The drugs that most people with chronic hepatitis B take every day — tenofovir and entecavir — are remarkably good at one thing and stubbornly incapable of another. They suppress the virus to undetectable levels in the blood, but they never eliminate it from the body. Fewer than 3% of patients on these medications achieve what researchers call a “functional cure” over a decade of continuous treatment. The rest face a lifetime of daily pills, because the moment they stop, the virus comes roaring back. For the estimated 254 million people worldwide living with chronic hepatitis B, this is the central frustration of modern treatment: control without cure. Consider a patient who begins taking tenofovir disoproxil fumarate after a diagnosis of chronic hepatitis B. Within 48 weeks, there is a 68 to 90% chance that the virus will become undetectable in their bloodstream.
Their liver inflammation subsides. Their risk of cirrhosis and liver cancer drops. By every measurable standard, the drug is working. But deep inside their liver cells, a stubborn molecular reservoir called covalently closed circular DNA — cccDNA — sits untouched, waiting. If that patient stops taking the medication, viral rebound and dangerous liver flares often follow within weeks. The drug controls the fire, but it never puts it out. This article examines why current hepatitis B antivirals cannot achieve a cure, what the biological obstacle of cccDNA actually means, and why this matters for brain health and dementia risk in aging populations with chronic infections. It also covers the most promising research breakthroughs of 2025 and 2026 — including bepirovirsen, an antisense therapy that could become the first treatment to offer a finite course and functional cure — and the enormous global treatment gap that leaves most people with hepatitis B without any therapy at all.
Table of Contents
- Why Do Current Hepatitis B Drugs Control the Virus but Never Cure It?
- The cccDNA Problem — The Biological Barrier No Current Drug Can Break
- Bepirovirsen — The First Drug That Might Actually Offer a Finite Cure
- Emerging Therapies and the Combination Strategy Physicians Favor
- The Global Treatment Gap and Who Gets Left Behind
- What Chronic Hepatitis B Means for Brain Health and Aging
- The Road Ahead — From Lifelong Suppression to Functional Cure
- Conclusion
- Frequently Asked Questions
Why Do Current Hepatitis B Drugs Control the Virus but Never Cure It?
The answer lies in a piece of viral DNA that current medications simply cannot reach. When hepatitis B infects a liver cell, it converts its genetic material into a structure called covalently closed circular DNA, or cccDNA, which embeds itself in the nucleus and functions like a permanent blueprint for making new virus. The first-line antiviral drugs — tenofovir disoproxil fumarate, tenofovir alafenamide, and entecavir — are nucleoside or nucleotide analogues that block the virus’s reverse transcriptase enzyme, effectively halting viral replication in the bloodstream. But they have little to no effect on cccDNA. It is the difference between cutting off a weed at the stem and pulling it out by the root. Long-term studies confirm just how effective these drugs are at suppression: virologic response rates approach 95% with very low resistance rates over years of continuous use.
That makes them excellent at preventing liver damage, reducing the risk of hepatocellular carcinoma, and keeping patients clinically stable. But the functional cure rate — defined as sustained loss of hepatitis B surface antigen, or HBsAg — remains below 3% after 10 years of treatment. For comparison, hepatitis C, once considered equally intractable, now has cure rates exceeding 95% with direct-acting antiviral regimens that last just 8 to 12 weeks. The practical consequence is lifelong medication. Stopping nucleoside analogue therapy frequently triggers viral rebound, where the virus rapidly resumes replication from the cccDNA reservoir, and this can produce severe hepatic flares that are sometimes more dangerous than the original chronic infection. Physicians must counsel patients that these drugs are not a bridge to coming off treatment — they are the treatment, indefinitely. This distinction matters enormously for older adults, for whom managing yet another daily medication alongside treatments for hypertension, diabetes, or cognitive decline adds real complexity to care.
The cccDNA Problem — The Biological Barrier No Current Drug Can Break
To understand why a cure has been so elusive, it helps to picture what is actually happening inside a single liver cell. Hepatitis B virus enters the hepatocyte and delivers its partially double-stranded DNA genome into the nucleus. There, host cell enzymes repair and close this DNA into a supercoiled minichromosome — the cccDNA — that hijacks the cell’s own transcription machinery to produce viral RNA and proteins. Because cccDNA is maintained by the cell’s normal DNA repair processes, it is extraordinarily stable. It can persist for the entire lifespan of the infected liver cell, and possibly longer through cell division, though this remains an area of active research. Current nucleoside analogues intervene downstream of this reservoir. They prevent new virions from forming by blocking reverse transcription of viral RNA back into DNA, but they do nothing to degrade the cccDNA template already established in the nucleus.
This means even a patient with years of undetectable viral load still harbors cccDNA in their liver. The reservoir is essentially invisible to treatment. It does not produce symptoms, it does not show up on standard blood tests, and it is not targeted by any approved medication on the market today. However, if the cccDNA reservoir could be silenced or destroyed, the virus would lose its ability to reactivate. This is why nearly all next-generation hepatitis B research is focused, in one way or another, on either degrading cccDNA directly, preventing its replenishment, or silencing the genes it expresses. The challenge is doing so without damaging the liver cell’s own DNA — a therapeutic needle-threading exercise that has taken researchers decades to approach. For patients with concurrent neurodegenerative conditions, the stakes are compounded: chronic hepatic inflammation from uncontrolled hepatitis B has been linked to systemic inflammatory states that may accelerate cognitive decline, making effective viral control all the more important even if cure remains out of reach.
Bepirovirsen — The First Drug That Might Actually Offer a Finite Cure
In January 2026, GSK announced positive results from the B-Well 1 and B-Well 2 Phase III clinical trials for bepirovirsen, an antisense oligonucleotide developed with Ionis Pharmaceuticals. If approved, bepirovirsen would be the first-in-class treatment to offer a finite course — roughly six months — that achieves functional cure in a meaningful percentage of chronic hepatitis B patients. This is not incremental progress. It represents a fundamentally different therapeutic mechanism from the lifelong suppressive approach that has defined hepatitis B treatment for more than two decades. Bepirovirsen works by binding directly to all hepatitis B viral messenger RNAs and triggering their degradation through the RNase H pathway. By destroying viral RNA before it can be translated into proteins, the drug reduces HBsAg levels in a way that nucleoside analogues simply cannot. The Phase III results showed that a defined subset of patients achieved sustained HBsAg loss — the benchmark for functional cure — after completing the treatment course.
While not every patient responds, the prospect of any finite treatment achieving functional cure marks a turning point. For decades, the answer to “when can I stop taking this medication?” has been “never.” Bepirovirsen may change that for some patients. The clinical significance extends beyond hepatology. For aging patients managing chronic hepatitis B alongside cognitive impairment or early-stage dementia, the possibility of discontinuing a daily antiviral after a six-month course would meaningfully simplify medication regimens. Polypharmacy — the concurrent use of multiple medications — is a well-documented risk factor for confusion, falls, and medication non-adherence in older adults. Any treatment that can safely reduce the pill burden while achieving durable viral control represents a genuine advancement in holistic patient care.
Emerging Therapies and the Combination Strategy Physicians Favor
Bepirovirsen is not the only candidate in the pipeline. Several other approaches have shown early promise, and the prevailing view among hepatologists is that combination therapy — rather than any single agent — will likely be required to achieve functional cure at scale. In a recent survey, 76.1% of physicians identified combination therapy with pegylated interferon-alpha as their preferred strategy for pursuing functional cure, and they set a minimum acceptable cure rate benchmark of 30%. Among the most watched experimental agents is KC13-M2G2, a small interfering RNA that targets the hepatitis B S region. Published in Nature Communications in 2025, preclinical data showed it outperformed both elebsiran and bepirovirsen in mouse models, with potent efficacy across all HBV genotypes. RNA interference therapies like this one work by silencing viral gene expression at the mRNA level, offering a complementary mechanism to antisense approaches.
Meanwhile, selgantolimod, a TLR-8 agonist developed by Gilead, takes an immunological approach: it stimulates the innate immune system to recognize and attack infected cells. In clinical trials, 26% of patients saw HBsAg reduction after 24 weeks, and 5% achieved outright HBsAg loss — modest but notable for an immune modulator. The tradeoff between these approaches involves efficacy, tolerability, and duration. Nucleoside analogues are well tolerated but require lifelong use. Interferon-based regimens offer higher functional cure rates but come with significant side effects — fatigue, flu-like symptoms, depression, and cytopenias — that make them particularly difficult for older adults or those with cognitive impairment. Newer agents like bepirovirsen and siRNAs aim to split the difference: finite courses with manageable side effect profiles. But until Phase III data matures across multiple combination regimens, the field remains in a period of cautious optimism rather than certainty.
The Global Treatment Gap and Who Gets Left Behind
Perhaps the most sobering fact about hepatitis B treatment is that the vast majority of the 254 million people living with chronic infection worldwide remain undiagnosed and untreated. The treatment access gap is concentrated in sub-Saharan Africa and the Western Pacific — regions where the burden of hepatitis B is highest and healthcare infrastructure is least equipped to deliver lifelong antiviral therapy. Even in high-income countries, screening rates remain far below targets, and many patients are diagnosed only after presenting with advanced liver disease. This gap has consequences beyond hepatology. Chronic hepatitis B drives systemic inflammation, and growing evidence suggests that persistent viral infections may contribute to neuroinflammatory processes relevant to dementia and cognitive decline. For patients who go decades without diagnosis or treatment, the liver is not the only organ at risk.
The inability to cure hepatitis B compounds the access problem: a treatment that requires daily medication for life demands a healthcare system capable of continuous follow-up, laboratory monitoring, and drug supply chain management. In resource-limited settings, this is often simply not feasible. If finite-duration treatments like bepirovirsen prove successful and become affordable, they could fundamentally reshape global hepatitis B control. A six-month treatment course is far more deliverable than a lifetime regimen, both logistically and economically. However, affordability is not guaranteed. First-in-class therapies often carry premium pricing, and without deliberate efforts to ensure equitable access, the patients who need these drugs most may be the last to receive them. The hepatitis C experience offers both a cautionary tale and a hopeful precedent: direct-acting antivirals were initially priced beyond reach for most patients worldwide, but generic competition and international negotiations eventually brought costs down dramatically.
What Chronic Hepatitis B Means for Brain Health and Aging
The connection between chronic hepatitis B and brain health deserves more attention than it typically receives. Chronic viral hepatitis is a state of persistent low-grade inflammation, and the liver’s central role in metabolic clearance means that hepatic dysfunction can have ripple effects throughout the body, including the central nervous system. Some studies have observed associations between chronic hepatitis B infection and increased risk of cognitive impairment, though the evidence is not yet strong enough to establish direct causation.
What is less controversial is the indirect impact. Patients with poorly controlled hepatitis B who develop cirrhosis are at risk for hepatic encephalopathy — a syndrome of confusion, personality changes, and impaired cognition caused by the liver’s failure to clear neurotoxic substances like ammonia from the blood. Even subclinical hepatic encephalopathy, which may not produce obvious symptoms, can subtly impair attention, processing speed, and executive function in ways that mimic or accelerate age-related cognitive decline. For older adults already navigating early-stage dementia, an undiagnosed or untreated hepatitis B infection can complicate the clinical picture in ways that are easily missed.
The Road Ahead — From Lifelong Suppression to Functional Cure
The next two to three years will likely determine whether functional cure becomes a realistic clinical goal for chronic hepatitis B or remains aspirational. The bepirovirsen Phase III results represent the most significant advance in decades, but regulatory review, real-world efficacy data, and pricing decisions will all shape how quickly — and how broadly — patients benefit. Combination regimens involving antisense oligonucleotides, siRNAs, immune modulators, and possibly next-generation nucleoside analogues are already being designed for Phase II and III trials, with the goal of achieving functional cure rates well above the 30% benchmark that physicians have identified as the minimum acceptable threshold.
For the millions of patients who have taken tenofovir or entecavir for years with no prospect of stopping, these developments represent something that has been absent from hepatitis B treatment for a long time: a plausible path to the end of therapy. The drugs that control the virus without curing it have saved countless lives and prevented enormous suffering. But they were always meant to be a bridge — not a destination. The science is finally, cautiously, beginning to build the other side.
Conclusion
Current hepatitis B antivirals — tenofovir and entecavir — remain indispensable tools for suppressing viral replication and preventing liver disease. They achieve undetectable viral levels in the vast majority of patients and have transformed chronic hepatitis B from a death sentence into a manageable condition. But they cannot touch the cccDNA reservoir that keeps the virus alive inside liver cells, which means fewer than 3% of patients on these drugs will ever achieve functional cure. For most people, treatment is indefinite, and stopping it is dangerous.
The emergence of bepirovirsen and other novel agents offers the first credible challenge to this paradigm. A finite treatment course that achieves functional cure — even in a subset of patients — would represent a fundamental shift in how chronic hepatitis B is managed. For older adults, particularly those dealing with cognitive decline or complex medication regimens, such a shift could have outsized benefits. The priority now is to ensure that the progress made in clinical trials translates into accessible, affordable treatment for the hundreds of millions of people who need it — not just in well-resourced healthcare systems, but globally.
Frequently Asked Questions
Can hepatitis B be fully cured with current medications?
No. Current first-line drugs — tenofovir disoproxil fumarate, tenofovir alafenamide, and entecavir — suppress the virus but do not eliminate it. The functional cure rate with these medications alone is less than 3% over 10 years. The virus persists in the form of cccDNA inside liver cells, which these drugs cannot target.
What happens if someone stops taking hepatitis B antiviral medication?
Stopping nucleoside analogue therapy frequently leads to viral rebound, where the virus resumes active replication from the cccDNA reservoir in liver cells. This can trigger hepatic flares — sudden, severe liver inflammation — that may be more dangerous than the original chronic infection. Patients should never stop treatment without close medical supervision.
What is bepirovirsen and how is it different from current treatments?
Bepirovirsen is an antisense oligonucleotide developed by GSK and Ionis Pharmaceuticals that targets hepatitis B viral RNA for degradation. Unlike current drugs that must be taken for life, bepirovirsen is designed as a finite treatment course of approximately six months. GSK’s Phase III trial results announced in January 2026 showed it achieved functional cure — sustained HBsAg loss — in a meaningful percentage of patients. If approved, it would be the first drug in its class.
Does chronic hepatitis B affect brain health?
There is growing recognition that chronic hepatitis B, as a persistent inflammatory condition, may have implications for brain health. Patients who develop cirrhosis are at risk for hepatic encephalopathy, which causes confusion and cognitive impairment. Even subclinical liver dysfunction can impair attention and processing speed. For older adults with or at risk for dementia, uncontrolled hepatitis B may complicate cognitive health in ways that deserve clinical attention.
Why are so many people with hepatitis B still untreated?
Of the approximately 254 million people living with chronic hepatitis B globally, the vast majority remain undiagnosed and untreated. The burden is concentrated in sub-Saharan Africa and the Western Pacific, where screening infrastructure and access to lifelong antiviral therapy are limited. Even in high-income countries, many patients are diagnosed only at advanced stages of liver disease.
What is the most promising strategy for achieving a hepatitis B cure?
Most experts favor combination therapy. In a recent survey, 76.1% of physicians identified combination treatment with pegylated interferon-alpha as the preferred approach for functional cure. Emerging agents — including RNA interference drugs like KC13-M2G2, immune modulators like selgantolimod, and antisense therapies like bepirovirsen — are being evaluated in various combinations to push functional cure rates above the 30% benchmark that physicians consider the minimum acceptable threshold.
