The FDA has accepted Intellia Therapeutics' biologics license application for lonvoguran ziclumeran (lonvo-z) and granted it priority review — a significant milestone not just for hereditary angioedema (HAE) treatment, but for gene-editing medicine as a whole. Lonvo-z is a one-time IV infusion that uses lipid nanoparticles to deliver CRISPR/Cas9 directly to liver cells, permanently disrupting the KLKB1 gene to reduce plasma prekallikrein — the key driver of HAE attacks. If approved, it would be the first in vivo CRISPR-based therapeutic to receive FDA authorization.

The application is backed by the phase 3 HAELO trial, which enrolled 80 patients aged 16 and older with HAE due to C1 inhibitor deficiency. Results were simultaneously published in The New England Journal of Medicine and presented at the 2026 EAACI Annual Congress.

By the Numbers:

• –87% reduction in monthly HAE attack rate (lonvo-z vs. placebo, weeks 5–28)
• 62% vs. 11% of patients remained attack-free in the lonvo-z vs. placebo groups
• 100% of lonvo-z recipients stayed long-term prophylaxis-free as of the data cutoff
• 0 serious adverse events or grade 3+ events in the lonvo-z group
• PDUFA target action date: March 10, 2027

Why it matters: Current HAE therapies require lifelong injections or daily oral dosing. Lonvo-z could eliminate that burden entirely — shifting the treatment goal from attack suppression to durable disease control. Experts caution that long-term safety, patient selection, and access and cost considerations will be critical as this therapy moves toward potential approval.