Ionis Pharmaceuticals receives FDA approval for Alexander disease treatment

The US Food and Drug Administration has approved Zanvastro (zilganersen), developed by Ionis Pharmaceuticals, as the first and only disease-modifying treatment for Alexander disease (AxD). The approval applies to both pediatric and adult patients.

Alexander disease is an ultra-rare, progressive, and often fatal neurological disorder caused by mutations in the GFAP gene, which leads to the toxic accumulation of glial fibrillary acidic protein in astrocytes. Previously, treatment was limited to symptom management. Zanvastro is an RNA-targeted medicine administered via quarterly intrathecal injections designed to reduce the production of the problematic protein.

In a pivotal clinical trial, patients treated with Zanvastro maintained stable walking speeds, whereas the control group experienced a 33% decline. Ionis expects the drug to reach US patients in the coming weeks.