FDA approves Zanvastro for Alexander disease treatment

The US Food and Drug Administration (FDA) has approved Zanvastro (zilganersen), the first disease-modifying therapy for Alexander disease. Developed by Ionis Pharmaceuticals, the antisense oligonucleotide treatment is indicated for both pediatric and adult patients.

Alexander disease is a rare neurodegenerative disorder caused by mutations in the GFAP gene, leading to the accumulation of toxic glial fibrillary acidic protein in astrocytes. This buildup can cause seizures, muscle weakness, and impaired movement. The disease is estimated to affect between one in one million and three million people globally.

The approval is supported by results from a phase 1-3 clinical study. In patients aged five and older, zilganersen demonstrated a statistically significant stabilization of gait speed at week 61 compared to a control group. In children aged two to four, the treatment showed improvements in gross motor function. The therapy is designed to target the underlying biological cause of the disease rather than merely managing symptoms.