uniQure has submitted ifezuntirgene inilparvovec, previously known as AMT-130, for accelerated approval in the United States, moving the one-time gene therapy into formal regulatory review for Huntington’s disease. The company also filed a Marketing Authorisation Application with the United Kingdom’s Medicines and Healthcare products Regulatory Agency, creating parallel review pathways for a treatment that could become the first approved therapy shown to slow progression of the inherited neurodegenerative disorder. uniQure has requested Priority Review from the United States Food and Drug Administration, which would shorten the review goal to six months after the agency completes its initial 60-day filing assessment.
The submissions are supported primarily by three-year Phase I/II data comparing patients treated with AMT-130 against a propensity score-matched external control derived from the Enroll-HD natural history database. The regulatory strategy remains unconventional because the clinical program did not include a conventional randomized Phase III efficacy trial, placing considerable importance on how regulators assess the external-control methodology, the durability of the treatment effect and the confirmatory study uniQure is preparing. Four-year data from the ongoing program are expected before the end of the third quarter and could provide another important test of the durability seen at three years.
Three-year AMT-130 results provide the clinical foundation for the accelerated approval filing
Huntington’s disease is caused by an expanded CAG repeat in the huntingtin gene and leads to progressive deterioration in movement, cognitive function and behavior. Approximately 75,000 people across the United States, Europe and the United Kingdom are estimated to have the disease, while substantially more people carry inherited risk. There are currently no approved medicines capable of delaying disease onset or slowing the underlying progression of Huntington’s disease.
AMT-130 is designed to reduce production of huntingtin protein through a gene-silencing approach. The therapy uses an adeno-associated virus serotype 5 vector carrying an artificial microRNA and is administered once through MRI-guided stereotactic neurosurgery directly into the striatum, including the caudate and putamen, brain regions that are heavily affected by Huntington’s disease.
The three-year analysis included clinical outcomes from 29 treated patients, including 17 who had received the high dose and 12 who had received the low dose, with 12 patients in each dosing group having reached the 36-month analysis point. In the high-dose group, uniQure reported a statistically significant 75% slowing of disease progression on the composite Unified Huntington’s Disease Rating Scale compared with the matched external control, meeting the prespecified primary endpoint with a p-value of 0.003.
Total Functional Capacity, a measure assessing patients’ ability to function independently, showed a statistically significant 60% slowing of deterioration relative to the external-control cohort, with a p-value of 0.033. Cerebrospinal fluid neurofilament light protein, a biomarker associated with neuronal injury, declined by an average 8.2% from baseline at 36 months in the high-dose group.
The therapy was reported to be generally well tolerated across the studied doses, with no new drug-related serious adverse events observed since December 2022. The most frequently reported adverse events were associated with the neurosurgical administration procedure, an important consideration because AMT-130 requires direct delivery into the brain rather than a conventional intravenous or oral treatment route.
FDA reversal earlier in 2026 explains why the AMT-130 filing carries unusual regulatory significance
The road to submission has not been straightforward. Following regulatory discussions earlier in 2026, the FDA initially stated that it could not agree that the Phase I/II data compared with an external control were sufficient to provide the primary evidence of effectiveness needed for a marketing application. At the time, the agency recommended a prospective randomized, double-blind study incorporating a sham surgical control.
That position changed following a Type B meeting in June. uniQure subsequently reported that the FDA considered the three-year Phase I/II analysis acceptable as the primary basis for a Biologics License Application seeking accelerated approval, while requesting alignment on the design of a post-approval confirmatory study. The potential confirmatory design has included consideration of patients receiving standard-of-care treatment as the concurrent control rather than requiring another sham neurosurgical procedure.
The reversal transformed AMT-130 from a program potentially facing years of additional pivotal development into one capable of entering regulatory review in 2026. It does not indicate that approval is assured, and the FDA can still conclude during its review that the existing evidence is insufficient, request additional information or determine that the external-control comparison does not provide sufficiently robust evidence of effectiveness.
Accelerated approval would also require uniQure to confirm clinical benefit through a post-approval study. The company has said the FDA expects that study to be feasible within a reasonable timeframe and sufficiently advanced, potentially even fully enrolled, by the time accelerated approval might be granted.
Four-year Huntington’s disease data could become the next major test of AMT-130 durability
The timing of the regulatory filing places additional focus on the upcoming four-year analysis. uniQure expects to present follow-up data from the first two Phase I/II cohorts before the end of the third quarter, including four-year outcomes from 24 patients, with 12 patients each from the high- and low-dose groups.
Durability is particularly important for a one-time gene therapy. A treatment involving invasive neurosurgical administration would need to demonstrate that its effect persists long enough to justify both the procedural burden and the long-term risks associated with permanent gene therapy.
A sustained separation from matched natural-history controls at four years would strengthen the argument that the three-year results represent a genuine modification of disease progression rather than a temporary difference. Conversely, weakening of the clinical effect or the emergence of additional safety issues could complicate regulatory assessment while the application is under review.
The use of an external control will remain one of the most closely examined aspects of the evidence. Matching methodologies can reduce differences between treated and untreated populations, but they cannot eliminate every potential source of bias in the way a randomized concurrent control can. The consistency of multiple clinical measures, biomarker results and longer-term follow-up will therefore be important to interpreting the strength of the treatment effect.
uniQure has strengthened its balance sheet ahead of a potential AMT-130 commercial launch
The company enters regulatory review with substantially more financial flexibility than it had earlier in development. uniQure ended June with approximately $810.3 million in cash, cash equivalents and current investment securities following an upsized public offering that generated roughly $259 million in gross proceeds. Management expects its current resources to fund projected operations into 2030, including preparation for a potential AMT-130 commercial launch and investment in the company’s broader gene therapy pipeline.
Second-quarter research and development expenses totaled $34 million, while selling, general and administrative expenses rose to $17.4 million as uniQure expanded personnel and infrastructure associated with potential commercialization. The company reported a net loss of $81.1 million for the quarter, reflecting the substantial spending required to support late-stage gene therapy development and launch preparation.
The financial position reduces near-term financing risk as the FDA and United Kingdom reviews proceed, but commercial execution would present another set of challenges. AMT-130 requires specialized neurosurgical administration, meaning treatment centers, physician training, reimbursement and patient-selection infrastructure would all be important components of any launch.
uniQure shares reverse early gains as investors weigh a highly anticipated regulatory milestone
uniQure shares initially rose about 5% in premarket trading following the submission announcement, according to Reuters, but the stock reversed after the market opened. Shares were trading around $46.28 by 11:25 a.m. Eastern, down approximately 3.3% from the previous close of $47.86 after reaching an intraday high near $50.97.
The reversal suggests that completion of the application was already substantially anticipated following the FDA alignment disclosed in June. Investor attention is now shifting toward filing acceptance, the Priority Review decision, the upcoming four-year data and ultimately whether regulators accept the external-control evidence as sufficient for accelerated approval.
Wall Street sentiment remains favorable but reflects substantial uncertainty. StockAnalysis reports a Strong Buy consensus among 12 analysts with an average price target of approximately $70.04, compared with the mid-$40s share price during September 2 trading. uniQure’s approximately $3.2 billion market capitalization already assigns considerable value to AMT-130, making regulatory developments particularly important to the stock.
The September 2 submission moves the Huntington’s disease program into its most consequential phase yet. AMT-130 has produced an encouraging three-year signal in a disease with no approved disease-modifying therapy, but the regulatory case depends on an unusual external-control strategy and a relatively small treated population. The coming months should clarify whether those data are sufficient to support the first gene therapy capable of altering the course of Huntington’s disease.
