Enzyme Replacement Therapy for Lysosomal Storage Disorders

Enzyme replacement therapy is the only authorized method for treating lysosomal storage disorders. During the last ten years, this method has been demonstrated to be both safe and effective for the treatment of many lysosomal storage disorder patients. Recent advances in enzyme replacement therapy address the pressing issues for this therapeutic strategy: high cost and ineffectiveness in certain disease manifestations. To address the costs of enzyme replacement therapy, a variety of expression systems including plant and insect cells have been developed for production of recombinant lysosomal enzymes in a more affordable manner. In addition, various chemical and biological strategies have been used to enhance enzyme activity and lysosome targeting efficiency. The range of diseases treatable with enzyme replacement therapy has been expanded by the development of expression and purification processes for unique lysosomal enzymes. Novel administration methods have also been developed which has been recently patented to effectively deliver lysosomal enzymes to brain tissues that are inaccessible by traditional intravenous administration. Because of these advances, together with the development of gene expression technology and metabolic engineering, more lysosomal storage disorder patients are expected to benefit from enzyme replacement therapy. Keywords: Enzyme replacement therapy, lysosomal storage disorders, insect cell expression systems, plant expression systems, glycosylation