Maroteaux-Lamy Syndrome (MPS VI)

Maroteaux-Lamy Syndrome is one of a family of lysosomal storage diseases called mucopolysaccharidoses (MPS). These are inherited diseases caused by a defect in one of the genes needed to break down glycosaminoglycans – long chain sugars. These glycosaminoglycans accumulate in the body’s cells and in connective tissues, significantly affecting the heart, muscle, bone, and skin. In Maroteaux-Lamy Syndrome, mental development is normal, but patients have smaller stature and other physical manifestations; the severity can vary widely, but is associated with a shortened life span, primarily due to the cardiac complications.

Status

The current therapy for Maroteaux-Lamy Syndrome is enzyme replacement therapy, in which the purified enzyme is regularly infused intravenously into patients. This ameliorates some symptoms, but is not a cure. Gene therapy for this disease involves delivering a normal copy of the N–acetylgalactosamine 4-sulfatase (arylsulfatase B) gene to the liver, allowing the liver to secrete enough enzyme to ameliorate symptoms without the need for repetitive infusion. ReGenX’s AAV Vector Technology includes novel AAV serotypes that are significantly more efficient in delivering genes to the liver than other serotypes, and more efficient than other gene therapy delivery systems such as lentivirus. These serotypes result in sustained high level expression of the therapeutic enzyme, which may be more efficacious than the changing levels of enzyme achieved by periodic infusions of purified protein. The proposed therapeutic is in the research stage of development.

Market

Maroteaux-Lamy Syndrome is a rare disease affecting approximately 1,100 people worldwide.¹ There is an estimate in the United States that 1 in 25,000 births will result in some form of MPS.² There is no cure for Maroteaux-Lamy Syndrome and the costs for treatment are estimated to be $480,000 annually.³