Hepatitis B virus antigens (HBV antigens) (HBV antigens)

Hepatitis B virus (HBV) antigens, specifically the surface antigen (HBsAg), core antigen (HBcAg), and the viral polymerase (Pol), are the primary targets for immunotherapeutic strategies aimed at treating chronic hepatitis B. In chronic infection, the host's immune system typically exhibits T-cell exhaustion and failure to clear the virus, leading to persistent viral replication and risk of liver disease. VTP-300 is a novel immunotherapeutic designed to overcome this immune tolerance by delivering these specific HBV antigens via a viral vector platform. By stimulating a robust and polyfunctional CD8+ T-cell response, the therapy seeks to achieve a functional cure, defined by the sustained loss of HBsAg and undetectable HBV DNA. This target is central to modern efforts in combining T-cell vaccines with other agents, such as checkpoint inhibitors or siRNA, to maximize the clearance of infected cells and restore long-term immune control.

Other names

Hepatitis B virus proteinsHBV Core antigen (HBcAg)HBV Surface antigen (HBsAg)HBV Polymerase (Pol)Hepatitis B virus X protein (HBx)

VTP-300 utilizes a heterologous prime-boost regimen consisting of a Chimpanzee Adenovirus Oxford 1 (ChAdOx1) vector followed by a Modified Vaccinia Ankara (MVA) vector, both encoding multiple HBV antigens (Core, Polymerase, and Surface). This approach is designed to induce high levels of antigen-specific CD8+ T cells that target and eliminate HBV-infected hepatocytes, aiming to restore the immune system's ability to control the infection and achieve a functional cure.