Background
STING agonist 12L is an agonist of stimulator of interferon genes (STING).1 It binds to wild-type STING (IC50 = 1.15 μM), as well as the STING R232, AQ, and Q variants (IC50s = 1.06, 0.61, and 1.12 μM, respectively) and induces reporter gene expression in THP-1 and RAW 264.7 cells (EC50s = 0.38 and 12.94 μM, respectively). STING agonist 12L (5 μM) induces IFNB1, CXCL10, and IL6 mRNA expression in THP-1 cells. In vivo, STING agonist 12L (10 mg/kg) increases plasma IFN-β levels and reduces tumor volume and the number of lung metastases in a B16/F10 murine melanoma model.