Agonist of stimulator of interferon genes as antitumor agents: a patent review (2008-2020)

INTRODUCTION: Stimulator of interferon genes (STING) is a transmembrane protein that localizes in the endoplasmic reticulum. As a crucial adaptor protein in the pathway of sensing cytosolic DNA, STING can regulate innate immune response by inducing the secretion of type Ι interferons and other cytokines after recognizing endogenous or exogenous DNA. Due to the key role of STING in the innate immune system, activation of the STING signaling pathway is expected to be an efficacious immunotherapeutic tactic for cancer and infectious diseases caused by pathogens. AREAS COVERED: This review summarizes the structures and biological activities of STING agonists published from 2008 to present, the progress in its structural modification of STING agonists, and the development of their clinical study. EXPERT OPINION: STING is an important adaptor protein in the process of triggering the innate immune response to viral infection. So far, substantial STING agonists and inhibitors have been published, and their viable curative effects for diverse diseases prove that STING is a promising therapeutic target.