CHF6563

CHF6563 is a novel ethanol-free sublingual formulation of buprenorphine developed by Chiesi Farmaceutici for the treatment of neonatal opioid withdrawal syndrome (NOWS), also known as neonatal abstinence syndrome. The drug was designed to provide an alternative to existing buprenorphine formulations that contain ethanol, which is undesirable in neonates. As a small molecule opioid partial agonist, buprenorphine acts primarily at the mu-opioid receptor to alleviate withdrawal symptoms in newborns exposed to opioids during pregnancy. Clinical development reached phase II but was terminated due to low patient recruitment and not for safety reasons[1][2][4]. The mechanism of action is consistent with that of buprenorphine—partial agonism at the mu-opioid receptor—but no explicit target/mechanism was listed in some sources[1][4].