The brief
- Phase 3 (Apr 2026): lonvo-z cut swelling attacks 87% vs placebo; 62% had none. Filing with the FDA for a 2027 launch.
- Oct 2025: a patient had severe liver injury and later died; the FDA paused nex-z trials. They restarted in 2026 with more liver checks.
- In Jan 2025 Intellia dropped outside-the-body editing and cut staff to focus on its two liver drugs.
Technical approach
A short-lived editor
Intellia sends temporary mRNA instructions instead of a permanent gene, so the editor exists only for days, limiting stray edits.
Fat bubbles that find the liver
Lipid nanoparticles naturally end up in liver cells, which is why the liver is the first organ where in-body CRISPR works.
Permanent gene silencing
The cut breaks the target gene (TTR for nex-z, KLKB1 for lonvo-z). Liver cells live long, so one dose aims to work for years.
A blood test shows it worked
Levels of the target protein in the blood drop, showing how well the edit worked long before symptoms change.
Intellia Therapeutics, two programs
Updated 8 Sep 2026
Research & demos
- Jun 2026paperHAELO Phase 3 results for lonvo-z (NEJM, presented at EAACI 2026) (opens doi.org)Lonvo-z (NTLA-2002)
First successful Phase 3 trial of an in-body gene-editing drug.
- Oct 2024paperCRISPR-based therapy for hereditary angioedema, Phase 2 (NEJM) (opens doi.org)Lonvo-z (NTLA-2002)
Controlled trial showing one dose of lonvo-z cut attacks vs placebo.
- Jun 2021paperCRISPR-Cas9 in vivo gene editing for transthyretin amyloidosis (NEJM) (opens doi.org)Nex-z (NTLA-2001)
First proof CRISPR can edit a gene inside the human body: the target protein fell 87% on average.
Open technical problems
- Liver safety of LNP editingActive research
Mild liver stress after dosing is common; the 2025 case showed rare severe reactions can happen, especially in sicker heart patients.
- One shot vs. existing drugsOpen
Both diseases already have good ongoing drugs, so a permanent edit must prove it's safe over many years.
- Beyond knockouts in the liverOpen
Reaching organs other than the liver, and fixing genes instead of just switching them off, are still unsolved.
Upcoming catalysts
- 2027Planned US launch of lonvo-zLonvo-z (NTLA-2002)by ~15 mo
- 10 Mar2027FDA decision date (PDUFA) for lonvo-z in hereditary angioedemaLonvo-z (NTLA-2002)in ~5 mo
Peers
Company & funding
- Listed
- NTLA (opens google.com)NASDAQ
- HQ
- US
- Founded
- 2014
Partners & customers
- Partner
Co-develops nex-z for ATTR amyloidosis.