Rett syndrome gene therapy trial expanded to include patients aged 12 years and older

Health Canada has authorized an amendment to the ongoing REVEAL phase 1/2 trial evaluating an AAV9 investigational gene transfer therapy that expands eligibility to patients with Rett syndrome aged 12 years and older.

According to a release from Taysha Gene Therapies Inc., REVEAL is the first-in-human, open-label, randomized, dose-escalation and dose-expansion study. The amendment will evaluate safety and preliminary efficacy of a single lumbar intrathecal injection of TSHA-102 in women and girls aged 12 and older with stage 4 Rett syndrome due to MECP2 loss of function mutation.

Dose escalation will evaluate two dose levels of TSHA-102 sequentially, before the established maximum tolerated or maximum administered dose is given during dose expansion.

Dosing of the third adult patient and completion of dosing in the low-dose cohort in the adult trial is anticipated in the fourth quarter of 2023 or the first quarter of 2024, Taysha said in the release.

“Amending our protocol broadens the patient population who can potentially benefit from TSHA-102. We look forward to further advancing the clinical development of TSHA-102 and building on the encouraging data demonstrated in the first two adult patients treated,” Taysha President and head of research and development Sukumar Nagendran, MD, said in the release.

The company expects to commence initial dosing of pediatric patients during the first quarter of 2024.