Ascending Dose Study of Genome Editing by the Zinc Finger Nuclease (ZFN) Therapeutic SB-913 in Subjects With MPS II

Exclusion Criteria

• •Known to be unresponsive to ERT
• •Neutralizing antibodies to AAV 2/6
• •Serious intercurrent illness or clinically significant organic disease (unless secondary to MPS II)
• •Receiving antiviral therapy for hepatitis B or C, or with active hepatitis B or hepatitis C or HIV 1/2
• •Lack of tolerance to idursulfase treatment with significant IARs or occurrence of anaphylaxis
• •Markers of hepatic dysfunction
• •Creatinine ≥ 1.5 mg/dL
• •Contraindication to the use of corticosteroids for immunosuppression
• •Current treatment with systemic (IV or oral) immunomodulatory agent or steroid use (topical treatment allowed)
• •Participation in prior investigational drug or medical device study within the previous 3 months
• •Prior treatment with a gene therapy product
• •Elevated or abnormal circulating α-fetoprotein (AFP)
• •Weight \< 20 kg at Screening Visit