Hepatitis B Drug Achieves Functional Cure in 1 in 5 Patients

For the first time in medical history, some chronic hepatitis B patients can stop treatment and still keep the deadly virus in check.

In two international trials involving 1,838 patients, researchers tested an experimental drug called bepirovirsen. About 1 in 5 people who received the weekly shots saw their virus drop to undetectable levels that stayed suppressed even after stopping all medications.

"We have not had a treatment which has come to this level of cure," said Dr. Seng Gee Lim of Singapore's National University Health System, who led the studies published Thursday in the New England Journal of Medicine.

Chronic hepatitis B infects more than 250 million people worldwide and kills 1.1 million each year through liver cancer and liver failure. While vaccines prevent infection, the 1.7 million Americans living with chronic hepatitis B have relied on daily pills that control the virus but never eliminate it.

The challenge lies in hepatitis B's ability to hide inside cells, ready to rebound the moment treatment stops. This new drug attacks differently by binding to the virus's genetic material, blocking replication and triggering the immune system to fight back.

Patients in the trials received weekly shots for six months alongside their regular pills. Those who showed no detectable virus for six months afterward could stop all treatment. Twenty percent of drug recipients maintained that virus-free state for another six months, something zero patients on placebo achieved.

The Bright Side

Early tracking shows the functional cure may last years. GSK researchers followed a small group from earlier trials and found most remained virus-free up to three years later without any medication.

The drug works best in patients who started with lower levels of a specific viral protein. Dr. Lim is now researching why some people respond while others don't, hoping to identify ideal candidates before treatment begins.

Side effects were minimal, mostly mild redness at injection sites and temporary enzyme changes. The U.S. Food and Drug Administration has the drug under fast-track review, with a decision expected in October. Japan, China, and Europe are also considering approval.

Dr. Anna Lok, a hepatitis expert at the University of Michigan not involved in the research, called the findings "a major step" while noting longer studies are needed to confirm durability.

After decades of searching for better options, this breakthrough offers hope that chronic hepatitis B might one day become a manageable condition requiring only temporary treatment.