BEDFORD, MA, USA I February 18, 2022 I Homology Medicines, Inc. (Nasdaq: FIXX), a genetic medicines company, announced today that the U.S. Food and Drug Administration (FDA) has notified the company that its pheNIX gene therapy trial of HMI-102 in adults with phenylketonuria (PKU) has been placed on clinical hold due to the need to modify risk mitigation measures in the study in response to observations of elevated liver function tests. The Company expects to receive an official clinical hold letter within 30 days. Homology plans to provide an update pending further clarity from the FDA.

“We look forward to working with the FDA to address the Agency’s questions and feedback once we receive the letter,” stated Arthur Tzianabos, Ph.D., President and Chief Executive Officer of Homology Medicines. “This hold on our PKU gene therapy trial is based on clinical observations in the pheNIX study and does not relate to CMC/manufacturing capabilities or Homology’s other clinical programs. We plan to provide next steps once we have more information following our FDA interactions.”

Homology has two ongoing clinical programs, the pheEDIT gene editing trial of HMI-103 for PKU and the juMPStart gene therapy trial of HMI-203 for Hunter syndrome, with program updates expected by the end of this year.

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. Homology’s clinical programs include HMI-102, an investigational gene therapy for adults with phenylketonuria (PKU); HMI-103, a gene editing candidate for PKU; and HMI-203, an investigational gene therapy for Hunter syndrome. Additional programs focus on metachromatic leukodystrophy (MLD), paroxysmal nocturnal hemoglobinuria (PNH) and other diseases. Homology’s proprietary platform is designed to utilize its family of 15 human hematopoietic stem cell-derived adeno-associated virus vectors (AAVHSCs) to precisely and efficiently deliver genetic medicines in vivo through a gene therapy or nuclease-free gene editing modality, as well as to deliver one-time gene therapy to produce antibodies throughout the body through the GTx-mAb 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, internal manufacturing capabilities and broad intellectual property position Homology as a leader in genetic medicines. For more information, visit www.homologymedicines.com.

SOURCE: Homology Medicines