Intellia Therapeutics says four-year follow-up of its one-dose CRISPR treatment for hereditary angioedema showed lasting reductions in attacks and that patients in a small early-stage study were free of preventive medication.
The update was presented at the American College of Allergy, Asthma & Immunology meeting on November 14. It concerns lonvoguran ziclumeran, or lonvo-z. The treatment is designed to switch off a liver gene involved in making kallikrein, a protein linked to swelling attacks.
In the 32-person Phase 1/2 study, at least 90% of participants were attack-free in each month after the first year, with follow-up extending to four years. Intellia also reported that all participants who received the 50-milligram dose were no longer taking long-term preventive treatment at the latest data cutoffs. The company said kallikrein levels fell by an average of 84% four weeks after treatment.
It said the reduction continued through follow-up. A previously reported analysis found that 31 of the 32 participants were both attack-free and off preventive medication at their last assessment. That analysis included follow-up of up to three years.
The four-year findings are encouraging. But they come from a small early-stage group. They do not establish how well the treatment will work or how safe it will be over the long term for a broader population.