Increases in myelin, white matter reported at 6 months with Canavan disease gene therapy

Key takeaways:

• Six-month post-treatment trial data show significant increases in myelin, white matter, grey matter and total brain volume.
• No serious drug-related adverse events were observed.

Myrtelle Inc. has reported promising 6-month trial data for a recombinant adeno-associated virus vector-based investigational gene therapy for Canavan disease.

According to a company release, data from the first-in-human, open-label phase 1/2 study of eight patients at Dayton Children’s Hospital in Ohio showed statistically significant increases from baseline measurements in myelin, white matter, grey matter and total brain volume, and reduction in the volume of cerebrospinal fluid by MRI.

Additionally, clinical measurements of motor and cognitive function using the Gross Motor Function Measure and Mullen Scales of Early Learning demonstrated mean absolute and percent improvements across multiple domains, some of which were compared with worsening in untreated age-matched patients with Canavan disease, the company stated. No serious drug-related adverse events have been observed to date.

“The 6-month functional and anatomic data observed in these patients are encouraging in showing positive changes in the patients’ motor, language, cognitive and visual skills,” Chris Janson, MD, principal study investigator and assistant professor of neurology and neuroscience at Wright State University Boonshoft School of Medicine, said in the release. “These improvements suggest the gene therapy is having its intended effect and encourages advancement of the gene therapy program to bring this potential treatment option to more [Canavan disease] patients.”

According to Myrtelle, patients with Canavan disease have impaired brain development because of a mutation in the ASPA gene that encodes the aspartoacylase enzyme. The investigational, oligodendrocyte-targeting gene therapy aims to restore ASPA function and thus brain development.

The company will present updated trial information at the ASGCT annual meeting in Los Angeles in May.