Highlights 

  • PBGENE-HBV demonstrated dose-dependent antiviral effects across nine Phase 1 patients. 
  • Therapy was tolerated across three ascending dose cohorts with no dose-limiting toxicities. 
  • Liver biopsy data shows the first evidence of HBV DNA gene editing in humans. 

Precision BioSciences, Inc. (NASDAQ:DTIL) reported new findings from its ongoing Phase 1 ELIMINATE-B study of PBGENE-HBV at the American Association for the Study of Liver Diseases (AASLD) The Liver Meeting® 2025. PBGENE-HBV is an in vivo gene editing therapy designed to target HBV cccDNA and integrated HBV DNA, addressing the underlying cause of chronic Hepatitis B. 

The late-breaking oral presentation, delivered by Dr. Man-Fung Yuen, Chair Professor of Gastroenterology and Hepatology at The University of Hong Kong, included results from nine patients who received a total of 22 doses across three dose cohorts: 0.2 mg/kg, 0.4 mg/kg, and 0.8 mg/kg. 

Safety and Tolerability 
Michael Amoroso, CEO of Precision BioSciences, stated, “The safety data and tolerability profile, along with dose-dependent durable reductions in hepatitis B surface antigen and the first liver biopsy data, provide evidence that antiviral activity is being achieved through directly editing the viral genome in patients with chronic Hepatitis B. With no observed dose-limiting toxicities to date, we look forward to finishing dosing the third cohort to generate additional data for PBGENE-HBV in our pursuit of a cure that has been so elusive in the field of Hepatitis B drug development.” 

PBGENE-HBV was well-tolerated across all cohorts. Adverse events were temporary, infusion-related reactions resolved without intervention, and liver enzyme elevations were transient with no sustained hepatic dysfunction observed. 

Antiviral Response and Biopsy Confirmation 
All nine participants experienced measurable reductions in hepatitis B surface antigen (HBsAg), confirming antiviral effects across all doses. Reductions were dose-dependent, with the 0.8 mg/kg cohort showing steep HBsAg declines by day 14 and cumulative decreases after repeated administrations. In the 0.4 mg/kg cohort, paired liver biopsy analysis confirmed ARCUS-mediated gene editing events in viral DNA, marking the first direct molecular evidence of HBV gene editing in humans. 

Study Progress and Next Steps 
The ELIMINATE-B Phase 1 study is enrolling HBeAg-negative patients at multiple international sites. Dosing for the third cohort is expected to be completed in Q1 2026, after which evaluations for nucleos(t)ide analogue withdrawal and functional cure testing may be conducted.  

About PBGENE-HBV and Precision BioSciences 
PBGENE-HBV is the only clinical-stage therapy specifically designed to eliminate cccDNA and inactivate integrated HBV DNA. Precision BioSciences develops in vivo gene editing therapies using its proprietary ARCUS® platform, targeting genetic and infectious diseases through precise genome modifications, including elimination, excision, and insertion.