XGR-101

XGR-101 is an AAV9-delivered miREX X-reactivation gene therapy developed by Alcyone Therapeutics. It is designed for the treatment of X-linked genetic disorders, with its lead program focused on Rett syndrome. Rett syndrome is a severe neurodevelopmental disorder caused by a loss-of-function mutation in the MeCP2 gene. XGR-101 functions by partially reactivating the silenced X chromosome within each cell, thereby enabling the production of functional Methyl-CpG-binding protein 2 (MeCP2) from the healthy X chromosome that was previously silenced. This mechanism is designed to avoid MeCP2 overexpression in cells where a healthy copy of the gene is already active. Preclinical studies in a severe mouse model of Rett syndrome have demonstrated that XGR-101 significantly slowed the progression of phenotypic abnormalities, including improvements in cognitive and breathing-related symptoms.