Safety and Antiviral Activity of a Monoclonal Hepatitis B Antibody (The SAMBA Study)

Hepatitis B virus (HBV) remains a major global health problem with an estimated 257 million people living with the infection worldwide. Chronic HBV (CHB) is a major cause of liver cirrhosis and hepatocellular carcinoma. While antiviral therapies are available and suppress viral levels, treatment is long-term, does not clear the infection and rarely leads to long-term control once discontinued. Moreover, treatment access is not ideal on a global level with less than 10% of people in need receiving treatment. Although a strategy that eliminates all viral particles from the body represents the "holy grail" of HBV therapy, a strategy that leads to HBsAg loss and allows patients to stop treatment is highly desirable. New strategies to achieve either complete viral clearance or a state of viral control without the need for long-term treatment are being developed, including approaches to restore immune responses. Antibodies are key modulators of immune responses because of their dual functionality. In addition to directly targeting a viral antigen, antibodies differ from direct antivirals in that they can recruit other immune cells to eliminate infected cells and accelerate viral clearance. This study will evaluate the safety and pharmacokinetics of a monoclonal antibody that was isolated from an HBV-vaccinated individual, HepB mAb19, as well as its potential effects on viral levels and antiviral immune responses in individuals living with CHB.