siRNA drug development against hepatitis B virus infection

Introduction: Hepatitis B virus (HBV) infection is the worldwide leading cause of liver cirrhosis and hepatocellular carcinoma. Currently available medication can suppress viral replication in the majority of patients, but clearance of the viral antigens can be achieved in only about 10%.Areas covered: RNA interference is a very attractive therapeutic option since a well-designed compound could possibly inhibit all HBV mRNA and thus synthesis of all its antigens, which could combine antiviral and immunomodulatory modes of action. The aim of the article is to provide current knowledge on possible use of small interfering RNA (siRNA) molecules in the treatment of chronic HBV infection.Expert opinion: Based on the current status of clinical trials, we should expect that within the coming five years at least one siRNA molecule will be registered for clinical use. However, most important at this stage of development will be the safety profile, improving the route of administration, selection of the optimal combination with other anti-HBV drugs (nucleoside analogues, interferons) and finally selection of the optimal system introducing siRNA molecules into infected cells. Current therapeutic options for HBV, the siRNA mechanism of action, as well as preclinical and clinical studies with siRNA molecules are presented in this article.