Taysha Gene Therapies (NASDAQ:TSHA) experienced a significant stock surge of 47.28% in premarket trading on October 2, 2025, following the U.S. Food and Drug Administration's decision to grant Breakthrough Therapy designation to its gene therapy candidate, TSHA-102, for Rett syndrome. This designation is expected to expedite the development and review process of the therapy. The FDA's alignment with Taysha on its pivotal trial protocol and statistical analysis plan further accelerates the path toward a Biologics License Application (BLA) submission. The decision comes after clinical data revealed a 100% response rate in achieving developmental milestones in early trials. Taysha plans to commence patient enrollment for its pivotal REVEAL trial in the fourth quarter of 2025, potentially leading to an earlier BLA submission.