A treatment using the CRISPR genome editing technology has succeeded in alleviating swelling caused by hereditary angioedema (HAE), a genetic disease, according to new data published by the Intellia Therapeutics company.
The data was presented at the 2022 Bradykinin Symposium in Berlin, Germany on Friday.
HAE patients suffer from recurring attacks which cause swelling of tissues in the hands, feet, limbs, face, intestinal tract or airway. This swelling can be debilitating and even fatal.
The treatment, called NTLA-2002, was intravenously infused into six patients, three of whom received a 25 mg dose and three of whom received a 75 mg dose.
The treatment works by entering the bloodstream and being guided to the liver, where it knocks out the KLKB1 gene which is responsible for producing kallikrein, an enzyme that produces bradykinin, a peptide responsible for the swelling attacks that HAE patients suffer from.
The interim results of the ongoing clinical study show that patients who received the 25 mg dose had their levels of kallikrein reduced by 65% on average after eight weeks, with the reduction continuing through at least 16 weeks. Patients who received the 75 mg dose had their levels reduced by 92% on average after eight weeks.
Additionally, swelling attack rates decreased on average by 91% throughout the 16-week observation period for the 25 mg patients. Two of the three patients have not had any HAE attacks since receiving treatment and all three were attack free since week 10. Patients in the 75 mg group had not yet completed the 16-week observation period when this data was published, with the data on that cohort set to be presented at the American College of Allergy, Asthma & Immunology (ACAAI) Annual Scientific Meeting in November.
Two of the three 25 mg patients were receiving medicine for their condition before the trial began and after the observation period, they were taken off the drugs and have not suffered an HAE attack since.
'A significant milestone'
“These initial data represent a significant milestone for both Intellia and people around the world suffering from genetic diseases, such as HAE,” said Intellia President and Chief Executive Officer John Leonard, M.D. in a press release.
“We are strongly encouraged by the greater than 90% reduction in HAE attacks observed in the 25 mg dose cohort, as these interim results support our belief that a single dose of NTLA-2002 has the potential to permanently prevent the debilitating swelling attacks associated with HAE."
"Additionally, today’s announcement continues to validate our genome editing approach and the modular platform we have built. This is now the second time in history clinical data have been generated suggesting we can precisely edit target cells within the human body to potentially treat genetic diseases with a single, systemic administration of a CRISPR-based therapy. We plan to move as quickly and judiciously as possible on behalf of people living with HAE and a number of additional genetic diseases in the months and years ahead.”
The majority of adverse effects reported during the trial were mild in severity and reactions related to the infusion. No serious adverse events were recorded.
“Many people living with HAE continue to experience breakthrough attacks despite currently available treatments and often find the burden of untreated attacks, frequent infusions or injections to be tremendously disruptive to their lives,” said Hilary Longhurst, M.D., Ph.D., Faculty of Medical and Health Sciences, University of Auckland, New Zealand, and the trial’s principal investigator in New Zealand. “These early data support NTLA-2002 as a potential one-time treatment capable of producing profound reductions in HAE attacks. While the clinical data are still emerging, I am highly optimistic that NTLA-2002 could become a new treatment option for the HAE community.”
Intellia Therapeutics will also evaluate a third dose of 50 mg in the ongoing study and will further evaluate two doses in Phase 2 of the study, which is expected to begin in the first half of 2023.
How CRISPR works
CRISPR technology works by using short RNA sequences to guide a CRISPR system to matching sequences of DNA, where Cas9, an enzyme produced by CRISPR, cuts and shuts the targeted gene off. The technology can also be used to activate gene expression instead.