DURHAM, N.C., May 27, 2026
Precision BioSciences announced new and late-breaking clinical data from the ELIMINATE-B study evaluating PBGENE-HBV, its investigational in vivo gene editing therapy for chronic hepatitis B virus (HBV) infection, during the European Association for the Study of the Liver (EASL) Congress 2026. The newly presented findings mark what researchers describe as the first-ever clinical evidence demonstrating direct elimination and permanent inactivation of covalently closed circular DNA (cccDNA) in liver biopsies collected from treated hepatitis B patients. The data position PBGENE-HBV as a potentially transformative therapy in the global effort to develop a functional or complete cure for chronic hepatitis B, a disease that affects hundreds of millions of people worldwide.
PBGENE-HBV Demonstrates Direct Elimination of cccDNA
According to the data presented at EASL 2026, PBGENE-HBV achieved a 1-log (10-fold) reduction in cccDNA-derived transcripts after only two administrations at the 0.4 mg/kg dose level. Researchers used advanced long-read transcript sequencing technology to distinguish the therapy’s impact on cccDNA versus integrated HBV DNA within liver tissue. The findings confirmed that PBGENE-HBV directly eliminated cccDNA through its primary antiviral mechanism, representing a milestone never previously achieved by either approved therapies or experimental hepatitis B treatment modalities.
Importantly, the small amount of remaining cccDNA — less than 1% — was further edited through a secondary mechanism involving indels that permanently disable viral polymerase function, effectively preventing continued viral replication. Investigators also observed cumulative editing effects following repeat dosing, with editing reaching approximately 80% of the remaining cccDNA after three administrations, suggesting the therapy may deliver increasingly durable viral eradication with optimized dosing schedules.
New Biomarker Data Strengthens Cure Potential
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The ELIMINATE-B study also established pgRNA as a critical biomarker directly reflecting cccDNA elimination by PBGENE-HBV. The therapy achieved complete loss of detectable pgRNA in 100% of patients who had measurable pgRNA levels before treatment across multiple dosing cohorts. Researchers emphasized that pgRNA originates exclusively from cccDNA and serves as a direct precursor for HBV DNA production, making it a highly relevant marker for monitoring treatment response and potential viral cure.
Additionally, all evaluable patients experienced substantial reductions in HBsAg levels, demonstrating broad antiviral activity across varying HBV genotypes, geographies, and baseline disease characteristics. One patient maintained durable HBsAg decline for more than one year following initial treatment, supporting the long-lasting nature of PBGENE-HBV’s gene-editing mechanism. These findings align with current FDA guidance that elimination of HBV DNA represents the preferred endpoint for hepatitis B therapeutic approval.
Michael Amoroso, President and CEO of Precision BioSciences, described the results as a transformational breakthrough for the hepatitis B field, stating that chronic HBV treatment may be shifting away from lifelong viral suppression toward finite therapies capable of complete viral elimination. He noted that PBGENE-HBV directly targets the root source of HBV replication, something no previous therapy has successfully achieved.
Safety Profile Supports Continued Clinical Expansion
As of the May 4, 2026 data cutoff, investigators administered 38 doses across 16 patients in five dosing cohorts. No dose-limiting toxicities were observed, and the therapy demonstrated a manageable safety profile. The most common adverse events were infusion-related reactions associated with lipid nanoparticle delivery systems. While some transient Grade 3 ALT/AST laboratory abnormalities and hypotension events occurred during dose escalation, researchers implemented mitigation strategies including slower infusion rates and increased steroid dosing. Following protocol adjustments, no additional severe hypotension or significant liver-related laboratory toxicities were reported.
The company plans to continue enrolling patients and collecting additional liver biopsy data as part of ongoing optimization efforts in the ELIMINATE-B trial. Future development phases are expected to include nucleoside analog withdrawal studies and expanded testing designed to evaluate the potential for complete viral cure. Precision BioSciences expects to provide further updates on the program before the end of 2026.
Founded as a clinical-stage gene editing company, Precision BioSciences is developing therapies using its proprietary ARCUS® genome editing platform, which is designed for highly precise therapeutic gene editing applications across infectious and genetic diseases. PBGENE-HBV has already received FDA Fast Track designation, reinforcing its significance within the rapidly evolving global gene editing and antiviral therapeutics market.
Source: Precision BioSciences press release
