Novel CRBN-Recruiting Proteolysis-Targeting Chimeras as Degraders of Stimulator of Interferon Genes with In Vivo Anti-Inflammatory Efficacy

Abstract

The activation of the cyclic GMP-AMP synthase-stimulator of interferon gene (STING) pathway has been associated with the pathogenesis of many autoimmune and inflammatory disorders, and small molecules targeting STING have emerged as a new therapeutic strategy for the treatment of these diseases. While several STING inhibitors have been identified with potent anti-inflammatory effects, we would like to explore STING degraders based on the proteolysis-targeting chimera (PROTAC) technology as an alternative strategy to target the STING pathway. Thus, we designed and synthesized a series of STING protein degraders based on a small-molecule STING inhibitor (<b>C-170</b>) and pomalidomide (a CRBN ligand). These compounds demonstrated moderate STING-degrading activities. Among them, <b>SP23</b> achieved the highest degradation potency with a DC₅₀ of 3.2 μM. Importantly, <b>SP23</b> exerted high anti-inflammatory efficacy in a cisplatin-induced acute kidney injury mouse model by modulating the STING signaling pathway. Taken together, <b>SP23</b> represents the first PROTAC degrader of STING deserving further investigation as a new anti-inflammatory agent.