ARB-CF0223

ARB-CF0223 is an investigational, inhaled small interfering RNA (siRNA) therapeutic developed by Arbutus Biopharma for the treatment of cystic fibrosis (CF). The drug utilizes Arbutus's proprietary lipid nanoparticle (LNP) delivery technology to transport siRNA directly to the lung epithelium via nebulization. ARB-CF0223 is designed to silence the expression of the alpha subunit of the epithelial sodium channel (ENaC), specifically the SCNN1A gene. In CF patients, ENaC is typically overactive, leading to excessive sodium and water reabsorption from the airway surface, which results in dehydrated, thick mucus. By reducing ENaC protein levels, ARB-CF0223 was intended to restore airway surface liquid volume and improve mucociliary clearance. Although it showed promise in preclinical models, Arbutus shifted its strategic focus toward its hepatitis B virus (HBV) portfolio, leading to the discontinuation of the CF program.