Virion Therapeutics Announces Positive VRON-0200 Clinical Data at APASL 2025

Virion Therapeutics, a clinical-stage biotechnology firm specializing in T cell-based immunotherapies, has released compelling data from its Phase 1b trial of VRON-0200, a pioneering therapeutic approach aimed at achieving a functional cure for chronic Hepatitis B Virus (HBV). Presented at the 34th Annual Meeting of APASL (The Asian Pacific Association for the Study of the Liver) by Professor Grace Wong from the Chinese University of Hong Kong, the trial results demonstrate significant advances in safety, tolerability, and immunogenicity, as well as promising anti-HBV activity.

The study involved 27 patients with chronic HBV infection, all of whom were receiving nucleos(t)ide antiviral therapy. They were administered either a single intramuscular prime dose or a prime and boost regimen of VRON-0200. Throughout over 7,680 patient safety days, the treatment was well-tolerated with no serious adverse events (SAEs) or laboratory abnormalities, including liver function tests. This marks a significant milestone in HBV treatment, as maintaining safety and tolerability is crucial for patient adherence to therapy.

Immunogenicity data revealed that VRON-0200 successfully induced CD8+ T cell responses in 30% of patients (7 out of 24), with notable increases observed at days 28 and 91 post-vaccination. Specifically, there was a 5.5-fold increase in T cell responses at day 28 and a 4.8-fold increase by day 91, indicating sustained immune activation. This is particularly important for individuals with limited pre-existing immunity, showcasing VRON-0200’s potential to invigorate the immune system against HBV.

Moreover, six patients exhibited continued declines in HBV surface antigen levels through day 154, with reductions ranging from -0.4 to -2.3 log10 IU/mL, despite VRON-0200 not directly targeting the surface antigen. This suggests that VRON-0200 could restore broad anti-HBV immune responses, making it a promising candidate for functional cure strategies.

Professor Wong highlighted the significance of these findings, noting the limited options available to restore HBV immune functions in chronically infected patients. Current treatments often rely on pegylated interferon, which has notable tolerability and convenience issues. VRON-0200, however, offers good tolerance and convenience, and even with a single dose, can establish broad and durable anti-HBV immune responses. This positions VRON-0200 as a potential alternative immune-modulator for combination treatments aimed at achieving an HBV functional cure.

Dr. Sue Currie, COO of Virion and a study author, emphasized the promising nature of VRON-0200’s clinical data, noting the compound's potential to replace pegylated-interferon and improve treatment responses for the nearly 300 million individuals living with chronic HBV. The ongoing research aims to further establish VRON-0200’s efficacy in bringing a cure to patients, with additional data anticipated from upcoming studies.

Professor Ed Gane from the University of Auckland, another study investigator, remarked on VRON-0200’s unique ability to lower HBV surface antigen levels without directly targeting it, which is a critical step toward functional cure. The upcoming presentation of VRON-0200’s first combination regimen is expected to underscore its potential as a foundational component for future treatment strategies.

The Phase 1b trial follows a multi-center, open-label, dose escalation design, assessing both prime only and prime plus boost regimens. Participants included non-cirrhotic patients with chronic HBV infection on nucleos(t)ide antiviral therapy, meeting specific HBV DNA and HBsAg criteria. The trial’s success fuels optimism for VRON-0200’s role in addressing the global health challenge posed by chronic hepatitis B, for which a definitive cure remains elusive.

Virion Therapeutics continues to innovate with a robust pipeline, leveraging proprietary platform technologies to advance treatments for both chronic infections and cancer. The company’s lead program, VRON-0200, exemplifies its commitment to developing groundbreaking immunotherapies that enhance and broaden CD8+ T cell responses.