UniQure’s Huntington’s disease gene therapy AMT-130 continued to slow disease progression at the four-year mark, but new additional-year follow-up data showed a weakening magnitude of benefit. The updates, cited by analysts as a potential issue for durability, caused the company’s stock to fall sharply. In the reported analysis, UniQure said the high-dose AMT-130 group showed a 44% slowdown versus matched participants drawn from an external natural history study; the difference was reported as not statistically significant in this dataset. The company also pointed to mitigating circumstances and the status of secondary endpoints. Regulatory review timing adds pressure: the article notes the FDA is beginning its marketing application review as the therapy’s long-term effect profile becomes a central question. For the gene-therapy field, the episode underscores how follow-up duration and endpoint interpretation can quickly swing sentiment even when the therapy demonstrates biological activity and consistent direction of effect.