STING Activation and its Application in Immuno-Oncology

Recent regulatory approval of several immune checkpoint inhibitors has ushered in a new era of cancer immunotherapies with the promise of achieving a durable response. This represents a paradigm shift in cancer treatment from directly targeting tumor cells to harnessing the power of a patient's own immune system to destroy them. The cGAS-STING pathway is the major cytosolic dsDNA sensing pathway that plays a pivotal role in the innate antitumor immune response. With a fundamentally different mode of action (MOA) than immune checkpoint modulators, STING activation can potentially enhance tumor immunogenicity and improve patient responses as a single agent or by synergizing with existing anti-cancer drugs. Therefore, there has been intense interest from the pharmaceutical industry and academic institutions in the search for potent STING agonists as immunotherapies in oncology. In this article, we review briefly the cGAS-STING pathway and STING agonists that are in the clinical and preclinical studies, summarize recently disclosed patent applications and published journal articles in the field and cover both cyclic dinucleotide (CDN) analogs and non-nucleic acid derived STING agonists.