ACT-1004-1239

ACT-1004-1239 is a first-in-class, orally available, potent, and selective small-molecule antagonist of the chemokine receptor CXCR7. It exhibits both immunomodulatory and promyelinating effects. Preclinical studies have demonstrated dose-dependent efficacy in animal models of multiple sclerosis and acute lung injury, with reductions in neuroinflammation and enhanced myelin repair. The drug increases plasma concentrations of its ligands CXCL11 and CXCL12 as biomarkers of target engagement, leading to reduced immune cell infiltration into the central nervous system or bronchoalveolar space. ACT-1004-1239 has shown favorable safety and tolerability profiles in phase I clinical trials involving healthy volunteers. It is being developed primarily for inflammatory demyelinating diseases such as multiple sclerosis, with additional investigation for cancer.