Extension Study of the Safety and Efficacy of Multi-dose Intravenous ARC-520 in Patients With Chronic Hepatitis B (HBV) Infection

Open-label, multi-center extension study of intravenous ARC-520 in combination with entecavir or tenofovir in patients with chronic HBV infection. Patients who successfully completed the Heparc-2002 (NCT02604199) and Heparc-2003 (NCT02604212) studies and responded to therapy are eligible to participate. Responders are defined as patients who showed a ½ log or greater reduction in their serum Hepatitis B Surface Antigen (HBsAg) levels from baseline to day 71 ± 3 days of the primary Heparc-2002 and Heparc-2003 studies. Patients who have signed a Human Research Ethics Committee approved informed consent and have met all of the protocol eligibility criteria will continue receiving daily oral entecavir or tenofovir and intravenous (IV) injections of ARC-520. Study visits will occur once every 4 weeks for a total of 9 visits for monitoring and ARC-520 administration.

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 electrocardiograms (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.