The mucopolysaccharidosis (MPS) disorders are a group of lysosomal storage diseases caused by lysosomal enzyme deficits that lead to glycosaminoglycan accumulation, affecting various tissues throughout the body based on the specific enzyme deficiency. These disorders are characterized by their progressive nature and a variety of somatic manifestations and neurological symptoms. There are established treatments for some MPS disorders, but these mostly alleviate somatic and non-neurological symptoms and do not cure the disease. Patients with MPS I, II, III, and VII can present with neurological manifestations such as neurocognitive decline and behavioral problems. Treatment of these neurological manifestations remains challenging due to the blood-brain barrier (BBB) that limits delivery of therapeutic agents to the central nervous system (CNS). New therapies that circumvent this barrier and target brain disease in MPS are currently under development. They primarily focus on facilitating penetration of drugs through the BBB, delivery of recombinant enzyme to the brain by gene therapy, or direct CNS administration. This review summarizes existing and potential future treatment approaches that target brain disease in MPS. The information in this review is based on current literature and presentations and discussions during a closed meeting by an international group of experts with extensive experience in managing and treating MPS.
Bibliographical noteFunding Information:
Prof. Scarpa received unrestricted research and educational grants from Actelion, BioMarin, Genzyme, and Shire. He has no personal financial interests in any of the drugs produced for lysosomal storage disorders.
Prof. Orchard received grant funding for translational and clinical research and honoraria from Genzyme, BioMarin, and Horizon.
Dr. Schulz acted as consultant for BioMarin and received grant and research support from BioMarin.
The authors would like to thank Joseph Muenzer for his contribution to the content of this manuscript. The authors are grateful to Ismar Healthcare NV for their assistance in the writing of this manuscript, which was funded by BioMarin Pharmaceutical Inc. The expert meeting in Stockholm was also sponsored by BioMarin Pharmaceutical Inc.
This work was supported by BioMarin Pharmaceutical Inc.
- Blood-brain barrier
- Enzyme replacement therapy
- Gene therapy