US approves new hepatitis B treatment

Washington, Oct 21 : The United States has approved a new treatment for chronic hepatitis B that could allow some patients to stop taking antiviral medicines while maintaining control over the virus. 

The US Food and Drug Administration (FDA) announced Tuesday that it had approved Hibsago (bepirovirsen), an injectable medicine developed by GSK, for certain adults with chronic hepatitis B who do not have cirrhosis.

The treatment is the first FDA-approved antisense oligonucleotide for hepatitis B, using a technology designed to interfere with the genetic instructions that allow the virus to reproduce and produce viral proteins.

The new approach offers some eligible patients the possibility of maintaining viral control after stopping all hepatitis B therapy.

"For many people living with chronic hepatitis B, treatment can mean taking antiviral medication for years to keep the virus suppressed," said Wendy Carter, acting director of the FDA's Office of Infectious Diseases.

"Hibsago provides a new treatment approach that gives some patients the possibility of maintaining control of the virus after all chronic HBV treatment has ended. This approval represents an important advance for people living with this serious disease," she said.

The approval applies to adults without cirrhosis who have received antiviral therapy for at least six months and have suppressed levels of hepatitis B virus in their blood.

Patients must also have hepatitis B surface antigen levels of 3,000 international units per millilitre or less, established through an FDA-authorised diagnostic test.

The FDA said the treatment was evaluated in two clinical trials comparing Hibsago with a placebo.

Patients received injections under the skin for up to 24 weeks while continuing their existing antiviral medication.

They were required to remain on their regular antiviral treatment for at least another 24 weeks after the final Hibsago injection.

Some participants were subsequently permitted to discontinue antiviral medicines if they satisfied specified medical and laboratory criteria.

Across the two trials, 24 per cent of patients receiving Hibsago met the requirements to stop their existing antiviral medication, compared with none in the placebo groups.

Twenty-four weeks after stopping all hepatitis B treatment, 19 per cent of Hibsago recipients continued to demonstrate viral control, with hepatitis B surface antigen no longer detectable in their blood.

The findings indicate that a proportion of patients may achieve sustained control without ongoing treatment, although the majority of participants did not reach that outcome.

The FDA emphasised that the medicine carries significant safety risks.

Its prescribing information includes a boxed warning for serious liver reactions and reduced platelet counts, which can increase the risk of potentially life-threatening bleeding.

Additional warnings concern worsening kidney function, serious inflammatory reactions, including vasculitis, and complications arising from improper administration.

Patients receiving the treatment will require regular blood tests and medical monitoring before and during therapy.

The most frequently reported side effects, apart from laboratory abnormalities, included reactions at the injection site, fever, fatigue and headache.

The FDA also authorised a companion diagnostic test developed by Roche to help identify eligible patients and monitor treatment.

The medicine received Fast Track and Breakthrough Therapy designations, as well as Priority Review, reflecting the agency's assessment of its potential to address an important medical need.

The approval was granted to GSK plc. The FDA announcement did not specify when the treatment would become commercially available outside the United States, including in India.

Chronic hepatitis B is a long-term viral infection affecting the liver. Many patients require prolonged antiviral therapy to suppress the virus and reduce the risk of complications, including cirrhosis and liver cancer.

Hepatitis B remains a major public health challenge in Asia, including India, where prevention, vaccination, screening and access to treatment are important components of disease control.