CAMBRIDGE, Mass. — September 8, 2026
Intellia Therapeutics announced that the U.S. Food and Drug Administration (FDA) has accepted the Biologics License Application (BLA) for lonvoguran ziclumeran (lonvo-z) for hereditary angioedema (HAE) and granted Priority Review, with a PDUFA target action date of March 10, 2027. The FDA has also advised that it is not currently planning an advisory committee meeting for the application. The regulatory milestone advances lonvo-z toward a potential U.S. approval and represents an important step for Intellia’s in vivo CRISPR gene-editing platform. If approved, lonvo-z could become the world’s first approved in vivo CRISPR-based therapy and the first one-time treatment for HAE. The BLA is supported by data from the global Phase 3 HAELO trial, positioning the program at a significant regulatory stage as Intellia continues its efforts to develop potentially durable treatments that address the underlying genetic drivers of serious disease.
Phase 3 HAELO Data Support Regulatory Application
The FDA submission is supported by positive Phase 3 HAELO results evaluating a single 50 mg dose of lonvo-z in adults and adolescents aged 16 years and older with Type 1 or Type 2 HAE. The study enrolled 80 participants and met its primary and all key secondary endpoints. During the efficacy evaluation period from weeks 5 through 28, lonvo-z demonstrated an 87% reduction in mean monthly HAE attacks compared with placebo (p<0.0001). In addition, 62% of patients receiving lonvo-z were completely attack-free and free from HAE therapy during the six-month efficacy evaluation period, compared with 11% of patients receiving placebo. Intellia reported that, as of the February 10, 2026 data cutoff, patients who received lonvo-z at baseline or following crossover after week 28 remained free from long-term prophylaxis therapy. These findings provide the principal clinical evidence supporting the regulatory review while highlighting the potential of a one-time genetic medicine to reduce the need for ongoing preventive treatment in HAE.
Lonvo-z Advances One-Time CRISPR Treatment Strategy
Lonvo-z is an investigational in vivo CRISPR/Cas9 gene-editing therapy designed to permanently reduce kallikrein production by inactivating the KLKB1 gene with a single dose. Unlike conventional HAE management approaches that generally require ongoing preventive or on-demand treatment, the program is designed around a one-time outpatient administration intended to provide durable pathway suppression. Intellia’s approach focuses on directly modifying the genetic target responsible for kallikrein production rather than relying on repeated administration of medicines to maintain suppression. The company has received several regulatory designations for lonvo-z, including FDA Orphan Drug and Regenerative Medicine Advanced Therapy (RMAT) designations, as well as Innovation Passport, PRIME and European Orphan Drug designations. The regulatory profile underscores the potential significance of the program as Intellia advances its broader strategy of developing CRISPR-based medicines designed to address disease at its genetic source.
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FDA Review Marks Key Milestone for Intellia
The FDA’s Priority Review places lonvo-z on a defined regulatory path toward the March 10, 2027 PDUFA date, making the program one of the most closely watched clinical-stage applications in the emerging field of in vivo gene editing. HAE is a rare genetic disorder characterized by recurrent, unpredictable and potentially life-threatening swelling attacks, while current preventive approaches can require chronic intravenous, subcutaneous or oral treatment. The HAELO findings therefore provide an important clinical foundation for Intellia’s regulatory strategy, although FDA acceptance and Priority Review do not guarantee approval. If the application receives authorization, lonvo-z could establish a new treatment model for HAE while marking a major regulatory milestone for in vivo CRISPR technology. For Intellia, the BLA acceptance, Priority Review and planned 2027 regulatory decision represent critical steps in translating its gene-editing platform from clinical development toward potential commercial use in a serious genetic disease.
Source: Intellia Therapeutics press release
