Intellia Therapeutics, Inc. (Nasdaq: NTLA), a leading biopharmaceutical company focused on revolutionizing medicine leveraging CRISPR gene editing and other core technologies, today announced positive topline results from the global Phase 3 HAELO clinical trial of lonvo-z (formerly known as NTLA-2002) in hereditary angioedema (HAE). HAE is a rare genetic condition in which patients experience recurrent and potentially life-threatening swelling (angioedema) attacks in various parts of their body, including the face, upper airway, abdomen and extremities due to an overproduction of bradykinin. Designed as a one-time treatment that is administered in an outpatient setting, lonvo-z is an in vivo CRISPR gene editing candidate that is intended to inactivate the kallikrein B1 (KLKB1) gene to permanently lower kallikrein and bradykinin levels.

Intellia separately announced today that it has initiated a rolling BLA submission to the FDA to seek regulatory approval. The company is preparing for a potential U.S. launch of lonvo-z in the first half of 2027.

“As the first Phase 3 data reported for an in vivo gene editing therapy, today’s HAELO results represent a profound milestone for Intellia, the broader CRISPR and precision medicine fields and, most importantly, the HAE community,” said John Leonard, M.D., Intellia President and Chief Executive Officer. “For those patients who have spent years battling unpredictable breakthrough swelling attacks, anxiety about their next attack or the many burdens associated with chronic prophylactic treatment, lonvo-z represents a potential paradigm shift in treatment. These data affirm lonvo-z’s potential, with one dose, to offer prolonged freedom from both attacks and the need for ongoing therapy.”

“We extend our deep gratitude to the many patients, caregivers and clinicians who have helped advance gene editing science by participating in our clinical trials. It is because of their contribution that we are advancing toward our first potential approval, with the goal of making lonvo-z available to U.S. patients in the first half of 2027,” Dr. Leonard concluded.

HAELO Topline Results
HAELO is a randomized, double-blind, placebo-controlled Phase 3 trial designed to evaluate the efficacy and safety of a one-time 50 milligram dose of lonvo-z in adults and adolescents aged 16 years and older with Type I or Type II HAE. Key endpoints of the trial focused on the number of HAE attacks experienced by patients, quality of life, safety and tolerability.

A total of 80 patients were enrolled, with 52 receiving lonvo-z and 28 receiving placebo. Of the total population, 49% of patients were enrolled in the United States and 71% were on long-term prophylaxis (LTP) therapy at study entry. Patients on LTP were required to discontinue those therapies in the weeks prior to dosing.

Key findings from HAELO include:

• The trial met its primary endpoint. For the six-month efficacy evaluation period (weeks 5 to 28), a one-time infusion of lonvo-z reduced attacks by 87% versus placebo, with a mean monthly attack rate of 0.26 in the lonvo-z arm compared with 2.10 in the placebo arm (p<0.0001).
• The trial met all of its key secondary endpoints with statistical significance (p<0.0001). These included a 62% rate of patients who were entirely attack free and therapy free in the lonvo-z arm for the six-month efficacy evaluation period, compared with 11% of patients in the placebo arm.
• Favorable safety and tolerability data were observed for lonvo-z. The most common treatment emergent adverse events (TEAEs) during the primary observation period (infusion through week 28) were infusion-related reactions, headache and fatigue. All TEAEs reported as of the data cutoff (February 10, 2026) were mild or moderate and there were no serious adverse events observed in the lonvo-z arm.
• As of the data cutoff, all patients who received lonvo-z at baseline or in crossover after week 28 remained LTP free.

Additional clinical data from HAELO will be presented at the 2026 European Academy of Allergy and Clinical Immunology Congress (EAACI), taking place June 12-15 in Istanbul, Türkiye (abstract #100217).

“Despite the availability of several HAE treatments, many patients continue to experience significant burdens related to the disease, including breakthrough attacks and challenges associated with chronic treatment,” said Aleena Banerji, M.D., Professor at Harvard Medical School, Director of Clinical Care, Center for Drug and Vaccine Allergy at Massachusetts General Hospital, and a HAELO principal investigator. “The results we are seeing from lonvo-z demonstrate its potential to eliminate the need for chronic medication and related challenges. If approved as a one-time treatment, I would expect lonvo-z to be an appealing option for many patients.”

Intellia Therapeutics Initiates Rolling Submission of Biologics License Application to FDA for Lonvoguran Ziclumeran (lonvo-z) as a One-Time Treatment for Hereditary Angioedema

Intellia Therapeutics, Inc. (Nasdaq: NTLA), a leading biopharmaceutical company focused on revolutionizing medicine leveraging CRISPR gene editing and other core technologies, today announced it has initiated a rolling submission of a biologics license application (BLA) to the U.S. Food and Drug Administration (FDA) seeking approval of lonvo-z (formerly known as NTLA-2002) for hereditary angioedema (HAE). Designed as a one-time treatment that is administered in an outpatient setting, lonvo-z is an in vivo CRISPR gene editing candidate that is intended to inactivate the kallikrein B1 (KLKB1) gene to permanently lower kallikrein and bradykinin levels.

Intellia also separately announced positive topline data today from the Phase 3 HAELO clinical trial of lonvo-z in HAE. The trial met its primary and all key secondary endpoints, demonstrating that a one-time dose of lonvo-z led to freedom from both HAE attacks and the use of ongoing therapy for most patients during the six-month primary observation period.

“If approved, lonvo-z will become the world’s first in vivo CRISPR-based gene editing therapy,” said John Leonard, M.D., Intellia President and Chief Executive Officer. “The promising results from HAELO reinforce our conviction that lonvo-z could revolutionize how HAE is treated for many patients, with the potential to free most of them from both attacks and the need for ongoing therapy with just one dose. We look forward to our continued engagement with the FDA as we seek to ease many of the burdens for people living with HAE.”

Pursuant to the Regenerative Medicine Advanced Therapy (RMAT) designation that the FDA granted to lonvo-z for the treatment of HAE, a rolling BLA allows Intellia to submit portions of the BLA on an ongoing basis and provides the FDA with an opportunity to expedite its review. In addition to the RMAT program, Intellia participated in the FDA’s Chemistry, Manufacturing, and Controls (CMC) Development and Readiness Pilot. This program allows sponsors to discuss their CMC product development strategies and goals with FDA review staff and address their questions. The increased communication is intended to help sponsors complete CMC activities to expedite their drug development programs to support application submission and earlier patient access.

Intellia anticipates completing its BLA submission in the second half of 2026. If the filing is accepted by the FDA, the agency is expected to determine if it will grant a priority review and provide a target action date to complete its evaluation. If approved, Intellia plans to launch lonvo-z commercially in the first half of 2027.