FDA Approves Zanvastro for Alexander Disease

The US Food and Drug Administration (FDA) has approved Zanvastro (zilganersen) injection for the treatment of Alexander disease in paediatric and adult patients. 

It is the first FDA-approved treatment for the rare neurological disorder and the first therapy designed to directly reduce the abnormal protein linked to the disease.

Alexander disease is caused by mutations in the gene responsible for producing glial fibrillary acidic protein (GFAP). 

Abnormal GFAP can accumulate in brain support cells, leading to progressive nervous system damage. 

The condition affects fewer than one in a million people and may cause seizures, developmental delays, difficulty walking, muscle weakness and increased pressure in the brain.

Zanvastro is an antisense oligonucleotide designed to reduce production of abnormal GFAP before it accumulates. 

The treatment is administered by injection into the spinal canal every three months by a trained healthcare professional.

The FDA reviewed data from a multicentre clinical study involving 49 patients aged two years and older, along with an open-label study involving four patients below two years. 

Results showed improved walking speed in treated patients aged five years and older, while younger children showed improvements in broader motor-function assessments.

Zanvastro was developed by Ionis Pharmaceuticals and received several FDA designations supporting development for this rare disease.