Clear-cut integration of Large payloads into Essential Alleles with spontaneous counterselection of NHEJ outcomes (CLEAN) for the treatment of Anderson-Fabry disease

Fabry disease is a rare genetic disorder caused by the lack of an important enzyme called alpha-galactosidase A (GLA). This leads to the buildup of harmful substances in various organs, especially the heart, kidneys, and brain. Although current treatments like enzyme replacement therapy (ERT) can help manage the disease, they do not cure it. Over time, people with Fabry disease often still develop serious complications, particularly heart problems, which are the leading cause of illness and death in these patients. Our team is working on a new and potentially transformative treatment approach using advanced gene editing technology. Instead of treating symptoms with repeated enzyme infusions, we aim to correct the disease at its root by modifying the patient’s own blood-forming stem cells. These cells are found in the bone marrow and can give rise to many types of blood and immune cells. By editing these cells outside the body (a process called “ex vivo” gene editing), we can insert a healthy copy of the GLA gene directly into a precise location in the cell’s DNA. This method, called CLEAN (Clear-cut integration of Large payloads into Essential Alleles with spontaneous counterselection of NHEJ outcomes), ensures that the gene is inserted accurately and efficiently. Our project focuses on applying this CLEAN strategy to Fabry disease. First, we will test different versions of the therapeutic gene in lab-grown cells to find the best one (Aim 1). Then, we will insert the best-performing version into human blood stem cells (Aim 2). Finally, we will study how well these cells and their descendants can produce the needed enzyme after being guided to develop into various blood cell types (Aim 3). This research represents a promising step toward a long-lasting, possibly one-time treatment for Fabry disease. The results will pave the way for validation studies and, eventually, clinical trials in patients.