REP 2139-Ca is nucleic acid polymer. Nucleic acid polymers have been previously shown to clear serum hepatitis B virus surface antigen (HBsAg) both preclinically (in duck HBV infected ducks) and in human patients and to act synergistically with immunotherapeutic agents such as pegylated interferon-alpha 2a or thymosin alpha-1 to restore host immunological control of HBV infection.