May 27, 2026 —
Precision BioSciences presented new late-breaking clinical data from the ELIMINATE-B study evaluating PBGENE-HBV, an investigational in vivo gene editing therapy for chronic hepatitis B, at the EASL Annual Congress 2026. The data represent what the company describes as the first clinical evidence of a therapeutic agent eliminating and inactivating cccDNA in liver biopsies from treated patients with chronic hepatitis B.
PBGENE-HBV is based on Precision’s proprietary ARCUS® gene editing platform, which is being developed for sophisticated in vivo editing strategies. ARCUS can be applied to gene elimination, such as removing viral DNA in the company’s PBGENE-HBV program; gene excision, such as removing a large defective region of a gene by delivering two ARCUS nucleases in a single AAV, as in PBGENE-DMD; and gene insertion, where DNA is inserted into a genomic site to restore or add function.
In chronic hepatitis B, cccDNA is a key reservoir that drives viral replication and persistence. Current therapies can suppress viral replication but generally do not eliminate the root source of HBV activity. PBGENE-HBV is designed to directly target this viral reservoir by editing and eliminating cccDNA, potentially shifting the field from lifelong viral suppression toward a finite, biomarker-guided curative approach.
As of the May 4, 2026 data cutoff, 38 doses had been administered to 16 patients across five cohorts. Liver biopsy analysis using long-read transcript sequencing showed a 1-log, or 10-fold, reduction in cccDNA transcripts after two administrations at the 0.4 mg/kg dose. Additional editing of remaining cccDNA occurred through indels that inactivate viral polymerase function, providing a second mechanism for disrupting viral replication.
The company also reported that pgRNA, a serum biomarker derived exclusively from cccDNA and required for HBV DNA production, became durably undetectable in 100% of patients who had detectable levels before treatment. In addition, all evaluable patients experienced substantial HBsAg declines, with responses observed across different geographies, baseline HBsAg levels, and HBV genotypes.
From a safety perspective, no dose-limiting toxicities were observed as of the cutoff. The most common adverse events were infusion-related reactions consistent with LNP delivery effects. Transient reversible ALT/AST elevations and hypotension were reported, but mitigation measures including slower infusion and adjusted steroid dosing have since been implemented.
Overall, the data provide early clinical support for ARCUS-mediated viral gene elimination as a potential functional or complete cure strategy for chronic hepatitis B. Precision plans to continue enrolling patients, collect additional liver biopsy data, optimize dosing schedules, and work toward future nucleoside analog withdrawal studies.
