Homology Medicines’ gene therapy approach utilizes our proprietary AAVHSC vectors to deliver a functional gene to a cell where there is a missing or mutated gene. Once delivered, the functional gene may lead to therapeutic protein expression. With gene therapy, the genes do not integrate into the genome so this approach can be curative in slow- or non-dividing cells (e.g., adult liver or central nervous system).
Our gene therapy construct includes a functional copy of the gene and a promoter sequence that is designed to enable the gene to be turned on in the cell and ultimately transcribed to express a therapeutic protein without integrating into the genome.
Our unique vectors have demonstrated significant systemic biodistribution to multiple tissue types in preclinical studies, including liver, central nervous system (CNS), muscle (skeletal and cardiac) and eye*. This enables us to potentially address a broad range of monogenic diseases.
Our lead development program is an AAVHSC-mediated gene therapy treatment for adults with the rare disease phenylketonuria. Learn more about our pipeline and therapeutic focus.
Our GTx-mAb platform is an extension of our gene therapy approach, which is designed to leverage our AAVHSCs to deliver one-time in vivo gene therapy to produce antibodies from the liver and deliver them throughout the body.
Initial proof of concept data targeting complement protein 5 (C5) demonstrated that, with a single dose, our AAVHSCs delivered vectors at a high efficiency that resulted in fully functional monoclonal antibodies (mAbs) that were produced continuously by the liver and delivered throughout the body at sustained expression levels consistent with C5 mAb therapeutics for up to 20 weeks (study duration) in a humanized murine model. A one-time gene therapy approach could potentially address challenges associated with the chronic dosing required with current mAb therapeutics, including lack of compliance, infusion/transfusion dependence and peaks and troughs with serum levels. These data were presented at the 2021 American Society of Gene & Cell Therapy Annual Meeting.
We plan to announce our first development candidate from the GTx-mAb platform for the rare blood disorder paroxysmal nocturnal hemoglobinuria (PNH) in 2021.
Our approach with the GTx-mAb platform unlocks the potential to expand our pipeline to address complement-related disorders and diseases with larger patient populations.