Intellia Therapeutics (NTLA) Study result summary

Background and Disease Overview

• Hereditary angioedema (HAE) is a rare, genetic, and potentially fatal disorder caused by C1 inhibitor deficiency, leading to unpredictable, recurrent swelling attacks and significant patient and treatment burden.

• Chronic HAE medications are costly, with the U.S. healthcare system spending about $4 billion annually for approximately 7,000 treated patients, and cumulative costs reaching $19.1B over five years.

• Current treatments require lifelong management, with most patients experiencing breakthrough attacks and substantial financial and access burdens.

Investigational Therapy: Lonvo-z

• Lonvo-z is an in vivo CRISPR-based gene-editing therapy designed to permanently inactivate the KLKB1 gene, aiming for a one-time, outpatient-administered, potentially curative treatment.

• Administered as a single outpatient infusion over 2–4 hours, with a short pre-treatment regimen.

Study Design and Patient Population

• The phase III HAELO trial was a randomized, double-blind, placebo-controlled study enrolling 80 patients (52 lonvo-z, 28 placebo), diverse in age and geography, including those with type 1 or 2 HAE and varying levels of disease control.

• Patients discontinued long-term prophylaxis before randomization; about 70% were on LTP at entry, and the trial was well-balanced demographically.

• The primary endpoint was attack rate reduction from weeks 5 to 28 post-dosing, with secondary endpoints including attack-free status, severity, quality of life, and safety.