Experts say Angelman syndrome drug failure leaves hope for similar antisense therapies

Ultragenyx announced that its late-stage trial of an experimental Angelman syndrome drug did not meet its primary endpoints, marking a setback for the rare-disease community.

Researchers such as Mark Zylka from the University of North Carolina emphasized that the result does not invalidate the antisense approach, noting that other programs are still in development at companies like Ionis, Oak Hill Bio, and Ultragenyx itself.

The broader implication is that a single failure may not derail efforts to apply genetic medicines to other neurodevelopmental disorders, where restoring cognition and communication remains a key goal.