Key Highlights

● uniQure traded near $25.32 at midday on Tuesday, September 29, 2026, after an even deeper drop in premarket trading.

● The Phase I/II study compared treated patients with an external control group instead of a placebo arm.

● At four years, more than half of the external-control data was missing, and the key result was not statistically significant.

● The company said the bias cuts against AMT-130, and the FDA had said 36-month data would underpin its filing.

uniQure N.V. (NASDAQ:QURE) plunged on Tuesday, September 29, 2026, as investors digested four-year data for AMT-130, its gene therapy for Huntington's disease, and a debate over the quality of the comparison group used to measure it. Shares traded near $25.32 at midday, after an even deeper drop in premarket trading, as the Russell 2000 finished lower.

The Problem With the Control Group

AMT-130's Phase I/II study did not use a traditional placebo arm. Instead, uniQure compared treated patients with an external control group, drawn from data on patients with Huntington's disease who did not receive the therapy. External controls are common in rare-disease research, where it can be hard or ethically difficult to give patients a sham treatment, especially one requiring brain surgery. But they rely on the comparison group being similar and on complete data.

What Four Years Showed

At four years, more than half of the external-control data was missing. That makes it harder to judge how much the therapy slowed the disease. The high-dose result on the composite Unified Huntington's Disease Rating Scale was not statistically significant, and the slowing was smaller than the company had reported at three years. The therapy also showed slowing on Total Functional Capacity.

uniQure's Case

The company argued the missing data made the therapy look worse, not better. Chief Executive Matt Kapusta said the comparator increasingly reflected a healthier population than at baseline, a bias that cuts against AMT-130. One way this can arise: if sicker patients dropped out of the control data over time, the remaining group would appear to decline more slowly than a true untreated population, shrinking the apparent benefit.

The Regulatory Backdrop

The FDA had said 36-month data would underpin uniQure's Biologics license application. The four-year data therefore did not replace the basis for the filing, but it added uncertainty to how the overall evidence might be viewed. ClearPoint Neuro, whose platform administers AMT-130 into the brain, plunged in sympathy.

Macro Crosscurrents

Rising long-term Treasury yields were the main weight on the market, with the 30-year at its highest level since 2002 and the 10-year near a two-decade high. Consumer confidence dropped to 81.9 from 88.6, the lowest since 2014, according to the Conference Board.

Upcoming Markers

Updates on the regulatory filing and FDA discussions, and whether further analyses address the gaps in the external-control data, are the next milestones. GDP and August PCE Inflation arrive on Wednesday, September 30, Nike reports on Thursday, October 1, and the September jobs report follows on Friday, October 2.