Hepatitis D virus infection: Progress on the path toward disease control and cure.

This article discusses the impact of Hepatitis D virus (HDV) infection as a major cause of liver-related morbidity and mortality in people with Hepatitis B virus (HBV) infection. The article reviews the current knowledge and unanswered questions about the epidemiology, pathogenesis, and natural history of HDV infection. Although effective treatments for HDV infection have been elusive, interferon alfa is recommended for at least 48 weeks. However, response rates with standard-of-care peginterferon alfa are suboptimal, leading to few patients with a sustained virologic response. The article proposes novel approaches to treating HDV and HBV, including targeting reduction or loss of hepatitis B surface antigen (HBsAg) reduction, and discusses potential strategies for achieving HBsAg loss in patients with chronic HBV infection. Finally, the article discusses the landmark decision of accepting viral and biochemical surrogates by regulatory authorities, opening the door for the clinical development of drugs for patients with HDV infection.