Myrtelle’s Gene Therapy Shows Promise for Canavan Disease in Landmark Study

NEW YORK, Sept. 16, 2025 – A groundbreaking gene therapy for the fatal childhood neurodegenerative disorder, Canavan disease, has shown promising results, according to a new study published in the journal Nature Medicine. The therapy, rAAV-Olig001-ASPA (MYR-101), developed by Myrtelle Inc., is the first-ever to specifically target and deliver a functional gene to oligodendrocytes, the brain cells responsible for producing myelin. This advancement offers a glimmer of hope for patients with a disease that currently has no approved treatments.

The Phase 1/2 clinical trial demonstrated significant improvements in several key areas among the eight children with typical Canavan disease who were followed for up to two years post-treatment. Preliminary results indicate that the aav therapy was well-tolerated, with no serious adverse events attributed to the treatment itself. The study’s authors highlighted the therapy’s ability to reduce N-acetylaspartate (NAA) levels in the cerebrospinal fluid (CSF), which provides early evidence of its therapeutic effect.

“The reductions in CSF NAA levels, gains in myelin volume, and functional improvements in treated patients mark a compelling step forward for patients who currently have no approved treatment options,” said Adrian Stecyk, CEO of Myrtelle. “The Nature Medicine publication underscores the potential of rAAV-Olig001-ASPA to serve as a disease-modifying therapy for Canavan disease.”

AAV Therapy Targets Root Cause

Canavan disease is caused by mutations in the ASPA gene, which leads to a deficiency of the aspartoacylase enzyme. This deficiency impairs the metabolism of NAA and results in severe dysmyelination, or the improper formation of the myelin sheath that insulates nerve fibers. MYR-101 uses a proprietary recombinant AAV vector to deliver a functional ASPA gene directly to oligodendrocytes. This aims to restore enzyme activity and facilitate myelin repair.

Using Synthetic MRI (SyMRI), researchers observed significant increases in brain myelin volume, indicating new myelination. An image of a Canavan patient’s brain before and 12 months after treatment showed an improvement in myelin volume and a reduction in brain water.

Functional Gains Observed

Beyond the biochemical and imaging improvements, participants in the trial also showed developmental improvements compared to historical controls. These gains were assessed using the Mullen Scales of Early Learning (MSEL), with all participants improving in at least two or more domains and most improving in three or more, reflecting broad functional gains. The results support the therapy’s potential as a disease-modifying treatment.

Regulatory Recognition

The rAAV-Olig001-ASPA (MYR-101) therapy has received significant regulatory attention. The U.S. Food and Drug Administration (FDA) selected it for the Support for Clinical Trials Advancing Rare Disease Therapeutics (START) pilot program. It is one of only four CBER-regulated gene therapies to receive this designation, which provides enhanced regulatory support to expedite development.

The product has also received several other key designations, including:

• Regenerative Medicine Advanced Therapy (RMAT)
• Orphan Drug, Rare Pediatric Disease, and Fast Track designations from the FDA
• Orphan Drug Designation and Advanced Therapy Medicinal Product (ATMP) classification from the European Medicines Agency (EMA)
• Innovative Licensing and Access Pathway (ILAP) designation from the UK Medicines and Healthcare products Regulatory Agency (MHRA)

About Canavan Disease

Canavan disease (CD) is a rare, fatal, and progressive genetic brain disease. Initial symptoms, which may appear around several months of age, include poor head control, an abnormally large head size, and developmental delays. As the disease progresses, children often face seizures, spasticity, and severe muscle deterioration, with most developing life-threatening complications by approximately 10 years of age. Currently, only palliative treatments are available. The publication of this study marks a significant step toward a potential cure for this devastating disease.