ADU-S100 disodium salt (MIW815; MIW-815; ML RR-S2-CDA) is the first agonist of stimulator of interferon genes (STING), with immunomodulatory and antitumor activities. ADU-S100 has high translational potential as a therapeutic intervention strategy to induce activation of the tumor microenvironment in multiple tumor types. ADU-S100 is the first STING pathway activator developed by Aduro in collaboration with Novartis. It is being evaluated clinical trials for the treatment of various cancers, as a single agent or in combination withother drugs such as ipilimumab and spartalizumab (PDR001), which are anti-PD-1 monoclonal antibody. ADU-S100 exhibits a higher affinity for binding to STING than c-di-AMP due to the presence of a 2’-5’, 3’-5’ mixed linkage, as found in endogenous human CDNs produced by cGAS (cyclic GMP-AMP (cGAMP) synthase). In addition, ADU-S100 can activate both human STING and murine STING. Furthermore, it contains two phosphorothioate diester linkages to protect against degradation by phosphodiesterases that are present in host cells or in the blood/systemic circulation. The Rp, Rp dithio diastereoisomer has been found to induce higher type I IFN production compared to the Rp/Sp dithio diastereoisomers or c-di-AMP. In vivo studies have demonstrated that 2’3’-c-di-AM(PS)2 (Rp,Rp) may potently prime tumor antigen-specific CD8+ T-cell responses and overcome antigen-enforced immune tolerance in combination with PD-L1 blockade.

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.