Cincinnati Children’s Hospital reported preclinical evidence that an AAV-based gene therapy expressing human FMRP reverses multiple fragile X syndrome deficits in mice. Published in Gene Therapy, the study used an AAV9 vector delivering the FMR1 gene to adolescent FXS model mice via intracerebroventricular or intravenous routes. Researchers reported restored FMRP expression across the brain with route-dependent distribution, plus normalization of clinically relevant traits including sensory hyperexcitability, adaptation to change and altered brain activity. The design emphasizes translational bridging by using a vector intended to perform in humans, supporting the case for moving toward clinical evaluation. In a separate gene therapy theme, Circio Holding and Avenue Biosciences announced a collaboration aimed at boosting long-term expression of secreted proteins by combining circVec circular RNA expression with protein-engineering tools to improve secretion.