On October 20, 2026, the FDA approved bepirovirsen (brand name Hibsago) from GSK and Ionis. It is the first drug that can let some people with chronic hepatitis B stop treatment altogether: in trials, 19% of patients kept the virus under control six months after quitting every medication.
Why it matters: hepatitis B can be held in check today, but it is almost never cured. Standard drugs, called nucleos(t)ide analogues, are often taken for life, and only about 1% of patients reach a functional cure on them (GSK and Ionis). The WHO estimates 240 million people live with chronic hepatitis B, and about 1.1 million died of its complications in 2024, mostly cirrhosis and liver cancer (WHO).
What a functional cure actually means
It does not mean every trace of the virus is gone. It means the virus no longer runs your life. The bar is strict: HBsAg (a protein from the virus's outer shell that blood tests look for) disappears, viral DNA becomes undetectable, and both stay that way for at least 24 weeks after treatment ends.
Bits of the virus still hide in liver cells, but the immune system keeps them in check without pills. Think of a campfire that is not soaked down to the last ember, yet no longer flares up, so nobody has to stand guard with a bucket.
How bepirovirsen works
Bepirovirsen is an antisense oligonucleotide: a short, lab-made strand that finds the virus's genetic blueprint and marks it for destruction. According to its developers, it slows viral replication, lowers HBsAg in the blood and gives the immune system a push (MIMS).
The course has an end date: one shot a week for up to 24 weeks, and patients can give it to themselves after the first dose (MedCity News). It is added on top of existing therapy, not used instead of it.
The trial results: what 19% means in people
The approval rests on two phase 3 trials, B-Well 1 and B-Well 2. Pooled together, 233 of 1,220 patients on bepirovirsen reached a functional cure (19%), versus none of the 614 on placebo, a dummy treatment (Consultant360).
The odds depend heavily on how much viral protein is in your blood before you start:
- HBsAg at or below 1,000 IU/mL: 26%, roughly one in four (200 of 768);
- all patients combined: 19%, roughly one in five;
- high HBsAg: 10% in one trial and 5% in the other, between one in ten and one in twenty.
That sounds modest until you remember the baseline: on standard treatment, about 1 person in 100 gets there. For people with low protein levels, the chance is roughly 25 times higher.
Who qualifies, and what the risks are
In the US, the drug is not approved for everyone. It is for adults who meet all of these conditions (GSK):
- no cirrhosis (scarring of the liver);
- at least six months on nucleos(t)ide analogues;
- viral DNA suppressed in the blood;
- HBsAg at or below 3,000 IU/mL on an approved test (the FDA cleared a Roche test alongside the drug to pick eligible patients).
The label carries a boxed warning, the FDA's strictest, calling for liver enzyme monitoring during treatment (AJMC). Other listed risks include thrombocytopenia (a drop in platelets, the cells that help blood clot) and immune-related reactions. GSK has not yet published a price.
Where you can get it, and where you can't yet
Japan approved bepirovirsen first, in August 2026 (GSK), and the US is second. As of April 2026, the companies said reviews were under way at the European Medicines Agency and China's drug regulator (Business Wire).
The cruel part: hepatitis B hits hardest where new drugs arrive last. Three quarters of deaths happen in Africa and the Western Pacific, and ten countries, including Nigeria, China, India, Indonesia, Vietnam and the Philippines, account for 69% of all hepatitis B deaths (WHO Global Hepatitis Report 2026).
Editorial view: this approval is a real shift. For the first time in decades, some patients can aim to finish treatment instead of staying on it forever. But the biggest barrier now is not science. The WHO says fewer than 5% of people with chronic hepatitis B get any treatment, and many do not know they are infected. For most people, step one is not a new drug. It is a basic blood test.
If you already have a diagnosis, do not stop your current pills on your own: quitting suddenly can trigger a flare. Ask your liver specialist what your HBsAg level is and whether you would qualify once the drug reaches your country. If you have never been tested, an HBsAg blood test takes a few minutes at a clinic.
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