Seattle biotech aims to cure hep B with breakthrough gene therapy

Driving the news: Following promising preclinical trials, Tune expects to bring the drug, Tune-401, to clinical trials by the end of the year, executive team members Blythe Sather and Heidi Zhang told Axios in an email.

The big picture: In the United States, up to 2.4 million people are living with chronic hepatitis B, with certain groups, especially those of Asian, Pacific Islander and African descent, disproportionately affected, according to the Hepatitis B Foundation.

• The opioid crisis has further fueled a surge in acute HBV infections across impacted states, with rates climbing as much as 450%, per the foundation.
• Spread through contact with infected blood and body fluids, hepatitis B infects an estimated one in three people worldwide.

Catch up quick: Epigenetics — the "editing" or regulation of gene expression through chemical modifications, like DNA methylation or histone modification — is emerging as a powerful tool in the fight against diseases and genetic conditions.

How it works: HBV can persist in liver cells for years by embedding its genes into human chromosomes, creating free-floating loops of DNA that act as "viral factories", per Sather and Zhang.

• The new drug uses lipid nanoparticles to deliver a molecule directly to liver cells, where it's converted into an epigenetic-silencing protein that adds methyl groups to the viral DNA.
• That effectively turns off viral genes without damaging human DNA.

What they're saying: A cure for hepatitis B would transform the lives of millions and free future generations from "a virus that has plagued humanity for millennia," Sather said.