A Functional Cure Within Reach? Phase 3 Data Reveal Breakthrough in Chronic Hepatitis B Treatment

Published: July 7, 2026

A groundbreaking scientific milestone has brought global health researchers closer to an elusive goal: a functional cure for chronic hepatitis B.

Data from the highly anticipated B-Well phase 3 clinical trials, published in The New England Journal of Medicine, reveal that an investigational medicine called bepirovirsen successfully cleared the virus in roughly 1 in 5 selected patients. The findings mark a pivotal shift in the fight against a chronic viral infection that affects an estimated 240 million people worldwide and claims more than one million lives each year due to liver complications.

For a global community accustomed to lifelong antiviral suppression, these results offer the first concrete evidence that a finite, time-limited treatment could allow some individuals to safely stop their daily medications.

The Breakthrough: What the Trials Showed

The B-Well clinical program evaluated 1,838 adults across two concurrent phase 3 trials (B-Well 1 and B-Well 2). The participants all had noncirrhotic chronic hepatitis B, were already stable on long-term standard nucleos(t)ide analogue therapy, and baseline testing showed they had relatively low levels of hepatitis B surface antigen (HBsAg).

Participants were randomly assigned to receive either weekly subcutaneous (under-the-skin) injections of bepirovirsen or a placebo for 24 weeks. Researchers then tracked the participants through week 72 to evaluate off-treatment durability.

The headline results were remarkably consistent:

• B-Well 1: 20% of patients achieved a functional cure.

• B-Well 2: 19% of patients achieved a functional cure.

• Placebo Groups: 0% of patients reached the endpoint in either trial.

What is a “Functional Cure”?

In chronic hepatitis B research, a functional cure means that the hepatitis B surface antigen (HBsAg) and viral DNA become completely undetectable in the blood, and remain so without the need for ongoing medication. However, it is not a “sterilizing cure.” The virus is not entirely erased from the body; it remains dormant in liver cells, but the patient’s immune system successfully keeps it suppressed.

Why This Matters for Global Public Health

For decades, standard hepatitis B therapies—such as daily nucleos(t)ide analogues—have been highly effective at suppressing viral replication and lowering the risk of cirrhosis and liver cancer. However, these treatments rarely eliminate HBsAg, meaning patients face a lifetime of daily pill burdens.

Furthermore, access remains a stark global challenge. According to the World Health Organization (WHO), fewer than 5% of people living with chronic hepatitis B were receiving treatment in 2024.

“Current standard therapies provide excellent viral suppression, but they are a lifelong commitment for the vast majority of patients,” notes an independent specialist in infectious diseases. “A 24-week therapy that can transition a significant subset of patients into long-term, off-treatment control is a monumental paradigm shift.”

By moving patients off lifelong medication, a functional cure could dramatically reduce the logistical burden on healthcare systems, lower long-term drug costs, and eliminate the risk of medication non-adherence.

Who Benefits Most? The Importance of Patient Selection

The B-Well data underscored a critical caveat: bepirovirsen does not work equally for everyone. The trial revealed that patient response relied heavily on the individual’s baseline viral burden before starting the new therapy.

• Patients who entered the trial with lower HBsAg levels (1,000 IU/mL or less) experienced significantly higher functional cure rates.

• Patients with baseline levels between 1,000 and 3,000 IU/mL saw notably lower success rates.

In an accompanying editorial in The New England Journal of Medicine, Anna S. F. Lok, MD, of the University of Michigan, emphasized that while a functional cure is now an achievable endpoint, these findings cannot yet be generalized to the broader hepatitis B population. The trial strictly excluded individuals with advanced liver cirrhosis, HIV coinfection, or baseline HBsAg levels exceeding 3,000 IU/mL.

For healthcare providers, this means that if bepirovirsen achieves regulatory approval, precise patient selection and pre-treatment screening will be vital to its success.

Safety Signals and Side Effects

Like any potent therapeutic advancement, bepirovirsen carries risks that require careful medical management. The pooled analysis of the trials revealed notable safety signals:

The most common severe complication observed was an elevation in alanine aminotransferase (ALT), a liver enzyme that flags liver inflammation or cell injury. While temporary “ALT flares” can sometimes indicate the immune system is actively fighting the virus, they require rigorous monitoring to prevent liver damage. Despite these side effects, only 3% of patients in the trials discontinued bepirovirsen treatment due to adverse events.

The Road Ahead: Combination Therapies and Prevention

Hepatitis B is a notoriously resilient virus. Because a single drug is unlikely to cure every patient, the scientific community is increasingly looking toward combination strategies.

In previous medical reviews, Dr. Lok noted that an ultimate cure strategy will likely require a multi-pronged approach: suppressing viral replication, reducing viral protein production (which is what bepirovirsen does), and simultaneously stimulating the patient’s own immune system to regain long-term control.

While bepirovirsen represents a major leap forward, public health officials warn that high-tech treatments should not overshadow basic prevention. The WHO Global Hepatitis Report underscores that viral hepatitis remains a global emergency, accounting for 1.34 million deaths annually.

The most effective tool against hepatitis B remains the preventative vaccine, which the WHO notes is more than 95% effective at preventing acute and chronic infections.

What Should Patients Do Now?

For health-conscious consumers and individuals living with hepatitis B, the practical takeaway is one of optimism, but also caution.

1. Do Not Alter Current Treatments: Anyone currently taking prescribed hepatitis B medication must not stop or alter their dosage based on these headlines. Abruptly halting antiviral therapy can cause dangerous viral rebounds and severe liver injury.

2. Prioritize Screening and Vaccination: For the general public, the most impactful steps remain getting tested, knowing your status, and ensuring you and your family are vaccinated.

3. Consult Your Physician: Treatment decisions remain highly individualized, dictated by liver inflammation, viral load, age, and liver scarring (fibrosis).

Bepirovirsen is not yet a routine clinical option, but the B-Well trials have officially opened the door to a new era of hepatitis care—one where freedom from chronic viral suppression may soon be a reality.

Medical Disclaimer

Medical Disclaimer: This article is for informational purposes only and should not be considered medical advice. Always consult with qualified healthcare professionals before making any health-related decisions or changes to your treatment plan. The information presented here is based on current research and expert opinions, which may evolve as new evidence emerges.

References

Study Citations

• Hou J, et al. Phase 3 Results of Bepirovirsen Treatment for Chronic Hepatitis B Virus Infection. New England Journal of Medicine. 2026. DOI: 10.1056/NEJMoa2515131.