Intellia Therapeutics has announced positive Phase II data for its CRISPR-based therapy, NTLA-2002, showing a substantial decrease in monthly attack rates for individuals with hereditary angioedema (HAE). The trial results, presented at the 2024 Scientific Meeting of the American College of Allergy, Asthma & Immunology, indicate a potential paradigm shift in HAE treatment.
NTLA-2002 Efficacy in HAE Attack Reduction
The Phase II study evaluated NTLA-2002 at doses of 25-mg and 50-mg. The 50-mg dose led to an 81% reduction in monthly HAE attack rates from weeks five through 16. Extending the observation period to weeks one through 16, the 25-mg and 50-mg doses resulted in a 75% and 77% decrease in attack rate, respectively. Notably, eight out of eleven patients in the 50-mg group achieved a complete response, experiencing no attacks during the 16-week observation period. This complete response was sustained in these eight patients through the latest follow-up, with a median duration of eight months.
Safety and Tolerability Profile
NTLA-2002 demonstrated a favorable safety profile in the Phase II trial. The most common adverse events reported were headaches, fatigue, and nasopharyngitis. There were no serious treatment-related toxicities observed, with the exception of one patient in the placebo group who experienced grade 4 tongue edema. No clinically significant laboratory abnormalities were reported.
Expert Commentary and Market Reaction
Intellia CEO John Leonard expressed enthusiasm about the results, stating that they "underscore the tremendous potential of our in vivo CRISPR gene editing therapy to be a functional cure" for HAE. He added that NTLA-2002 could "redefine the treatment paradigm" for this condition. The company is advancing the 50-mg dose into a Phase III study (HEALO), which is currently screening patients.
Despite the positive data, Intellia's stock experienced a decline following the announcement. Jefferies analyst Maury Raycroft attributed this to an overreaction from investors who had anticipated even greater attack rate reductions based on earlier Phase I data. Truist Securities analyst Joon Lee noted the competitive landscape, citing potentially superior data from Pharvaris' oral daily pill, which demonstrated a 93% reduction in monthly attack rates. William Blair analyst Myles Minter acknowledged the competitive pressures but emphasized the "impressive magnitude of response when achieved" with NTLA-2002.
Implications for HAE Treatment
Hereditary angioedema is a rare genetic disorder characterized by recurrent episodes of severe swelling. Current treatments often involve chronic therapies to manage symptoms. NTLA-2002 offers the potential for a one-time treatment, providing a functional cure for HAE. The ongoing Phase III HEALO study will further evaluate the efficacy and safety of NTLA-2002, with the aim of providing a new treatment option for individuals with HAE.
