Myrtelle Announces Positive 6-month Post-Treatment Data in Patients in Its First-in-Human Clinical Study of rAAV-Olig001-ASPA Gene Therapy in Canavan Disease

Myrtelle, a gene therapy company focused on developing transformative treatments for neurodegenerative diseases, has announced encouraging initial data and a favorable safety profile at the 6 month post-treatment time point in the 8 patients treated with the Company’s recombinant adeno-associated virus (rAAV) vector-based investigational gene therapy in its open-label Phase 1/2 First-in-Human (FIH) clinical trial for Canavan disease (CD), a fatal genetic brain disorder in children.

Assessments showed statistically significant mean absolute and/or percent increases from baseline measurements in myelin, white matter, grey matter, and total brain volume, and reduction in the volume of cerebrospinal fluid (CSF) by magnetic resonance imaging (MRI) in these patients. Additionally, clinical measurements of motor and cognitive function using the Gross Motor Function Measure (GMFM) and Mullen Scales of Early Learning (MSEL) demonstrated mean absolute and percent improvements across multiple domains. In several domains, the observed improvement in treated patients are in contrast to the observed deterioration in untreated age-matched CD patients within Myrtelle’s natural history data set. No serious drug-related adverse events have been observed to date.

The Myrtelle FIH trial utilizes the Company’s proprietary rAAV vector to directly target oligodendrocytes, the brain cells affected in Canavan disease that are responsible for producing myelin – the insulating material that enables proper neuronal function. In CD, normal brain development is impaired due to a mutation in the ASPA gene that encodes the enzyme Aspartoacylase (ASPA). The deficiency of ASPA enzyme results in multiple biochemical and anatomic changes, including the inability to metabolize N-Acetylaspartate (NAA) which in turn leads to impaired bioenergetics and abnormal brain development. The oligodendrocyte-targeting rAAV vector-based gene therapy is intended to restore ASPA function and hence the metabolism of NAA and brain development in patients with CD.

“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,” said Chris Janson, MD, Principal Investigator and Assistant Professor of Neurology and Neuroscience at Wright State University Boonshoft School of Medicine and Director of Human Gene Therapy Center at Wright State Neuroscience Institute in Dayton, OH. “Improvements in functional scores were observed across multiple domains on the GMFM and MSEL assessment tools. In addition, volumetric MRI (magnetic resonance imaging) measurements showed increases in multiple brain tissue compartments and reductions in CSF volume. Reductions in brain NAA, measured by MRS (magnetic resonance spectroscopy) were also seen. 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 CD patients.”