Study of ARC-520 With or Without Other Drugs Used in the Treatment of Chronic Chronic Hepatitis B Virus (HBV)

This is a multicenter, open-label study of ARC-520 based treatment regimens administered to patients with HBeAg positive or HBeAg negative immune active chronic Hepatitis B Virus (HBV) infection of various genotypes, or patients with Hepatitis D Virus (HDV). Eligible patients naive to previous treatment, and who have signed an Ethics Committee - approved informed consent, will be enrolled and will receive ARC-520 alone or ARC-520 plus additional treatments such as entecavir (ETV) or tenofovir (TDF) and/or pegylated interferon alpha 2a (PEG IFN) therapy. The study may initially involve up to a total of 96 eligible chronic HBV and HDV infected patients. Patients in all cohorts will receive a total of 13 doses of ARC-520 at 2mg/kg or 4 mg/kg. 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 assessment (AEs), 12-lead ECGs, liver fibrosis testing, concomitant medication assessment, blood sample collection for hematology, coagulation, chemistry, exploratory Pharmacodynamic (PD) measures, urinalysis, HBV serology, cytokines, Follicle Stimulating Hormone (FSH) testing (post-menopausal females) and pregnancy testing for females of childbearing potential. Clinically significant changes including AEs will be followed until resolution, until the condition stabilizes, until the event is otherwise explained, or until the patient is lost to follow-up. For each patient, the duration of the study is approximately 96 weeks, from enrolment to last visit. Prior to enrolment there is a 60 day screening period. Addition of new cohorts and additional treatment regimens are anticipated for this study.