UniQure's Huntington's Disease Gene Therapy Gets FDA Priority Review

UniQure's Huntington's disease gene therapy application has been accepted for priority review by the U.S. Food and Drug Administration, with a target decision date of May 1, 2026. The therapy, ifezuntirgene inilparvovec, also known as AMT-130, has received Breakthrough Therapy, Regenerative Medicine Advanced Therapy, and Fast Track designations from the agency.

The submission is based on data from a Phase 1/2 trial. That study showed a 75% slowing of disease progression after 36 months in patients receiving a high dose. The FDA had previously required a sham-controlled Phase 3 study before an application could be submitted, but later accepted the filing. The agency is tentatively planning to discuss the application at a future advisory committee meeting, likely the Cellular, Tissue, and Gene Therapies Advisory Committee.

UniQure's chief executive officer, Matt Kapusta, called the FDA's acceptance of the application an important milestone for the Huntington's disease community. The therapy is designed for a rare, fatal, inherited neurodegenerative disorder that causes motor symptoms, behavioral abnormalities, and cognitive decline. If approved, it would be the first treatment shown to modify the course of the disease.

Clinical trial design and endpoints

A confirmatory study is required as part of the regulatory process. This trial will be a randomized, standard-of-care controlled study enrolling approximately 200 patients. Participants will be assigned in a 2:1 ratio, with more patients receiving the gene therapy than standard care.

The primary endpoint will be a measurement of Total Functional Capacity at 36 months. Patient screening in the United States for this confirmatory trial is planned to begin by the end of 2026. To date, 51 patients have been dosed with ifezuntirgene inilparvovec across two clinical trials.

The gene therapy uses a microRNA designed to silence the huntingtin gene. It is administered in a single procedure using MRI-guided, convection-enhanced stereotactic neurosurgical delivery directly into a region of the brain called the striatum.

Analyst expectations and market potential

Wall Street analysts view the regulatory update positively. They see it as a key step for the first potential disease-modifying treatment for Huntington's. Analyst Joseph Thome of TD Cowen expects key physicians to adopt the therapy following a potential approval. He currently models annual sales reaching $1.6 billion in 2039.

Other analysts agreed the BLA acceptance was a positive sign. Stifel analysts viewed it as supportive of an accelerated approval pathway. William Blair analysts described the announcement as an incremental positive. Analyst Lachlan Hanbury-Brown stated the acceptance removes a degree of regulatory risk for the therapy.

In separate pharmaceutical development news, Teva Pharmaceuticals discontinued a mid-stage trial of its multiple system atrophy drug, emrusolmin. The study was halted after an interim data check met predefined criteria for futility, indicating a lack of efficacy. The pill was developed by Teva in collaboration with Modag GmbH. Analyst Dennis Ding called the outcome disappointing but noted it was not core to the investment thesis for Teva.

Patient screening in the United States will begin by the end of 2026.