Intellia Therapeutics said on Jan 27 that the U.S. drug regulator has removed a clinical hold on one of its late-stage gene therapy trials, clearing the way for the company to restart testing of its experimental CRISPR-based treatment in patients with a rare nerve disease.
The company noted that the regulator lifted the pause on the trial of nexiguran ziclumeran in individuals with hereditary transthyretin amyloidosis with polyneuropathy, commonly abbreviated ATTRv-PN. Intellia said it plans to resume enrolling patients at the soonest opportunity.
Intellia described the therapy as a one-time infusion intended for patients in whom a misshapen protein accumulates in nerves and causes progressive damage. In premarket trading following the announcement, shares of the drug developer rose by more than 20%.
The regulator had placed two related studies on hold in October after a patient from an earlier dosing cohort experienced severe liver-related side effects. Intellia said it agreed with regulators on stronger safety monitoring measures, and those measures underpinned the agency’s decision to allow the nerve-disease study to proceed.
However, Intellia emphasized that a separate study of the same therapy in patients with cardiac involvement remains paused. The company is continuing discussions with the regulator on that cardiac program and will provide an update once the parties agree on a path forward.
Intellia also said it has expanded the nerve disease study’s enrollment target to approximately 60 patients, up from an initial goal of 50. The trial design will compare participants who receive the gene therapy against those assigned to a placebo control.
Context and implications
- The cleared trial focuses on ATTRv-PN, a hereditary condition where malformed protein deposits damage peripheral nerves.
- Regulatory agreement on enhanced safety monitoring allowed the nerve-disease trial to resume, while the cardiac-focused trial remains under regulatory review.
- The expanded enrollment and randomized, placebo-controlled design aim to support data collection across a larger patient cohort.
Intellia’s statement confined itself to the regulatory developments and operational steps the company will take next; it said it will restart enrollment and continue working with the regulator on the paused cardiac study. The company’s disclosure of prior severe liver-related side effects and the agreed safety measures were central to the regulator’s decision to lift the hold on the nerve-disease trial.