SIT-003

SIT-003 is a preclinical-stage small molecule inhibitor of three-prime repair exonuclease 1 (TREX1), being developed by Cancer Research Horizons in partnership with Sitryx Therapeutics. TREX1 is a major mammalian 3' to 5' DNA exonuclease that degrades cytosolic double-stranded DNA (dsDNA), thereby preventing the activation of the cGAS-STING (cyclic GMP-AMP synthase-stimulator of interferon genes) pathway. By inhibiting TREX1, SIT-003 aims to promote the accumulation of cytosolic DNA in the tumor microenvironment, triggering an innate immune response and enhancing anti-tumor immunity. The program is part of a portfolio of immunometabolism targets licensed from Cancer Research UK (now Cancer Research Horizons) and is currently being evaluated for the treatment of multiple cancer indications.