MSA-2 is an orally available non-nucleotide STING agonist. The non-covalent dimer of MSA-2 binds to STING with nanomolar affinity. It shows anti-tumor activity in syngeneic mouse tumor models, synergizes with anti-PD-1, stimulates tumor secretion of interferon-β, induces tumor regression, and has long-lasting anti-tumor immunity. [3] https://www.targetmol.com/compound/msa-2