Taysha Gene Therapies announces FDA BTD to TSHA-102

Taysha Gene Therapies (TSHA) announced the U.S. Food and Drug Administration, FDA, has granted Breakthrough Therapy designation, BTD, to TSHA-102, an intrathecally delivered AAV9 gene therapy with disease modifying potential, for the treatment of Rett syndrome. Additionally, the Company announced that it has finalized alignment with the FDA on the REVEAL pivotal trial protocol and statistical analysis plan that are intended to support the planned Biologics License Application submission for TSHA-102, following the resolution of remaining clinical and statistical queries. Previously aligned upon key design elements for the REVEAL pivotal trial protocol and SAP in support of the planned BLA submission remain unchanged, including: Inclusion of a 6-month interim analysis that may serve as the basis for BLA submission: enabled by the rigorous, objective evaluation criteria used to evaluate developmental milestone achievement in Part A of the REVEAL Phase 1/2 trials and the unprecedented 83% response rate seen at six months following high dose TSHA-102 in Part A that deepened over time. Response rate of 33% is the minimum threshold for success sufficient to reject the null hypothesis: based on Taysha’s natural history data analysis, the null hypothesis is that one out of 15 patients aged greater than or equal to6 years may gain/regain one of the 28 natural history defined developmental milestone without treatment, corresponding to a response rate of 6.7%