Therapeutic vaccine for hepatitis B enters first clinical trial

Research

7/24/2025
Reading time 3 min.

TherVacB, a therapeutic vaccine for chronic hepatitis B, has entered its first clinical trial in patients. The first patient was enrolled in June 2025 and treated with the vaccine. In a previous trial in healthy volunteers, the vaccine demonstrated a favorable safety profile and triggered the desired immune responses.

A corridor in a hospital — In the study, patients with chronic hepatitis B are being treated with the therapeutic vaccine in clinics in five countries. The safety, tolerability and efficacy of the vaccine are being investigated.

Chronic hepatitis B is an infectious disease, affecting 254 million people worldwide. It significantly increases the risk of liver damage, cirrhosis, and liver cancer. Although preventive vaccines and antiviral treatments exist, no curative therapy has been developed to date. Current treatments suppress the virus but require lifelong use and are not universally available. According to the World Health Organization (WHO), hepatitis B causes 1.1 million deaths per year.

“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 Ulrike Protzer, inventor of the vaccine, Professor of Virology at the Technical University of Munich (TUM) and Director of the Institute of Virology at Helmholtz 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).

Vaccine covers almost all virus strains.

TherVacB uses a so-called heterologous prime-boost strategy: it first introduces proteins that prime the immune system, followed by a modified viral vector 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.

"Results could redefine global strategy for managing 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.

Further information and links

Detailed information on the Phase 1b/2a study with patients
Prof. Ulrike Protzer, is Professor of Virology at the TUM School of Medicine and Health and Director of the Institute of Virology at TUM and Helmholtz Munich as well as Deputy Head of the Molecular Targets and Therapeutics Center at Helmholtz Munich. She is the inventor of the TherVacB vaccine.
Prof. Michael Hoelscher is Director of the Institute of Infectious Diseases and Tropical Medicine, and Chair of Global Health & Infectious Diseases at the Medical Faculty of the LMU Munich, Head of the Unit Global Health (UGH) at Helmholtz Munich, Sponsor Representative of the LMU University Hospital for the TherVacB Phase 1b/2a Trial.
Funding for the study is provided by the European Union through the Horizon 2020 research program.