uniQure Shares Plunge Over 60% as Huntington's Trial Data Raises Statistical Concerns

Shares of uniQure (NASDAQ: QURE) plummeted 62.3% in pre-market trading on September 29, 2026, after the gene therapy developer released four-year follow-up data from its Phase I/II trial for AMT-130, an investigational treatment for Huntington’s disease.

Data Undermined by Control Group Issues

In a press release, uniQure presented the results for ifezuntirgene inilparvovec (AMT-130) with a positive interpretation. Chief Medical Officer Walid Abi-Saab stated that "four years after a single administration, ifezuntirgene inilparvovec continues to show meaningful slowing of disease progression."

However, investors focused on a critical flaw in the data's presentation. The trial's outcomes were compared against an external control group derived from the ENROLL-HD natural history dataset. According to the source, this comparison was significantly weakened because data was missing for 53% of the matched control subjects at the 48-month evaluation point. This high level of missing data raises serious questions about the statistical credibility of the comparison, a concern that has previously led to regulatory setbacks for the program.

Regulatory and Market Context

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The market's severe reaction was compounded by the data's regulatory context. The U.S. Food and Drug Administration (FDA) had previously communicated to uniQure that the 36-month data from a specific patient group would form the primary basis for a Biologics License Application (BLA) under the accelerated approval pathway. The four-year results released today were not part of that key submission, leaving investors to question their immediate utility in securing regulatory approval.

This data release was one of the most anticipated catalysts for uniQure, with the company guiding for a September 2026 readout. The market had priced in expectations for a clean, confirmatory result, especially after uniQure had previously attempted to address critiques about its control group selection. The failure to provide a statistically robust comparison proved to be a major disappointment.

Investor Verdict on Trial Results

The sharp sell-off reflects a combination of factors: a statistically compromised control group, uncertainty about the data's relevance for the pending BLA submission, and a technically weak stock position heading into the announcement. The market's verdict indicates a significant gap between the company's optimistic framing and investor expectations for a more robust data package to support the Huntington's disease therapy.