A new drug has cured 20% of patients with a chronic, cancer-causing disease — which was previously incurable.

A viral infection — and the world’s leading cause of liver cancer — the disease has long thwarted scientists who have searched for a serviceable treatment strategy.

Now, a paper published in the New England Journal of Medicine suggests a functional cure for hepatitis B has been found.

“The results are remarkable,” said study Dr. Anna S. Lok, assistant dean for clinical research at the University of Michigan Medical School. She added that the success of the treatment “represents a major step forward.”

Over 296 million people are living with hepatitis B, making it the most common liver infection in the world.

The virus is primarily spread through contact with infected blood or other body fluids, typically via sex, needle-sharing and childbirth when the mother is infected.

About 95% of adults clear the virus on their own within about six months. But when the immune system fails to clear the virus, acute hepatitis B becomes chronic hepatitis B, which can lead to liver scarring, failure and cancer if left untreated.

Current treatment for chronic hepatitis B is a lifelong protocol that includes antivirals and immune-boosting medications that do not eliminate the virus — nor the risk of liver cancer.

This new study included more than 1,838 patients across 29 countries in Asia, Europe, and North and South America who were suffering from the chronic form of the infection.

Researchers say a new drug, bepirovirsen, administered as a weekly injection, can make the virus undetectable in patients’ bodies.

Developed by Ionis Pharmaceuticals and GlaxoSmithKline, bepirovirsen prevents hepatitis B virus replication and enables the immune system to effectively attack it.

Researchers reported that a functional cure was achieved in 20% of patients who received bepirovirsen. In these patients, the virus remained undetectable 48 weeks after treatment.

None of the patients who received the placebo were cured.

Patients with cirrhosis, HIV infections, or very high levels of hepatitis B. were excluded from the study.

There were 17,650 new reports of chronic hepatitis B and 1,769 hepatitis B-related deaths in 2023, according to the CDC.

Last year, a federal vaccine advisory committee voted to end the longstanding recommendation that all U.S. babies get the hepatitis B vaccine on the day they’re born.

A loud chorus of medical and public health leaders decried the panel’s actions, whose current members were all appointed by US Health Secretary Robert F. Kennedy Jr. an outspoken anti-vaccine activist.

In 1991, the Advisory Committee on Immunization Practice recommended universal vaccination for all infants.

The first dose is given within 24 hours of birth. The second is administered at 1 to 2 months of age, and the third between 6 and 18 months. The vaccine protects about 98% of healthy infants, the CDC said.

Side effects, which are usually mild and short-lived, may include pain at the injection site, soreness, redness, headache, and fatigue.

The American Academy of Pediatrics said in June of last year that the US is on track to eliminate perinatal hepatitis B, but ditching the birth dose would “jeopardize this progress.”