Intellia reports additional results for in vivo gene editing therapy in HAE trial

Intellia Therapeutics has published the full dataset from its phase 3 HAELO trial of its in vivo CRISPR gene editing candidate, lonvo-z, in hereditary angioedema (HAE).

Presented last week at EAACI 2026 in Istanbul and simultaneously published in the New England Journal of Medicine, the data confirm what Intellia announced at topline in April: A single infusion of lonvo-z reduced mean monthly HAE attacks by 87% versus placebo over the six-month efficacy evaluation period.

In addition, among the secondary endpoints, 62% of lonvo-z patients were entirely attack-free and off all prophylactic therapy for the full six months, compared with 11% in the placebo arm. There were no serious adverse events in the treatment arm; most common TEAEs were infusion reactions, headache and fatigue, all grade 1-2.

Designed as a one-time treatment that is administered in an outpatient setting, lonvo-z is intended to inactivate the kallikrein B1 (KLKB1) gene to permanently lower kallikrein and bradykinin levels. HAE is a rare genetic condition in which patients experience recurrent and potentially life-threatening swelling attacks in various parts of their body due to an overproduction of bradykinin.

Intellia initiated a rolling BLA submission in April under its RMAT designation and is targeting a U.S. launch in the first half of 2027.