Hepatitis delta: recent advances and future therapies

Chronic hepatitis delta (CHD) affects millions worldwide with many undiagnosed. It requires the presence of hepatitis B virus (HBV) for viral propagation, and those who are coinfected have a more rapid development of cirrhosis, hepatocellular carcinoma and fulminant liver failure. Treatments licensed for HBV have been ineffective in those with CHD. As an orphan disease, there is only one licensed treatment for CHD in Europe, which has relatively limited efficacy and viral control. This review focuses on current treatments, recent advances and unresolved issues in hepatitis delta management. Plain language summary: Chronic hepatitis delta is a very serious liver disease caused by the hepatitis delta virus, which can only infect people who already have hepatitis B. Worldwide, about 15 to 20 million people are affected. The disease can lead to severe liver damage and liver cancer. Medications that work for hepatitis B do not work for hepatitis delta, and until recently, there were no specific treatments approved for it. A new drug called bulevirtide was approved in Europe in 2020, and the UK in 2023, and is showing promise in ongoing studies around the world. It offers hope for better management of the disease. However, it is a daily injection needed indefinitely. Many people do not completely clear the virus. This article discusses new treatment strategies, including combining bulevirtide with other drugs, to improve the lives of the people living with the condition. These approaches aim to either significantly reduce the virus in the liver or (ideally) get rid of it completely.