AB-423 (Capsid Inhibitor)

HBV core protein, or capsid, is required for viral replication and core protein may have additional roles in cccDNA function. Current nucleot(s)side analog therapy significantly reduces HBV DNA levels in the serum but HBV replication continues in the liver, thereby enabling HBV infection to persist. Effective therapy for patients requires new agents which will effectively block viral replication.


We are developing core protein inhibitors (also known as capsid assembly inhibitors) as oral therapeutics for the treatment of chronic HBV infection. By inhibiting assembly of the viral capsid, the ability of hepatitis B virus to replicate is impaired, resulting in reduced cccDNA. We presented preclinical combination data from our lead core protein/capsid assembly inhibitor AB-423 at scientific conferences in April 2016 and June 2016. We plan to file an IND (or equivalent filing) for AB-423 in the second half of 2016. In addition to AB-423, our core protein/capsid assembly inhibitor discovery effort is active and ongoing and has already generated promising back-up compounds.