Intellia Therapeutics Inc. (NASDAQ:NTLA) declined 3% on Monday, reversing earlier gains that followed the release of positive Phase 3 results for its hereditary angioedema (HAE) therapy. The data marks the first global Phase 3 outcome for an in vivo gene editing treatment.
The company said its Phase 3 HAELO trial evaluating lonvoguran ziclumeran (lonvo-z) achieved its primary endpoint along with all key secondary endpoints. Results showed that a single dose reduced HAE attack rates by 87% compared to placebo over six months, with patients experiencing a mean monthly attack rate of 0.26 versus 2.10 in the placebo group.
Trial Results Highlight Durable Efficacy
The study included 80 participants, with 52 receiving lonvo-z and 28 assigned to placebo. According to Intellia, most treated patients remained free from both HAE attacks and the need for ongoing therapy throughout the six-month evaluation period. Additionally, all individuals in the treatment group remained off long-term prophylaxis as of the February 10 data cutoff.
Regulatory Pathway and Potential Launch Timeline
Intellia has begun a rolling biologics license application submission to the U.S. Food and Drug Administration and is targeting a potential U.S. launch in the first half of 2027, pending approval. The therapy is designed as a one-time outpatient treatment that disables the KLKB1 gene, leading to sustained reductions in kallikrein and bradykinin levels.
Safety Profile and Upcoming Data Presentation
The trial also demonstrated a favorable safety and tolerability profile. The most commonly reported treatment-emergent adverse events included infusion-related reactions, headache, and fatigue. All recorded events were mild to moderate in severity, and no serious adverse events were observed in the lonvo-z group as of the data cutoff.
Further findings from the HAELO study are expected to be presented at the European Academy of Allergy and Clinical Immunology Congress 2026 in June.
More about Intellia Therapeutics Inc.
Intellia Therapeutics Inc. is a clinical-stage biotechnology company focused on developing CRISPR-based gene editing therapies designed to treat genetic diseases through in vivo and ex vivo approaches.