UniQure said the FDA has signaled that data from its Phase I/II studies of AMT‑130, a gene therapy for Huntington’s disease, may no longer be sufficient to support a Biologics License Application. The agency reversed earlier guidance that appeared to permit an accelerated pathway based on an external-control comparison. UniQure reported dramatic clinical readouts in September showing slowed disease progression, but the company now says the timing of a U.S. submission is unclear after the pre‑BLA meeting. UniQure intends to review the agency minutes and urgently engage FDA staff to define a path forward. Markets reacted sharply to the agency’s shift: uniQure shares plunged on the news, reflecting investor concern about timing and evidentiary requirements for complex gene‑therapy dossiers. The episode underscores continuing regulatory scrutiny over single‑arm studies and external controls in rare‑disease approvals.