'Epigenetic' editing is here: gene-tagging technique banishes hepatitis B virus

A wave of epigenetic therapies is offering hope as ways to cure chronic hepatitis B — a lingering liver infection that is caused by the hepatitis B virus (HBV) and affects more than 250 million people around the world. Currently available drugs often fail to eradicate the virus from the body.

Gene-editing therapies — which make cuts to the DNA strands — have been explored but for hepatitis B, they can increase cancer risks. Researchers are turning instead to epigenetic editing, which modifies markers attached to the DNA to alter how genes are turned on and off. 

Scientists working at the biotechnology firm nChroma Bio in Boston, Massachusetts, and at institutes in Milan, Italy, have now placed chemical tags onto the HBV genome to shut down its gene activity and prevent it from producing viral particles. They achieved promising results in experiments on human liver cells and in mice, and the therapy generated only minimal and temporary side effects when tested in monkeys. The study was published in Nature Biomedical Engineering on 21 September¹.

The efficacy of a...