AstriVax Therapeutics has initiated a phase 1 clinical trial of AVX70371, a novel immunotherapy designed to treat chronic hepatitis B virus infection by stimulating a targeted T-cell immune response. The candidate, which uses the company’s Launch-iT platform, is the third asset from AstriVax to enter clinical testing.

The trial, known as Ruby, is taking place at the Centre for Vaccinology at Ghent University in Belgium. It aims to evaluate the safety, tolerability and immunogenicity of multiple doses of AVX70371 in healthy adult volunteers. The study has now administered the first dose of AVX70371 to all participants, and an interim analysis is expected before the end of 2025. The trial is projected to complete in the second half of 2026.

AVX70371 has been specifically designed to elicit a T-cell immune response against hepatocytes actively replicating hepatitis B virus. In patients with chronic hepatitis B, the immune system often fails to control the infection due to T-cell exhaustion. AstriVax aims to address this by developing an approach that targets infected liver cells and potentially helps re-establish immune function.

“AVX70371 has been designed to elicit a specific T-cell immune response against infected hepatocytes in which HBV is actively replicating. Knowing that patients with chronic hepatitis B suffer from immune exhaustion, this targeted immunotherapy approach is expected to intervene at the source of the chronic viral infection,” said Mathieu Peeters, chief development officer at AstriVax Therapeutics. “Starting clinical development with AVX70371 is the first step in the development of a new approach that could form the basis of a functional cure for chronic HBV infection.”

Despite the availability of preventive vaccines, more than 250 million people globally live with chronic hepatitis B infection, many of whom rely on long-term antiviral therapy. AstriVax believes there is still a need for more effective therapeutic options.

“Following positive results from our first clinical study in 2024, which evaluated the safety and immunogenicity of our Launch-iT technology platform, starting the clinical development with our first therapeutic Launch-iT program is a significant milestone for AstriVax Therapeutics,” said Hanne Callewaert, co-founder and chief executive officer. “Despite available preventive vaccines, chronic hepatitis B still affects over 250 million people worldwide, so there is an ongoing need for improved options for patients beyond life-long antiviral treatment.”

She added that the company is in the process of selecting a second Launch-iT candidate to treat human papilloma virus infection, with plans to move that programme into clinical development soon.

The Launch-iT platform is a plasmid-based technology used to generate viral vectors encoding disease-specific antigens. The system has previously been tested in the SAFYR study using yellow fever and rabies vaccine constructs. Results from that study indicated that a single injection could induce strong, lasting immune responses and was well tolerated.