ATI-1645

ATI-1645 is an investigational small-molecule hepatitis B virus (HBV) capsid assembly modulator developed by Antios Therapeutics as part of its chronic hepatitis B portfolio.[3][6][11] It is described as a fourth‑generation, class II HBV capsid assembly modulator (CAM) with ultra‑potent antiviral activity in nonclinical models, designed to interfere with HBV core protein interactions and disrupt proper nucleocapsid assembly, thereby inhibiting viral replication and reducing production of new virions and covalently closed circular DNA (cccDNA) replenishment.[7][9][11] ATI-1645 advanced through IND‑enabling preclinical development, but its global development status is currently listed as discontinued, and it has not entered or completed clinical trials.[3][6][9]