New drug shows promise for Hep B cure

• New drug bepirovirsen shows potential for hepatitis B functional cure
• About 20% of patients achieved viral suppression in international trials
• FDA fast-track review decision is expected in October 2024

Researchers have reported that a novel drug for hepatitis B allows some patients to discontinue treatment while maintaining undetectable levels of the

virus, potentially leading to what is termed a 'functional cure.' The findings emerged from two international studies presented on Thursday. Approximately 20% of patients receiving the experimental drug achieved significant viral suppression, enabling their immune systems to manage the virus effectively. The studies were led by Dr. Seng Gee Lim of the National University Health System of Singapore and funded by GSK.

Overview of the Drug and Studies

The drug, known as bepirovirsen, or 'bepi,' was developed by GSK and Ionis Pharmaceuticals and is currently undergoing fast-track review by the U.S. Food and Drug Administration, with a decision anticipated in October. The findings were also published in the New England Journal of Medicine on the same day.

Chronic hepatitis B poses severe health risks, including liver cancer and liver failure, claiming approximately 1.1 million lives globally each year. The research aims to improve upon existing lifelong therapies that are often difficult for patients to maintain or access.

Expert Insights and Future Research

Dr. Anna Lok, a hepatitis expert at the University of Michigan who was not involved in the research, acknowledged the significance of the findings but emphasized the necessity for further studies to determine the duration of this remission-like state.

The trials involved 1,838 patients who received either a bepi injection or a placebo weekly for six months, alongside their standard antiviral medications. Those whose virus levels remained undetectable for six months after halting the injections could also stop their regular treatments.

Mechanism of Action and Patient Outcomes

Bepi functions by targeting the genetic components of hepatitis B, inhibiting viral replication and a crucial surface protein, while also enhancing the immune response. GSK vice president Melanie Paff highlighted that patients with lower baseline levels of the S protein had a higher likelihood of achieving a functional cure.

Tracking from earlier studies indicates that most patients who achieved this functional cure maintained their health for up to three years. Reported side effects were mild, including temporary injection-site reactions and minor enzyme fluctuations indicative of liver stress.

Limitations of Current Research

Dr. Lok noted that the studies did not include participants with cirrhosis or other complicating health factors, which may limit the applicability of the findings. As research continues, understanding the response variability among patients remains a priority for further investigation.