PHILADELPHIA, PA — Virion Therapeutics reported new long-term data showing its experimental hepatitis B immunotherapy, VRON-0200, produced sustained reductions in key disease markers for more than two years after a single dose, a result that could support efforts to develop finite treatments for chronic hepatitis B infection.
The findings, presented at the European Association for the Study of the Liver (EASL) Congress 2026 and published in The Lancet Microbe, come from a Phase 1b study evaluating the safety and biological activity of VRON-0200 in patients with chronic hepatitis B virus (HBV) infection.
The company said the treatment was well tolerated, with no serious treatment-related adverse events, treatment discontinuations or treatment-related laboratory abnormalities reported.
At the end of the one-year study period, 23 of 27 patients, or 85%, experienced sustained or continuing declines in hepatitis B surface antigen (HBsAg), a key marker of infection. Twelve of those patients achieved reductions greater than 50%, including four patients with declines of at least 1 log10 IU/mL.
Longer-term follow-up data were available for 12 patients up to 846 days after receiving the treatment. According to Virion, 11 of those patients continued to show declining HBsAg levels, while none experienced a rebound. Two patients achieved complete HBsAg loss, a milestone often associated with functional cure.
The results are significant because chronic hepatitis B affects an estimated 260 million people worldwide, and current antiviral therapies often suppress the virus without eliminating the need for long-term treatment. Achieving a functional cure generally requires maintaining viral control after treatment has ended.
“The goal of therapy in chronically HBV-infected patients is to have a finite course of treatment that, upon discontinuation, maintains viral suppression without the need to re-initiate antiviral agents,” said Dr. Edward Gane of the University of Auckland, who presented the data at EASL. He said the absence of viral rebound and continued antigen declines suggest immune restoration may play a meaningful role in long-term viral control.
Virion is positioning VRON-0200 as an immune-based therapy designed to stimulate hepatitis B-specific T-cell responses. The company believes the treatment could potentially be used alone in some patients or combined with antiviral therapies in a so-called “Spark and Fan” strategy, in which the immunotherapy primes an immune response before additional treatment is introduced.
The company said it is planning a Phase 2b trial, known as SPARK-B, that will evaluate functional cure rates after discontinuation of standard nucleos(t)ide antiviral therapy. The study is expected to include patients with higher baseline HBsAg levels than those typically enrolled in current cure-focused trials.
Virion is also evaluating potential future development of VRON-0200 in patients with hepatitis B and HIV co-infection, hepatitis D co-infection, and metabolic dysfunction-associated steatohepatitis, or MASH.
The Phase 1b study is listed on ClinicalTrials.gov under identifier NCT06070051.
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