ST-301

ST-301 is a potent and highly selective small molecule inhibitor of Toll-like receptor 7 (TLR7) with similar potency in humans and mice. Developed by Singularity Therapeutics in collaboration with Hillhouse Medical Group, ST-301 is designed to block the TLR7 signaling pathway, which is a key driver of endosomal innate viral RNA sensing and systemic autoimmune diseases. In preclinical murine models of systemic lupus erythematosus (SLE) and lupus nephritis (such as MRL/lpr and NZB/W mice), treatment with ST-301 has demonstrated robust efficacy, including delaying the onset and progression of lupus nephritis, reducing proteinuria, decreasing autoantibody production (such as anti-dsDNA), inhibiting IgG immune complex deposition in the kidneys, reducing kidney interstitial fibrosis, and significantly improving survival.