Myrtelle Announces Positive Preliminary Clinical Data for Its Proprietary Gene Therapy in Canavan Disease

Myrtelle’s Phase 1/2 clinical trial introduces first-of-its-kind proprietary recombinant adeno-associated virus (rAAV) vector designed to enable targeting of oligodendrocytes

To date, 3 patients received gene therapy with the rAAV vector at a dose of 3.7 x 10¹³ vg delivered via intracerebroventricular administration

Available follow-up data in treated patients demonstrate favorable safety and tolerability with encouraging initial efficacy results

WAKEFIELD, Mass.–(BUSINESS WIRE)–Myrtelle Inc. (“Myrtelle” or the “Company”), a gene therapy company focused on developing transformative treatments for neurodegenerative diseases, today announced that its recombinant adeno-associated virus (rAAV) vector-based investigational gene therapy administered to 3 patients thus far in the Company’s open-label Phase 1/2 First-in-Human (FIH) clinical trial at Dayton Children’s Hospital (Dayton, Ohio) has shown favorable safety and tolerability with no drug-related adverse events. Myrtelle’s FIH trial utilizes the Company’s proprietary rAAV vector to directly target oligodendrocytes, the cells in the brain responsible for producing myelin – the insulating material that enables proper neuronal function. In Canavan disease (CD), the production of myelin is affected due to a mutation in the Aspartoacylase gene (ASPA) responsible for coding the enzyme Aspartoacylase (ASPA). The oligodendrocyte-targeting rAAV vector-based gene therapy is intended to restore ASPA function, thus enabling metabolism of N-Acetylaspartate (NAA), a neurochemical that is abundant in the brain, and thereby supporting myelination. Myrtelle entered into an exclusive worldwide licensing agreement with Pfizer Inc. in 2021 to develop and commercialize this novel gene therapy for the treatment of CD.

Per the FIH trial protocol, the gene therapy is administered as a single total dose of 3.7 x 10¹³ vg delivered by intracerebroventricular (ICV) injection to target the oligodendrocytes of the brain where ASPA activity needs to be restored for successful treatment of CD. “We are encouraged by the initial findings in the 3 patients treated thus far in this landmark gene therapy trial in Canavan disease. These initial patients are between 36 to 60 months old, representing the oldest study cohort, and have now been followed for at least 6 months post-treatment. The efficacy measures include Gross Motor Function Measurement (GMFM) and the Mullen Scales of Early Learning (MSEL) as well as relevant biomarkers such as NAA levels and white matter and myelin content. We are looking forward to treating additional patients and moving forward with the clinical development of this novel gene therapy,” said Christopher Janson, MD, Principal Investigator and Assistant Professor of Neuroscience at Wright State University Boonshoft School of Medicine and Director of Human Gene Therapy Center at Wright State Neuroscience Institute in Dayton, OH.

“All treated patients have exhibited favorable safety and tolerability to date. The gene therapy is administered via an intracerebroventricular route, and the post-procedure course has been in line with expected recovery in patients undergoing similar neurosurgical procedures. Based on the available data, the Data Monitoring Committee recommended opening the study to the younger cohorts: 15 to <36 months and 3 to <15 months old, as previously announced in January of this year,” said Robert Lober, MD, PhD, FAANS, Co-Principal Investigator and Associate Professor of Pediatrics at Wright State University Boonshoft School of Medicine and Attending Neurosurgeon at Dayton Children’s Hospital in Dayton, OH.

Myrtelle plans to enroll additional patients starting in the 2nd quarter of 2022 to provide safety and efficacy data in the broad range of patients with CD. “We are encouraged by these early observations in the FIH trial supporting the hypothesis that delivery of a functional ASPA gene may lead to restoration of ASPA enzyme activity and improvements in biochemical and functional brain markers. The ongoing clinical trial is expected to continue to generate the critical data needed for further development of this novel gene therapy in the patients with Canavan disease,” said Armen Asatryan, MD, MPH, Chief Medical Officer of Myrtelle.

ABOUT MYRTELLE

Myrtelle Inc. is a gene therapy company focused on developing transformative treatments for neurodegenerative diseases. The company has a proprietary platform, intellectual property, and portfolio of programs and technologies supporting innovative gene therapy approaches for neurodegenerative diseases. Myrtelle has an exclusive worldwide licensing agreement with Pfizer Inc. for its Canavan disease program. For more information, please visit the Company’s website at: www.myrtellegtx.com.

ABOUT CANAVAN DISEASE

Canavan disease (CD) is a fatal childhood genetic brain disease in which mutations in the Aspartoacylase gene (ASPA) prevent the normal expression of Aspartoacylase (ASPA), a critical enzyme produced in oligodendrocytes that breaks down the neurochemical N-Acetylaspartate (NAA). When not properly metabolized by oligodendrocytes, NAA accumulates in the brain and negatively affects bioenergetics, myelin production, and brain health. CD patients are impacted at birth but may appear normal until several months old when symptoms begin to develop.

Poor head control, abnormally large head size, difficulty in eye tracking, excessive irritability, severely diminished muscle tone, and delays in reaching motor milestones, such as rolling, sitting, and walking, are the typical initial manifestations of CD. As the disease progresses, seizures, spasticity, difficulties in swallowing, and overall muscle deterioration emerge with most affected children developing life-threatening complications by approximately 10 years of age. Currently, there are no cures for CD and only palliative treatments are available.

More information on Myrtelle’s clinical study in Canavan disease can be found on https://clinicaltrials.gov/ under the identifier NCT04833907 or by emailing [email protected].

FORWARD-LOOKING STATEMENTS

This press release contains forward-looking statements. Words such as “may,” “believe,” “will,” “expect,” “plan,” “anticipate,” “estimate,” “intend” and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. Forward-looking statements are based upon current estimates and assumptions and include statements regarding plans to enroll additional patients starting in the 2nd quarter of 2022 to provide safety and efficacy data in the broad range of patients with CD, delivery of a functional ASPA gene leading to restoration of ASPA enzyme activity and improvements in biochemical and functional brain markers and the ongoing clinical trial continuing to generate the data needed for further development of the novel gene therapy in patients with Canavan disease. While Myrtelle believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based in information available to us on the date of this release. These forward-looking statements are subject to various risks and uncertainties, many of which are difficult to predict, that could cause actual results to differ materially from current expectations and assumptions from those set forth or implied by any forward-looking statements. Important factors that could cause actual results to differ materially from current expectations include, among others, Myrtelle’s program demonstrating safety and efficacy, as well as results that are consistent with prior results, the ability to generate the data needed for further development of this novel gene therapy in the patients with Canavan disease, and the ability to continue its trials and to complete them on time and achieve the desired results. All forward-looking statements are based on Myrtelle’s expectations and assumptions as of the date of this press release. Actual results may differ materially from these forward-looking statements. Except as required by law, Myrtelle expressly disclaims any responsibility to update any forward-looking statement contained herein, whether as a result of new information, future events or otherwise.

Contacts

Media:

Jordana Holovach

Head of Communications and Community

Myrtelle Inc.

781-621-2797 Ext. 102

[email protected]