A new study presents promising interim results of a first-in-human phase 1/2 trial of NTLA-2002, an investigational therapy for patients with hereditary angioedema (HAE), noting that a single infusion of the new treatment has the goal of achieving life-long control of HAE attacks.

The study is published in the Annals of Allergy, Asthma, and Immunology.

The research team, headed by Hilary Longhurst, MD, of the University of Auckland in New Zealand, assessed the safety and tolerability of a single administration of NTLA-2002 at 3 doses, 25, 50, and 75 mg, in 3, 4, and 3 patients with HAE, respectively, over a period of16 weeks.

NTLA-2002 targets the KLKB1 gene encoding the protease kallikrein, which plays an important role in triggering the inflammatory mediators involved in acute HAE attacks. While most current prophylactic therapies directly target kallikrein and have been shown to reduce attack rates, they are extremely expensive and require ongoing administration.

Read more about HAE therapies

The concept behind NTLA-2002 is that by editing the KLKB1 gene that encodes kallikrein, it could be possible to achieve life-long prevention of HAE attacks with a single administration. If found to be safe and effective, the new therapy would represent a significantly more cost-effective treatment compared with the current prophylactic therapies.

The interim results found that at all 3 doses, the infusions led to a rapid and sustained drop in plasma kallikrein levels 1 month after the therapy, as well as a reduction or elimination of swelling episodes over the study period.

All patients received the full NTLA-2002 dose. Most of the treatment-emergent adverse events were mild to moderate, and no serious adverse events were reported. The results were presented at the annual American College of Allergy, Asthma & Immunology meeting from November 10 to 14 in Louisville, Kentucky.


Longhurst H, Fijen L, Lindsay K, et al. In vivo CRISPR/CAS9 editing of KLKB1 in patients with hereditary angioedema: a first in-human study. Ann Allergy Asthma Immunol. November 2022. doi:10.1016/j.anai.2022.08.536