Adeno-associated virus serotype 9 (AAV9) is highly valued in gene therapy because it can cross the blood-brain barrier. It is primarily used to treat monogenic neurological and neuromuscular disorders, most notably Spinal Muscular Atrophy (SMA).

AAV9 vectors deliver functional genetic material to replace or suppress faulty genes. Approved treatments and advanced clinical trials using AAV9 include:

Spinal Muscular Atrophy (SMA): The FDA-approved therapy Zolgensma (onasemnogene abeparvovec-xioi) uses AAV9 to deliver a functional copy of the SMN1 gene to motor neurons in children under two years old.

Pompe’s Disease: AAV9 gene therapies are in late-stage clinical development to deliver a working GAA gene to infants and patients, improving motor function and cardiac outcomes.

GM1 Gangliosidosis: Intravenous AAV9 gene therapy is in clinical trials (such as AAV9-GLB1) to address the central nervous system degeneration and enzyme deficiency in this rare lysosomal storage disease.

Other Neurological & Rare Diseases: AAV9 is actively being investigated in clinical trials for conditions such as Giant Axonal Neuropathy, Rett Syndrome, Friedreich’s Ataxia, and CLN7 Batten Disease.