Definition

An orally bioavailable small molecule agonist of CD11b (integrin alpha-M; ITGAM; integrin alpha M chain), with potential immunomodulating activity. Upon administration, CD11b agonist GB1275 targets and binds to CD11b, thereby activating CD11b. This leads to CD11b-mediated signaling and promotes pro-inflammatory macrophage polarization while suppressing immunosuppressive macrophage polarization. This reduces influx of tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment (TME), promotes anti-tumor immune responses, induces cytotoxic T lymphocytes (CTLs) and suppresses tumor growth. CD11b, a member of the integrin family of cell adhesion receptors highly expressed on immune system cells, is a negative regulator of immune suppression and activates anti-tumor innate immunity.