A new experimental drug from Ionis Pharmaceuticals and GlaxoSmithKline has achieved what researchers call a functional cure in roughly 20% of chronic hepatitis B patients, marking the first significant treatment advance for the condition in decades. The medication, bepirovirsen, rendered the virus undetectable in patients 48 weeks after treatment concluded.

Chronic hepatitis B affects over one million Americans, who currently face lifelong antiviral treatment that fails to eliminate liver cancer risk. Unlike the acute form that most people recover from naturally, chronic infections embed in the liver and can cause cirrhosis and liver cancer. The 24-week trials involved 1,838 patients across 29 countries, with no cures observed among placebo recipients.

Dr. Anna S. Lok of University of Michigan Medical School called the results remarkable, though the studies excluded patients with cirrhosis or HIV. Ionis has filed for FDA approval with a decision expected by October 26. If approved, this could transform treatment for a disease that currently lacks curative options and represents a substantial market opportunity.

The breakthrough positions both pharmaceutical companies at the forefront of hepatitis treatment innovation, potentially generating billions in revenue while addressing a significant unmet medical need.