Intellia Raises Stakes in HAE Dosing with Durable One-Time Treatment

The treatment landscape for hereditary angioedema (HAE) is evolving rapidly, with Intellia Therapeutics making significant strides in gene-editing solutions. Intellia's latest data reveal that a single dose of their candidate therapy, NTLA-2002, results in a substantial and durable reduction in HAE attacks, setting the stage for a potential one-time treatment option.

At the 2024 European Academy of Allergy and Clinical Immunology Annual Congress in Valencia, Spain, Intellia presented impressive results for NTLA-2002. The data showed a 98% average reduction in monthly HAE attack rates and a 99% average decrease in moderate to severe attacks after just one dose. These results were derived from an in vivo CRISPR-based gene-editing approach.

Patients observed a 90% reduction in attacks from the first week of treatment up to the 16th week. This reduction increased to 92% from weeks five to 16 and reached 98% during the overall study period. These findings are consistent with previous results from 10 patients presented at the same conference last year, which reported a 95% reduction in monthly attack rates.

Notably, eight out of 10 patients remained free of attacks after the 16-week observation period, with the latest follow-up data extending to February of this year. On average, patients have been followed for 20 months. Importantly, none of the patients who discontinued their prophylactic treatments after receiving NTLA-2002 needed to resume them.

John Leonard, CEO of Intellia, expressed his excitement over the results, stating, "We are thrilled to see that the majority of patients have been attack-free for over 18 months or longer. These remarkable attack rate reductions have been consistent, even in patients with the most severe symptoms."

Regarding safety, NTLA-2002 was generally well tolerated. Most adverse events were mild, primarily involving infusion-related reactions and fatigue. There were no reports of dose-limiting toxicities, serious adverse events, or grade 3 or higher adverse events.

Intellia's promising data came shortly after Ionis Pharmaceuticals released information on their RNA-targeting prophylactic therapy donidalorsen. Ionis reported that donidalorsen led to an 81% reduction in the monthly rate of swelling attacks in patients who received the drug every four weeks. Analysts from William Blair have praised donidalorsen's competitive profile, noting that it might have an advantage over CSL Behring's garadacimab, which requires more frequent injections and an initial in-office loading dose.

With Intellia demonstrating the potential for a one-time treatment option with NTLA-2002, the competitive landscape for HAE treatments is heating up. The ability to provide a durable, single-dose solution could significantly impact the standard of care for patients suffering from this debilitating condition.