Intellia Therapeutics

To evaluate the efficacy and safety of a single dose of NTLA-2001 compared to placebo in participants with ATTR-CM.

Participants in this study have a genetic mutation, specifically in the coagulation (blood clotting) Factor 9 gene that causes severe or moderately severe hemophilia B. This study is researching an experimental gene insertion therapy (the adding of a gene into your DNA) called REGV131-LNP1265, also called the "study drug". Gene insertion therapy aims to teach the body how to produce clotting factor long-term, without the need for factor replacement therapy. The main aim of this study is to find a safe and well-tolerated dose of the study drug by checking the side effects that may happen from taking it, both in the near term and over time. The study is looking at several other research questions including: * How much study drug is in the blood at different times * Whether the body makes antibodies against parts of the study drug, which could make the drug less effective or could lead to side effects. Antibodies are proteins produced by the body's immune system in response to a foreign substance * Whether the body makes antibodies against the clotting factor replacement therapy * How often factor replacement therapy is needed, both on a regular basis for prevention of bleeding, and as needed to treat bleeding events (and it if changes after taking study drug) * Whether there is a difference in 2 different methods for measuring Factor 9 activity in the bloodShow more

This Phase 3 study aims to evaluate the efficacy and safety of NTLA-2002 compared to placebo in participants with HAE.

This study will be conducted to evaluate the safety, tolerability, activity, pharmacokinetics, and pharmacodynamics of NTLA-2002 in adults with Hereditary Angioedema (HAE).

Intellia Therapeutics is a Cambridge, Massachusetts biotech that bet on a deceptively simple idea: what if the body could be edited once, and the disease could be fixed permanently? Founded in 2014 and publicly traded on the NASDAQ under the ticker NTLA, Intellia develops in vivo CRISPR gene-editing therapies, designed as one-time IV infusions that travel to a target organ (typically the liver) and edit a specific gene directly inside the body. Most rare disease therapies have to be taken regularly for life, but a gene-edited treatment, in theory, can be administered once and continue to work indefinitely.

The company's biggest moment to date came on April 27, 2026, when Intellia reported positive Phase 3 results from the HAELO trial of lonvoguran ziclumeran (lonvo-z, formerly NTLA-2002) for hereditary angioedema (HAE), a rare genetic disorder where patients suffer unpredictable swelling attacks that can close the airway. Lonvo-z works by editing the KLKB1 gene in the liver to lower production of kallikrein and bradykinin, the proteins responsible for triggering HAE attacks. A single dose of lonvo-z reduced HAE attacks by 87% versus placebo over the 6-month evaluation period, and 62% of treated patients were both attack-free and therapy-free during that window compared to 11% of placebo patients. The trial met its primary endpoint and all key secondary endpoints, and was the first Phase 3 readout for any in vivo gene-editing therapy in any disease. Intellia completed its BLA submission, and on September 8, 2026, the FDA accepted the application and granted it Priority Review with a target action date of March 10, 2027. The FDA has also indicated it does not currently plan to hold an advisory committee meeting to discuss the application. If approved, lonvo-z would be the first in vivo CRISPR-based therapy approved anywhere in the world.

The company's other late-stage program has had a much more difficult arc. Nexiguran ziclumeran (nex-z, formerly NTLA-2001) is a one-time CRISPR therapy that edits the TTR gene in the liver to treat ATTR amyloidosis, a rare disease where misfolded TTR protein accumulates in the heart and nerves. Nex-z is being studied in MAGNITUDE for the cardiomyopathy form of the disease and MAGNITUDE-2 for the polyneuropathy form. In late 2025, the FDA placed both trials on clinical hold after a Grade 4 liver adverse event in the cardiomyopathy study led to a participant's death on November 5, 2025. The FDA lifted the hold on MAGNITUDE-2 on January 27, 2026, with enhanced liver monitoring, and lifted the hold on MAGNITUDE for cardiomyopathy on March 2, 2026.

Earlier programs in Intellia's pipeline include in vivo CRISPR approaches to hemophilia B and alpha-1 antitrypsin deficiency, alongside ex vivo edited cell therapies for autoimmune disease. The thesis remains as it was at founding. If a single gene change drives a disease, edit it once at the source and free the patient from a lifetime of repeated treatment.

None as of November 2026. Intellia Therapeutics has no FDA-approved drug yet; the FDA is reviewing its most advanced program.

Most advanced: Lonvoguran ziclumeran (under FDA review).

Where to watch: the FDA calendar lists any Intellia Therapeutics application once a decision date is public, and the trials list on this page shows what is recruiting now.