Intellia Therapeutics filed a rolling biologics license application for lonvo-z Monday, backed by Phase 3 data showing an 87% reduction in hereditary angioedema attacks versus placebo.
The HAELO study enrolled 80 patients with HAE over a six-month evaluation period. Patients on lonvo-z saw 87% fewer disease attacks, and 62% were completely attack-free. Only 11% of placebo patients were free of attacks over that stretch. Leerink Partners said the readout “clears the path for Intellia’s transition to a commercial company” and positions lonvo-z to disrupt the HAE market with a “functional cure.”
It’s also a first: HAELO is the industry’s first Phase 3 study of an in vivo CRISPR-based gene editor to deliver positive outcomes. Safety held up, too.
That matters because lonvo-z’s sister asset, nex-z, triggered an FDA clinical hold in October 2025 after a patient in transthyretin amyloidosis trials developed grade 4 liver enzyme elevations and died. Lonvo-z showed no serious adverse events and no liver toxicity. The FDA lifted the hold on nex-z last month, but William Blair flagged design similarities between the two programs as a concern.
Lonvo-z reduces kallikrein protein levels, disrupting the cascade that drives severe, recurrent inflammation in HAE patients. HAE affects roughly 1 in 50,000 people worldwide and can’t currently be cured, only managed chronically. Intellia says lonvo-z is designed as a one-time treatment.
Intellia expects to complete the BLA package this year. If cleared, lonvo-z would become the world’s first in vivo CRISPR-based gene editing therapy, with a potential launch in the first half of 2027.
Intellia stock was up 4.2% to $14.20 before Monday’s open.
— Sarah Chen