The Cas9 protein together with RNA and DNA (orange; artist’s illustration). A new therapy uses the CRISPR-Cas9 gene editing system to treat a rare genetic disease called hereditary angioedema. Credit: Alfred Pasieka/Science Photo Library

A pioneering therapy that edits genes inside a recipient’s body continues to be effective four years after treatment, according to data released by its developer, Intellia Therapeutics.

The therapy, named lonvoguran ziclumeran (lonvo-z), was designed to treat one form of a genetic disorder that causes episodes of painful and potentially dangerous swelling in the throat and other parts of the body. Lonvo-z deploys the CRISPR-Cas9 gene-editing system to disable the gene that produces prekallikrein, a protein made in the liver that promotes blood-vessel leakage.

Bigger than CRISPR?…