About Chronic Hepatitis B

Hepatitis B Virus (HBV) is a serious global health problem.  The virus infects liver cells (hepatocytes) and can lead to acute or chronic infection with potentially fatal consequences. An estimated 350-400 million people world-wide are living with Chronic Hepatitis B (CHB) infection. Of this population, 25%, or approximately 100 million patients, suffer from active disease, while 30-40% are immune tolerant and 35-45% have inactive disease. Active disease is characterized by high levels of HBV DNA and elevated markers of liver injury (high-ALT levels).  Patients with active disease are at a greater risk of death from cirrhosis and hepatocellular carcinoma (liver cancer) – nearly one million deaths per year are attributable to serious liver diseases caused by chronic HBV infection. Immune tolerant CHB patients typically present high levels of HBV DNA and other markers of the infection (HBV antigens), but do not present elevated markers of liver injury (high-ALTs). Although the immune tolerant phase of HBV can persist for long periods of time, approximately 90-100% of patients with immune tolerant CHB will progress to active disease.  Patients with inactive disease typically have low levels of HBV DNA and normal levels of markers of liver injury (normal-ALTs). Current clinical guidelines only recommend treatment for patients who present active CHB infection. As such, given the global prevalence of a disease treated only chronically, new classes of therapies with novel mechanisms of action are essential to offer meaningful functional cure rates and decrease the global burden of HBV.