Taysha Gene Therapies, Inc. announced that the second Rett syndrome patient has been dosed with TSHA-102 in the REVEAL Phase 1/2 adult trial in Canada. Enrollment in the low-dose cohort is expected to be complete in the fourth quarter of 2023 with the dosing of the third patient. The REVEAL adult trial is being conducted at CHU Sainte-Justine, the Universit de Montral mother and child university hospital centre in Montreal, Canada, under Principal Investigator Dr. Elsa Rossignol, M.D., FRCP, FAAP, Associate Professor Neuroscience and Pediatrics at CHU Sainte -Justine.

The United States Food and Drug Administration (FDA) cleared the Investigational New Drug (IND) application for TSHA-102 in pediatric patients with Rett syndrome, and the Company expects to dose the first pediatric patient in the first quarter of 2024. Additionally, the Company submitted a Clinical Trial Application to the United Kingdom Medicines and Healthcare products Regulatory Agency (MHRA) for TSHA-102 iniatric patients with Rett syndrome and expects to receive MHRA feedback in the second half of 2023. TSHA-102 is a self-complementary intrathecally delivered AAV9 investigational gene transfer therapy in clinical evaluation for Rett syndrome.

TSHA-102 utilizes a novel miRNA-Responsive Auto-Regulatory Element (miRARE) platform designed to mediate levels of MECP2 in the CNS on a cell-by-cell basis without risk of overexpression. TSHA-102 has received Fast Track designation and Orphan Drug and Rare Pediatric Disease designations from the FDA and has been granted Orphan Drug designation from the European Commission. Rett syndrome is a rare neurodevelopmental disorder caused by mutations in the X-linked MECP2 gene, which is a gene that's essential for neuronal and synaptic function in the brain.

The disorder is characterized by intellectual disabilities, loss of communication, seizures, slowing and/or regression of development, motor and respiratory impairment, and shortened life expectancy. words such as "ant anticipates, "bel believes," "ex expects," "intends," " plans," and " future" or similar expressions are intended to identify forward-looking statements.