FDA sets May 2027 decision date for one-time Huntington's gene therapy

US regulators have formally taken up uniQure’s request to approve its one-time gene therapy for Huntington’s disease. The company said on November 2, 2026, that the US Food and Drug Administration (FDA) accepted its application for review, granted it priority review, a faster review track, and set a target date of May 1, 2027, to make a decision¹.

This is the next step after the company asked US and UK regulators to approve the therapy, which Biohack covered in early September, followed by the company’s longer-term results later that month. What is new now is that the FDA has agreed the filing is ready to be reviewed and has put a date on its answer.

What happened

The therapy is known in the lab as AMT-130, with the generic name ifezuntirgene inilparvovec¹. uniQure submitted it under the FDA’s Accelerated Approval pathway, a route that depends on a later “confirmatory” trial to check that the benefit holds up¹. The FDA granted priority review and set the target action date of May 1, 2027¹.

The company also said the FDA’s acceptance letter stated the agency is tentatively planning to discuss the application at an Advisory Committee meeting, where outside experts weigh in on the evidence¹. uniQure said it will be told the date once it is set¹.

uniQure said that if approved, the therapy would be the world’s first treatment that changes the course of Huntington’s disease, rather than easing symptoms¹. That is the company’s description of what approval would mean, not a finding by the FDA.

“The FDA’s acceptance of our BLA for review marks an important milestone for the Huntington’s disease community, which has waited generations for a treatment that changes the course of this devastating disease,” stated Matt Kapusta, chief executive officer of uniQure.

The quote is from the company’s announcement¹.

The therapy and the disease

Huntington’s disease is a rare, inherited brain disease that causes uncontrolled movements, changes in behavior and a decline in thinking, getting worse over time¹. It is caused by a faulty stretch of the huntingtin gene, which leads the brain to make and clump an abnormal protein¹. A child of an affected parent can inherit it from just one copy of the gene¹. The company puts the number of people with the disease in the US, EU and UK at about 75,000¹.

The therapy is designed to quiet the huntingtin gene. It carries a small genetic instruction, a type of molecule called a microRNA, meant to switch down the gene and a particularly harmful fragment of the protein it makes¹. It is given once, through brain surgery guided by MRI scans, directly into a deep brain area called the striatum, made up of the caudate and putamen¹.

The evidence behind the application

The application rests on three-year results from the company’s early-stage studies, which combine the first tests of safety with an early look at whether a treatment helps¹. In those results, treated patients were compared with an “external control”: similar untreated people picked from Enroll-HD, a long-running database that tracks how Huntington’s naturally progresses¹. A statistical method called propensity score matching was used to choose untreated people who resembled the treated ones¹. The company first announced this analysis on September 24, 2025¹.

In total, 51 patients have received the therapy across two studies¹:

• A US study enrolled 26 patients who got either a low dose (6), a high dose (10) or a sham (imitation) surgery (10). Four people from the sham group later switched to the treatment after about 12 months¹.
• A European study enrolled 13 patients, 6 on the low dose and 7 on the high dose¹.
• A third group of 12 patients tried both doses along with drugs to dampen the immune system¹. The European study’s registry record lists those drugs as dexamethasone, sirolimus and rituximab².
• A fourth group of six US patients is testing the high dose in people whose striatum is smaller than in earlier groups¹.

The public trial registries describe the main goals of both studies as safety. The US study’s main measure is the number and type of side effects over 12 months³. The European study’s main measures are safety checks at 6 months, including blood tests, brain scans and spinal fluid tests².

What it does not show yet

FDA acceptance means the agency will review the filing. It does not mean the FDA has concluded the therapy is safe or that it slows the disease. That decision is due by May 1, 2027¹.

The main comparison behind the filing is not against a placebo group in the same trial. It uses untreated people from a database¹. Matching methods try to make the groups alike, but people in a separate database were not chosen at random alongside the treated patients, so differences between the groups can remain. The US study did include a sham surgery group, but four of those 10 people later crossed over to the therapy¹.

The numbers are small. Fifty-one people have been treated, split across different doses and groups¹. Neither study has posted results on the public registry yet, and both are listed as active but no longer recruiting²³. The registries list the main data collection as running until 2029²³.

The sources also do not fully agree on the details. The company’s announcement calls the European study open-label, meaning everyone knows what treatment they got, and lists 13 patients¹. The registry record describes that study as randomized and double-blind and lists 14 people actually enrolled². The US registry lists an estimated 43 participants across its groups³.

Who is behind it

uniQure is a gene therapy company based in Lexington, Massachusetts, and Amsterdam, listed on the Nasdaq stock exchange¹. A uniQure subsidiary, UniQure Biopharma B.V., sponsors both studies²³. The results and the description of the FDA’s decision come from the company’s own announcement¹.

The therapy already holds several FDA designations meant to speed up development: Breakthrough Therapy, Regenerative Medicine Advanced Therapy (RMAT) and Fast Track¹. The company says it is the first experimental Huntington’s therapy to receive both the Breakthrough and RMAT designations¹. These designations help a drug move through review faster. They are not approvals.

The follow-up trial

Because the company applied for accelerated approval, a larger confirming trial matters. uniQure said it and the FDA have agreed on key parts of its design¹. The plan is a randomized trial of about 200 patients, with two people getting the therapy for every one who receives standard care¹. The main measure will be Total Functional Capacity, a scale of how well people manage daily life such as work, money and household tasks, after 36 months¹.

The company plans to start screening patients in the US by the end of 2026¹. Kapusta said the study is expected to be “well underway” by the time of a possible approval¹. That means the stronger, randomized evidence would arrive years after any decision based on the current data.

What to watch next

• An advisory committee date. The FDA has said it tentatively plans to bring the application before outside experts¹. Their discussion would be the first public look at how independent reviewers read the database comparison.
• The confirming trial’s start. Whether screening begins in the US by the end of 2026, as planned¹.
• The May 1, 2027 decision. The FDA’s target date for approving or turning down the application¹.
• The UK review. The company also filed in the UK, as covered in Biohack’s earlier article; the new announcement does not give an update on that filing.
• Published results. Both early studies are still running, with no results posted on the public registry yet²³.