Patients will undergo the following evaluations at regular intervals during the study: medical history, physical examinations, vital sign measurements (blood pressure, heart rate, respiratory rate and temperature), weight, adverse events (AEs), 12-lead electrocardiogramss (ECGs), concomitant medications, blood sample collection for hematology, coagulation, chemistry, creatine kinase, troponin, hemoglobin A1c, exploratory pharmacodynamic (PD) measures, urinalysis, HBV serology, immunogenicity, and pregnancy testing for females of childbearing potential. Patients will be monitored for HBV virology, AEs, and exploratory PD measures for a total of 24 weeks after the last dose of ARC-520.