Shares of uniQure N.V. opened down nearly 40% on September 29, 2026, following the release of mixed 48-month clinical data for AMT-130, its gene therapy for Huntington's disease. Although the therapy continued to show evidence of slowing disease progression, the four-year results failed to meet a key statistical measure and appeared less compelling than earlier three-year data that had been utilized as the basis for a Biologics License Application (BLA). This disappointed investors and raised concerns regarding the treatment's long-term durability and its prospects for regulatory approval.