Definition

A small molecule second-generation agonist of the intracellular innate immune adaptor stimulator of interferon genes protein (STING; transmembrane protein 173; TMEM173), with potential immunoactivating and antineoplastic activities. Upon administration, STING agonist BI 1703880 targets and binds to STING and activates the STING pathway in immune cells in the tumor microenvironment (TME). This leads to the production of pro-inflammatory cytokines, including interferons (IFNs), enhances the cross-presentation of tumor-associated antigens (TAAs) by dendritic cells (DCs), and induces a cytotoxic T-lymphocyte (CTL)-mediated immune response against cancer cells. STING, a transmembrane protein that activates immune cells in the TME, plays a key role in the activation of the innate immune system.