STING synergist 67 is a selective STING synergist with EC50 of 20.5 uM, binds to carboxy-terminal domain (CTD) of STING (SPR KD=12.2 uM), amplifies cGAMP-induced pathway activation without inherent agonist properties.
STING synergist 67 binds to various hSTING alleles and mSTING with a low micromolar affinity, demonstrating broad-spectrum binding activity
STING synergist 67 demonstrated stable synergistic effects at low concentrations, reducing the EC50 values of cGAMP by 9.58 and 5.98-fold in human and murine STING cells, respectively.
STING synergist 67 cannot independently induce cytokine secretion in THP-1 cells, but it significantly potentiates cGAMP-mediated cytokine release; in combination with cGAMP, the secretion of IFN-β, CXCL-10, and IL-6 was enhanced by 3.38-fold, 7.10-fold, and 4.16-fold, respectively, compared to cGAMP treatment alone.
STING synergist 67 demonstrated strong antitumor activity, which was further amplified when administered in combination with the cGAMP or PD-L1 antibody.