Table 1

Table summarizing STING activating therapies as anti-cancer treatments

CategoryMechanism of actionExamplesCombination therapy with ICB
Direct STING agonistBinds to STING to activate IFN/NF-κB signalingcGAMP mimics
Non-nucleotide STING agonist
(e.g., MSA-2)
Small molecules
(e.g., MK-1454 and TAK-676)
cGAMP mimics and small molecules combined with anti-PD-1 in clinical trial
Indirect STING activatorsInduce DNA damage/micronuclei to trigger STING activationChemotheraypy/radiotherapy
PARP inhibitors (e.g., olaparib)
Cell cycle inhibitors (e.g., palbociclib and paclitaxel)
PARP inhibitors and cell cycle inhibitors combined with anti-PD-1 in clinical trial
Nuclease inhibitorsBlock DNA/cGAMP degradation to amplify STING signalingTREX1 inhibitors
ENPP1 inhibitors
Under investigation
Nanoparticle deliveryEnhances STING agonist delivery/tumor targetingRGD@Ce6@MSA-2@Liposome
ZIF-67 nanoparticles
Combined with anti-PD-1 in clinical trial

cGAMP, cyclic GMP-AMP; DNA, deoxyribonucleic acid; ENPP1, ectonucleotide pyrophosphatase/phosphodiesterase 1; ICB, immune checkpoint blockade; IFN, interferon; NF-κB, nuclear factor kappa B; PARP, poly(ADP-ribose) polymerase; PD-1, programed death-1; STING, stimulator of interferon genes; TREX1, three prime repair exonuclease 1.