Positive interim data announced in phase 1/2 trial of gene therapy for Canavan disease

Myrtelle Inc. announced updated findings of the open-label phase 1/2 clinical trial of its recombinant adeno-associated virus vector-based investigational gene therapy for Canavan disease, a fatal genetic disorder in children.

According to a release from Myrtelle, early data from the first in-human study, which is being conducted at Dayton Children’s Hospital in Ohio, revealed that all eight patients have shown increases in white matter, grey matter and total brain volumes through their 3-month follow-up visits. In addition, most patients demonstrated a reduction in the volume of cerebrospinal fluid evidenced by MRI.

Additionally, per the release, clinical measurements of motor and cognitive function using the Gross Motor Function Measure and Mullen Scales of Early Learning tools have yielded improvements across several domains, in contrast to continuous clinical decline expected for untreated patients with Canavan disease.

“We are encouraged by early findings in Myrtelle’s Phase 1/2 clinical trial in Canavan disease as we continue to follow up on patients and their progress,” Mark Pykett, PhD, Myrtelle CEO, told Healio. “We look forward to meeting with regulatory authorities with an eye toward expediting approval for this gene therapy as we drive to bring this therapy to patients who currently do not have treatment options.”

The first three patients treated with the novel therapy in the first cohort are now at least 18 months into therapy. Assessments of these initial participants at later time points also showed improvements on imaging and validated functional scale measurements. No serious drug-related adverse events have been observed in treated patients to date, the company stated in the release.

The current trial utilizes Myrtelle’s proprietary recombinant adeno-associated virus vector to directly target oligodendrocytes, the brain cells affected in Canavan disease that are responsible for producing myelin, the release stated. This oligodendrocyte-targeting gene therapy is intended to restore functionality of the aspartoacylase enzyme, which is deficient in individuals with Canavan disease, thus prompting metabolism of N-acetylaspartate and brain development in these patients.

According to the release, the investigational gene therapy previously received orphan drug, rare pediatric disease and fast track designations from the FDA, as well as orphan drug designation and advanced therapeutic medicinal product classification from the European Medicines Agency.

“The early results to date in patients treated in Myrtelle’s phase 1/2 clinical trial are encouraging,” Rob Lober, MD, principal study investigator and attending neurosurgeon at Dayton Children’s Hospital, said in the release. “Given these data, we are encouraged to continue tracking these treated patients and to advance development of the candidate gene therapy to bring this potential treatment options to [Canavan disease] patients.”