RTY-694

RTY-694 is a potent, orally active small molecule positive functional modulator (PFM) that acts as a dual-targeted activator of the ABCB4 (also known as MDR3) and BSEP (also known as ABCB11) membrane transporters. Developed by Rectify Pharmaceuticals, RTY-694 is designed to restore and enhance the function of these two key proteins involved in bile formation and secretion. By increasing both ABCB4 and BSEP protein levels, RTY-694 improves bile composition—specifically by increasing biliary phospholipids and enhancing bile acid efflux—which helps buffer toxic components in bile, reduce inflammation, cholestasis, ductular reaction, fibrosis, and overall liver injury. The drug’s differentiated mechanism directly addresses the underlying pathophysiology of primary sclerosing cholangitis (PSC) and other hepatobiliary diseases characterized by transporter dysfunction. Preclinical studies have shown that RTY-694 leads to improved markers of liver health in mouse models relevant to PSC and progressive familial intrahepatic cholestasis type 2 (PFIC2), including reductions in serum bile acids, ALT/ALP levels, inflammation markers, ductular proliferation/fibrosis indicators such as TGF-beta activation[1][5][6][7][8][9][10].