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Homology Medicines Presents New Data Characterizing AAVHSCs as Potential Gene Therapies for Nervous System Disorders

- Data Demonstrate AAVHSCs Crossed the Blood-Brain-Barrier and Blood-Nerve-Barrier, Produced Normal Levels of Human Protein and Reduced Key Biochemical Markers of Disease in Preclinical Models -

BEDFORD, Mass. – February 13, 2020 – Homology Medicines, Inc. (Nasdaq: FIXX), a genetic medicines company, announced today presentations demonstrating that its proprietary adeno-associated virus vectors derived from hematopoietic stem cells (AAVHSCs) crossed the blood-brain-barrier and blood-nerve-barrier in preclinical models. Additionally, in the oral presentation on metachromatic leukodystrophy (MLD), a lysosomal storage disorder caused by mutations in the ARSA gene, Homology’s gene therapy candidate HMI-202 reduced key biomarkers of disease and produced normal levels of human ARSA protein in the murine model of MLD. These data presented at the WORLDSymposium™ 2020 Conference support the further development of AAVHSC-based gene therapies for diseases of the nervous system. 

“The data presented this week build upon our previously published AAVHSC biodistribution data to  include characterization of 11 of our AAVHSC vectors and showed that all of them crossed the blood-brain-barrier and blood-nerve-barrier in NHPs,” stated Albert Seymour, Ph.D., Chief Scientific Officer. “This enables us to choose the most suitable vector for different diseases, just as we have done in selecting HMI-202 for our MLD program, which is in IND-enabling studies. We look forward to pursuing additional opportunities to develop gene therapies based on our AAVHSCs for the treatment of neurological disorders as well as other rare diseases.”  In the poster presentation, “AAVHSC Characterization for Developing Treatments for Human Genetic Diseases of the Nervous System,” 11 of Homology’s AAVHSCs were evaluated and, following a single I.V. administration in non-human primates (NHPs), demonstrated broad tissue tropism (entering the cells) in the central and peripheral nervous systems. Specifically, AAVHSCs: 

  • Crossed the blood-brain-barrier and blood-nerve-barrier.
  • Demonstrated various levels of tropism within the spinocerebellar pathway, suggesting individual AAVHSCs may be preferentially chosen based on disease biology.
  • Showed broad tissue tropism, making them amenable for potential therapeutic applications. 

In the oral presentation, “HMI-202: Investigational Gene Therapy for Treatment of Metachromatic Leukodystrophy (MLD),” a single I.V. administration of HMI-202 was evaluated in the MLD ARSA knockout murine model and in NHPs. A single administration of HMI-202 resulted in:

  • Durable and high levels (>100%) of human ARSA (hARSA) activity in the central nervous system (CNS) of the MLD murine model, with hARSA detected in all cell types of the nervous system.
  • Reductions in key biochemical markers of MLD, including a reduction in LAMP-1 accumulation and a significant decrease in brain sulfatide levels in the murine model.
  • Presence of hARSA in the peripheral nervous system and CNS in NHPs, suggesting that HMI-202 crossed the blood-brain-barrier and blood-nerve-barrier.

About Metachromatic Leukodystrophy (MLD)

MLD is a rare lysosomal storage disorder caused by mutations in the ARSA gene. ARSA is responsible for the creation of the arylsulfatase A (ARSA) protein, which is required for the breakdown of cellular components. In MLD, these cellular components accumulate and destroy myelin-producing cells in the peripheral and central nervous system leading to progressive and serious neurological deterioration. The late infantile form of the disorder is estimated to affect 1 in 40,000 people, and it is fatal within five to ten years after onset.

About Homology Medicines, Inc. 

Homology Medicines, Inc. is a genetic medicines company dedicated to transforming the lives of patients suffering from rare genetic diseases with significant unmet medical needs by curing the underlying cause of the disease. Homology’s proprietary platform is designed to utilize its human hematopoietic stem cell-derived adeno-associated virus vectors (AAVHSCs) to precisely and efficiently deliver genetic medicines in vivo either through a gene therapy or nuclease-free gene editing modality across a broad range of genetic disorders. Homology has a management team with a successful track record of discovering, developing, and commercializing therapeutics with a particular focus on rare diseases, and intellectual property covering its suite of 15 AAVHSCs. Homology believes that its compelling preclinical data, scientific expertise, product development strategy, manufacturing capabilities and intellectual property position it as a leader in the development of genetic medicines. For more information, please visit

Forward-Looking Statements 

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation statements regarding our expectations surrounding the potential, safety, efficacy, and regulatory and clinical progress of our product candidates; our pursuit of additional opportunities to develop gene therapies based on our AAVHSCs for the treatment of neurological disorders and other rare diseases; beliefs about preclinical data and the properties and potential of our AAVHSCs; and our position as a leader in the development of genetic medicines. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: we have and expect to continue to incur significant losses; our need for additional funding, which may not be available; failure to identify additional product candidates and develop or commercialize marketable products; the early stage of our development efforts; potential unforeseen events during clinical trials could cause delays or other adverse consequences; risks relating to the capabilities and potential expansion of our manufacturing facility; risks relating to the regulatory approval process; our product candidates may cause serious adverse side effects; inability to maintain our collaborations, or the failure of these collaborations; our reliance on third parties; failure to obtain U.S. or international marketing approval; ongoing regulatory obligations; effects of significant competition; unfavorable pricing regulations, third-party reimbursement practices or healthcare reform initiatives; product liability lawsuits; failure to attract, retain and motivate qualified personnel; the possibility of system failures or security breaches; risks relating to intellectual property and significant costs as a result of operating as a public company. These and other important factors discussed under the caption “Risk Factors” in our Quarterly Report on Form 10-Q for the quarter ended September 30, 2019 and our other filings with the SEC could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change.

Company Contacts:
Theresa McNeely
Chief Communications Officer and Patient Advocate

Media Contact:
Cara Mayfield
Senior Director, Patient Advocacy and Corporate Communications