FDA Approves Bepirovirsen Injection to Treat Chronic Hepatitis B

The FDA approved GSK’s bepirovirsen (Hibsago) injection for the treatment of hepatitis B virus (HBV), alongside existing antiviral treatment, in adults without cirrhosis, according to a release.¹ Crucially combining injections with existing therapy among patients, this new treatment avenue was found to eliminate the need for any medicine by 24 weeks.

“For many people living with chronic hepatitis B, treatment can mean taking antiviral medication for years to keep the virus suppressed,” said Wendy Carter, DO, acting director of the Office of Infectious Diseases in the FDA’s Center for Drug Evaluation and Research (CDER). “Hibsago provides a new treatment approach that gives some patients the possibility of maintaining control of the virus after all chronic HBV treatment has ended.”

Under regulatory guidelines, bepirovirsen is indicated for adults without cirrhosis who have maintained viral suppression on antiviral therapy for at least 6 months and have hepatitis B surface antigen levels at or below 3000 IU per mL.¹

Key Bepirovirsen Trial Findings

To guide patient selection, the FDA authorized the Roche Elecsys HBsAg II quant II RxDx assay as a companion diagnostic to measure surface antigen concentrations and assist in monitoring throughout treatment. Administered via weekly subcutaneous injection for up to 24 weeks alongside existing oral antivirals, bepirovirsen targets genetic instructions to reduce viral load and surface antigen levels.

In clinical trials, 24% of patients receiving bepirovirsen met requirements to stop all hepatitis B medications, compared with none on placebo. Furthermore, 19% of treated patients maintained viral suppression with undetectable surface antigen levels 24 weeks after stopping all therapy.¹

READ MORE: From Binder to Action: Making Infectious Disease Outbreak Plans Operational

This approval was granted to GSK following Fast Track, Breakthrough Therapy, and Priority Review designations. By providing a finite treatment protocol that can enable therapy discontinuation, bepirovirsen represents a major shift from lifelong oral antiviral suppression.

Mechanism and Design of Antisense Therapies

As an antisense oligonucleotide, bepirovirsen targets viral RNA directly rather than inhibiting downstream viral proteins. The single-stranded oligonucleotide binds complementary messenger RNA (mRNA) through Watson-Crick base pairing.^1,2

This heteroduplex recruits endogenous RNase H1 enzymes in host cells, triggering enzymatic degradation of target transcripts and halting viral replication. Synthetic backbone and sugar modifications protect the oligonucleotide from nuclease degradation while optimizing binding affinity.²

This approach highlights the growth of RNA-targeted drug discovery for previously challenging chronic diseases.

Bepirovirsen carries a boxed warning for severe liver reactions and low platelet counts. Thrombocytopenia increases bleeding risks, requiring regular hematologic monitoring. Additional warnings involve worsening renal function, systemic inflammatory reactions like vasculitis, and risks associated with improper administration.¹

Common side effects include injection site reactions, fever, fatigue, and headache. Providers must conduct regular blood tests before and during therapy to manage these risks.

Expanding the Role of Pharmacists in Community Care

For pharmacists, antisense therapies add new dimensions to hepatitis care. Standard treatments like entecavir or tenofovir require long-term adherence to keep viral DNA suppressed.^1,3

Pharmacists actively manage these oral regimens through drug interaction checks, lab monitoring, and adherence counseling. With bepirovirsen, pharmacists will counsel patients on dual-therapy protocols, injection administration, and mandatory lab schedules.

Additionally, community pharmacies serve as accessible sites for viral hepatitis screening, testing, and care coordination. Meta-analysis data indicates that delivering care within pharmacy settings significantly increases patient follow-up and retention across the care cascade.⁴

Through collaborative practice agreements, pharmacists can facilitate screening and treatment management, bridging access gaps for patients with chronic liver disease.^3,4

“The evolving epidemiology, prevention strategies, and treatment paradigms of hepatitis A through E highlight the expanding responsibilities of pharmacists within modern health care systems,” concluded authors of the U.S. Pharmacist study.³ “As health care systems continue to emphasize preventive care and population health, pharmacists must remain engaged leaders in hepatitis education, vaccination efforts, and treatment optimization to support long-term disease control and elimination.”

READ MORE: Infectious Disease Resource Center

REFERENCES

1. FDA approves first-of-its-kind chronic hepatitis b treatment. FDA. News Release. October 20, 2026. Accessed October 21, 2026. https://www.fda.gov/news-events/press-announcements/fda-approves-first-its-kind-chronic-hepatitis-b-treatment?utm_medium=email&utm_source=govdelivery

2. Dhuri K, Bechtold C, Quijano E, et al. Antisense oligonucleotides: an emerging area in drug discovery and development. J Clin Med. 2020;9(6):2004. 2020 Jun 26. doi:10.3390/jcm9062004

3. Colquitt C, Jackson TS. Key viral hepatitis insights for pharmacists. U.S. Pharmacist. 2026;51(4):8-13. https://www.uspharmacist.com/article/key-viral-hepatitis-insights-for-pharmacists

4. Hayes MJ, Beavon E, Traeger MW, et al. Viral hepatitis testing and treatment in community pharmacies: a systematic review and meta-analysis. EClinicalMedicine. 2024;69:102489. 2024 Feb 27. doi:10.1016/j.eclinm.2024.102489