FIXX Homology Medicines Inc

Homology Medicines, Inc. (Nasdaq: FIXX), a genetic medicines company, announced today that Julie Jordan, M.D., has been promoted to Chief Medical Officer. Previously, Dr. Jordan held the role of Senior Vice President, Head of Clinical Development and Operations, at Homology, and she has been instrumental in advancing Homology’s gene editing and gene therapy clinical programs. Under her leadership, Homology is conducting the pheEDIT trial for phenylketonuria (PKU) evaluating gene editing candidate HMI-103 designed to maximize PAH enzyme through both genome integration and episomal expression, and the juMPStart trial for Hunter syndrome (MPS II) evaluating systemic gene therapy candidate HMI-203 designed to address peripheral and central nervous system components of the disease. Initial clinical data from pheEDIT is expected mid-year and juMPStart initial data is anticipated in the second half of 2023.

“Since joining Homology, Julie’s extensive expertise in trial design, clinical development and operations, as well as the strong relationships she has built with the rare disease physician and patient communities, have been invaluable as we continue to move pheEDIT and juMPStart forward,” stated Albert Seymour, Ph.D., President and Chief Executive Officer of Homology Medicines. “Julie and her team’s efforts have led to the first patient being dosed in our gene editing trial for PKU, the growing interest in our MPS II trial, and the foundation being laid to support the clinical development of our future pipeline candidates. Julie is a tremendous asset to Homology, and we all look forward to working with her in her new role as Chief Medical Officer.”

“I started my career in medicine because I have always been passionate about wanting to make a difference in the lives of patients and their families,” stated Dr. Jordan. “Being part of the Homology team has provided me the opportunity to develop and deliver potentially life-changing, one-time treatments to patients whose medical needs are not being met with standard-of-care therapies. I look forward to continuing to work closely with the community while advancing our clinical programs and pipeline.”

Dr. Jordan brought vast industry experience to Homology, including the design and execution of global clinical trials across multiple development areas. Prior to Homology, Dr. Jordan was responsible for clinical and scientific development activities at Cerevel Therapeutics, including global trials for schizophrenia, focal epilepsy and anxiety disorder. Previously, she was Executive Director of Global Clinical Development at Avanir Pharmaceuticals, Inc., responsible for late-stage clinical programs for neuropsychiatry indications. Dr. Jordan held positions of increasing research and development and clinical responsibility at Teva Pharmaceutical Industries, and prior to that was Medical Director at Medpace, Inc. Before joining industry, Dr. Jordan was a Clinical Instructor of Medicine at Harvard Medical School, treating patients at Massachusetts General Hospital (MGH). Dr. Jordan holds an A.B. in Biology from Harvard College and an M.D. from Harvard Medical School, and she completed her residency in internal medicine at MGH, Harvard Medical School.

About Homology Medicines, Inc.Homology Medicines, Inc. is a clinical-stage genetic medicines company dedicated to transforming the lives of patients suffering from rare diseases by addressing the underlying cause of the disease. The Company’s clinical programs include HMI-103, a gene editing candidate for phenylketonuria (PKU); HMI-203, an investigational gene therapy for Hunter syndrome; and HMI-102, an investigational gene therapy for adults with PKU. Additional programs focus on paroxysmal nocturnal hemoglobinuria (PNH), metachromatic leukodystrophy (MLD) and other diseases. Homology’s proprietary platform is designed to utilize its family of 15 human hematopoietic stem cell-derived adeno-associated virus (AAVHSCs) vectors to precisely and efficiently deliver genetic medicines in vivo through a nuclease-free gene editing modality, gene therapy, or GTx-mAb, which is designed to produce antibodies throughout the body. Homology established an AAV manufacturing and innovation business in partnership with Oxford Biomedica, which was based on Homology’s internal process development and manufacturing platform. Homology has a management team with a successful track record of discovering, developing and commercializing therapeutics with a focus on rare diseases. Homology believes its initial clinical data and compelling preclinical data, scientific and product development expertise and broad intellectual property position the Company as a leader in genetic medicines. For more information, visit www.homologymedicines.com.

Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. We intend such forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. 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: changes to our leadership team; our expectations surrounding the potential, safety, efficacy, and regulatory and clinical progress of our product candidates; the potential of our gene therapy and gene editing platforms, including our GTx-mAb platform; our plans and timing for the release of additional preclinical and clinical data; our plans to progress our pipeline of genetic medicine candidates and the anticipated timing for these milestones; and our position as a leader in the development of genetic medicines. The words “believe,” “may,” “will,” “estimate,” “potential,” “continue,” “anticipate,” “intend,” “expect,” “could,” “would,” “project,” “plan,” “target,” and similar expressions are intended to identify forward-looking statements, though not all forward-looking statements use these words or expressions. 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 regulatory approval process; interim, topline and preliminary data may change as more patient data become available, and are subject to audit and verification procedures that could result in material changes in the final data; 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, including for the manufacture of materials for our research programs, preclinical and clinical studies; 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; securities class action litigation; the impact of the COVID-19 pandemic on our business and operations, including our preclinical studies and clinical trials, and on general economic conditions; failure to attract, retain and motivate qualified personnel; the possibility of system failures or security breaches; risks relating to intellectual property and significant costs incurred 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, 2022 and our other filings with the Securities and Exchange Commission 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:Cara MayfieldVice President, Patient Advocacyand Corporate Communicationscmayfield@homologymedicines.com781-691-3510

Investor Contact:Brad Smith Chief Financial and Business Officer bsmith@homologymedicines.com 781-301-7277