Gene-editing therapy that works inside the body goes before the United States drug regulator

12 November 2026

Intellia Therapeutics, based at Cambridge in Massachusetts, has applied to the United States Food and Drug Administration for approval of lonvoguran ziclumeran, a CRISPR therapy for hereditary angioedema, a genetic disorder that causes episodes of swelling. The therapy edits the gene that produces prekallikrein, a liver-made protein that promotes leakage from blood vessels. It is given in vivo, meaning the editing happens inside the patient's body: fatty particles carrying messenger RNA for the CRISPR-Cas9 components are infused into the blood and taken up by the liver, in a procedure that takes one day. Earlier approved CRISPR treatments work ex vivo, with a patient's cells removed, edited outside the body and returned. The regulator has a decision date of 10 March. The Food and Drug Administration is the agency of the United States government that approves medicines there.