Ulevostinag (isomer 1)
A synthetic cyclic dinucleotide (CDN) and agonist of stimulator of interferon genes protein (STING), with potential immunoactivating and antineoplastic activities. Upon intratumoral (IT) administration, STING agonist MK-1454 binds to STING and activates the STING pathway, which promotes IKK-related kinase TANK-binding kinase 1 (TBK1) signaling and activates nuclear factor-kappa B (NF-kB) and interferon regulatory factor 3 (IRF3) in immune cells in the tumor microenvironment; this leads to the production of pro-inflammatory cytokines, including interferons (IFNs). Specifically, expression of IFN-beta (IFNb) enhances the cross-presentation of tumor-associated antigens by CD8alpha-positive and CD103-positive dendritic cells (DCs) to cytotoxic T lymphocytes (CTLs). This results in a CTL-mediated immune response against tumor cells and causes tumor cell lysis.