Pembrolizumab is an approved anti–PD‑1 monoclonal antibody immune checkpoint inhibitor marketed as Keytruda, which blocks the programmed cell death protein 1 pathway to promote antitumor immunity[2][3]. The combination aims to synergistically enhance antitumor responses by targeting both myeloid-derived suppressive cells via LILRB4 inhibition (IO‑202) and T-cell checkpoints via PD‑1 blockade (pembrolizumab)[5].