Mucopolysaccharidosis Type I (MPS I) is a rare genetic disease caused by a mutation in the gene responsible for making human α-l-iduronidase (IDUA), an enzyme needed by cells to break down long chains of sugar molecules known as mucopolysaccharides. These sugar molecules are cellular waste products. As these waste products build up in tissues, like the central nervous system (CNS), they can cause bone and joint deformities, spinal cord compression, excessive accumulation of fluid in the brain (hydrocephalus) and cognitive impairment.
Individuals with severe forms of MPS I typically display symptoms before the age of two, and experience severe cognitive decline after an initial period of normal development. Currently available treatments do not adequately treat the effects of MPS I in the CNS, so there remains a significant unmet need to reach long-term, lasting expression of the IDUA enzyme in the CNS.
Our investigational therapy, RGX-111, is designed to use the AAV9 vector to deliver the human IDUA gene directly to the CNS. We believe that once the AAV9 vector delivers the gene to cells, the cells can begin making the needed IDUA enzyme, potentially preventing the progression of cognitive deficits.
We are advancing RGX-111 in preclinical (animal) studies, and plan to seek approval for a clinical trial thereafter.