Sangamo's Gene Therapy for Hunter Syndrome Gets FDA Orphan Designation
Good news for people with mucopolysaccharidosis Type II (MPS II), also known as Hunter syndrome. The FDA has granted orphan drug designation to SB-913.
SB-913 is a type of gene therapy that uses Sangamo's zinc finger nuclease (ZFN) genome editing technology to provide stable, continuous production of iduronate 2-sulfatase for the lifetime of the patient. Hunter syndrome is due to low levels of functioning iduronate 2-sulfatase.
According to Sangamo, the treatment is being designed as a ‘single treatment strategy’.
A Phase 1/2 clinical trial evaluating SB-913 is currently underway. Similar trials are also being conducted in Hurler syndrome (MPS I) and hemophilia B.
Zinc Finger Nuclease (ZFN) Genome Editing
Sangamo's ZFN-mediated in vivo genome editing approach makes use of the endogenous albumin gene locus, a highly expressing and liver-specific site that can be edited with ZFNs to accept and express therapeutic genes. The approach is designed to enable the patient's liver to permanently produce circulating therapeutic levels of a corrective protein.
About Hunter Syndrome
Hunter syndrome is a lysosomal storage disorder caused by inadequate activity of the enzyme iduronate-2-sulfatase, which is needed to break down complex sugars produced by the body. The buildup of these complex sugars, known as mucopolysaccharides, interferes with functioning of certain cells and organs, leading to serious complications including developmental delays and mental impairment.