REP 9

REP 9 is a first-generation nucleic acid polymer (NAP) developed by Replicor Inc. for the treatment of chronic hepatitis B virus (HBV) infection. Chemically, it is a 40-mer random-sequence phosphorothioate oligonucleotide. The drug's primary mechanism of action is the inhibition of the release of hepatitis B surface antigen (HBsAg) from infected hepatocytes into the blood. By blocking the assembly and secretion of HBsAg-containing subviral particles, REP 9 reduces the circulating HBsAg levels that typically exhaust the host's immune system. This reduction is intended to allow for the restoration of the host's innate and adaptive immune responses, potentially leading to viral clearance. Although REP 9 served as a critical proof-of-concept molecule in early clinical studies, it has been succeeded in development by more optimized NAPs, such as REP 2139 and REP 2165, which offer improved safety and potency profiles.

Other names

Random sequence 40-mer phosphorothioate oligonucleotide