ABSTRACT: Objectives: The main objectives are to identify strategies to purge the hepatitis B virus (HBV) reservoir to permit the discontinuation of anti-HBV therapy for life. We will identify new antiviral agents and combined modalities to target reduction or elimination of cccDNA by disrupting HBV core protein concentration [Cp], which together with viral polymerase inhibitors could provide preclinical data towards the potential eradication of HBV, eliminating the need for lifetime chronic treatment. Research Plan: To test a focused library of novel heteroaryldihydropyrimidines (HAP) in both hepatic cells along with a novel primary cell system in search of a novel therapeutic agent to alter capsid assembly and disrupt HBV covalently closed-circular DNA (cccDNA). This novel and original cell based assay can also be used to select for resistant viruses, which until now has not been possible. Methods: We have discovered a novel non-toxic nanomolar capsid inhibitor for HBV that we will evaluate further and optimize. We will also design and synthesize novel chemical derivatives and determine their physico-chemical properties of capsid assembly as well as the resultant changes in [Cp], and assess their in vitro cytotoxicity, resistance profiles, selection for resistant mutations, and in ivo efficacy and in combination regimens. Clinical Relevance: Current oral anti-HBV therapy does not cure, requiring costly lifetime therapy to suppress virus. Our novel approaches target the HBV cccDNA that is associated with viral persistence in HBV-infected hepatocytes, potentially eliminating the major HBV reservoir leading to a sustained virological response or cure.