Taysha Gene Therapies, Inc. announced that Health Canada has authorized the protocol amendment to the ongoing REVEAL Phase 1/2 adult trial evaluating TSHA-102 that expands eligibility to include patients aged 12 and older with Rett syndrome. TSHA-102 is being evaluated in the REVEAL Phase 1/2 adult trial in Canada, a first-in-human, open-label, randomized, dose-escalation and dose-expansion study evaluating the safety and preliminary efficacy of TSHA-102 in females aged 12 and older with stage four Rett syndrome due to MECP2 loss-of-function mutation. TSHA-102 is administered as a single lumbar intrathecal injection.

Dose escalation will evaluate two dose levels of TSHA-102 sequentially. The maximum tolerated dose (MTD) or maximum administered dose (MAD) established will then be administered during dose expansion. Dosing of the third adult patient and completion of dosing in cohort one (low dose) in the adult trial is anticipated in the fourth quarter of 2023 or the first quarter of 2024.

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.