UniQure said its Huntington’s gene therapy AMT-130 continued to slow disease progression four years after implantation, but with waning benefit magnitude versus earlier analyses. The update arrives as the FDA prepares its marketing application review, making durability interpretation central to the regulatory discussion. In the company’s reported analysis, the high dose slowed progression by 44% compared with matched participants using an external natural history control group; the difference was not statistically significant. The result contrasts with a prior year’s analysis that showed a stronger separation. The durability question matters for gene therapies where one-time administration is expected to deliver sustained effect; it also shapes trial-extrapolation debates around endpoints, background variability and statistical framing in follow-up analyses.