Intellia’s Gene-Edited Therapy for HAE Shows Durable Efficacy, Paving Way for 2027 U.S. Launch

CAMBRIDGE, Mass. – June 15, 2025 – Intellia Therapeutics, Inc. (NASDAQ: NTLA) announced compelling three-year follow-up data from the Phase 1 portion of its ongoing Phase 1/2 study of lonvoguran ziclumeran (lonvo-z, also known as NTLA-2002), a CRISPR-based gene editing therapy for hereditary angioedema (HAE). The results, presented at the European Academy of Allergy and Clinical Immunology (EAACI) Congress 2025, highlight the potential for a one-time treatment to provide lasting relief for patients.

“Today’s results underscore the promising potential of Intellia’s approach to gene editing therapy – a one-time treatment that was well tolerated and offered a highly differentiated, durable effect for patients suffering from a serious disease,” said Intellia President and Chief Executive Officer John Leonard, M.D. “Seeing all 10 patients in the Phase 1 portion of this study free from both HAE attacks and chronic therapy at nearly two years of median follow-up is incredibly encouraging.”

Sustained Attack Reduction and Favorable Safety

A single intravenous dose of lonvo-z (25 mg, 50 mg, or 75 mg) led to a mean reduction in monthly HAE attack rate of 98% over the study period, compared to pre-treatment baseline. All 10 patients in the Phase 1 cohort were attack-free and treatment-free for a median of nearly two years at the data cutoff. The therapy also achieved deep, dose-dependent, and durable reductions in plasma kallikrein protein levels through the latest assessment.

Lonvo-z demonstrated a favorable safety profile, consistent with earlier data. The most frequent adverse events were infusion-related reactions, which were mostly Grade 1 and resolved without complication. No treatment-emergent serious adverse events were observed, and no treatment-related adverse events occurred after 28 days post-dosing, with up to three years of follow-up.

Advancing Towards Commercialization

Intellia’s global Phase 3, randomized, double-blind, placebo-controlled HAELO trial for lonvo-z at the 50 mg dosage has successfully completed patient screening ahead of schedule. The company expects to report top-line results from this pivotal study in the first half of 2026.

Based on these promising results and the expedited development, Intellia plans to submit a Biologics License Application (BLA) in 2026, with an aim for a U.S. launch in 2027. Lonvo-z, which utilizes Nobel Prize-winning CRISPR/Cas9 technology, is designed to prevent HAE attacks by inactivating the KLKB1 gene. It has already received several key regulatory designations, including Orphan Drug and RMAT Designation by the FDA.