Simple explanation
People with hereditary angioedema get sudden, dangerous swelling attacks and must take medication indefinitely to prevent them. Lonvo-z is a single infusion that switches off a liver gene in the chain of events that causes the attacks. In its Phase 3 trial it reduced attacks, and the company has said it will apply for approval in the second half of 2026.
Go deeper
Lonvoguran ziclumeran is a lipid-nanoparticle CRISPR-Cas9 therapy knocking out hepatic KLKB1 (prekallikrein) to reduce bradykinin generation in hereditary angioedema. Intellia reported positive results from the global Phase 3 HAELO study — described as the first positive Phase 3 readout for an in vivo gene-editing therapy — with enrolment complete and a biologics licence application signalled for the second half of 2026 and an anticipated US launch in the first half of 2027.
Why this programme matters to the whole field
Every in vivo editing company is watching this file. It will be the first test of how regulators evaluate a one-time, permanent, systemically delivered gene edit for approval — what long-term follow-up they require, how they weigh irreversibility, and what evidence of durability satisfies them. The precedent set here will shape programmes in diseases nobody has started yet.