Clinical Report: FDA approves first therapy for Alexander disease

Overview

The FDA has approved zilganersen (Zanvastro) injection for patients with Alexander disease, a rare neurological condition.

Background

Alexander disease is a rare, progressive neurologic disorder caused by mutations affecting glial fibrillary acidic protein (GFAP) production. The disease leads to severe neurological symptoms and affects fewer than 1 in 1 million people.

Data Highlights

Key Findings

• Zilganersen is an antisense oligonucleotide targeting GFAP.
• FDA approval was based on a multicenter, randomized, controlled study of 49 patients.
• Patients aged 5 years and older showed significant improvement in walking speed at 61 weeks.
• Patients aged 2 to 4 years improved on a broader motor assessment.
• Common adverse reactions include vomiting, back pain, cough, headache, and post-lumbar puncture syndrome.
• Aseptic meningitis has been reported in patients treated with zilganersen.

Clinical Implications

Clinicians should be aware of the common adverse reactions associated with this therapy.

Conclusion

The approval of zilganersen marks a milestone in the management of Alexander disease.

Related Resources & Content

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9. FDA Approves First Drug to Treat Alexander Disease | FDA
10. Ionis presents new data from pivotal study of zilganersen in Alexander disease (AxD) at AAN 2026 Annual Meeting | Ionis Pharmaceuticals, Inc.
11. Alexander Disease - GeneReviews® - NCBI Bookshelf