Therapeutic Vaccine for Chronic Hepatitis B Enters First Clinical Trial in Patients

“After 13 years of research, seeing TherVacB enter patient trials is exciting as it is a critical step towards providing a potential cure for chronic hepatitis B,” says Prof. Ulrike Protzer, the vaccine's inventor and Director of the Institute of Virology at Helmholtz Munich and Chair for Virology at the Technical University of Munich. “This vaccine aims to activate the natural immune response in a way that could finally enable the body to eliminate the virus,” Protzer adds, who also coordinates the "Hepatitis" research area in German Center for Infection Research (DZIF).

TherVacB uses an innovative heterologous prime-boost strategy: it first introduces proteins that prime the immune system, followed by a modified viral vector (MVA) to boost the cellular immune response. This approach is designed to stimulate both antibody and T-cell responses targeted at the hepatitis B virus. The vaccine is also tailored to cover over 95 percent of global HBV strains, making it potentially effective for the more than 250 million chronically infected humans worldwide.

Sponsored by LMU University Hospital Munich and led by sponsor representative Prof. Michael Hoelscher, Director of the Institute of Infectious Diseases and Tropical Medicine and DZIF Partner Site Speaker Munich, the current trial is being conducted at clinical sites in Germany, Italy, Spain, England, and Tanzania. It aims to evaluate the safety, tolerability, and immune activity of the vaccine in patients with chronic hepatitis B whose infections are currently managed with antiviral medication. 81 patients will participate in two phases. In the first part (phase 1b), participants receive increasing doses of the vaccine components to determine the safest and most effective dose. In the second part (phase 2a), the best dose identified will be tested in a larger group of patients to confirm its safety and determine how well it stimulates the immune system to control the virus. The aim is to determine the optimal dose that is both safe and effective in helping the body fight hepatitis B.

If successful, TherVacB could represent a breakthrough in the treatment of chronic hepatitis B. The ability to stimulate a functional immune response in already-infected patients could lay the groundwork for a true cure – something no existing therapy offers.

“The outcomes of this trial may not only shape future phases of clinical development but also redefine the global strategy for managing hepatitis B – especially in regions with high disease burden and limited access to existing treatments,” says Michael Hoelscher.